BAHAN KAJIAN: STELA-SMNO.FPUB.APRIL2013
CONCEPTS, DEFINITIONS AND PRINCIPLES
"Lahan adalah area tertentu di permukaan bumi, yang
melingkupi semua atribut biosfir di atas dan di bawah
permukaan, termasuk iklim di dekat permukaan, tanah
dan bentuk lahan, hidrologi permukaan (termasuk
danau dangkal, sungai, rawa-rawa),
the near-surface sedimentary layers and associated
groundwater reserve,
populasi tumbuhan dan binatang,
pola permukiman dan sifat fisik akibat aktivitas
manusia (terras, bangunan air dan drainage, jalan raya
dan bangunan gedung, dll.).“
Sumber: FAO Land and Water Bulletin No. 5. 1997
Fungsi-fungsi lahan:
1. Fungsi Produksi
2. Fungsi Lingkungan Biotik
3. Fungsi regulasi iklim
4.· hydrologic function
5.· storage function
6.· waste and pollution control function
7.· living space function
8.· archive or heritage function
9.· connective space function
Sumber: FAO Land and Water Bulletin No. 5. 1997
FUNGSI PRODUKSI
Lahan merupakan basis bagi berbagai sistem
penunjang kehidupan, melalui produksi
biomasa yang menyediakan makanan, pakanternak, serat, bahan-bakar, bahan bangunan
dan material biotik lainnya bagi manusia,
secara langsung atau melalui budidaya ternak,
termasuk akuakultur dan perikanan tangkap.
Sumber: FAO Land and Water Bulletin No. 5. 1997
FUNGSI LINGKUNGAN BIOTIK
Lahan merupakan basis bagi
buiodiversitas terrestris dengan
menyediakan habitat biologis dan
plasma nutfah bagi tanaman,
binatang, dan mikroba yang hidup di
atas dan di bawah permukaan.
Sumber: FAO Land and Water Bulletin No. 5. 1997
FUNGSI LAHAN: REGULASI IKLIM
land and its use are a source and sink of
greenhouse gases and form a co-determinant
of the global energy balance - reflection,
absorption and transformation of radiative
energy of the sun, and of the global
hydrological cycle
Fungsi Lahan: Koneksi Ruang
land provides space for the transport of people,
inputs and produce, and for the movement of
plants and animals between discrete areas of
natural ecosystems
Sumber: FAO Land and Water Bulletin No. 5. 1997
FUNGSI LAHAN
FUNGSI HIDROLOGI
Land regulates the storage and flow of surface
and groundwater resources, and influences their
quality
FUNGSI GUDANG
land is a storehouse of
raw materials and
minerals for human use
FUNGSI PENGENDALI
PENCEMARAN DAN LIMBAH
land has a receptive,
filtering, buffering and
transforming function of
hazardous compounds
Sumber: FAO Land and Water Bulletin No. 5. 1997
FUNGSI RUANG KEHIDUPAN
land provides the physical basis for human settlements,
industrial plants and social
activities such as sports and recreation.
FUNGSI ARSIP ATAU WARISAN
Land is a medium to store and protect the
evidence of the cultural history of humankind,
and source of information on past climatic
conditions and past land uses.
Sumber: FAO Land and Water Bulletin No. 5. 1997
Lahan mempunyai Atribut, Karakteristik, Sifat & Ciri, dan
Kualuitas (atau Kondisi/Pembatas):
1. an attribute, or variable, is a neutral, over-arching term for a single
or compound aspect of the land;
2. a characteristic is an attribute which is easily noticed and which
serves as a distinguishing element for different types of land; it
may or may not have a practical meaning (e.g., soil colour or
texture, or height of forest cover are characteristics without giving
direct information on land quality);
3. a property is an attribute that already gives a degree of
information on the value of the land type;
4. a land quality (or limitation) is a complex attribute of land which
acts in a manner distinct from the actions of other land qualities in
its influence on the suitability of land for a specified kind of use.
Sumber: FAO Land and Water Bulletin No. 5. 1997
Land qualities are not absolute values, but have to be assessed in
relation to the functions of the land and the specific land use that one
has in mind. Some examples:
1. Land recently cleared from forest has a positive quality in respect of arable cropping
(clearing, as "development costs", adding to the value of potential agricultural land), but
has a negative quality in respect of sustainable use of the natural vegetative cover;
2. Land with a high degree of short-distance variation in soil and terrain conditions has a
positive quality for biodiversity, is a large drawback to large-scale mechanized arable
farming, but has a smaller limitation - or even an advantage - for smallholders' mixed
farming;
3. The presence of scattered clumps of trees or shrubs in an open savannah area with harsh
climatic conditions is a positive quality for extensive grazing (shelter against cold, heat or
wind) but may be less important, or negative, for arable farming;
4. The presence of small land parcels, of woody or stony hedgerows and terraces, or of
archaeological remains, is a positive quality in relation to the archival function of the land,
but can conflict with its production function;
5. The propensity of the soil surface to seal and crust is a negative quality for arable farming
(poor seedbed condition; reduced moisture intake of the soil), but is an asset of the land as
regards water harvesting possibilities for crop growing in lower parts of the landscape
wherever rainfall is submarginal.
