BAHAN KAJIAN
MK. MANAJEMEN SUMBERDAYA LAHAN &
PENGEMBANGAN WILAYAH
Diabstraksikan oleh:
Soemarno, FEBR 2013
AGROEKOSISTEM SAWAH
Ekosistem padi sawah terdiri atas
air permukana, lapisan tanah olah
dan subsoil, dan tanah olah yg
dibagi menjadi dua lapisan; lapisan
tipis tanah oksidasi dan lapisan
tanah reduksi.
Lapisan-lapisan tanah ini
dihubungkan oleh air perkolasi.
Selain itu, akar tanaman padi
tumbuh-berkembang dan residu
tganaman seperti jerami setelah
panen dimasukkan ke dalam tanah
lapisan olah.
Tapak mikro ini merupakan habitat
yang berbeda-beda bagi mikroba,
dan komunitas mikroba yg unik ini
menggantungkan hidupnya pada
tapak-mikro tersebut.
Diunduh dari sumber: http://www.agr.nagoya-u.ac.jp/~soil/Soil_Biology_and_Chemistry-e/Researches.html …….. 28/10/2012
SAWAH
Sawah adalah lahan usaha pertanian yang secara fisik permukaan
BIDANG OLAHNYA rata, dibatasi oleh pematang, serta dapat
ditanami padi, palawija atau tanaman budidaya lainnya.
Biasanya sawah digunakan untuk bercocok tanam padi. Untuk
keperluan ini, sawah harus mampu menyangga genangan air
karena padi memerlukan penggenangan pada periode tertentu
dalam pertumbuhannya. Untuk mengairi sawah digunakan sistem
irigasi dari mata air, sungai atau air hujan.
Sawah yang airnya berasal dari hujan dikenal sebagai sawah
tadah hujan, sementara yang lainnya adalah sawah irigasi.
Padi yang ditanam di sawah dikenal sebagai padi lahan basah
(lowland rice).
EKOSISTEM SWAH
Dalam usaha budidaya padi harus diketahui faktor-faktor yang
mempengaruhi pertumbuhan tanaman secara ekologi, baik faktor
biotik dan abiotik di lingkungan tumbuh tanaman tersebut.
Pertanaman padi sawah adalah monokultur, selain itu terdapat
beberapa flora dan fauna di sekitar pertanaman yang akan
mempengaruhi pertumbuhan tanaman padi.
Organisme yang ada di sekitar tanaman padi adalah mikrofauna
dalam tanah, mesofauna, makrofauna dan vegetasi (gulma) yang
ada di sekitar persawahan.
BUDIDAYA PADI SAWAH
Sawah merupakan suatu sistem budidaya tanaman yang khas dilihat dari sudut kekhususan
pertanaman yaitu padi, penyiapan tanah, pengelolaan air dan dampaknya atas lingkungan.
Lahan sawah perlu diperhatikan secara khusus dalam penatagunaan lahan.
Meskipun di lahan sawah dapat diadakan pergiliran berbagai tanaman, namun pertanaman
pokok selalu padi.
Jadi, kajian tentang sawah tentu berkaitan dengan produksi padi dan beras.
PADI SAWAH
Teknik bercocok tanam yang baik sangat diperlukan untuk mendapatkan
hasil yang sesuai dengan harapan. Hal ini harus dimulai dari awal, yaitu
sejak dilakukan persemaian sampai tanaman itu bisa dipanen.
Dalam proses pertumbuhan tanaman hingga berbuah ini harus dipelihara
yang baik, terutama harus diusahakan agar tanaman terhindar dari serangan
hama dan penyakit yang sering kali menurunkan produksi.
Tanaman yang sehat ialah tanaman yang tidak terserang oleh hama dan penyakit, tidak mengalami
defisiensi hara, baik unsur hara yang diperlukan dalam jumlah besar maupun dalam jumlah kecil.
Sedangkan tanaman subur ialah tanaman yang pertumbuhan clan perkembangannya tidak terhambat,
entah oleh kondisi biji atau kondisi lingkungan.
Interaksi antara sistem sosial
dengan agroekosistem setelah
terjadinya revolusi industri
Setelah revolusi industri, pertanian
mengalami perubahan dnegan
digunakannya mesin-mesin untuk
menggantikan tenaga kerja manusia
dan hewan untuk mengolah tanah
dan panen tanaman.
Starting with mechanization, the
chain of effects can be traced.
Machines gave farmers the ability to
cultivate larger areas of land. Farm
sizes increased dramatically because
mechanized agriculture is more
efficient on a larger scale (economy
of scale).
These initial changes in the social
system and the ecosystem set in
motion a series of changes through
interconnected positive feedback
loops in the ecosystem and social
system
Diunduh dari Sumber: http://gerrymarten.com/humanecology/chapter07.html…..30/10/2012
Koevolusi dan Ko-adaptasi Sistem Sosial Manusia dan Ekosistem
Interaction, coevolution and coadaptation of the human social system with the ecosystem
Source: Adapted from Rambo, A and Sajise, T (1985) An Introduction to Human Ecology Research on
Agricultural Systems in Southeast Asia, University of the Philippines, Los Banos, Philippines
Diunduh dari Sumber: http://gerrymarten.com/human-ecology/chapter07.html…..30/10/2012
BUDIDAYA PADI
Budidaya padi sawah (Ing. paddy atau paddy field), diduga dimulai dari daerah lembah Sungai
Yangtse di Tiongkok.
Budidaya padi lahan kering, dikenal manusia lebih dahulu daripada budidaya padi sawah.
Budidaya padi lahan rawa, dilakukan di beberapa tempat di Pulau Kalimantan.
Budidaya gogo rancah atau disingkat gora, yang merupakan modifikasi dari budidaya lahan
kering. Sistem ini sukses diterapkan di Pulau Lombok, yang hanya memiliki musim hujan
singkat.
Budidaya Padi Sawah Model SRI
SRI adalah salah satu jawaban dari krisis pangan yang dihadapi Indonesia. Akan tetapi berbeda
dengan metode penanaman padi yan lain, SRI Indonesia dipelopori oleh seorang engineer. Ternyata
SRI lebih bisa dimengerti oleh mereka yang memahami engineering walaupun tidak menutup
kemungkinan adanya pendekatan lain yang dapat menjelaskan fenomena SRI.
Apa Itu SRI ?
SRI merupakan singkatan dari System of Rice Intensification, suatu sistem pertanian yang
berdasarkan pada prinsip Process Intensification (PI) dan Production on Demand (POD). SRI
mengandalkan optimasi untuk mencapai delapan tujuan PI, yaitu cheaper process (proses lebih
murah), smaller equipment (bahan lebih sedikit), safer process (proses yang lebih aman), less energy
consumption (konsumsi energi/tenaga yang lebih sedikit), shorter time to market (waktu antara
produksi dan pemasaran yang lebih singkat), less waste or byproduct (sisa produksi yang lebih
sedikit), more productivity (produktifitas lebih besar), and better image (memberi kesan lebih baik).
Teknologi budidaya
Bercocok tanam padi mencakup persemaian, pemindahan atau penanaman,
pemeliharaan (termasuk pengairan, penyiangan, perlindungan tanaman, serta
pemupukan), dan panen.
Aspek lain yang penting namun bukan termasuk dalam rangkaian bercocok tanam padi
adalah pemilihan kultivar, pemrosesan gabah dan penyimpanan beras.
Penanganan bibit padi secara seksama.
Hal ini terdiri atas, pemilihan bibit unggul, penanaman bibit dalam usia muda (kurang
dari 10 hari setelah penyemaian), penanaman satu bibit per titik tanam, penanaman
dangkal (akar tidak dibenamkan dan ditanam horizontal), dan dalam jarak tanam yang
cukup lebar.
Bagi yang telah terbiasa menanam padi secara konvensional, pola penanganan bibit ini
akan dirasakan sangat berbeda. Hal ini karena metode konvensional memakai bibit
yang tua (lebih dari 15 hari sesudah penyemaian), ditanam sekitar 5-10 bahkan lebih
bibit per titik tanam, ditanam dengan cara dibenamkan akarnya, dan jarak tanamnya
rapat.
BUDIDAYA PADI SECARA INTENSIF
SRI
( SYSTEM OF RICE INTENSIFICATION)
Suatu cara budidaya tanaman padi yang efesien dengan
proses manajemen sistem perakaran yang berbasis pada
pengelolaan air, tanah, dan tanaman
SRI berasal dari Madagascar dikembangkan sejak sekitar 1980-an
oleh Fr. Henri de Laulanié, SJ (biarawan asal Perancis) dan
berkembang ke sekitar 24 negara sejak sekitar 1993
BUDIDAYA PADI SECARA INTENSIF
PERMASALAHAN BUDIDAYA TANAMAN PADI
1.
2.
3.
4.
Penurunan kesehatan dan kesuburan tanah
Kecenderungan potensi padi untuk berproduksi lebih tinggi mandeg
Penggunaan unsur kimia anorganik dan pestisida sintesis meningkat
Perilaku petani sudah jauh dari kearifan dalam memanfaatkan potensi lokal
Petani bekerja di lahan sawah
Many people from the district of Rembang, Java,
work in the labour intensive rice paddy industry. The
production of rice is a commercial industry and
provides income for many families.
Diunduh dari Sumber: http://www.flickr.com/photos/planasia/6334120996/in/photostream/ …..30/10/2012
BUDIDAYA PADI SECARA INTENSIF
DASAR PEMIKIRAN METODE SRI
1. Tanaman Padi mempunyai potensi yang besar untuk
menghasilkan produksi yang banyak
2. Produksi yang optimal dapat dicapai dengan terpenuhinya
kondisi yang optimal
3. Produksi optimal dapat dicapai melalui proses pengelolaan
tanah, tanaman dan air serta unsur agroekosistemnya
4. Ada kecenderungan penurunan produksi
5. Padi bukan tanaman air, tetapi padi tanaman yang
membutuhkan banyak air
6. Pada kondisi tanah tidak tergenang, akar tanaman tumbuh
subur dan besar, sehingga dapat menyerap hara yang banyak,
serta mendorong tumbuhnya ANAKAN yang optimal.
BUDIDAYA PADI SECARA INTENSIF
PENYEBAB TERJADINYA PENURUNAN PRODUKSI PADI
1. Penurunan kesuburan tanah akibat penggunaan pupuk secara
intensif dan terus-menerus
2. Mikroba dalam tanah tidak berfungsi secara optimal
3. Aliran energi dari bawah ke atas permukaan tanah tidak
seimbang
4. Suplai hara-tersedia dalam tanah sangat kurang
5. Tanaman menunggu suplai hara dari luar tanah, berupa pupuk
sintesis
6. Penggunaan pupuk dan pestisida sintesis yang berlebihan
mengakibatkan rantai makanan dalam ekosistem sawah
menjadi terputus
7. Musuh Alami hanya menunggu makanan dari keberadaan hama
8. Jenjang hirerkis Musuh Alami lebih tinggi maka hama akan
berkembang lebih pesat .
BUDIDAYA PADI SECARA INTENSIF
CARA PANDANG KURANG ARIF
1. Orang beranggapan di sawah hanya ada tanaman dan hama
2. Untuk memenangkan persaingan hama harus dibunuh
3. Pestisida yang berkuasa untuk memusnahkan hama
4. Pestisida tidak bisa mengentaskan masalah karena hama
5. Hama menjadi kebal
6. Terjadi peledakan gangguan hama dan penyakit
7. Pencemaran lingkungan
8. Terbunuhnya jasad non sasaran
9. Pengurangan keaneka-ragaman hayati
10. Gangguan terhadap kesehatan manusia .
BUDIDAYA PADI SECARA INTENSIF
BUDIDAYA PADI SECARA INTENSIF
SRI Di Indonesia antara lain oleh Pak Engkus Kuswara dan Pak Alik Sutaryat
(Tahun 1999). Hal-hal yang diterapkan adalah :
• Tanam Tunggal Dan Dangkal
• Umur Semai Kurang 15 Hari
• Penanaman cepat kurang 15 Menit
• Pupuk Organik
SRI merupakan singkatan dari System of Rice Intensification, suatu sistem pertanian yang
berdasarkan pada prinsip Process Intensification (PI) dan Production on Demand (POD).
1.
2.
3.
4.
5.
6.
7.
8.
SRI mengandalkan optimasi untuk mencapai delapan tujuan PI, yaitu :
Cheaper process (proses lebih murah),
Smaller equipment (bahan lebih sedikit),
Safer process (proses yang lebih aman),
Less energy consumption (konsumsi energi/tenaga yang lebih sedikit),
Shorter time to market (waktu antara produksi dan pemasaran yang lebih singkat),
Less waste or byproduct (sisa produksi yang lebih sedikit),
More productivity (produktifitas lebih besar), and
Better image (memberi kesan lebih baik).
BUDIDAYA PADI SECARA INTENSIF
METODE SRI :
1.
2.
3.
4.
Tanaman Hemat Air (Max 2 Cm = Macak-macak dan juga ada periode pengeringan
sampai tanah pecah-pecah)
Hemat Biaya (butuh bibit 5 Kg/Ha, Tidak butuh biaya Pencabutan, Pemindahan, Irit
tenaga tanam, dll)
Hemat Waktu (bibit ditanam muda 3 - 10 HSS dengan jarak tanam lebar dan Panen
lebih awal sekitar 10 – 14 hari)
Produksi Bisa Mencapai 7 - 14 Ton/Ha.
METODE SRI
Penanganan bibit padi secara seksama.
Hal ini terdiri atas, pemilihan bibit unggul, penanaman bibit dalam usia muda (kurang dari
10 hari setelah penyemaian), penanaman satu bibit per titik tanam, penanaman dangkal
(akar tidak dibenamkan dan ditanam horizontal), dan dalam jarak tanam yang cukup lebar.
Bagi yang telah terbiasa menanam padi secara konvensional, pola penanganan bibit ini akan
dirasakan sangat berbeda.
Hal ini karena metode konvensional memakai bibit yang tua (lebih dari 15 hari sesudah
penyemaian), ditanam sekitar 5-10 bahkan lebih bibit per titik tanam, ditanam dengan cara
dibenamkan akarnya, dan jarak tanamnya rapat.
PENGARUH PENGGENANGAN AIR TERHADAP PERTUMBUHAN PADI
1.
2.
3.
4.
Merangsang pertumbuhan memanjang tanaman, menghasilkan lebih banyak jerami
Menghambat pertumbuhan anakan/tunas
Tanaman kurang dapat mengambil unsur hara yang dibutuhkan
Penggenangan yang terlalu dalam dan lama dapat merubah sifat-sifat kimia tanah
sawah, antara lain : kandungan O2 yang sedikit, kandungan CO2 yang berlebihan,
terjadi akumulasi H2S, yang dapat meracuni tanaman sehingga tanaman menjadi
kerdil.
METODE SRI
Penyiapan lahan tanam.
Penyiapan lahan tanam untuk metode SRI berbeda dari metode konvensional terutama
dalam hal penggunaan air dan pupuk sintetis (untuk kemudian disebut pupuk).
SRI hanya menggunakan air sampai keadaan tanahnya sedikit terlihat basah oleh air
(macak-macak) dan tidak adanya penggunaan pupuk karena SRI menggunakan
kompos.
Sangat berbeda dengan metode konvensional yang menggunakan air sampai pada tahap
tanahnya menjadi tergenang oleh air serta pemupukan minimal dua kali dalam satu
PRINSIP SRI
1.
2.
3.
4.
5.
6.
7.
Pengolahan tanah dan pemupukan kompos organik
Benih bermutu dan ditanam muda
Benih ditanam tunggal dan langsung
Jarak tanam Lebar
Pemupukan tidak dengan pupuk sintesis
Pengelolaan air yang macak-macak dan bersamaan dengan penyiangan
PHT tidak memakai pestisida sintesis
METODE SRI
Keterlibatan mikro-organisme lokal (MOL) dan kompos sebagai ’tim sukses’ dalam
pencapaian produktivitas yang berlipat ganda.
Dalam hal ini peran kompos sering disalah-artikan sebagai pengganti dari pupuk. Hal ini salah,
karena peran kompos lebih kompleks daripada peran pupuk. Peran kompos, selain sebagai
penyuplai nutrisi juga berperan sebagai komponen bioreaktor yang bertugas menjaga proses
tumbuh padi secara optimal. Konsep bioreaktor adalah kunci sukses dari SRI.
Bioreaktor yang dibangun oleh kompos, mikrooganisme lokal, struktur padi, dan tanah menjamin
bahwa padi selama proses pertumbuhan dari bibit sampai padi dewasa tidak mengalami hambatan.
Fungsi bioreaktor sangat kompleks, antara lain adalah penyuplai nutrisi sesuai POD melalui
mekanisme eksudat, kontrol mikroba sesuai kebutuhan padi, menjaga stabilitas kondisi tanah
menuju kondisi yang ideal bagi pertumbuhan padi, bahkan kontrol terhadap penyakit yang dapat
menyerang padi.
UJI BENIH BERMUTU DENGAN LARUTAN GARAM
Caranya :
1.
2.
3.
4.
5.
6.
Siapkan ember atau panci atau wadah lain beriisi air
Masukan garam aduk-aduk sampai larut,
Masukan telur ayam mentah kedalam larutan garam tersebut, bila telur masih
tenggelam maka perlu penambahan garam.
Pemberian garam dianggap cukup apabila telur sudah mengapung.
Masukan benih yang sudah disiapkan kedalam larutan tersebut.
Benih yang tenggelam yang digunakan sebagai benih yang akan ditanam.
PENYIAPAN BENIH
Benih dapat diseleksi dengan bantuan penggunaan air garam dan telur ayam/itik/bebek.
Telur yang bagus umumnya dalam air akan tenggelam, namun bila pada air ini diberi
garam yang cukup dan diaduk maka telur yang bagus itu akan mengapung. Bila telur
belum juga mengapung maka tambahkan lagi garamnya sampai telur ini mengapung
karena berat jenisnya (BJ) menjadi lebih rendah daripada air garam.
Air garam yang sudah mampu mengapungkan telur ini dapat digunakan untuk seleksi
benih
PERENDAMAN DAN PEMERAMAN BENIH
1. BENIH DIRENDAM, Setelah diuji, benih direndam dengan mempergunakan
air bersih dengan tujuan mempercepat perkecambahan selama 24 – 48 jam.
2. BENIH DIPERAM, Benih yang telah direndam kemudian diangkat ke dalam
tempat tertentu yang telah dilapisi dengan daun pisang dengan tujuan untuk
memberikan udara masuk / penganginan / ngamut selama 24 jam.
Benih yang baik kemudian dicuci dengan bersih sampai rasa asinnya hilang dari
benih tersebut, juga akan lebih baik dicuci menggunakan wadah yang berlubang
dan pada air yang mengalir untuk meyakinkan benih benar-benar akan terbebas
dari garam;
Benih yang sudah bebas dari garam direndam dalam air biasa selama sekitar 24
jam;
Setelah benih direndam, kemudian lakukan pemeraman selama sekitar 36 jam
yaitu benih di bungkus dengan karung goni atau kain yang basah. Penyimpanan
benih yang dibungkus kain basah ini akan lebih baik ditempat yang hangat
misalnya di dapur asalkan kainnya tetap dijaga basah dan lembab;
Setelah berkecambah atau muncul akar pendek, benih siap disemai atau ditebar.
CARA MEMBUAT PERSEMAIAN
1. Campurkan Tanah dan kompos 1 : 1
2. Masukan campuran tanah dan kompos ke dalam baki atau pipiti yang
dilapisi daun pisang
3. Taburkan benih ke dalam nampan
4. Tutup dengan jerami atau kompos
Persemaian padi dengan Menggunakan Pupuk
HOSC sebagai pupuk Semai , menunjukkan
pertumbuhan yang bagus dan perkembangan
akar yang sempurna pada usia 9 hari, dan pada
usia 13 hari benih padi
CARA PENANAMAN BENIH
Tanam benih berusia muda antara 3 - 10 hari (maksimal berdaun 2), usahakan di bawah 8 hari
setelah semai.
Tanam hanya 1 (satu) benih per lubang dengan jarak tanam 30x30 cm atau 35x35 cm
Bibit ditanam dangkal 1 – 1,5 cm dengan perakaran seperti huruf L.
Pindah tanam (transplanting) harus segera (kurang dari 15 menit) secara hati-hati
Petak sawah tidak selalu tergenang, kondisi air hanya ‘macak-macak’ (1-2 cm) dan pada periode
tertentu harus dikeringkan sampai retak (intermittent irrigation)
Penyiangan dilakukan lebih awal pada 10 hst diulang 3 s/d 4 kali dengan interval waktu setiap 10
hari ( mengunkan tenaga manusia/lalandak ) .
PENYEMAIAN
Penyemaian dapat dilakukan di sawah, di ladang atau dalam wadah seperti kotak plastik
atau besek/pipiti yang diberi alas plastik/daun pisang dan berada di area terbuka yang
mendapatkan sinar matahari.
Tanah untuk penyemaian tidak menggunakan tanah sawah tetapi menggunakan tanah
darat yang gembur dicampur dengan kompos dengan perbandingan tanah:kompos
sebaiknya minimal 2:1 dan akan lebih baik bila 1:1, dapat juga ditambahkan pada
campuran ini abu bakar agar medianya semakin gembur sehingga nantinya benih semakin
mudah diambil dari penyemaian untuk menghindari putusnya akar.
Luas area yang diperlukan untuk penyemaian minimal adalah sekitar 20 m2 untuk setiap 5
kg benih, sehingga bila penyemaian dilakukan pada wadah dapat dihitung jumlah wadah
yang diperlukan menyesuaikan dengan ukuran masing-masing wadah dan tentunya akan
lebih baik lagi bila tempat penyemaiannya lebih luas untuk pertumbuhan benih yang lebih
sehat.
KETERBATASAN
1.
2.
3.
4.
5.
SRI
Membutuhkan tenaga kerja lebih banyak (pada awalnya)
Perlu drainase untuk membuang kelebihan air
Lebih banyak waktu untuk untuk mengatur pengairan
Lebih banyak waktu dan tenaga kerja untuk penyiangan
Pembuatan kompos
PRINSIP PENANAMAN SRI
1.
2.
3.
4.
5.
6.
7.
Penanaman Bibit Muda;
Penanaman Bibit Tunggal dan Jarak Antar Tanaman yang Lebar;
Penanaman Segera Untuk Menghindari Trauma Pada Bibit;
Penanaman Dangkal;
Lahan Sawah Tidak Terus Menerus Direndam Air;
Penyiangan Mekanis;
Menjaga Keseimbangan Biologi Tanah.
Hama-hama penting
tanaman padi
1.
Penggerek batang padi putih
("sundep", Scirpophaga innotata)
2. Penggerek batang padi kuning (S.
incertulas)
3. Wereng batang punggung putih
(Sogatella furcifera)
4. Wereng coklat (Nilaparvata
lugens)
5. Wereng hijau (Nephotettix
impicticeps)
6. Lembing hijau (Nezara viridula)
7. Walang sangit (Leptocorisa
oratorius)
8. Ganjur (Pachydiplosis oryzae)
9. Lalat bibit (Arterigona exigua)
10. Ulat tentara/Ulat grayak
(Spodoptera litura dan S. exigua)
11. Tikus sawah (Rattus
argentiventer)
Sistem pertanian sawah terpadu
(Sumber: tani-organik.blogspot.com/2008/0...sri.html)
Penyakit-penyakit penting
1. Blas (Pyricularia oryzae, P. grisea)
2. Hawar daun bakteri ("kresek",
Xanthomonas oryzae pv. oryzae)
3. Bercak coklat daun
(Helmintosporium oryzae).
4. Garis coklat daun (Cercospora
oryzae)
5. Busuk pelepah daun (Rhizoctonia sp)
6. Penyakit fusarium (Fusarium
moniliforme)
7. Penyakit noda (Ustilaginoidea virens)
8. Hawar daun (Xanthomonas
campestris)
9. Penyakit bakteri daun bergaris
(Translucens)
10. Penyakit kerdil (Nilaparvata lugens)
11. Penyakit tungro (Nephotettix
impicticeps)
James Stordahl
Extension Educator, Clearwater and Polk
Counties
Plants need three factors for disease to develop.
The host plant must be susceptible, the pathogen
must be present (usually in the soil), and the
environmental conditions must be right. This
typically involves wet leaves over some period of
time.
Diunduh dari Sumber: http://blog.lib.umn.edu/efans/small-farms/commercial-horticulture/ …..30/10/2012
HUBUNGAN AIR-TANAH-TANAMAN
Unsur hara & daya
simpan hara
Bahan Organik
Tanah
Makro-fauna
Tanah
Mikroba Tanah
PENGELOLAAN AIR PADA TANAH SAWAH
Produksi padi sawah akan menurun jika tanaman padi menderita
cekaman air (water stress). Gejala umum akibat kekurangan air
antara lain daun padi menggulung, daun terbakar (leaf scorching),
anakan padi berkurang, tanaman kerdil, pembungaan tertunda,
dan biji hampa.
Tanaman padi membutuhkan air yang volumenya berbeda untuk
setiap fase pertumbuhannya. Variasi kebutuhan air tergantung
juga pada varietas padi dan sistem pengelolaan lahan sawah.
Pengaturan air untuk sistem mina-padi berbeda dengan sistem
sawah tanpa ikan.
Pengelolaan air di lahan sawah tidak hanya menyangkut sistem
irigasi, tetapi juga sistem drainase pada saat tertentu dibutuhkan,
baik untuk mengurangi kuantitas air maupun untuk mengganti air
yang lama dengan air irigasi baru sehingga memberikan peluang
terjadinya sirkulasi oksigen dan hara.
SAWAH IRIGASI
Di Indonesia, sawah sering dikategorikan menjadi tiga yaitu
(a) sawah beririgasi;
(b) sawah tadah hujan; dan
(c) sawah rawa (lebak dan pasang surut).
Sistem pengelolaan air pada ketiga macam sawah tersebut sangat berbeda, karena
perbedaan kondisi hidrologi dan kebutuhan air.
Teknik pengelolaan air lahan sawah didasarkan pada kebutuhan air untuk tanaman (baik
padi maupun palawija) dan sistem pengelolaan lahan sawah.
KEBUTUHAN AIR IRIGASI
Kebutuhan air tanaman didefinisikan sebagai jumlah air yang dibutuhkan oleh tanaman pada suatu
periode untuk dapat tumbuh dan produksi secara normal. Kebutuhan air nyata untuk areal usaha pertanian
meliputi evapotranspirasi (ET), sejumlah air yang dibutuhkan untuk pengoperasian secara khusus seperti
penyiapan lahan dan penggantian air, serta kehilangan selama pemakaian. Sehingga kebutuhan air dapat
dirumuskan sebagai berikut (Sudjarwadi 1990):
KAI = ET + KA + KK
Dimana: KAI = Kebutuhan Air Irigasi; ET = Evapotranspirasi; KA = Kehilangan air; KK = Kebutuhan
Khusus.
Diunduh dari sumber: http://surososipil.files.wordpress.com/2008/10/irigasi1-bab-4-kebutuhan-irigasi.pdf………. 28/10/2012
Hidrologi lahan sawah
Pengetahuan tentang hidrologi lahan sawah sangat diperlukan dalam merancang strategi
pengelolaan air.
Karakteristik hidrologi lahan sawah sangat ditentukan oleh kondisi biofisik lahan.
Hidrologi sawah beririgasi berbeda dengan sawah tadah hujan maupun sawah rawa. Oleh
karena itu strategi pengelolaan air pada lahan sawah beririgasi akan berbeda dengan pada
lahan sawah tadah hujan maupun sawah rawa.
Types of Response to Water
Scarcity
Sumber:
Irrigation Management in
Rice-Based Cropping Systems: Issues and
Challenges in Southeast Asia .
Randolph Barker and Francois Molle.
Diunduh dari sumber: http://fftc.imita.org/library.php?func=view&id=20110722052543………. 30/10/2012
NERACA AIR LAHAN SAWAH
Masukan air ke lahan padi sawah diperlukan untuk menggantikan kehilangan air akibat
rembesan-seepage, perkolasi, evaporasi dan transpirasi.
Seepage is the lateral subsurface flow of water and percolation is the down flow of water below the root
zone. Typical combined values for seepage and percolation vary from 1-5 mm d-1 in heavy clay soils to
25-30 mm d-1 in sandy and sandy loam soils. Evaporation occurs from the ponded water layer and
transpiration is water loss from the leaves of the plants. Typical combined evapotranspiration rates of rice
fields are 4-5 mm d-1 in the wet season and 6-7 mm d-1 in the dry season, but can be as high as 10-11
mm d-1 in subtropical regions before the onset of the monsoon. Total seasonal water input to rice fields
(rainfall plus irrigation) varies from as little as 400 mm in heavy clay soils with shallow groundwater
tables to more than 2000 mm in coarse-textured (sandy or loamy) soils with deep groundwater tables.
Around 1300-1500 mm is a typical value for irrigated rice in Asia. Outflows of water by seepage and
percolation account for about 25-50% of all water inputs in heavy soils with shallow water tables of 20-50
cm depth, and for 50-85% in coarse-textured soils with deep water tables of 150 cm depth or more.
Diunduh dari sumber: http://www.knowledgebank.irri.org/rkb/1-the-water-balance-of-lowland-rice.html ………. 30/10/2012
KARAKTERISTIK
HIDROLOGI LAHAN
SAWAH
1.
2.
3.
4.
5.
. Hydrological processes in a paddy field. (a) Hydrologic
Characteristics of a paddy field. (b) Outline of runoff
simulation model in paddies.