Sumber: FAO Land and Water Bulletin No. 5. 1997
KUALITAS LAHAN & PRODUKTIVITAS TANAMAN
1. Crop yields (a resultant of many qualities listed below).
2. KETERSEDIAAN LENGAS TANAH.
3. KETERSEDIAAN HARA.
4. KETERSEDIAAN OKSIGEN DI ZONE AKAR.
5. Adequacy of foothold for roots.
6. KONDISI PERKECAMBAHAN.
7. Workability of the land (ease of cultivation).
8. SALINITAS ATAU SODISITAS.
9. TOKSISITAS TANAH.
10.RESISTENSI TERHADAP EROSI TANAH.
11.Pests and diseases related to the land.
12.Flooding hazard (including frequency, periods of inundation).
13.REGIM SUHU.
14.RADIASI ENERGI DAN FOTOPERIODE.
15.Climatic hazards affecting plant growth (including wind, hail, frost).
16.Air humidity as affecting plant growth.
17.PERIODE KERING UNTUK PEMASAKAN/PEMATANGAN TANAMAN.
Sumber: FAO Land and Water Bulletin No. 5. 1997
Crop yields (a resultant of many qualities listed
below).
Crop production provides the food for human beings, fodder for
animals and fiber for cloths. Land is the natural resource which is
unchanged & the burden of the population is tremendously increasing,
thereby decrease the area per capita. Therefore it is necessary to
increase the production per unit area on available land. This
necessitates the close study of all the factors of crop production viz.
1. TANAH sebagai TEMPAT MENANAM TANAMAN
2. Air yang dibutuhkan dan digunakan oleh tanaman
3. Tanaman yg menghasilkan bahan-bahan pangan dan pakan
4. Ketrampilan pengelolaan (budidaya) oleh petani
5. Iklim di luar kendali manusia, tetapi mempengaruhi pertumbuhan
dan produksi tanaman.
6. Karakter genetik tanaman yg menjadi kekayaan genetik dan dapat
dieksploitasi untuk produksi tanaman.
Sumber: http://agriinfo.in/?page=topic&superid=1&topicid=311
KETERSEDIAAN LENGAS TANAH
Kapasitas air-tersedia merupakan jumlah air yg dapat disimpan tanah
untuk dimanfaatkan oleh tanaman.
Air tanah ini ditahan di antara kapasitas-lapang dan titik-layu.
Kapasitas lapang merupakan air yg ditahan dalam tanah yg
berdrainage bebas selama dua hari setelah hujan atau irigasi.
Titik layu merupakan kandungan air-tanah pada saat mana kecambah
bunga-matahari mengalami layu secara irreversible.
Available water is expressed as a volume fraction (0.20), as a
percentage (20%), or as an amount (in inches). An example
of a volume fraction is water in inches per inch of soil. If a
soil has an available water fraction of 0.20, a 10 inch zone
then contains 2 inches of available water.
Sumber: http://soils.usda.gov/sqi/publications/files/avwater.pdf
KETERSEDIAAN LENGAS TANAH
Tekstur Tanah
Fraksi air tersedia
Sands, and loamy sands and Less than
sandy loams in which the sand is
not dominated by very fine sand
0.10
Loamy sands and sandy loams
in which very fine sand is the
dominant sand fraction, and
loams, clay loam, sandy clay loam,
and sandy clay
0.10 - 0.15
Silty clay, and clay
0.10 - 0.20
Silt, silt loam, and silty clay loam
0.15 - 0.25
Sumber: http://soils.usda.gov/sqi/publications/files/avwater.pdf
KETERSEDIAAN HARA.
This soil quality is decisive for successful low level input farming and to
some extent also for intermediate input levels. Diagnostics related to
nutrient availability are manifold.
Important soil characteristics of the topsoil (0-30 cm) are:
Texture/Structure, Organic Carbon (OC), pH and Total Exchangeable
Bases (TEB).
Untuk subsoil (30-100 cm), karakteristik yang sangat penting :
Tekstur/Structur, pH dan TEB.
Berbagai Karakteristik tanah yg relevan dengan ketersediaan hara
dalam tanah ternyata saling berkorelasi. Sehingga faktor pembatas ini
dikombinasikan dengan karakteristik tanah yg mencerminkan kualitas
tanah.
Soil Qualities
Nutrient availability
Soil Characteristics
Soil texture, soil organic carbon, soil pH, total
exchangeable bases
Sumber: http://www.fao.org/nr/land/soils/harmonized-world-soil-database/soil-quality-for-crop-production/en/
pH – KEMASAMAN TANAH
Crops vary in their response to pH; calcifuge plants dislike
lime while calciphilous plants are lime-loving.
There are very few crops that grow well in calcareous soils
that do not grow equally well at a pH above 6 under limefree conditions. Several crops, such as tea, require acid
conditions. Many crops are affected by micro-nutrient
deficiencies or toxicities at certain pH levels.