Lahan sawah Pluvial
Sumber air berasal dari air
hujan
Kelebihan air hilang melalui
perkolasi dan aliran
permukaan
Terdapat di daerah landai
sampai lereng curam
Air tanah dalam, drainase
baik, tidak ada gejala jenuh
air dalam profil tanah
Padi ditanam sebagai padi
gogo
Simulations of storm hydrographs in a mixed-landuse watershed using a modified TR-20 model
T.I. Jang, H.K. Kim, S.J. Im, S.W. Park.
Agricultural Water Management. Volume 97, Issue 2, February 2010, Pages 201–207.
KARAKTERISTIK HIDROLOGI
LAHAN SAWAH
Schematics of water balance components in a paddy
field.
Lahan sawah Phreatik
1. Sumber air berasal dari air hujan
dan air tanah
2. Air tanah (phreatic) dangkal, paling
tidak pada waktu musim tanam
3. Kelebihan air hilang melalui aliran
permukaan
4. Tidak pernah tergenang lebih dari
beberapa jam
5. Dalam profil tanah ada gejala jenuh
air (gley motting)
6. Bila tanpa perataan (leveling) dan
pembuatan pematang, akan lebih
baik ditanami padi gogo
7. Bila dengan perataan dan
pembuatan pematang dapat
dikembangkan untuk padi sawah .
Model development for nutrient loading from paddy rice fields
Sang-Ok Chung, Hyeon-Soo Kim, Jin Soo Kim.
Agricultural Water Management. Volume 62, Issue 1, 19 August 2003, Pages 1–17
Karakteristik hidrologi
lahan sawah
Schematic diagram of a paddy field. (hmin, hmax and Hp denote the three
critical depths; Ecan, Epot and Es denote the three kinds of evaporation
from the free water in canopies, the water body surface and the soil water
respectively; Ep denotes the crop transpiration.
Lahan sawah fluxial
1. Sumber air seluruhnya atau
sebagian berasal dari aliran
permukaan, air sungai dan air
hujan langsung
2. Dalam keadaan alami
tergenang air selama
beberapa bulan yaitu selama
padi ditanam
3. Terdapat di daerah lembah,
dataran aluvial sungai dan
sebagainya
4. Drainase permukaan dan
drainase dalam (perkolasi)
lambat sehingga genangan air
mudah terjadi
5. Padi ditanam sebagai padi
sawah .
Development and test of SWAT for modeling hydrological processes in irrigation districts with paddy rice
Xianhong Xie, Yuanlai Cui.
Journal of Hydrology. Volume 396, Issues 1–2, 5 January 2011, Pages 61–71.
MANAJEMEN AIR YANG BAGUS UNTUK LAHAN SAWAH
Beberapa prinsip Manajemen Air yang bagus di lahan sawah
SALURAN AIR TERBUKA
In many paddy fields, water flows from one field
to another through breaches in the bunds. Under
such conditions, water in an individual field can
not be controlled and field-specific water
management is not possible - construction of
channels to convey water to and from each field,
or group of fields, greatly improves the irrigation
and drainage of water.
PERATAAN TANAH
A well-leveled field is a prerequisite for good
water management.
When a field is not level, water may stagnate in
the depressions whereas higher parts may fall
dry.
This results in uneven crop emergence, uneven
early growth, uneven fertilizer distribution, and
weed problems. See the fact sheets on land
leveling for more information .
PENGOLAHAN TANAH
Wet land preparation can consume up to a third of the total water used in
paddy rice. In large-scale irrigation systems, synchronizing operations and minimizing the duration of the land
preparation period can reduce water use.
Large amounts of water can be lost during soaking prior to puddling when large and deep cracks are present. A shallow
tillage to fill the cracks before soaking can greatly reduce this water loss.
After soaking, thorough puddling results in a compacted plow sole that reduces water losses by percolation. The
efficacy of puddling depends on soil properties. Puddling may not be effective in coarse soils, whereas it is very
efficient in clay soils that form cracks during the fallow period. Puddling may not be necessary in heavy clay soils with
limited internal drainage. In such soils, direct dry seeding on land that is tilled in a dry state is possible with minimal
percolation losses.
Diunduh dari sumber: http://www.knowledgebank.irri.org/factsheetsPDFs/watermanagement_FSWaterSavingGeneral.pdf ………. 30/10/2012
MANAJEMEN AIR YANG BAGUS UNTUK LAHAN SAWAH
Beberapa prinsip Manajemen Air yang bagus di lahan sawah
PEMATANG SAWAH
Good bunds are a prerequisite to limit water
losses by seepage and under-bund flows.
Bunds should be well compacted and any
cracks or rat holes should be plastered with
mud at the beginning of the crop season.
Also, check for, and repair new rat holes,
cracks, and porosity caused by earth worms
throughout the growing season.
Lembaran plastik dapat dipakai untuk
memperbaiki pematang, terutama bagianbagian pematang yang “rembes” (bocor)
air.
KEDALAMAN
GENANGAN AIR
Menjaga kedalaman
genangan air sekitar 5 cm
dapat meminimumkan
kehilangan air melalui
rembesan- seepage dan
perkolasi.
Diunduh dari sumber: http://www.knowledgebank.irri.org/factsheetsPDFs/watermanagement_FSWaterSavingGeneral.pdf ……….
30/10/2012
MANAJEMEN AIR YANG BAGUS UNTUK LAHAN SAWAH
Good water management in lowland rice focuses on practices that conserve water (by eliminating the
unproductive water flows of seepage, percolation, and evaporation) while ensuring sufficient water for the
crop.
Water management practices are given for the different periods of the crop cycle from pre-planting
activities to the ripening stage.
It is assumed that farmers have access to sufficient irrigation to maintain flooded conditions. Water-saving
technologies for conditions of insufficient water are described in subsequent paragraphs.
Pra- tanam
Jumlah air yg diperlukan untuk mengolah tanah pada lahan sawah dapat sebesar 100-150 mm,
tetapi juga dapat mencapai hingga 900 mm dalam sistem irigasi sekala besar dan periode
penyiapan lahan yang cukup panjang.
Various options exist to minimize the amount of water used in the pre-planting period. Land
preparation lays the foundation for the whole cropping season and it is important in any situation
to “get the basics right” for good water management afterwards.
Especially important for good water management are field channels, land leveling, and tillage
operations (puddling, bund preparation and maintenance).
Diunduh dari sumber: http://www.knowledgebank.irri.org/rkb/2-sound-water-management.html………. 30/10/2012
MANAJEMEN AIR YANG BAGUS UNTUK LAHAN SAWAH
Saluran lapangan untuk mengelola air
Dalam berbagai sistem irigasi, tidak ada saluran air terbuka (saluran tersier , kuarter atau
saluran drainage) dan air mengalir dari satu petak-lahan ke petakan lainnya mellaui lubanglubang pada pematang. Sistem seperti ini disebut irigasi “plot-to-plot”.
The amount of water flowing in and out of a rice field can not be controlled and field-specific
water management is not possible. This means that farmers may not be able to drain their fields
before harvest because water keeps flowing in from other fields. Also, they may not be able to
have water flowing in if upstream farmers retain water in their fields or let their fields dry out
to prepare for harvest. Moreover, a number of technologies to cope with water scarcity require
good water control for individual fields. Finally, the water that continuously flows through the
rice fields may remove valuable (fertilizer) nutrients.
Constructing separate channels to convey water to (irrigation) and from (drainage) each field
greatly improves the individual control of water, and is the recommended practice in any type
of irrigation system. Alternatively, if field channels can not be constructed for individual fields,
they should be constructed to serve a limited number of fields together.
Diunduh dari sumber: http://www.knowledgebank.irri.org/rkb/2-sound-water-management.html………. 30/10/2012
MANAJEMEN AIR YANG BAGUS UNTUK LAHAN SAWAH
PROSES PELUMPURAN
A rice field can be compared with a bath tub: the material of a bath tub is impregnable and it holds water
well – however, you only need to have one hole (by removing the plug) and the water runs out
immediately. Rice fields just need a few rat holes or leaky spots and they will rapidly loose water by
seepage and percolation.
Thorough puddling results in a good compacted plow sole that reduces the percolation rates throughout
the crop growing period. The efficacy of puddling in reducing percolation depends greatly on soil
properties. Puddling may not be effective in coarse soils, which do not have enough fine clay particles to
migrate downward and fill up the cracks and pores in the plow sole. On the other hand, puddling is very
efficient in clay soils that form cracks during the fallow period that penetrate the plow pan. Although
puddling reduces percolation rates of the soil, the action of puddling itself consumes water, and there is a
trade-off between the amount of water used for puddling and the amount of water “saved” during the crop
growth period by reduced percolation rates.
Pelumpuran mungkin tidak diperlukan pada tanah-tanah liat-berat yang permeabilitasnya
rendah atau drainage internalnya sangat terbatas. Pada tanah-tanah seperti ini, tanam benih
langsung di lahan yg tidak dilumpurkan tetapi diolah kering , sangat dimungkinkan dengan
kehilangan perkolasi minimum.
Diunduh dari sumber: http://www.knowledgebank.irri.org/rkb/2-sound-water-management.html………. 30/10/2012
MANAJEMEN AIR YANG BAGUS UNTUK LAHAN SAWAH
PENYIAPAN DAN PEMELIHARAAN PEMATANG
Good bunds are a prerequisite to limit water losses by seepage and underbund flows. To limit
seepage losses, bunds should be well compacted and any cracks or rat holes should be plastered
with mud at the beginning of the crop season. Make bunds high enough (at least 20 cm) to avoid
overbund flow during heavy rainfall.
Small levees of 5-10 cm height in the bunds can be used to keep the ponded water depth at that
height. If more water needs to be stored, it is relatively simple to close these levees.
Researchers have used plastic sheets in bunds in field experiments to reduce seepage losses.
Although such measures are probably financially not attractive to farmers, the author has come upon
a farmer in the Mekong delta in Vietnam who used old plastic sheets to block seepage through very
leaky parts of his bunds.
Liang tikus harus dibuntu
Diunduh dari sumber: http://www.knowledgebank.irri.org/rkb/2-sound-water-management.html………. 30/10/2012
MANAJEMEN AIR UNTUK LAHAN SAWAH
BIDANG OLAH IRIGASI DIBATASI PEMATANG
Most lowland rice is established by transplanting rice plants from a seed bed into the main
field. In large-scale irrigation systems, seed beds are often found in corners of individual
farmers’ fields scattered throughout the area. If there are no field channels to separately irrigate
the seed beds, the whole field is flooded while the rice plants grow in the seed bed.
All water losses from the main field through evaporation, seepage, and percolation, are a
wasteful loss as no crop grows yet in the field. One remedy is to construct field channels that
bring water to the seed beds only so that the main field only needs to be soaked and puddled a
few days before transplanting (3-4 days). Seed beds are best located close to the main canals so
that little water is lost by transporting it over long distances through field channels.
Community seed beds may be an option to concentrate the raising of seedlings in one place to
use the irrigation water most efficiently. In some areas, private companies produce seedlings
that farmers can purchase so they save their own irrigation water.
Diunduh dari sumber: http://www.knowledgebank.irri.org/rkb/2-sound-water-management.html………. 30/10/2012
MANAJEMEN AIR YANG BAGUS UNTUK LAHAN SAWAH
FASE PERTUMBUHAN AWAL VEGETATIF
After crop establishment, continuous ponding of water generally provides the best growth environment
for rice and will result in the highest yields. Flooding also helps suppress weed growth, improves the
efficiency of use of nitrogen and, in some environments, helps protect the crop from fluctuations in
temperatures. After transplanting, water levels should be around 3 cm initially, and gradually increase to
5-10 cm with increasing plant height. With direct wet seeding, the soil should be kept just at saturation
from sowing to some 10 days after emergence, and then the depth of ponded water should gradually
increase with increasing plant height. With direct dry seeding, the soil should be moist but not saturated
from sowing till emergence, else the seeds may rot in the soil. After sowing, apply a flush irrigation if
there is no rainfall to wet the soil. Saturate the soil when plants have developed 3 leaves, and gradually
increase the depth of ponded water with increasing plant height.
Under certain conditions, allowing the soil to dry out for a few days before reflooding can be beneficial to
crop growth. In certain soils high in organic matter, toxic substances can be formed during flooding that
can be removed through intermittent soil drying. Intermittent soil drying promotes root growth which can
help plants resist lodging better in case of strong winds later in the season. Intermittent soil drying can
also help control certain pests or diseases that require standing water for their spread or survival, such as
golden apple snail. The farmers often practice a period of 7-10 days “mid-season drainage” (during which
the soil is left to dry out) during the active tillering stage. This practice should reduce the number of
excess and nonproductive tillers, but these benefits are not always found.
Intermittent soil drying is also used in the System of Rice Intensification (SRI) and is suggested to lead to
improved soil health. Other research, however, shows that nonflooded soil promotes the occurrence of
certain soils pests such as nematodes.
Diunduh dari sumber: http://www.knowledgebank.irri.org/rkb/2-sound-water-management.html………. 30/10/2012
MANAJEMEN AIR YANG BAGUS UNTUK LAHAN SAWAH
FASE PERTUMBUHAN REPRODUKTIF
Lowland rice is extremely sensitive to water shortage at the
flowering stage, and drought effects occur when soil water contents
drop below saturation.
Drought at flowering results in increase spikelet sterility, decreased
percentage filled spikelets, and, therefore, decreased number of
grains per panicle and decreased yields. Keep the water level in the
fields at 5 cm at all times during this stage.
Diunduh dari sumber: http://www.knowledgebank.irri.org/rkb/2-sound-water-management.html………. 30/10/2012
MANAJEMEN AIR YANG BAGUS UNTUK LAHAN SAWAH
FASE PEMASAKAN
This period does not necessarily require flooding. Soil that is 80–90% saturated is
sufficient. However, for easy operations, keeping the fields flooded may still be the
simplest management approach.
Draining the fields some 10-15 days before the expected harvest date hastens maturity
and grain ripening, prevents excessive nitrogen uptake, and makes the land better
accessible (because it is dryer) for harvest operations.
Diunduh dari sumber: http://www.knowledgebank.irri.org/rkb/2-sound-water-management.html………. 30/10/2012
MANAJEMEN AIR YANG BAGUS UNTUK LAHAN SAWAH
PEMBASAHAN DAN PENGERINGAN YG BERGANTIAN (AWD)
In alternate wetting and drying (AWD), irrigation water is applied to obtain flooded conditions after a
certain number of days have passed after the disappearance of ponded water. AWD is also called
‘intermittent irrigation’ or ‘controlled irrigation’.
The number of days of nonflooded soil in AWD before irrigation is applied can vary from 1 day to more
than 10 days. A practical way to implement AWD is to monitor the depth of the water table on the field
using a simple perforated ‘field water tube’. After an irrigation application, the field water depth will
gradually decrease in time. When the water level (as measured in the tube) is 15 cm below the surface of
the soil, it is time to irrigate and flood the soil with a depth of around 5 cm.