Ketersediaan hara mikro dan makro dipengaruhi oleh
kondisi pH tanah; akan tetapi ketersediaan hara ini juga
beragam dui antara jenis-jenis tanaman.
Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm#a.10%20sodicity
Relative availability of common elements in mineral soils with pH (after Truog 1948)
Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm#a.10%20sodicity
KAPASITAS RETENSI HARA
Nutrient retention capacity is of particular importance for the
effectiveness of fertilizer applications and is therefore of special
relevance for intermediate and high input level cropping conditions.
Nutrient retention capacity refers to the capacity of the soil to retain added nutrients
against losses caused by leaching. Plant nutrients are held in the soil on the exchange
sites provided by the clay fraction, organic matter and the clay-humus complex.
Losses vary with the intensity of leaching which is determined by the rate of
drainage of soil moisture through the soil profile. Soil texture affects nutrient
retention capacity in two ways, through its effects on available exchange sites on the
clay minerals and by soil permeability.
The soil characteristics used for topsoil are respectively: Organic Carbon (OC), Soil
Texture (Text), Base Saturation (BS), Cation Exchange Capacity of soil (CECsoil), pH,
and Cation Exchange Capacity of clay fraction (CECclay). Soil pH serves as indicator
for aluminum toxicity and for micro-nutrient deficiencies.
Kualitas Tanah:
Karakteristik Tanah:
Nutrient retention
capacity
Soil Organic carbon, Soil texture, base saturation, cation
exchange capacity of soil and of clay fraction
Sumber: http://www.fao.org/nr/land/soils/harmonized-world-soil-database/soil-quality-for-crop-production/en/
Ketersediaan Oksigen di Zone Perakaran
Oxygen availability in soils is largely defined by drainage characteristics
of soils. The determination of soil drainage classes is based on
procedures developed at FAO (FAO 1995).
These procedures take into account soil type, soil texture, soil phases
and terrain slope.
Apart from drainage characteristics, the soil quality of oxygen
availability may be influenced by soil and terrain characteristics that
are defined through the occurrence of specific soil phases.
Kualitas Tanah:
Karakteristik Tanah:
Oxygen availability Soil drainage and soil phases affecting soil
to roots
drainage.
Sumber: http://www.fao.org/nr/land/soils/harmonized-world-soil-database/soil-quality-for-crop-production/en/
TEMPAT PANCANGNYA AKAR TANAMAN
The rooting depth affects the total available water capacity
in the soil. A soil that has a root barrier at 20 inches and an
available water fraction of 0.20 has 4 inches of available
water capacity.
Another soil, that has a lower available water fraction of
0.10, would, if the roots extended to a depth of 60 inches,
have 6 inches of available water capacity.
For shallow rooting crops, like onions, the available water
below 1-2 feet has little significance.
For deeper rooting crops, like corn, the available water at
the greater depth is very important.
Sumber:http://soils.usda.gov/sqi/publications/files/avwater.pdf
KONDISI UNTUK PERKECAMBAHAN
KONDISI PERAKARAN
Rooting conditions include effective soil depth (cm) and effective soil volume (vol. %)
related to presence of gravel and stoniness. Rooting conditions may be affected by
the presence of a soil phase either limiting the effective rooting depth or decreasing
the effective volume accessible for root penetration. Rooting conditions address
various relations between soil conditions of the rooting zone and crop growth.
The following factors are considered in the evaluation:
1. Adequacy of foothold, i.e., sufficient soil depth for the crop for anchoring;
2. available soil volume and penetrability of the soil for roots to extract nutrients;
3. space for root and tuber crops for expansion and economic yield in the soil; and
4. absence of shrinking and swelling properties (vertic) affecting root and tuber
crops.
Soil depth/volume limitations affect root penetration and may constrain yield
formation (roots and tubers). Relevant soil properties considered are: soil depth, soil
texture/structure, vertic properties, gelic properties, petric properties and presence
of coarse fragments. This soil quality is estimated by multiplying of the soil depth
limitation with the most limiting soil or soil phase property .
Sumber: http://www.fao.org/nr/land/soils/harmonized-world-soil-database/soil-quality-for-crop-production/en/
KONDISI PERAKARAN.
Soil phases that relevant for rooting conditions vary somewhat with
source of soil map and soil classification used. In the HWSD these are:
1. FAO 74 soil phases: stony, lithic, petric, petrocalcic, petrogypsic,
petroferric, fragipan and duripan.
2. FAO 90 soil phases: rudic, lithic, pertroferric, placic, skeletic,
fragipan and duripan.
3. ESB soil phases and other soil depth/volume related
characteristics: stony, lithic, petrocalcic, petroferric, fragipan and
duripan, and presence of gravel or concretions, obstacles to roots
(6 classes), and impermeable layers (4 classes).
Rooting conditions
Soil textures, bulk density, coarse fragments, vertic
soil properties and soil phases affecting root
penetration and soil depth and soil volume
Sumber: http://www.fao.org/nr/land/soils/harmonized-world-soil-database/soil-quality-for-crop-production/en/
Workability of the land (ease of cultivation).