Around flowering, from 1 week before to one week after the peak of flowering, ponded water should be
kept at 5 cm depth to avoid any water stress that would result in potentially severe yield loss. The
threshold of 15 cm is called ‘Safe AWD” as this will not cause any yield decline since the roots of the rice
plants will still be able to take up water from the saturated soil and the perched water in the rootzone.
The field water tube helps farmers see this “hidden” source of water. In Safe AWD, water savings may be
relatively small, in the order of 15%, but there is no yield penalty. After creating confidence that Safe
AWD does not reduce yield, farmers may experiment by lowering the threshold level for irrigation to 20,
25, 30 cm, or even deeper. Some yield penalty may be acceptable when the price of water is high or when
water is very scarce.
Diunduh dari sumber: http://www.knowledgebank.irri.org/rkb/2-sound-water-management.html………. 30/10/2012
Irigasi Permukaan
Irigasi Permukaan merupakan sistem irigasi yang
menyadap air langsung di sungai melalui bangunan
bendung maupun melalui bangunan pengambilan bebas
(free intake) kemudian air irigasi dialirkan secara
gravitasi melalui saluran sampai ke lahan pertanian.
Dalam irigasi dikenal saluran primer, sekunder, dan
tersier.
Pengaturan air ini dilakukan dengan pintu air.
Prosesnya adalah gravitasi, tanah yang tinggi akan
mendapat air lebih dulu.
Bangunan irigasi untuk menyalurkan air irigasi ke swah intensif di Kab. Jember
Irigasi Lokal
Sistem ini air distribusikan dengan cara pipanisasi. Di sini juga berlaku gravitasi, di
mana lahan yang tinggi mendapat air lebih dahulu. Namun air yang disebar hanya
terbatas sekali atau secara lokal.
Sistem irigasi pertanian di Niigata
Dari pintu pengeluaran air tersebut dialirkan ke
sawahnya melalui pipa yang berada di bawah
permukaan sawahnya. Kalau di tanah air kita pada
umumnya air dialirkan melalui permukaan sawah.
Diunduh dari sumber: http://informasi-budidaya.blogspot.com/2007/06/sistem-irigasi-pertanian-di-niigata.html ………. 28/10/2012
Irigasi Tradisional dengan Ember
Di sini diperlukan tenaga kerja secara perorangan yang banyak sekali.
Di samping itu juga pemborosan tenaga kerja yang harus menenteng ember.
Small-scale drip irrigation systems
BUCKET SYSTEM
The bucket system consists of two drip lines,
each 15-30 m long, and a 20-litre bucket for
holding water. Each of the drip lines is connected
to a filter to remove any particles that may clog
the drip nozzles.
The bucket is supported on a bucket stand, with
the bottom of the bucket at least 1 m above the
planting surface. One bucket system requires 2-4
buckets of water per day and can irrigate 100200 plants with a spacing of 30 cm between the
rows.
For crops such as onions or carrots, the number
of plants can be as many as the bed can
accommodate.
A farmer growing for the market can usually
recover this investment within the first crop
Diunduh dari
sumber: http://www.infonet-biovision.org/default/ct/293/soilconservation………. 28/10/2012
season.
Irigasi Pasang-Surut di Sumatera, Kalimantan, dan Papua
Dengan memanfaatkan pasang-surut air di wilayah Sumatera, Kalimantan, dan Papua dikenal apa
yang dinamakan Irigasi Pasang-Surat (Tidal Irrigation).
Teknologi yang diterapkan di sini adalah: pemanfaatan lahan pertanian di dataran rendah dan
daerah rawa-rawa, di mana air diperoleh dari sungai pasang-surut di mana pada waktu pasang air
dimanfaatkan.
Di sini dalam dua minggu diperoleh 4 sampai 5 waktu pada air pasang.
LAHAN PASANG-SURUT
Lahan pasang surut adalah lahan yang pada musim penghujan (bulan desember-mei) permukaan air
pada sawah akan naik sehingga tidak dapat di tanami padi.
Pada musim kemarau (bulan juli-september) air permukaan akan surut yang mana pada saat itu
tanaman padi sawah baru dapat ditanam (pada lokasi yang berair). (LIPI Kalimantan, 1994)
Combined drainage
and irrigation system
using tidal differences
(source ESCAP 1978)
Irigasi Tanah Kering atau Irigasi Tetes
Di lahan kering, air sangat langka dan pemanfaatannya harus efisien. Jumlah air irigasi yang
diberikan ditetapkan berdasarkan kebutuhan tanaman, kemampuan tanah memegang air, serta
sarana irigasi yang tersedia.
Ada beberapa sistem irigasi untuk tanah kering, yaitu:
(1) irigasi tetes (drip irrigation),
(2) irigasi curah (sprinkler irrigation),
(3) irigasi saluran terbuka (open ditch irrigation), dan
(4) irigasi bawah permukaan (subsurface irrigation).
Untuk penggunaan air yang efisien, irigasi tetes [3] merupakan salah satu alternatif. Misal sistem
irigasi tetes adalah pada tanaman cabai.
DRIP IRRIGATION
In drip irrigation, water flows through a
filter into special drip pipes, with emitters
located at different spacings. Water is
discharged through the emitters directly into
the soil near the plants through a special
slow-release device.
Diunduh dari sumber: http://www.infonet-biovision.org/default/ct/293/soilconservation………. 28/10/2012
TRANSPOR AIR:
Tanah – Tanaman - Atmosfir
Air bergerak dari tanah, melalui akar, batang, daun, memasuki
atmosfer
Laju aliran air ini merupakan fungsi
F (selisih potensial, resistensi)
Potential unit name
Corresponding value
Water height (cm)
1
10
100
1000
15850
pF (-)
0
1
2
3
4.2
Bar (bar)
0.001
0.01
0.1
1
15.85
Pascal (Pa)
100
1000
10000
10000
1585000
Kilo Pascal (kPa)
0.1
1
10
100
1585
Mega Pascal (MPa)
0.0001
0.001
0.01
0.1
1.585
TEGANGAN AIR
Potential air bernilai positif dalam kondisi “free liquid water”
Potential dalam sistem tanah-tanaman-atmosfir bernilai negatif
(dalam tanah sawah tergenang, potential air positif)
Air bergerak dari potential tinggi (top of hill) menuju ke potential rendah (bottom of hill)
Tegangan adalah – potential: air bergerak dari tegangan rendah menuju tegangan
tinggi
Rice plants take up water from the soil and transport it
upward through the roots and stems and release it
through the leaves and stems as vapor in the
atmosphere (called transpiration).
The movement of water through the plant is driven by
differences in water potential: water flows from a high
potential to a low potential (imagine free water flow
over a sloping surface: water flows from the top, with a
high potential, to the bottom, with a low potential). In
the soil-plant-atmosphere system, the potential is high
in the soil and low in the atmosphere. Therefore water
moves from soil to plant and to the atmosphere.
Diunduh dari sumber: http://www.knowledgebank.irri.org/ewatermgt/courses/course1/modules/module02/m02l03.htm ……….
POTENSIAL AIR DALAM TANAMAN DAN TANAH
Potential = 0
Potential is +
Potential = -
Potential = 0
Potential = +
TEGANGAN LENGAS TANAH SELAMA PERTUMBUHAN TANAMAN
100
Soil moisture tension (kPa)
90
80
70
60
50
40
30
20
Panicle
initiation
10
0
175
200
Flowering
225
250
Harvest
275
300
Day number
Potential during the growing season in an aerobic soil
(aerobic rice, Changping, China, 2002)
Tanah liat mampu menyimpan banyak air, tetapi dengan
tegangan yang tinggi, sehingga akar tanaman sulit
menyerapnya
Tanah berpasir menyimpan sedikit air , tetapi dengan
tegangan rendah , sehingga akar tanaman mudah
menyerapnya
A medium-textured, loamy soil, holds intermediate levels
of water at intermediate tensions, so there is relatively
much water for extraction by roots
Tidak ada masalah pada tanah sawah tergenang, tetapi
menjadi masalah serius kalau tanah mengering selama
periode kering
Dampak KEKERINGAN
When the soil is too dry (high soil water tension), it becomes too difficult for roots to take
up water and water flow in the plant gets reduced:
• Reduksi transpirasi
• Reduksi photosynthesis
• Reduksi luas daun
• Daun menggulung
• Percepatan kematian daun
• Gabah hampa.
USING WATER EFFECTIVELY IN A DRY
CLIMATE OR DRY SEASON
Water must be used economically in dry areas.
To do this, the home garden manager should:
1. prepare the soil so that the plant will grow
in a basin-like or sunken space, to help
prevent surface water runoff;
2. select crops that grow well under drier
conditions (e.g. cassava, sweet potato,
eggplant, guava, mango, groundnut,
safflower and nug);
3. grow short-term vegetable crops near a
water source such as a water well, a drain
from a washing area, or a water tank.
Diunduh dari sumber: http://www.fao.org/docrep/003/X3996E/x3996e30.htm ………. 28/10/2012
Reduksi transpirasi sbg fungsi tegangan lengas tanah (IR72)
leaf (Tact/Tpot)
Soil water tension
Sterilitas Gabah
Turner (1986): relationship between leaf rolling –
increased canopy temperature
Spikelet sterility
Less grains
Less yield
EFEK KEKERINGAN
Soil moisture tension
Less canopy
transpiration
Reduced leaf
expansion
Less
leaves
Less canopy
photosynthesis
Reduced
partitioning to
shoot
Reduced leaf
photosynthesis,
transpiration
Leaf rolling
Spikelet sterility
Accelerated leaf
death
Less light
interception
Less
bioma
ss
Less grains
Less yield
O’Toole, 1984
Efek waktu terjadinya kekeringan: Paling peka saat pembungaan
Kekeringan di Serang, Banten.
Minggu, 5 Agustus 2012 08:22
Beberapa petani membuat sumur bor di tengah sawah
untuk menyelamatkan padi yang kekeringan di Kampung
Astana, Ds Walikukun, Kec Carenang, Serang, Banten.
Puluhan hektar sawah di lokasi itu terancam gagal panen
akibat dilanda kekeringan sementara untuk membuat
sumur bor tak semua petani mampu melakukannya karena
harus mengeluarkan biaya tambahan.
Diunduh dari: http://beritadaerah.com/denyuts/getContent/57414 ….. 31/10/2012
Kekeringan Landa Pemalang, Lahan Sawah Jadi Retak-retak
Sabtu, 21 Juli 2012 00:57 WIB
Para petani tanaman padi di daerah Pantura (Pantai Utara), Jawa
Tengah, kesulitan mendapatkan air irigasi di musim kemarau.
Akibatnya, ribuan hektar tanaman padi di daerah Pemalang
terancam gagal panen. Untuk menyelamatkan tanamannya, petani
terpaksa harus membuat sumur bor yang disedot dengan mesin
pompa air diesel.
Kondisi ini menyebabkan biaya produksi meningkat.
Bahkan, akibat kurangnya air irigasi ke sawah para petani, tanah
sawah mengering dan retak-retak, membuat kondisi tanaman padi
tidak maksimal. Jika tanah sawahnya tidak mendapatkan air,
dikhawatirkan petani mengalami gagal panen.
Diunduh dari: http://www.lensaindonesia.com/2012/07/21/kekeringan-landa-pemalang-lahan-sawah-jadi-
Dampak kekeringan pada tanaman padi muda
Irigasi Kering, Puluhan Hektar Sawah Kekeringan
(Post date: 05/07/2012 - 20:19 REPORTER: ab. EDITOR: mdika
Lebak - Sedikitnya 30 hektar lahan persawan di desa Talaga Hiang,
Kecamatan Cipanas, Kabupaten Lebak, kekeringan. Dinas Pertanian
Kabupaten Lebak masih terus melakukan upaya mengairi sawah warga
tersebut dengan cara melakukan penyedotan air di Leuwi Herang untuk
disalurkan ke saluran irigasi Leuwi Dolog.
Kepala Bidang Sarana Dinas Pertanian Lebak, Rahmat Yuniar didampingi
Kabid Produksi, Yuntani, mengatakan, saat ini lahan tanam petani di Desa
Talaga Hiang yang luasnya mencapai 30 HA dilanda kekeringan akibat
kemarau, bahkan sarana irigasi yang ada di daerah setempat yaitu Irigasi
Leuwi Dolog tidak jalan sehingga tidak dapat membantu memenuhi
kebutuhan air yang dibutuhkan para petani desa setempat
DIUNDUH DARI: http://mediabanten.com/content/irigasi-kering-puluhan-hektarsawah-kekeringan ….. 31/10/2012
. 5100 Hektare Sawah di Bekasi Terancam Kekeringan
Posted by korantrans pada Agustus 22, 2009
. Trans, Bekasi : Akibat bencana alam yang menimpa bangunan bagi sadap (BKG/4)
di daerah irigasi (DI) Kedung Gede, Desa Cipayung, Bekasi, maka seluas 5100 dari
13.000 hektare lahan sawah di daerah itu akan terncam kekeringan. Apabila tidak
diatasi segera maka sejumlah petani di daerah tersebut, atau yang berada di saluran
Rengas Bandung tidak bisa menggarap sawahnya karena tidak tersedianya air.
Menurut Kusmana, untuk mengantisipasi agar tidak terjadinya kekeringan, maka
pihaknya bekerjasama dengan Perusahaan Jasa Tirta Jatiluhur akan membuat
saluran pengelak (kisdam) dengan cara pemasangan cerucuk bambu dan karung
pasir. Hal ini dalakukan untuk menaikan debit ar pada saluran. Sementara untuk
penanganan jangka panjangnya harus dilaksanakan pembangunan baru yang biaya
fisiknya saja diperkirakan antara Rp 1 sampai Rp 2 miliar.
Masalah bencana alam di BKG/4 ini sudah dilaporkan ke pusat melalui Balai
Pengelola Wilayah Sungai (BPWS) Citarum di Bandung.
Selain itu pihak PPK Irigasi 1 sekarang sedang melakukan koordinasi dengan pihak
kecamatan dan Pemkab Bekasi, terutama dalam masalah jika ada pembebasan lahan
apabila adanya pembangunan saluran baru. “ Akibaat bencana alam itu, BKG/4 ini
memang perlu segera diatasi dengan pembangunan baru. Namun sebagai orang
lapangan, saya usulkan pembangunannya lebih baik dilaksanakan dalam dua tahap.
Hal ini mengingat waktu yang sudah mepet ke akhir tahun anggaran,” (Kusmana).
Diunduh dari: http://korantrans.wordpress.com/2009/08/22/5100-hektare-sawah-di-bekasi-terancam-
PENANAMAN PADI SISTEM LEGOWO
Pola Tanam
Pada areal beririgasi, lahan dapat ditanami padi 3 x setahun, tetapi pada
sawah tadah hujan harus dilakukan pergiliran tanaman dengan palawija.
Pergiliran tanaman ini juga dilakukan pada lahan beririgasi, biasanya setelah
satu tahun menanam padi.
Untuk meningkatkan produktivitas lahan, seringkali dilakukan tumpang sari
dengan tanaman semusim lainnya, misalnya padi gogo
dengan jagung atau padi gogo di antara ubi kayu dan kacang tanah.
Pada pertanaman padi sawah, tanaman tumpang sari ditanam
di pematang sawah, biasanya berupa kacang-kacangan.
SAWAH BER-TERAS-BANGKU
Analysis of percolation and seepage through paddy bunds
Han-Chen Huang, Chen-Wuing Liu, Shih-Kai Chen, Jui-Sheng Chen.
Journal of Hydrology. Volume 284, Issues 1–4, 22 December 2003, Pages 13–25.
This study investigates percolation and seepage through the bunds of flat and terraced paddies. Field
experiments were conducted in Hsin-Pu of Hsin-Chu County, Taiwan, to measure the soil water content of
various types of bund. Measurements revealed that the soil was unsaturated along the sloped surface of
the terrace.
Experimental results also indicated that seepage face flow did not develop even after 2 days of heavy
rainfall. A three-dimensional model, FEMWATER, was adopted to simulate percolation and lateral
seepage under various bund conditions. In a flat paddy, the rate of percolation of bunds under which a
plow sole was located, was 0.40 cm d−1, close to the average infiltration rate of a flooded paddy. The
percolation of the bund without plow sole was 0.85 cm d−1, or double the average infiltration rate of a
flooded paddy.
Infiltration in the central area of a terraced paddy is mainly vertically downward, whereas flow near the
bund is predominantly lateral. The paddy field near the bund has a high hydraulic gradient. The
simulated infiltration flux into the bund (1.47 cm d−1) after 85 days of rice cultivation exceeded that into
the central area (0.54 cm d−1) by a factor of 2.72. The final percolation flux from the bund (1.24 cm d−1)
also exceeded the final percolation from the plow sole (0.68 cm d−1) by a factor of 1.82. The lateral seepage
fluxes through the bund, downward and upward along the slope surface, are 2.01 and −2.12 cm d−1,
respectively. However, the lateral seepage flux does not fully saturate the surface of the hillside soil.
A simulation clearly shows that the seepage upstream of the paddy field does not move water downstream
and is reused as subsurface return flow. Both experimental and simulation results clarify the mechanisms
of water movement in the terraced paddy and reveal the existence of an unsaturated seepage face along
the sloping surface of the terraced field.
Diunduh dari sumber:
http://www.sciencedirect.com/science/article/pii/S0022169403002282…….. 29/10/2012
SAWAH BER-TERAS-BANGKU
Analysis of percolation and seepage through paddy bunds
Han-Chen Huang, Chen-Wuing Liu, Shih-Kai Chen, Jui-Sheng Chen.
Journal of Hydrology. Volume 284, Issues 1–4, 22 December 2003, Pages 13–25.
Dua tipe
rembesan air
lateral melalui
pematang sawah
Diunduh dari sumber:
http://www.sciencedirect.com/science/article/pii/S0022169403002282…….. 29/10/2012
SAWAH BER-TERAS-BANGKU
Analysis of percolation and seepage through paddy bunds
Han-Chen Huang, Chen-Wuing Liu, Shih-Kai Chen, Jui-Sheng Chen.
Journal of Hydrology. Volume 284, Issues 1–4, 22 December 2003, Pages 13–25.
Skema irisan
melintang lahan
sawah beterras
dan terminologi
yang lazim
digunakan.
Open arrows
indicate soil
water sampling
locations and
directions
Diunduh dari sumber:
http://www.sciencedirect.com/science/article/pii/S0022169403002282…….. 29/10/2012
SAWAH BER-TERAS-BANGKU
Analysis of percolation and seepage through paddy bunds
Han-Chen Huang, Chen-Wuing Liu, Shih-Kai Chen, Jui-Sheng Chen.
Journal of Hydrology. Volume 284, Issues 1–4, 22 December 2003, Pages 13–25.
Kecepatan aliran
lapangan Darcy
untuk rembesan
lateral pada lahan
sawah berteras
(cm d−1).
Diunduh dari sumber:
http://www.sciencedirect.com/science/article/pii/S0022169403002282…….. 29/10/2012
Jaring-jaring Makanan dalam Ekosistem Sawah
Hubungan trofik
pada ekosistem
padi sawah yg
menunjukkan
pentingnya
detritivores dan
komponen vegetasi
non-tanaman.
Sumber:
The three planks
for ecological
engineering
(Heong et al. 2012)
Diunduh dari sumber: http://allplantprotection.blogspot.com/2012/05/cultivating-flowers-on-rice-fieldedges.html …….. 28/10/2012
Ecological Sustainability of the Paddy Soil-Rice System in Asia Kazutake Kyuma
Department of Environmental Science
The University of Shiga Prefecture
2500 Hassaka-cho, Hikone City
Japan 522, 1995-09-01
Nutrient Status of Paddy Soils
General Redox Transformations under Waterlogged Conditions
The most characteristic management practice in paddy rice cultivation is waterlogging, or submergence of
the land surface. This brings about anaerobic conditions in the soil, due to the very slow diffusion rate of
oxygen through water. Biologically, after the oxygen reserve in the soil is exhausted and aerobic
microorganisms have all died, facultative anaerobes dominate for some time. As the anaerobioc
conditions continue, these microorganisms are gradually replaced by obligate or strict anaerobes.
The biological changes are accompanied by a very characteristic succession of chemical transformations
of materials. Following the disappearance of molecular oxygen, nitrate is used as a substrate for
denitrifiers. Manganic oxides are solubilized as a result of reduction to manganous ions, likewise orange
yellow to reddish colored iron oxides are reduced to soluble ferrous ions, decolorizing the soil.
Many fermentation reactions based on various organic substrates proceed along with these mineral
transformations, producing carbon dioxide, ammoniacal nitrogen, low molecular weight organic acids,
and so forth. As the soil becomes even more reductive, sulfate reducers, which are strict anaerobes,
produce sulfides; and methanobacteria, also strict anaerobes, produce methane.
Diunduh dari sumber: http://www.agnet.org/library.php?func=view&id=20110721171053&type_id=4 …….. 28/10/2012
Ecological Sustainability of the Paddy Soil-Rice System in Asia Kazutake Kyuma
Department of Environmental Science
The University of Shiga Prefecture
2500 Hassaka-cho, Hikone City
Japan 522, 1995-09-01
All these biochemical changes occur vigorously for the first month after submergence,
when readily decomposable organic matter, the energy source for microorganisms, is
abundantly available. Past this stage, there will be a period when the supply of oxygen
by diffusion, though extremely slow, exceeds its consumption at the soil/water interface.
As all the oxygen is trapped by such reduced substances as ferrous and manganous
ions at the interface, a thin oxidized, orange colored layer (normally a few millimeters
thick) is differentiated from the underlying bulk of the strongly reduced, bluish-gray
plow layer.
Successive Chemical Transformations in Submerged Soils
Diunduh dari sumber: http://www.agnet.org/library.php?func=view&id=20110721171053&type_id=4 …….. 28/10/2012
Ecological Sustainability of the Paddy Soil-Rice System in Asia Kazutake Kyuma
Department of Environmental Science
The University of Shiga Prefecture
2500 Hassaka-cho, Hikone City
Japan 522, 1995-09-01
Supply of Basic Cations through Irrigation Water
At least 1000 to 1500 mm of water is used to irrigate paddy fields during one rice
cropping season. Nutrients dissolved in water, particularly basic cations such as
calcium, magnesium and potassium, as well as silica, are supplied to rice in the water. If
we assume that 1000 mm of water is used for one crop of rice, 1 mg kg -1 or 1 ppm of a
substance dissolved in water amounts to 10 kg/ha.
According to the mean water quality of Japanese rivers, irrigation of 1000 mm of water
brings to a paddy field 88 kg/ha of Ca, 19 kg/ha of Mg, 12 kg/ha of K, and 190 kg/ha of
SiO 2. Usually more than 1000 mm of water is used for irrigation, so the amount of
nutrients supplied to rice is larger.
Water Quality of Japanese and Thai Rivers
Diunduh dari sumber: http://www.agnet.org/library.php?func=view&id=20110721171053&type_id=4 …….. 28/10/2012
Ecological Sustainability of the Paddy Soil-Rice System in Asia Kazutake Kyuma
Department of Environmental Science
The University of Shiga Prefecture
2500 Hassaka-cho, Hikone City
Japan 522, 1995-09-01
Supply of Nitrogen through Biological Nitrogen Fixation
There are paddy areas where rice has been cultivated for hundreds of years without receiving
any fertilizer, but where yields are sustained at 1.5 to 2 mt/ha. It is estimated that about 20 kg
of N is required to harvest 1 mt of paddy. Thus, it is difficult to explain how rice yields can be
sustained for so long without any application of N.
The greater part of N in paddy soils exists in soil organic matter. This tends to be conserved
more in paddy soils than in upland soils, because of the anaerobic conditions. Microbial
decomposition of the organic matter gradually releases ammoniacal N (NH 4 +-N). As NH 4 +-N is
stable under anaerobic conditions, it is retained as a cation on negatively charged soil mineral
and organic particles, until the time when rice roots take it up. Thus, the leaching of NH 4 +-N
from paddy fields into the environment is not significant.
Besides soil organic matter, there is another important source of N, i.e. biological N fixation. In
paddy soils there are many microbes that are capable of fixing atmospheric N, such as bluegreen algae, Clostridia, photosynthetic bacteria, and many of the heterotrophic bacteria in the
rice rhizosphere. Estimates of the amount of biologically fixed N per crop of rice vary quite
widely, but 30 to 40 kg/ha would be a reasonable figure. This amount of N is two or three times
higher than the amount of N fixed in ordinary upland soils planted in non-leguminous crops.
Interestingly enough, this amount of fixed N can explain the average yields of paddy obtained
in unfertilized fields in southeast Asia (1.5 to 2 mt/ha) on the basis of 20 kg of N for 1 mt of
Diunduh dari sumber: http://www.agnet.org/library.php?func=view&id=20110721171053&type_id=4
…….. 28/10/2012
paddy.
Ecological Sustainability of the Paddy Soil-Rice System in Asia Kazutake Kyuma
Department of Environmental Science
The University of Shiga Prefecture
2500 Hassaka-cho, Hikone City
Japan 522, 1995-09-01
Tanah sawah dilengkapi
dnegan mekanisme siklus
N yg bagus, dengan input
melalui fiksasi N biologis
dan outputnya melalui
denitrification.
Hal ini menjadi landasan
bagu sustainabilitas
budidaya padi sebagai
sistem produksi pangan
yg efisien.
Diunduh dari sumber: http://www.agnet.org/library.php?func=view&id=20110721171053&type_id=4 …….. 28/10/2012
Ecological Sustainability of the Paddy Soil-Rice System in Asia Kazutake Kyuma
Department of Environmental Science
The University of Shiga Prefecture
2500 Hassaka-cho, Hikone City
Japan 522, 1995-09-01
Negative Aspects of Soil Reduction
Rice is known to suffer some physiological disorders under strongly reduced conditions. The
best known is a root rot, caused by hydrogen sulfide evolved in soils that are poor in readily
reducible iron oxides. These soils are often derived from pale colored, sandy, granitic
sediments. They are poor, not only in iron oxides, but also in some other plant nutrients such
as Mg, K and SiO 2. It is now known that root rot due to hydrogen sulfide is an acute case of
the more general "akiochi" phenomenon observed in these "degraded paddy soils", as
characterized above.
In Japan, a nationwide project was carried out during the post-war period to ameliorate
degraded paddy soils by dressing the soil with Fe-rich, more juvenile materials. With the aid of
a government subsidy, the project was successfully completed, so that "akiochi" is no longer
seen in Japan.
There are large areas of paddy fields in southeast Asian countries that are characterized by
the very low inherent potentiality of the soil. In fact, some of these deserve the name of
"degraded" paddy soils. However, because of the generally low levels of both fertilizer inputs
Diunduh
sumber:at
http://www.agnet.org/library.php?func=view&id=20110721171053&type_id=4
…….. 28/10/2012
and
ricedariyields,
present they may not be clearly differentiated from "normal"
soils.
Ecological Sustainability of the Paddy Soil-Rice System in Asia Kazutake Kyuma
Department of Environmental Science
The University of Shiga Prefecture
2500 Hassaka-cho, Hikone City
Japan 522, 1995-09-01
Advantages of Paddy Rice Cultivation
Comparison of Paddy Soils and Upland Soils
The high level of resistance of paddy soils to erosive forces is even more important, from the
viewpoint of sustainability. Upland soils tend to be eroded away unless they are properly
protected. This is particularly true in the tropics, where the erosivity of rainfall is very high,
and where upland soils usually have poor resistance to erosion. Paddy soils are most resistant
to erosion when they are terraced and there are ridges around the field, as measures to retain
surface water. In addition, paddy fields in the lowlands receive new sediments deposited from
run-off that carries eroded topsoil down from the uplands, thus perpetuating soil fertility and
productivity.
Paddy soils have other advantages. In upland farming, crop rotation is a necessity to avoid a
decline in yield due to diseases and pests that arise from a monoculture situation (soil
sickness). In paddy fields, on the other hand, rice can be grown year after year without any
clear sign of yield decline, over a considerable length of time. The alternation from aerobic to
anaerobic conditions in a yearly cycle of rice farming is the best measure to remove the
causes of soil sickness. No pathogens or soil-borne animals can survive such a drastic change
Diunduh dari sumber: http://www.agnet.org/library.php?func=view&id=20110721171053&type_id=4 …….. 28/10/2012
in the redox environment.
Ecological Sustainability of the Paddy Soil-Rice System in Asia Kazutake Kyuma
Department of Environmental Science
The University of Shiga Prefecture
2500 Hassaka-cho, Hikone City
Japan 522, 1995-09-01
Intensification of Paddy Rice Cultivation and the Environment
Rice is the staple food for more than two billion people, most of whom live in developing
countries where the population is still rapidly increasing.
A study conducted by the International Rice Research Institute (IRRI 1989) reveals that to meet
the projected growth in the demand for rice, the world's annual rough rice production must
increase from 458 million mt in 1987 to 556 million mt by 2000 and to 758 million tons by
2020. This represents a 65% increase. For the leading rice-growing countries of south and
southeast Asia, the same study indicates that the increase needed in rice production by 2020 is
even higher, at about double the present level.
The potential for expanding the area planted in rice seems to have become very restricted in
south and southeast Asia. Most land resources have already been exploited to their fullest
extent, and most of the readily manageable water resources also have been developed to
irrigate paddy fields. Therefore, any further increase in the production of rice depends heavily
on intensification in existing rice lands.