Workability or ease of tillage depends on interrelated soil
characteristics such as texture, structure, organic matter content, soil
consistence/bulk density, the occurrence of gravel or stones in the
profile or at the soil surface, and the presence of continuous hard rock
at shallow depth as well as rock outcrops. Some soils are easy to work
independent of moisture conditions, other soils are only manageable
at an adequate moisture status, in particular for manual cultivation or
light machinery. Irregular soil depth, gravel and stones in the profile
and rock outcrops, might prevent the use of heavy farm machinery.
Kualitas Lahan:
Karakteristik Lahan:
Land Workability
(constraining field
management)
Soil texture, effective soil depth/volume, and
soil phases constraining soil management (soil
depth, rock outcrop, stoniness,
gravel/concretions and hardpans)
Sumber: http://www.fao.org/nr/land/soils/harmonized-world-soil-database/soil-quality-for-crop-production/en/
Salinity or sodicity.
KELEBIHAN GARAM
Akumulasi garam-garam dapat menyebabkan salinitas. Excess of free salts referred
to as soil salinity is measured as Electric Conductivity (EC in dS/m) or as saturation of
the exchange complex with sodium ions, which is referred to as sodicity or sodium
alkalinity and is measured as Exchangeable Sodium Percentage (ESP).
Salinity affects crops through inhibiting the uptake of water. Moderate salinity
affects growth and reduces yields; high salinity levels may kill the crop. Sodicity
causes sodium toxicity and affects soil structure leading to massive or coarse
columnar structure with low permeability. Apart from soil salinity and sodicity,
conditions indicated by saline (salic) and sodic soil phases may affect crop growth
and yields.
Dalam kasus kejadian simultan tanah-tanah saline (salik) dan sodik, maka faktor
pembatasnya digabungkan. Faktor yang paling membatasi di antara salinitas tanah
dan/atau sodisitas tanah, dan kejadian tanah saline (salic) dan/atau sodik, maka
faktor itulah yang ditetapkan sebagai pembatas.
Excess salts.
Soil salinity, soil sodicity and soil phases influencing salt
conditions
Sumber: http://www.fao.org/nr/land/soils/harmonized-world-soil-database/soil-quality-for-crop-production/en/
Salinity
The adverse effects of soil salinity on plant growth vary with the crop
being grown. The presence of salinity in the soil solution resulting
from either indigenous salt in the soil, or from salt added by irrigation
water can affect growth (i) by reducing water available to the crop (the
osmotic effect) and (ii) by increasing the concentration of certain ions
that have a toxic effect on plant metabolism (the specific ion effect).
Many plants, for example, barley, wheat and maize, are sensitive to
the osmotic effect during germination and the early seedling stages,
but have greater tolerances at later stages (USDA 1954). Salt damage is
aggravated by hot, dry conditions and may be less severe in cool
humid conditions.
Data toleransi garam untuk tanaman tertentu tidak dapat dianggap
sebagai nilai yang “tetap”, tetapi harus dianggap sebagai suatu
“Arahan”.
Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm#a.10%20sodicity
Toleransi garam berbagai jenis tanaman terhadap salinitas, diukur
dalam ekstraks jenuh ECe. Tanaman pangan.
Sumber: Maas and Hoffmann 1977; James et al 1982.
EFEK FISIKA SODISITAS
The presence of excessive amounts of exchangeable sodium
in soil promotes the dispersion and swelling of clay minerals.
The soil becomes impermeable to both air and water.
The infiltration and hydraulic conductivity decrease to the
extent that little or no water movement occurs.
The soil is plastic when wet and becomes hard (brick-like)
when dry.
Tillage becomes difficult and soil crusting occurs. Recent
research (Frenkel et al. 1978) has indicated that dispersion
blocks soil pores, whereas swelling reduces pore sizes.
Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm#a.10%20sodicity
EFEK FISIKA SODISITAS
The effect is most pronounced on soils containing clays
which swell and shrink. Soils containing non-expanding clays
such as kaolinite and sesquioxides are relatively insensitive
to the physical effects of exchangeable sodium. However,
heavy cracking clays may be so impermeable when wet that
the decreased permeability associated with a high sodium
content may not matter.
Sodisitas ditentukan sebagai “the exchangeable sodium
percentage” (ESP). Dalam menilai sodisitas harus
dipertimbangkan perubahan ESP yang berlangsung setelah
lahan di-irigasi.
Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm#a.10%20sodicity
CRITICAL LIMITS FOR SODICITY TOLERANCE
1. 1/ Ratings may be raised one level if permeability is more than 2
cm/hr (e.g. as in loamy and sandy soils).
2. 2/ Soil depth ranges in cm.
3. 3/ SAR may be used if ESP figures seem unreliable.