Diunduh dari sumber: http://www.agnet.org/library.php?func=view&id=20110721171053&type_id=4 …….. 28/10/2012
Ecological Sustainability of the Paddy Soil-Rice System in Asia Kazutake Kyuma
Department of Environmental Science
The University of Shiga Prefecture
2500 Hassaka-cho, Hikone City
Japan 522, 1995-09-01
Impact of Irrigation/Drainage and Chemical Inputs
Intensifying rice cultivation could have various impacts on the environment. If good irrigation
and drainage are provided, improved rice cultivars may be introduced, along with better
management of fertilizer, weeds and pests. The construction of dams, and of irrigation and
drainage canals, would normally bring more benefits than disadvantages to the regional
environment, as long as they are properly planned and implemented. It improves water use
efficiency, regulates floods and droughts, and, through these, improves the environmental
quality.
Increased use of chemical preparations, such as fertilizers, pesticides and herbicides, could be
more hazardous. It is possible that they might pollute irrigation water and soil, and sometimes
cause human health problems. This must, however, also be evaluated in comparison with the
upland cultivation of other crops.
Generally speaking, paddy rice cultivation could be less hazardous to the environment if it is
intensified, with a high level of chemical inputs, than upland crop cultivation.
Diunduh dari sumber: http://www.agnet.org/library.php?func=view&id=20110721171053&type_id=4 …….. 28/10/2012
Ecological Sustainability of the Paddy Soil-Rice System in Asia Kazutake Kyuma
Department of Environmental Science
The University of Shiga Prefecture
2500 Hassaka-cho, Hikone City
Japan 522, 1995-09-01
Impact of Gas Emissions from Paddy Fields
In relation to the global environment, air pollution from soil emissions is receiving more and
more attention. The production of nitrous oxide (N 2O) from N fertilizers and manures is now
considered to have an environmental impact. The gas is evolved in both nitrification and
denitrification processes. The former is considered more important at present. It affects the
destruction of ozone to oxygen, and also acts as a greenhouse gas. However, N 2O emissions
from paddy fields are considered to be very low (De Datta and Buresh 1989).
Paddy fields have been emitting methane since time immemorial. Therefore, the issue at the
present time is the reason for the recent rapid increase in the atmospheric methane
concentration of about 1% annually. Certainly, there was a large increase in the area planted in
rice during the early postwar period, but if we take the most recent decade, 1980 to 1990, the
world-wide annual rate of increase in rice area has been only 0.23% (IRRI 1993).
Diunduh dari sumber: http://www.agnet.org/library.php?func=view&id=20110721171053&type_id=4 …….. 28/10/2012
.. Methane emission from a simulated rice field ecosystem as influenced by hydroquinone and
dicyandiamide
Xingkai Xu, Yuesi Wang, Xunhua Zheng, Mingxing Wang, Zijian Wang, Likai Zhou, Oswald Van Cleemput.
Science of The Total Environment, Volume 263, Issues 1–3, 18 December 2000, Pages 243–253.
A simple apparatus for collecting methane emission from a simulated rice field ecosystem was formed.
With no wheat straw powder amended all treatments with inhibitor(s) had so much lower methane
emission during rice growth than the treatment with urea alone (control), which was contrary to
methane emission from the cut rice–soil system.
Especially for treatments with dicyandiamide (DCD) and with DCD plus hydroquinone (HQ), the total
amount of methane emission from the soil system and intact rice–soil system was 68.25–46.64% and
46.89–41.78% of the control, respectively.
Hence, DCD, especially in combination with HQ, not only increased methane oxidation in the
floodwater–soil interface following application of urea, but also significantly enhanced methane
oxidation in rice root rhizosphere, particularly from its tillering to booting stage.
Wheat straw powder incorporated into flooded surface layer soil significantly weakened the abovementioned simulating effects.
Regression analysis indicated that methane emission from the rice field ecosystem was related to the
turnover of ammonium-N in flooded surface layer soil.
Diminishing methane emissions from the rice field ecosystem was significantly beneficial to the growth
of rice.
Diunduh dari sumber:
http://www.sciencedirect.com/science/article/pii/S0048969700007129…….. 28/10/2012
.. Methane emission from a simulated rice field ecosystem as influenced by hydroquinone
and dicyandiamide
Xingkai Xu, Yuesi Wang, Xunhua Zheng, Mingxing Wang, Zijian Wang, Likai Zhou, Oswald Van Cleemput.
Science of The Total Environment, Volume 263, Issues 1–3, 18 December 2000, Pages 243–253.
Hubungan antara emisi
CH4 dari ekosistem padi
sawah yang dilakukan
aplikasi jerami gandum
dan konsentrasi NH4+-N
dalam air genangan (mg
N l−1).
Diunduh dari sumber:
http://www.sciencedirect.com/science/article/pii/S0048969700007129…….. 28/10/2012
.. Methane emission from a simulated rice field ecosystem as influenced by hydroquinone
and dicyandiamide
Xingkai Xu, Yuesi Wang, Xunhua Zheng, Mingxing Wang, Zijian Wang, Likai Zhou, Oswald Van Cleemput.
Science of The Total Environment, Volume 263, Issues 1–3, 18 December 2000, Pages 243–253.
Hubungan antara
emisi CH4 dari
ekosistem padi
sawah tanpa
aplikasi jerami
gandum
dan
konsnetrasi NH4+N dalam air
genangan.
Diunduh dari sumber:
http://www.sciencedirect.com/science/article/pii/S0048969700007129…….. 28/10/2012
SAWAH = WETLANDS
Atmospheric methane (CH4) is an important
greenhouse gas. On a scale of 100 years, it is
approximately 20 times more effective than
carbon dioxide (CO2). The total annual CH4
emission both from natural and
anthropogenic terrestrial sources to the
atmosphere is about 580 Tg (CH4) yr-1. The
contribution of natural and man-made
wetlands (e.g. rice paddy) to this global total
varies between 20 and 40%. Thereby, natural
wetlands are the major non-anthropogenic
source of methane at present and rice
agriculture accounts for some 17% of the
anthropogenic CH4 emissions. This is
because of the prevailing anaerobic
conditions in these ecosystems, their high
organic matter contents and their global
distribution.
Northern wetlands (>30° N) for example
constitute about 60% of the global wetland
area and emit a quarter to a third of the total
CH4 originating from wet soils.
Microbial turnover of methane and transport
pathways of gases in wetlands.
Diunduh dari sumber: http://www.ibp.ethz.ch/research/environmentalmicrobiology/research/Wetlands …….. 28/10/2012
The value of gas exchange as a service by rice paddies in suburban Shanghai, PR China
Yu Xiao, Gaodi Xie, Chunxia Lu, Xianzhong Ding, Yao Lu.
Agriculture, Ecosystems & Environment. Volume 109, Issues 3–4, 1 September 2005, Pages 273–283
Valuating ecosystem services is crucial for making the importance of ecosystem functioning explicit to the public and
decision makers as well as scientists. Investigations of the value of agricultural ecosystems have focused mainly on
value food and fibre production and been carried out at relatively coarse scales. However, such studies may have
underestimated services provided by agricultural ecosystems because they did not consider additional services such as
gas regulation, pollination control, nutrient transformation, and landscape aesthetics.
We present the results of a field experimental study of gas regulation services and their economic values provided by
rice paddy ecosystems in suburban Shanghai, China. Two major components of gas regulation by paddy fields are O 2
emissions and greenhouse gases (GHGs) regulation (including the uptake of CO 2 and emissions of CH4 and N2O).
Seasonal emissions of O2 from experimental plots with different urea application rates ranged from 25,365 to
32,612 kg ha−1 year−1, with an economic value of 9549–12,277 RMB ha−1 year−1 (Chinese currency;
1 euro = 10.7967 RMB, Jan 18, 2005).
The net GHGs regulation ranged from 705 to 2656 kg CO2C ha−1 year−1, with an economic value ranging from 531 to
2000 RMB ha−1 year−1. Thus, the overall economic value of gas regulation provided by the rice paddy ecosystems
ranged from 10,080 to 14,277 RMB ha−1 year−1.
Our results refined, and in some cases, modified previous estimates of agricultural ecosystem services based mainly on
coarse-scale studies.
Our study also demonstrated a systematic method to valuate the gas regulation services provided by rice paddy
ecosystems, which will be useful for understanding regulation of atmospheric chemistry and greenhouse effects by
other agriculture ecosystems..
Diunduh dari sumber:
http://www.sciencedirect.com/science/article/pii/S0167880905001374…….. 28/10/2012
The value of gas exchange as a service by rice paddies in suburban Shanghai, PR China
Yu Xiao, Gaodi Xie, Chunxia Lu, Xianzhong Ding, Yao Lu.
Agriculture, Ecosystems & Environment. Volume 109, Issues 3–4, 1 September 2005, Pages 273–283
.
Ilustrasi bilik
statis yg dipakai
untuk mengukur
aliran emisi gas
di lahan padi
sawah.
Diunduh dari sumber:
http://www.sciencedirect.com/science/article/pii/S0167880905001374…….. 28/10/2012
The value of gas exchange as a service by rice paddies in suburban Shanghai, PR China
Yu Xiao, Gaodi Xie, Chunxia Lu, Xianzhong Ding, Yao Lu.
Agriculture, Ecosystems & Environment. Volume 109, Issues 3–4, 1 September 2005, Pages 273–283
Estimasi nilai-nilai
ekonomi serapan
CO2, emisi CH4,
emisi N2O, dan
keseluruhan
regulasi gas rumah
kaca dari ekosistem
padi sawah selama
musim tumbuhnya
dnegan berbagai
dosis aplikasi urea
di daerah suburban Shanghai,
China.
Diunduh dari sumber:
http://www.sciencedirect.com/science/article/pii/S0167880905001374…….. 28/10/2012
DINAMIKA NITROGEN EKOSISTEM SAWAH
A coupled soil water and nitrogen balance model for flooded rice fields in India
V.M. Chowdary, N.H. Rao, P.B.S. Sarma.
Agriculture, Ecosystems & Environment. Volume 103, Issue 3, August 2004, Pages 425–441.
In the present study a simple model for assessing concentration of nitrate in water percolating out of the
flooded rice (Oryza Sativa) fields is presented. The model considers all the important nitrogen (N)
transformation processes that take place in flooded rice fields such as urea hydrolysis, volatilization,
nitrification, mineralization, immobilization, denitrification, crop uptake and leaching. It is based on
coupling of soil water and N-balance models.
The coupled model also accounts for weather, and timings and amounts of water and fertilizer
applications. All the N-transformations except plant uptake and leaching are considered to follow firstorder kinetics.
The simulation results show that urea hydrolysis is completed within 7 days of fertilizer application.
It was also observed that the volatilization loss of N varies from 25 to 33% of the applied fertilizer and
75% of the total volatilization loss occurs within 7 days of urea application.
The modeled leaching losses from the field experiments varied from 20 to 30% of the applied N. The Nuptake by the crop increased immediately after the application of fertilizer and decreased at 60 days after
transplanting.
The model is sufficiently general to be used in a wide range of conditions for quantification of nutrient
losses by leaching and developing water and fertilizer management strategies for rice in irrigated areas.
Diunduh dari sumber: http://www.sciencedirect.com/science/article/pii/S016788090300433X …….. 29/10/2012
DINAMIKA NITROGEN EKOSISTEM SAWAH
A coupled soil water and nitrogen balance model for flooded rice fields in India
V.M. Chowdary, N.H. Rao, P.B.S. Sarma.
Agriculture, Ecosystems & Environment. Volume 103, Issue 3, August 2004, Pages 425–441.
Skematik transformasi N pada lahan padi sawah yg tergenang
Diunduh dari sumber: http://www.sciencedirect.com/science/article/pii/S016788090300433X …….. 29/10/2012
DINAMIKA NITROGEN EKOSISTEM SAWAH
A coupled soil water and nitrogen balance model for flooded rice fields in India
V.M. Chowdary, N.H. Rao, P.B.S. Sarma.
Agriculture, Ecosystems & Environment. Volume 103, Issue 3, August 2004, Pages 425–441.
Zonasi ideal lahan sawah untuk penelitian neraca N.
Diunduh dari sumber: http://www.sciencedirect.com/science/article/pii/S016788090300433X …….. 29/10/2012
DINAMIKA NITROGEN EKOSISTEM SAWAH
A coupled soil water and nitrogen balance model for flooded rice fields in India
V.M. Chowdary, N.H. Rao, P.B.S. Sarma.
Agriculture, Ecosystems & Environment. Volume 103, Issue 3, August 2004, Pages 425–441.
Schematic representation of nitrogen balance model.
Diunduh dari sumber: http://www.sciencedirect.com/science/article/pii/S016788090300433X …….. 29/10/2012
DINAMIKA NITROGEN EKOSISTEM SAWAH
A coupled soil water and nitrogen balance model for flooded rice fields in India
V.M. Chowdary, N.H. Rao, P.B.S. Sarma.
Agriculture, Ecosystems & Environment. Volume 103, Issue 3, August 2004, Pages 425–441.
Serapan Nitrogen
tanaman padi di
Pantnagar, Uttar
Pradesh, India.
(a) aplikasi pupuk
Basal
(80 kg N ha−1)
dan
(b) aplikasi
bertahap
(40+20+20 kg N ha−1).
Diunduh dari sumber: http://www.sciencedirect.com/science/article/pii/S016788090300433X …….. 29/10/2012
AIR DAN PADI SAWAH
Rice and Water
B.A.M. Bouman, E. Humphreys, T.P. Tuong, R. Barker.
Advances in Agronomy. Volume
. 92, 2007, Pages 187–237.
Rice environments also provide unique—but as yet poorly understood—ecosystem services such as the
regulation of water and the preservation of aquatic and terrestrial biodiversity. Rice production under
flooded conditions is highly sustainable. In comparison with other field crops, flooded rice fields produce
more of the greenhouse gas methane but less nitrous oxide, have no to very little nitrate pollution of the
groundwater, and use relatively little to no herbicides.
Flooded rice can locally raise groundwater tables with subsequent risk of salinization if the groundwater
carries salts, but is also an effective restoration crop to leach accumulated salts from the soil in
combination with drainage.
Water scarcity is expected to shift rice production to more water‐abundant delta areas, and to lead to crop
diversification and more aerobic (nonflooded) soil conditions in rice fields in water‐short areas. In these
latter areas, investments should target the adoption of water‐saving technologies, the reuse of drainage
and percolation water, and the improvement of irrigation supply systems.
A suite of water‐saving technologies can help farmers reduce percolation, drainage, and evaporation
losses from their fields by 15–20% without a yield decline. However, greater understanding of the
adverse effects of increasingly aerobic field conditions on the sustainability of rice production,
environment, and ecosystem services is needed. In drought‐, salinity‐, and flood‐prone environments, the
combination of improved varieties with specific management packages has the potential to increase
on‐farm yields by 50–100% in the coming 10 years, provided that investment in research and extension is
intensified.
Diunduh dari sumber: http://www.sciencedirect.com/science/article/pii/S0065211304920044 …….. 29/10/2012
AIR DAN PADI SAWAH
Rice and Water
B.A.M. Bouman, E. Humphreys, T.P. Tuong, R. Barker.
Advances in Agronomy. Volume 92, 2007, Pages 187–237.
Neraca air di lahan
padi sawah dataran
rendah. C, rumbai
kapiler; E, evaporasi;
I, irrigasi; O,
limpasan atas
pematang; P,
perkolasi; R, curah
hujan; S, rembesansamping (seepage);
T, transpirasi.
Diunduh dari sumber: http://www.sciencedirect.com/science/article/pii/S0065211304920044 …….. 29/10/2012
AIR DAN PADI SAWAH
Rice and Water
B.A.M. Bouman, E. Humphreys, T.P. Tuong, R. Barker.
Advances in Agronomy. Volume 92, 2007, Pages 187–237.
Aliran air permukaan
dna bawah
permukaan pada
lahan sawah.
D, drainage
(overbund flow);
I, irigasi;
P, perkolasi;
S, rembesan-seepage.
Diunduh dari sumber: http://www.sciencedirect.com/science/article/pii/S0065211304920044 …….. 29/10/2012
HEMAT AIR PADI SAWAH
. On-farm strategies for reducing
water input in irrigated rice; case studies in the
Philippines
D.F. Tabbal, B.A.M. Bouman, S.I. Bhuiyan, E.B. Sibayan, M.A. Sattar.
Agricultural Water Management. Volume 56, Issue 2, 30 July 2002, Pages 93–112.
This paper reports results of on-farm experiments in the Philippines to reduce water input by water-saving
irrigation techniques and alternative crop establishment methods, such as wet and dry seeding.
With continuous standing water, direct wet-seeded rice yielded higher than traditional transplanted rice by
3–17%, required 19% less water during the crop growth period and increased water productivity by 25–
48%.
Direct dry-seeded rice yielded the same as transplanted and wet-seeded rice, but can make more effective
use of early season rainfall in the wet season and save irrigation water for the subsequent dry season.
Direct seeding can further reduce water input by shortening the land preparation period.
In transplanted and wet-seeded rice, keeping the soil continuously around saturation reduced yields on
average by 5% and water inputs by 35% and increased water productivity by 45% compared with flooded
conditions. Intermittent irrigation further reduced water inputs but at the expense of increased yield loss.
Under water-saving irrigation, wet-seeded rice out-yielded transplanted rice by 6–36% and was a suitable
establishment method to save water and retain high yields. Groundwater depth greatly affected water use
and the possibilities of saving water. With shallow groundwater tables of 10–20 cm depth, irrigation water
requirements and potential water savings were low but yield reductions were relatively small.
The introduction of water-saving technologies at the field level can have implications for the hydrology
and water use at larger spatial scale levels.
Diunduh dari sumber: http://www.sciencedirect.com/science/article/pii/S0378377402000070 …….. 29/10/2012
HEMAT AIR PADI SAWAH
. On-farm
strategies for reducing water input in irrigated rice; case studies
in the Philippines
D.F. Tabbal, B.A.M. Bouman, S.I. Bhuiyan, E.B. Sibayan, M.A. Sattar.
Agricultural Water Management. Volume 56, Issue 2, 30 July 2002, Pages 93–112.
Komponenkomponen
neraca air di
lahan sawah
yg tergenang
dan
dilumpurkan
.
Diunduh dari sumber: http://www.sciencedirect.com/science/article/pii/S0378377402000070 …….. 29/10/2012
NERACA AIR SAWAH TADAH-HUJAN
Water balance simulation model for optimal sizing of on-farm reservoir in rainfed
farming system
Dipankar Roy, Sudhindra N. Panda, B. Panigrahi.
Computers and Electronics in Agriculture. Volume 65, Issue 1, January 2009, Pages 114–124.
. The on-farm reservoir (OFR) is used to harvest the surplus water from the diked crop field and recycle
the stored water as supplemental irrigation to rice in monsoon (rainy) and non-rice (dry) crops in winter
season under rainfed farming system. A user-friendly software, using Visual Basic 6.0 program, is
developed to find out the optimal size of the OFR in terms of percentage of field area (here in called as
OFR sizes throughout the manuscript) by simulating the water balance model parameters of the crop field
and the OFR. The software is meant for all the concerned including the engineers, planners and farming
community for any monsoon influenced cropping area, which uses rainfed agriculture. The menu driven
system is flexible enough to simulate the OFR sizes for various combinations of the OFR geometry, field
sizes, and the cropping systems. The user has to specify the crops to be grown in the fields, irrigation
management practices of the crops, types of OFR (lined or unlined), side slope, depth of OFR, and field
sizes. Evapotranspiration sub-model is embedded with the main model to compute the ET from the
meteorological data. As model application, the developed model is used to simulate the OFR sizes for the
rice–mustard and rice–groundnut cropping systems using the experimental observed and meteorological
data of the study area located at Indian Institute of Technology, Kharagpur in eastern India. The water
balance model parameters of the crop field are validated with 2 years of observed data from the
experimental field of above mentioned study area. The study reveals that rice–groundnut cropping system
requires higher OFR sizes than rice–mustard cropping systems. Moreover, it is observed that as the field
areas increase, the OFR sizes for each cropping systems is found to decrease.
Diunduh dari sumber: http://www.sciencedirect.com/science/article/pii/S0168169908001968…….. 29/10/2012
NERACA AIR SAWAH TADAH-HUJAN
Water balance simulation model for optimal sizing of on-farm reservoir in rainfed
farming system
Dipankar Roy, Sudhindra N. Panda, B. Panigrahi.
Computers and Electronics in Agriculture. Volume 65, Issue 1, January 2009, Pages 114–124.
Skematik
parameter
neraca air
lahan padi
sawah dan
OFR dengan
volume
kontrolnya.
Diunduh dari sumber: http://www.sciencedirect.com/science/article/pii/S0168169908001968…….. 29/10/2012
KEHILANGAN AIR DARI SAWAH
. Causes of high water losses from irrigated rice fields: field measurements
and results from analogue and digital models
S.H. Walker.
Agricultural Water Management. Volume 40, Issue 1, 1 March 1999, Pages 123–127.
Pada lahan sawah dengan pematang yang permanen, banyak
air yg hilang memalui rembesan-seepage lateral dari bidang
olah memasuki pematang dan dari pematang air bergerak
vertikal ke bawah menuju groundwater.
Lateral percolation losses increase with increases in field water
depth, bund width, aquifer thickness and depth to groundwater.
These losses do not occur in systems where the bunds are
reformed every year.
Diunduh dari sumber: http://www.sciencedirect.com/science/article/pii/S0378377498000924…….. 29/10/2012
KEHILANGAN AIR DARI SAWAH
. Causes
of high water losses from irrigated rice fields: field measurements
and results from analogue and digital models
S.H. Walker.
Agricultural Water Management. Volume 40, Issue 1, 1 March 1999, Pages 123–127.
Hypothesis:
Perkolasi lateral
ke arah bawah
melalui pematang
lebih besar
dibandingkan
dnegan perkolasi
vertikal melalui
lapisan tapak
kedap air di
bidang olah lahan
sawah.
Diunduh dari sumber: http://www.sciencedirect.com/science/article/pii/S0378377498000924…….. 29/10/2012
KEHILANGAN AIR DARI SAWAH
. Causes
of high water losses from irrigated rice fields: field measurements
and results from analogue and digital models
S.H. Walker.
Agricultural Water Management. Volume 40, Issue 1, 1 March 1999, Pages 123–127.
Observasi
lapangan
membuktikan
adanya inflow
ke pematang
dari lahan yang
di sekitarnya.
Diunduh dari sumber: http://www.sciencedirect.com/science/article/pii/S0378377498000924…….. 29/10/2012
CO2 & PANAS PADA EKOSISTEM SAWAH
. CO2/heat fluxes in rice fields: Comparative assessment of flooded and non-flooded fields in the
Philippines
Ma. Carmelita R. Alberto, Reiner Wassmann, Takashi Hirano, Akira Miyata, Arvind Kumar, Agnes Padre, Modesto Amante.
Agricultural and Forest Meteorology. Volume 149, Issue 10, 1 October 2009, Pages 1737–1750.
The aerobic rice fields had higher sensible heat flux (H) and lower latent heat flux (LE)
compared to flooded fields. On seasonal average, aerobic rice fields had 48% more sensible
heat flux while flooded rice fields had 20% more latent heat flux. Consequently, the aerobic
rice fields had significantly higher Bowen ratio (0.25) than flooded fields (0.14), indicating that
a larger proportion of the available net radiation was used for sensible heat transfer or for
warming the surrounding air.
The total C budget integrated over the cropping period showed that the net ecosystem exchange
(NEE) in flooded rice fields was about three times higher than in aerobic fields while gross
primary production (GPP) and ecosystem respiration (Re) were 1.5 and 1.2 times higher,
respectively. The high GPP of flooded rice ecosystem was evident because the photosynthetic
capacity of lowland rice is naturally large.
The Re of flooded rice fields was also relatively high because it was enhanced by the high
photosynthetic activities of lowland rice as manifested by larger above-ground plant biomass.
The NEE, GPP, and Re values for flooded rice fields were −258, 778, and 521 g C m−2,
respectively. For aerobic rice fields, values were −85, 515, and 430 g C m−2 for NEE, GPP, and
Re, respectively. The ratio of Re/GPP in flooded fields was 0.67 while it was 0.83 for aerobic
rice fields.
Diunduh dari sumber: http://www.sciencedirect.com/science/article/pii/S0168192309001476…….. 29/10/2012
CO2 & PANAS PADA EKOSISTEM SAWAH
. CO2/heat fluxes in rice fields: Comparative assessment of flooded and non-flooded fields
in the Philippines
Ma. Carmelita R. Alberto, Reiner Wassmann, Takashi Hirano, Akira Miyata, Arvind Kumar, Agnes Padre, Modesto
Amante.
Agricultural and Forest Meteorology. Volume 149, Issue 10, 1 October 2009, Pages 1737–1750.
Radiasi matahari
(SR), curah
hujan, dan suhu
ambient selama
musim kering
2008 , 11
January hingga
15 May.
Diunduh dari sumber: http://www.sciencedirect.com/science/article/pii/S0168192309001476…….. 29/10/2012
CO2 & PANAS PADA EKOSISTEM SAWAH
. CO2/heat fluxes in rice fields: Comparative assessment of flooded and non-flooded fields
in the Philippines
Ma. Carmelita R. Alberto, Reiner Wassmann, Takashi Hirano, Akira Miyata, Arvind Kumar, Agnes Padre, Modesto
Amante.
Agricultural and Forest Meteorology. Volume 149, Issue 10, 1 October 2009, Pages 1737–1750.
Hubungan antara jumlah respirasi
ekosistem harian (Re) dan potensial
air tanah (SWP) pada kedalmaan
tanah 15 cm lahan sawah aerobik
selama musim kering 2008.
Daily Re was grouped into 24 bins
and averaged with equal number of
data points per bin.
Triangles denote values during
vegetative to panicle initiation stage;
squares denote values during
reproductive to ripening stage; circles
denote values during harvest stage.
Diunduh dari sumber: http://www.sciencedirect.com/science/article/pii/S0168192309001476…….. 29/10/2012
CO2 & PANAS PADA EKOSISTEM SAWAH
. CO2/heat fluxes in rice fields: Comparative assessment of flooded and non-flooded fields
in the Philippines
Ma. Carmelita R. Alberto, Reiner Wassmann, Takashi Hirano, Akira Miyata, Arvind Kumar, Agnes Padre, Modesto
Amante.
Agricultural and Forest Meteorology. Volume 149, Issue 10, 1 October 2009, Pages 1737–1750.
Hubungan antara produksi primer
bruto harian (GPP) dan potensial air
tanah (SWP) pada kedalaman tanah
15 cm sawah aerobik semala musim
kering 2008.
Daily GPP was grouped into 24 bins and
averaged with equal number of data
points per bin.
Vertical bars denote standard error.
Triangles denote values during vegetative
to panicle initiation stage; squares denote
values during reproductive to ripening
stage; circles denote values during
harvest stage.
Diunduh dari sumber: http://www.sciencedirect.com/science/article/pii/S0168192309001476…….. 29/10/2012
CO2 & PANAS PADA EKOSISTEM SAWAH
. CO2/heat fluxes in rice fields: Comparative assessment of flooded and non-flooded fields
in the Philippines
Ma. Carmelita R. Alberto, Reiner Wassmann, Takashi Hirano, Akira Miyata, Arvind Kumar, Agnes Padre, Modesto
Amante.
Agricultural and Forest Meteorology. Volume 149, Issue 10, 1 October 2009, Pages 1737–1750.
Hubungan antara pertukaran neto CO2
ekosistem (NEE) pada radiasi aktif
fotosintetik (PAR) lebih dari
1000 μmol m−2 s−1 dan defisit tekanan
uap (VPD) di lahan sawah aerobik (a)
ketika potensial air tanah (SWP) pada
kedalaman tanah 15 sebesar <−100 kPa
dan (b) lahan sawah tergenang, selama
musim kering 2008.
Half-hourly data were sorted by VPD
and bin averaged with equal number of
data per bin. Vertical bars denote
standard error.
Diunduh dari sumber: http://www.sciencedirect.com/science/article/pii/S0168192309001476…….. 29/10/2012
CO2 & PANAS PADA EKOSISTEM SAWAH
. CO2/heat fluxes in rice fields: Comparative assessment of flooded and non-flooded fields
in the Philippines
Ma. Carmelita R. Alberto, Reiner Wassmann, Takashi Hirano, Akira Miyata, Arvind Kumar, Agnes Padre, Modesto
Amante.
Agricultural and Forest Meteorology. Volume 149, Issue 10, 1 October 2009, Pages 1737–1750.
Variasi musim untuk parameter
harian (a) NEE, Re, dan GPP ;
dan (b) potensial air tanah
(SWP) pada kedalaman tanah
5 cm dan 15 cm lahan sawah
aerobik selama musim kering
2008 mulai 21 January hingga
12 May.
The vertical bars show the
different growth stages of the
aerobic rice (vegetative,
tillering to panicle initiation,
reproductive, heading to
flowering, ripening, and
harvest).
Diunduh dari sumber: http://www.sciencedirect.com/science/article/pii/S0168192309001476…….. 29/10/2012
JASA-JASA EKOSISTEM SAWAH
. Ecosystem services by paddy fields as substitutes of natural wetlands in
Japan
Yosihiro Natuhara
Ecological Engineering. Available online 22 May 2012.
Ecosystem services provided by paddy fields include; groundwater recharge, production of non-rice
foods, flood control, soil erosion and landslide prevention, climate-change mitigation, water purification,
culture and landscape, and support of ecosystems and biodiversity. Among these services, the value of
services that regulate ecosystem functions was estimated to be US$ 72.8 billion in Japan.