ESP %
ESP %
SAR 3/
SAR
Factor Ratings
1/
(0 - 30) 2/
(30 - 90)
(0 - 30)
(30 - 90)
s1
<10
<20
<8
<18
s2
10 - 20
20 - 35
8-18
18 - 38
s3
20 - 35
35 - 50
18 - 38
38 - 68
n
>35
>50
>38
>68
Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm#a.10%20sodicity
Sodium toxicity
Plants vary considerably in their ability to tolerate sodium ions. Most
tree crops and other woody-type perennials are particularly sensitive
to low concentrations of sodium.
Most annual crops are less sensitive, but may be affected by higher
concentrations. Sodium toxicity is often modified and reduced if
calcium is also present, therefore a reasonable evaluation of the
potential toxicity is possible using the SAR for the soil water extract
and the SAR of the irrigation water.
Symptoms of sodium toxicity may appear only after a period of time
during which toxic concentrations accumulate in the plant: the
symptoms appear as a burn or drying of tissues first appearing at the
outer edges of leaves. Table |40 can be used to evaluate the sodium
hazard for representative crops.
Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm#a.10%20sodicity
TOLERANCE OF VARIOUS CROPS TO EXCHANGEABLE SODIUM (ESP)
UNDER NONSALINE CONDITIONS
Tolerance to ESP and
range at which affected
JENIS TANAMAN
Growth response under field
conditions
Extremely sensitive
(ESP = 2-10)
Deciduous fruits Nuts Citrus (Citrus spp.)
Avocado (Persea americana Mill.)
Sodium toxicity symptoms even at low
ESP values
Sensitive
(ESP = 10-20)
Beans (Phaseolus vulgaris. L)
Moderately tolerant
(ESP = 20-40)
Clover (Trifolium spp.)
Oats (Avena sativa L.)
Tall fescue (Festuca arundinacea Schreb.)
Rice (Oryza sativa L.)
Dallis grass (Paspalum dilatum Poir.)
Stunted growth at these ESP values
even though the physical condition of
the soil may be good
Stunted growth due to both nutritional
factors and adverse soil conditions
Tolerant
(ESP = 40-60)
Wheat (Triticum aestivum L.)
Cotton (Gossypium hirsutum L.)
Alfalfa (Medicago sativa L.)
Barley (Hordeum vulgare L.)
Tomatoes (Lycopersicon esculentum Mill.)
Beets (Beta vulgaris L.)
Most tolerant
(ESP = more than 60)
Stunted growth usually due to adverse
physical conditions of soil
Crested and Fairway wheatgrass (Agropyron Stunted growth usually due to adverse
spp.)
physical conditions of soil
Tall wheatgrass (Agropyron elongatum (Host)
Beau.)
Rhodes grass (Chloris gayana Kunth)
Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm#a.10%20sodicity
TOKSISITAS TANAH
Low pH leads to acidity related toxicities, e.g., aluminum, iron, manganese toxicities,
and to various deficiencies, e.g., of phosphorus and molybdenum. Calcareous soils
exhibit generally micronutrient deficiencies, for instance of iron, manganese, and
zinc and in some cases toxicity of molybdenum. Gypsum strongly limits available soil
moisture. Tolerance of crops to calcium carbonate and gypsum varies widely (FAO,
1990; Sys, 1993).
Low pH and high calcium carbonate and gypsum are mutually exclusive. Acidity
related toxicities such as aluminum toxicities and micro-nutrient deficiencies are
accounted for respectively in nutrient availability, and in nutrient retention capacity.
This soil quality is therefore only including calcium carbonate and gypsum related
toxicities. The most limiting of the combination of excess calcium carbonate and
gypsum in the soil, and occurrence of petrocalcic and petrogypsic soil phases is
selected for the quantification.
Soil Toxicity
Calcium carbonate and gypsum
Sumber: http://www.fao.org/nr/land/soils/harmonized-world-soil-database/soil-quality-for-crop-production/en/
KETAHANAN EROSI
Climate, soil and topographic characteristics determine
runoff and erosion potential from agricultural lands. The
main factors causing soil erosion can be divided into three
groups
1. Energy factors: rainfall erosivity, runoff volume, wind
strength, relief, slope angle, slope length.
2. Protection factors: population density, plant cover,
amenity value (pressure for use) and land management.
3. Resistance factors: soil erodibility, infiltration capacity
and soil management.
Sumber: http://users.ictp.it/~pub_off/lectures/lns018/21Lobo.pdf
ERODIBILITAS TANAH
The soil erodibility factor (K-factor) is a quantitative description of the
inherent erodibility of a particular soil; it is a measure of the
susceptibility of soil particles to detachment and transport by
rainfall and runoff.
For a particular soil, the soil erodibility factor is the rate of erosion per
unit erosion index from a standard plot.
The factor reflects the fact that different soils erode at different rates
when the other factors that affect erosion (e.g., infiltration rate,
permeability, total water capacity, dispersion, rain splash, and
abrasion) are the same.
Texture is the principal factor affecting Kfact, but structure, organic
matter, and permeability also contribute. The soil erodibility factor
ranges in value from 0.02 to 0.69 (Goldman et al. 1986; Mitchell
and Bubenzer 1980).