More than 5000 species have been recorded in paddy fields and the surrounding environment. Because
paddy fields are artificially disturbed by water level management, plowing, and harvest, most species
move between paddy fields and the surrounding environment. The linkage between paddy fields and the
associated environment plays an important role in biodiversity.
Two changes that have affected the ecosystem of paddy fields are modernization and abandonment of
farming. Satoyama, a traditional socio-ecological production landscape, which provided a functional
linkage between paddy fields and the associated environment has lost its functions.
Biodiversity-conscious rice farming has been promoted by collaborations among farmers, consumers and
governments. Biodiversity certification programs are successful examples of biodiversity-conscious
framing. In these programs incentives include direct payments and/or premium prices paid by consumers,
as well as farmers willingness to improve the safety of food and environment.
Diunduh dari sumber: http://www.sciencedirect.com/science/article/pii/S092585741200153X …….. 29/10/2012
JASA-JASA EKOSISTEM SAWAH
. Ecosystem services by paddy fields as substitutes of natural wetlands in Japan
Yosihiro Natuhara
Ecological Engineering. Available online 22 May 2012.
Lanskap sawah dan pergerakan spesies.
Diunduh dari sumber: http://www.sciencedirect.com/science/article/pii/S092585741200153X …….. 29/10/2012
JASA-JASA EKOSISTEM SAWAH
. Ecosystem services by paddy fields as substitutes of natural wetlands in Japan
Yosihiro Natuhara
Ecological Engineering. Available online 22 May 2012.
Pengelolaan air di lahan sawah dan siklus hidup spesies.
Periode waktu genangan dan drainage mempengaruhi daya
hidup spesies akuatik O. albistylum.
Diunduh dari sumber: http://www.sciencedirect.com/science/article/pii/S092585741200153X …….. 29/10/2012
JASA-JASA EKOSISTEM SAWAH
. Ecosystem services by paddy fields as substitutes of natural wetlands in Japan
Yosihiro Natuhara
Ecological Engineering. Available online 22 May 2012.
Konsolidasi lahan dna
perbaikan drainage.
Conversion to fields
equipped with deeper
ditches for rapid draining
has almost eliminated wet
winter paddy fields.
The gap between paddy and
drainage ditch prevents fish
from migrating to the
paddy.
Diunduh dari sumber: http://www.sciencedirect.com/science/article/pii/S092585741200153X …….. 29/10/2012
JASA-JASA EKOSISTEM SAWAH
. Ecosystem services by paddy fields as substitutes of natural wetlands in Japan
Yosihiro Natuhara
Ecological Engineering. Available online 22 May 2012.
Dampak perubahan lahan sawah pada ikan (sumber: Katano, 2000).
Diunduh dari sumber: http://www.sciencedirect.com/science/article/pii/S092585741200153X …….. 29/10/2012
NERACA KARBON EKOSISTEM SAWAH
. Rice paddy fields are also one of
the typical agricultural
ecosystems in Monsoon Asia.
Among them, single rice cropping
paddies that dominates in
northeastern Asia are
characterized by two contrasting
periods, a flooded growing period
and dry fallowed period which
lasts two thirds of a year. From
the analyses using stable isotopes
of water and carbon, the largest
carbon input was CO2 fixation by
photosynthesis of rice, where 6465% of the fixed carbon was
harvested in autumn. Inflow and
outflow of dissolved carbon
accounted for 5-9% of the total
input and output
Diunduh dari sumber: http://www.niaes.affrc.go.jp/annual/r2003/html/no52.html …….. 29/10/2012
Management-induced organic carbon accumulation in paddy soils: The role of organo-mineral
associations
Livia Wissing, Angelika Kölbl, Werner Häusler , Peter Schad, Zhi-Hong Cao, Ingrid Kögel-Knabner.
Soil and Tillage Research. Volume 126, January 2013, Pages 60–71.
Iron (Fe) oxides strongly interact with organic matter in soil and play an important role in the stabilization of organic
matter. These processes are often influenced by soil cultivation, including tillage, crop rotation and irrigation.
We assessed the effect of Fe oxides on organic carbon (OC) accumulation during the development of soils used for
paddy rice production in comparison to non-irrigated cropping systems. Soil samples were taken from two
chronosequences derived from uniform parent material in the Zhejiang Province (PR China). Bulk soils and soil
fractions were analyzed for OC concentrations, soil mineralogy and soil organic matter (SOM) composition was
determined by solid-state 13C NMR spectroscopy.
Paddy soils were characterized by increasing OC concentrations, from 18 mg g−1 to 30 mg g−1, during 2000 years of
rice cultivation, but OC concentrations of non-paddy soils were low in all age classes (11 mg g−1). SOM composition
revealed from Solid-state 13C NMR spectroscopy did not change during pedogenesis in either chronosequence.
Selective enrichment of lignin-derived compounds, caused by long-term paddy rice management, could not be
confirmed by the present study.
The management of paddy soils creates an environment of Fe oxide formation which was different to those in nonpaddy soils. Paddy soils are dominated by poorly crystalline Fe oxides (Feo) and significantly lower content of
crystalline Fe oxides (Fed − Feo). This was in contrast to non-paddy soils, which are characterized by high proportions
of crystalline Fe oxides. The paddy-specific Fe oxide composition was effective after only 50 years of soil
development and the proportion Fe oxides did not alter during further pedogenesis.
This chronosequence study revealed that the potential for OC accumulation was higher in paddy versus non-paddy
soils and was already reached at earliest stages of paddy soil development. Changes in paddy soil management
associated with redox cycle changes will not only affect Fe oxide composition of paddy soils but most probably also
OC storage potential.
Diunduh dari sumber: http://www.sciencedirect.com/science/article/pii/S016719871200164X …….. 31/10/2012
Management-induced organic carbon accumulation in paddy soils: The role of organo-mineral
associations
Livia Wissing, Angelika Kölbl, Werner Häusler , Peter Schad, Zhi-Hong Cao, Ingrid Kögel-Knabner.
Soil and Tillage Research. Volume 126, January 2013, Pages 60–71.
Hubungan antara besi ekstraks
oksalat (Feo) dan bahan organik (OC)
pada tanah-tanah padi sawah (P) dan
non-paddy (NP) fraksi tanah (20–
6.3 μm = debu medium; 6.3–
2 μm = debu halus; 2–0.2 μm = liat
kasar; <0.2 μm = liat halus).
Diunduh dari sumber: http://www.sciencedirect.com/science/article/pii/S016719871200164X …….. 31/10/2012
PLoS One. 2012; 7(5): e34642. Published online 2012 May 4.
Effects of Tillage and Nitrogen Fertilizers on CH4 and CO2 Emissions and Soil Organic Carbon in Paddy Fields
of Central China
Li Cheng-Fang, Zhou Dan-Na, Kou Zhi-Kui, Zhang Zhi-Sheng, Wang Jin-Ping, Cai Ming-Li, and Cao Cou-Gui.
Quantifying carbon (C) sequestration in paddy soils is necessary to help better understand the effect of
agricultural practices on the C cycle.
The objective of the present study was to assess the effects of tillage practices [conventional tillage (CT)
and no-tillage (NT)] and the application of nitrogen (N) fertilizer (0 and 210 kg N ha−1) on fluxes of CH4
and CO2, and soil organic C (SOC) sequestration during the 2009 and 2010 rice growing seasons in
central China.
Application of N fertilizer significantly increased CH4 emissions by 13%–66% and SOC by 21%–94%
irrespective of soil sampling depths, but had no effect on CO2 emissions in either year. Tillage
significantly affected CH4 and CO2 emissions, where NT significantly decreased CH4 emissions by 10%–
36% but increased CO2 emissions by 22%–40% in both years.
The effects of tillage on the SOC varied with the depth of soil sampling. NT significantly increased the
SOC by 7%–48% in the 0–5 cm layer compared with CT. However, there was no significant difference in
the SOC between NT and CT across the entire 0–20 cm layer. Hence, our results suggest that the potential
of SOC sequestration in NT paddy fields may be overestimated in central China if only surface soil
samples are considered.
Diunduh dari sumber: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3344821/…….. 31/10/2012
PLoS One. 2012; 7(5): e34642. Published online 2012 May 4.
Effects of Tillage and Nitrogen Fertilizers on CH4 and CO2 Emissions and Soil Organic Carbon in Paddy Fields
of Central China
Li Cheng-Fang, Zhou Dan-Na, Kou Zhi-Kui, Zhang Zhi-Sheng, Wang Jin-Ping, Cai Ming-Li, and Cao Cou-Gui.
Keseluruhan proses emisi CH4 dari sawah, termasuk produksi, oksidasi, dan transpornya ke artmosfir
dipengaruhi oleh praktek pertanian , seperti pengolahan tanah dan pemupukan nitrogen [1]–[3].
Tillage affects a range of biological, chemical, and physical properties, thereby affecting the release of
CH4 [4]. No-tillage (NT) has been reported to reduce CH4 emissions from paddy soils because rice straw
is placed on the soil surface under NT and the soil conditions are more oxidative than those of
conventional tillage (CT) [3], [5].
Emisi CH4 dari sawah dilaporkan sangat dipemngaruhi oleh bentuk dan dosis pupuk N [6].
1.
2.
3.
4.
5.
6.
Chu H, Hosen Y, Yagi K. NO, N2O, CH4 and CO2 fluxes in winter barley field of Japanese Andisol as affected by N fertilizer
management. Soil Biol Biochem. 2007;39:330–339.
Guo J, Zhou C. Greenhouse gas emissions and mitigation measures in Chinese agroecosystems. Agric Forest Meteorol.
2007;142:270–277.
Harada H, Kobayashi H, Shindo H. Reduction in greenhouse gas emissions by no-tilling rice cultivation in Hachirogata polder,
northern Japan: life-cycle inventory analysis. Soil Sci Plant Nutr. 2007;53:668–677.
Oorts K, Merckx R, Gréhan E, Labreuche J, Nicolardot B. Determinants of annual fluxes of CO2 and N2O in long–term no–tillage
and conventional tillage systems in northern France. Soil Till Res. 2007;95:133–148.
Liang W, Shi Y, Zhang H, Yue J, Huang GH. Greenhouse gas emissions from northeast China rice fields in fallow season.
Pedosphere. 2007;17(5):630–638.
Minami K. The effect of nitrogen fertilizer use and other practices on methane emission from flooded rice. Fertil Res. 1995;40:71–
84.
Diunduh dari sumber: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3344821/…….. 31/10/2012
PLoS One. 2012; 7(5): e34642. Published online 2012 May 4.
Effects of Tillage and Nitrogen Fertilizers on CH4 and CO2 Emissions and Soil Organic Carbon in Paddy Fields
of Central China
Li Cheng-Fang, Zhou Dan-Na, Kou Zhi-Kui, Zhang Zhi-Sheng, Wang Jin-Ping, Cai Ming-Li, and Cao Cou-Gui.
Perubahan emisi CH4 dari lahan sawah dengan beragam pengelolaannya selama periode
musim tanam padi 2009 dan 2010.
The pattern of seasonal CH4 emission fluxes was similar across NT and CT treatments during
the 2009 and 2010 rice growing seasons . In both years, the CH4 emission fluxes in the four
treatment groups were all initially low, increased gradually, and then peaked in mid-July (about
4–5 weeks after sowing). Thereafter, the CH4 emission fluxes declined gradually and remained
relatively low until harvesting when the CH4 emission fluxes were lowest.
Diunduh dari sumber: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3344821/…….. 31/10/2012
PLoS One. 2012; 7(5): e34642. Published online 2012 May 4.
Effects of Tillage and Nitrogen Fertilizers on CH4 and CO2 Emissions and Soil Organic Carbon in Paddy Fields
of Central China
Li Cheng-Fang, Zhou Dan-Na, Kou Zhi-Kui, Zhang Zhi-Sheng, Wang Jin-Ping, Cai Ming-Li, and Cao Cou-Gui.
EMISI CO2
Application of N fertilizer increases plant biomass production, stimulating soil biological activity, and
consequently, CO2 emission [40]. Wilson and Al-Kaisi [41], as well as Iqbal et al. [13], observed
increased CO2 emissions caused by N fertilizer application. By contrast, Burton et al. [15] and DeForest
et al. [16] indicated that reduced extracellular enzyme activities and fungal populations resulting from N
fertilizer application resulted in decreased soil CO2 emissions. We observed no significant effect of N
fertilizer application on cumulative CO2 emissions , consistent with the results reported by Almaraz et al.
[42]. This finding may be due to the fact that CO2 is reduced to CH4 under anaerobic conditions, thus
leading to significant differences in CH4 emissions rather than in CO2 emissions between fertilized and
unfertilized treatment areas.
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[13]. Iqbal J, Hu RG, Lin S, Hatano R, Feng ML, et al. CO2 emission in a subtropical red paddy soil (Ultisol) as affected by straw
and N fertilizer applications: a case study in Southern China. Agric Ecosyst Environ. 2009;131:292–302.
[14]. Xiao Y, Xie G, Lu G, Ding X, Lu Y. The value of gas exchange as a service by rice paddies in suburban Shanghai, PR China.
Agric Ecosyst Environ. 2005;109:273–283.
[15]. Burton AJ, Pregitzer KS, Crawford JN, Zogg GP, Zak DR. Simulated chronic NO3-deposition reduces soil respiration in
Northern hardwood forests. Global Change Biol. 2004;10:1080–1091.
[16]. DeForest JL, Zak DR, Pregitzer KS, Burton AJ. Atmospheric nitrate deposition, microbial community composition, and
enzyme activity in Northern hardwood forests. Soil Sci Soc Am J. 2004;68:132–138.
[40]. Dick RP. A review: long term effects of agricultural systems on soil biochemical and microbial parameters. Agric Ecosyst
Environ. 1992;40:25–36.
[41]. Wilson HM, Al-Kaisi MM. Crop rotation and nitrogen fertilization effect on soil CO2 emissions in central Iowa. Appl Soil
Ecol. 2008;39:264–270.
[42]. Almaraz JJ, Zhou XM, Mabood F, Madramootoo C, Rochette P, et al. Greenhouse gas fluxes associated with soybean
production under two tillage systems in southwestern Quebec. Soil Till Res. 2009;104:134–139.
Diunduh dari sumber: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3344821/…….. 31/10/2012
Arsenic as a Food Chain Contaminant: Mechanisms of Plant Uptake and Metabolism and Mitigation Strategies
Annual Review of Plant Biology. Vol. 61: 535-559 (Volume publication date June 2010)
Fang-Jie Zhao, Steve P. McGrath, and Andrew A. Meharg
Tanaman padi sangat efisien mengakumulasikan As karena kondisi tergenang yang
mengakibatkan mobilisasi arsenite, dan efisien menyerap arsenite melalui jalur
transpor silikon.
Diunduh dari sumber: http://www.annualreviews.org/doi/abs/10.1146/annurev-arplant-042809-112152?journalCode=arplant ……..