Sumber: http://mepas.pnnl.gov/mepas/formulations/source_term/5_0/5_32/5_32.html
Stewart et al. (1975) also developed a table indicating the general magnitude of the
K-factor as a function of organic matter content (Pom) and soil textural class.
Pom(%)
Textural Class
<0.5
2
4
Sand
0.05
0.03
0.02
Fine sand
0.16
0.14
0.10
Very finesand
0.42
0.36
0.28
Loamy sand
0.12
0.10
0.08
Loamy finesand
0.24
0.20
0.16
Loamy veryfine sand
0.44
0.38
0.30
Sandy loam
0.27
0.24
0.19
Fine sandyloam
0.35
0.30
0.24
Very fine sandy loam
0.47
0.41
0.33
Loam
0.38
0.34
0.29
Silt loam
0.48
0.42
0.33
Silt
0.60
0.52
0.42
Sandy clayloam
0.27
0.25
0.21
Clay loam
0.28
0.25
0.21
Silty clayloam
0.37
0.32
0.26
Sandy clay
0.14
0.13
0.12
Silty clay
0.25
0.23
0.19
Clay
0.13-0.2
Sumber: http://mepas.pnnl.gov/mepas/formulations/source_term/5_0/5_32/5_32.html
Soil ERODIBILITY Factor (K).
The soil texture, and other soil characteristics, affect its susceptibility
to erosion. The soil K factors were determined experimentally in test
plots that were 72.6 ft long and had a uniform slope of 9%.
The nomograph used to determine the K factor for a soil, based on its
texture (% silt plus very fine sand, % sand, % organic matter, soil
structure, and permeability.
Significant disturbance and modifications of the soil obviously occurs
at construction sites and care needs to be taken to ensure that the K
factor is based on the actual surface soil conditions. As an example,
the organic matter (decreases as the top soils are removed),
permeability (decreases with compaction with heavy equipment), and
soil structure (subsurface soils more massive than surface soils) could
all likely change, causing the K factor to increase for a soil undergoing
modification at a construction site.
Sumber: http://rpitt.eng.ua.edu/Class/Erosioncontrol/Module3/Module3.htm
Soil ERODIBILITY Factor (K).
USDA nomograph used to calculate soil erodibility (K) factor.
Sumber: http://rpitt.eng.ua.edu/Class/Erosioncontrol/Module3/Module3.htm
Pests and diseases related to the land.
The categories of problem may be listed as due to (i) wild
animals, (ii) arthropods including insects and mites, (iii)
parasitic nematodes, (iv) fungal pathogens, (v) bacterial
pathogens, and (vi) virus diseases. In reconnaissance studies
these should be considered in selecting alternative LUTs.
Pests, diseases and weeds may be 'class-determining'
because of the variability from one land unit to another in
exposure to wild animals, in microclimate or soils, or in
other land characteristics. Insect problems, particularly in
cotton, have led to the failure of large irrigation schemes.
Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm#a.10%20sodicity
BAHAYA BANJIR
In shallow water rice areas and in areas producing other crops,
spasmodic floods not only affect the crop, but also damage the soil
and the infrastructure, e.g. rice-field bunds, pathways, temporary and
permanent houses, roads and bridges etc. Flood damage is most likely
to occur on river flood plains, alluvial and coastal plains, regions with
large seasonal variations in rainfall and liable to intensive rain over
hours or days. The detailed pattern of incidence is thus related to
landforms.
In setting critical limits for flood hazard, two criteria may be used:
period of inundation, and flood frequency. The period of inundation is
the average number of days during the cropping season or year when
the land is covered by water. This may be obtained from records or
estimated. The flood frequency is the probability of occurrence of
damaging floods during the year.
Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm#a.13.2%20flood%20hazard
Flooding hazard (including frequency, periods of
inundation).
A damaging flood is one that destroys or causes severe damage to the
crop, land or infrastructure. Where required, a damaging flood may be
defined quantitatively in terms of period of inundation and/or speed
of flow or volume of discharge of moving water. The following scale
can be applied quantitatively where data are available, but will usually
form the basis for subjective estimation.
Frequency of damaging floods:
Very rare or never
Rare
Infrequent
Very frequent
Less than 1 year in 20 or never known to
occur
Less than 1 year in 5
Between 1 year in 5 and one per year
More than 5 times per year
Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm#a.13.2%20flood%20hazard
Storm, hail and wind hazard
The exposure of land to storm and wind and the
susceptibility or tolerance to these for different crops often
needs assessment in land evaluation. A judgement needs to
be made of the economic impact which is probable for
respective land units and crops.
Two aspects are the general prevalence of the hazard (e.g.
wind) and the occurrence of special events such as high
intensity rainfall, cyclones and hurricanes. The latter are
considerations in the selection of LUTs, but the extent of the
damage and the ability of the crop to survive and sustain
production after the event may be aggravated at specific
sites, which could be differentiated into factor ratings.
Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm#a.13.2%20flood%20hazard
Storm, hail and wind hazard
Amongst crops there is a clear distinction between shortterm crops and perennial crops. The survival of short-term
crops in the event of an infrequent storm hazard is of less
consequence than for tree crops and orchards which might
be completely destroyed. Bananas have the capability of
regrowth from underground shoots if the above ground
parts of the plant are destroyed; most tree crops do not
have this capability.
Hail can severely damage or destroy crops in many parts of
the world and may have a bearing on the crops chosen. Hail
damage is often very localized. The possibility of insurance
against hail damage may also affect the choice of crops.
Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm#a.13.2%20flood%20hazard
Frost hazard
Where it occurs, frost can be an important land classdetermining factor. Frost pockets occur in valley floors owing
to katabatic air movements. Frost can destroy the flowers of
temperate fruit crops and consequently affect yields. Rare
frosts are particularly important in the case of orchards (e.g.
citrus) where trees of all ages may be destroyed.
Damaging frosts can be defined in terms of temperatures,
duration, and periods of the year during which damage may
occur using data from climatic records. Local experience is
often helpful in indicating the effect of landforms (i.e. the
greater incidence in valley floors and the increase in
incidence with altitude).
Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm#a.13.2%20flood%20hazard
SOIL TEMPERATURE REGIME.
In soil taxonomy, soil temperature regimes are based on mean annual
soil temperatures. Soil temperatures are taken at a depth of 50 cm
from the soil surface, using the Celsius (centigrade) scale. These
regimes greatly affect the use and management of soils, particularly
for the selection of adapted plants. The ten soil temperature regimes
are cryic, frigid, hyperthermic, isofrigid, isohyperthermic, isomesic,
isothermic, mesic, pergelic, and thermic.
Rezim Suhu Tanah Cryic
has mean annual soil temperatures of greater than 0 °C, but less than
8 °C, with a difference between mean summer and mean winter
soil temperatures greater than 5 °C at 50 cm, and cold summer
temperatures.
Sumber:
http://passel.unl.edu/pages/informationmodule.php?idinformationmodule=1130447033&topicorder=12&maxto=13
REZIM SUHU TANAH
The frigid soil temperature regime has mean annual soil
temperatures of greater than 0 °C, but less than 8 °C, with a
difference between mean summer and mean winter soil
temperatures greater than 5 °C at 50 cm below the surface,
and warm summer temperatures.
The hyperthermic soil temperature regime has mean annual
soil temperatures of 22 °C or more and a difference between
mean summer and mean winter soil temperatures of less
than 5 °C at 50 cm below the surface.
Sumber:
http://passel.unl.edu/pages/informationmodule.php?idinformationmodule=1130447033&topicorder=12&maxto=13
REZIM SUHU TANAH
The isofrigid soil temperature regime has mean annual soil
temperatures of greater than 0 °C, but less than 8 °C, with a
difference between mean summer and mean winter soil
temperatures of less than 5 °C at 50 cm. below the surface,
and warm summer temperatures.
The isohyperthermic soil temperature regime has mean
annual soil temperatures of 22 °C or more and a difference
between mean summer and mean winter soil temperatures
of less than 5 °C at 50 cm below the surface.
Sumber:
http://passel.unl.edu/pages/informationmodule.php?idinformationmodule=1130447033&topicorder=12&maxto=13
REZIM SUHU TANAH
The isomesic soil temperature regime has a mean annual soil
temperatures of 8 °C or more, but a difference between mean summer
and mean winter soil temperatures of less than 5 °C at 50 cm below
the surface.
The isothermic soil temperature regime that has mean annual soil
temperatures of 15 °C or more but, 5 °C difference between mean
summer and mean winter soil temperatures at 50 cm. below the
surface.
The mesic soil temperature regime has mean annual soil temperatures
of 8 °C or more, but less than 15 °C, and the difference between mean
summer and mean winter soil temperatures is greater than 5 °C at 50
cm below the surface.
Sumber:
http://passel.unl.edu/pages/informationmodule.php?idinformationmodule=1130447033&topicorder=12&maxto=13
REZIM SUHU TANAH
The pergelic soil temperature regime has mean annual soil
temperatures of less than 0 °C at 50 cm below the
surface. In this terperature regime, permafrost is present.
Thermic
The thermic soil temperature regime has mean annual soil
temperatures of 15° C or more, but less than 22 °C; and a
difference between mean summer and mean winter soil
temperatures of greater than 5 °C at 50 cm below the
surface.
Sumber:
http://passel.unl.edu/pages/informationmodule.php?idinformationmodule=1130447033&topicorder=12&maxto=13
Radiation energy and photoperiod.
Three relevant aspects of radiation are (i) daylength, (ii) its influence on
photosynthesis and dry matter accumulation in crops, and (iii) its effects on
evapotranspiration. Radiation levels may also be important in the drying and
ripening of crops, but this is evaluated under heading B.17.
Daylength may be a relevant class-determining factor in evaluations carried out at
low intensity across different latitudes as already discussed under 'Growing Period'
(Tables 32 and 33). Daylength affects photoperiod-sensitive cultivars of crops such as
rice, influencing floral initiation and the onset or length of vegetative and
reproductive phases of growth and development. The interaction of daylength with
water availability or temperature can sometimes prove 'class-determining' at project
level (e.g. in influencing the flowering of sugarcane, flowering and fruiting of
mangoes, and in the bulbing and ripening of onions, etc.).
The influence of radiation on photosynthesis and dry matter
accumulation in crops has been reviewed by Monteith (1972).
Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm
PHOTOPERIODISME.
Photoperiodism is the physiological reaction of
organisms to the length of day or night. It occurs in
plants and animals.
Photoperiodism can also be defined as the developmental
responses of plants to the relative lengths of the light and
dark periods.
Here it should be emphasized that photoperiodic effects
relate directly to the timing of both the light and dark
periods.
Sumber: http://en.wikipedia.org/wiki/Photoperiodism
Radiation energy and photoperiod.
Long-day plants flower when the day length exceeds their
critical photoperiod. These plants typically flower in the
northern hemisphere during late spring or early summer as
days are getting longer. In the northern hemisphere, the
longest day of the year is on or about 21 June (solstice).
After that date, days grow shorter (i.e. nights grow longer)
until 21 December (solstice). This situation is reversed in the
southern hemisphere (i.e. longest day is 21 December and
shortest day is 21 June).
In some parts of the world, however, "winter" or "summer"
might refer to rainy versus dry seasons, respectively, rather
than the coolest or warmest time of year.
Sumber: http://en.wikipedia.org/wiki/Photoperiodism
Radiation energy and photoperiod.
Short-day plants flower when the day lengths are less than their
critical photoperiod. They cannot flower under long days or if a pulse
of artificial light is shone on the plant for several minutes during the
middle of the night; they require a consolidated period of darkness
before floral development can begin. Natural nighttime light, such as
moonlight or lightning, is not of sufficient brightness or duration to
interrupt flowering.
In general, short-day (i.e. long-night) plants flower as days
grow shorter (and nights grow longer) after 21 June in the
northern hemisphere, which is during summer or fall. The
length of the dark period required to induce flowering
differs among species and varieties of a species.
Sumber: http://en.wikipedia.org/wiki/Photoperiodism
Calculating Photoperiods.
Convert sunrise and sunset numbers to a
24-hour clock and subtract sunrise from
sunset.
sunset 9:36
convert to 24
hour clock
21:36
sunrise 6:14
- 6:14
photoperiod
15:22
15 hours and 22
minutes
Sumber: http://www.learner.org/jnorth/tm/mclass/KidsCalculatingPhotoperiod.html
Photoperiod: Duration of Irradiation
Duration refers to the period of time in 24 hours that plants are
exposed to light. In temperate regions where greenhouse crops are
grown, day length changes seasonally. This change results occurs
because the earth's axis is tilted 23½ degrees from a line perpendicular
to the plane of the earth's orbit about the sun.
At the equator, the day length is relative constant at 12 hours and 7
minutes during the year. As the distance from the equator increases
(north latitude), day lengths are longer in the summer and shorter in
the winter.
The longest day of the year is the summer solstice (≃ June 21) and the
shortest is the winter solstice (≃ December 21). Day and night lengths
are equal on the autumnal equinox (≃ September 21) and vernal
equinox (≃ March 21). When considering day length, weather services
report sunrise to sunset, however many plants can perceive twilight.
So day length for plants is sunrise to sunset plus twilight.
Sumber: http://www.ag.auburn.edu/hort/landscape/lightduration.html
Illustration of the radiation balance.
Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm
Solar radiation (Rs)
Solar radiation (Rs) is that part of the extraterrestrial radiation which is
not absorbed and scattered when passing through the atmosphere,
together with some of the scattered radiation that also reaches the
earth's surface. A proportion of this radiation (about 50%) is
photosynthetically active radiation (PAR) (Szeicz 1974). Values of solar
radiation can be obtained from direct measurements or approximated
by using:
Rs = (0.25 + 0.05 n/N) Ra,
where n is the actual bright sunshine hours (e.g. measured with a
Campbell Stokes solarimeter) and M is the maximum possible
sunshine hours for a given month and latitude
Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm
Climatic hazards affecting plant growth (including
wind, hail, frost).
Definition of a climatic hazard:
1. Extreme climatic/weather event(s) causing harm and damage to
people, property, infrastructure and land uses.
2. It includes not only the direct (primary) impacts of the
climate/weather event itself but also
3. the other indirect (secondary) hazards 'triggered' by that event e.g.
land slides 'triggered' by torrential rain.
The Impact is dependent upon:
1.
2.
3.
The severity of the event and also the path/track and spatial extent of that
weather event.
The density and distribution of the people and density and types of human
activity in the areas affected.
The preparedness and capacity of the authorities and people to cope with the
impact of the event.
Sumber: http://www.geogonline.org.uk/g3a_ki4.2.htm
HAIL = HUJAN ES-BATU
Hail is a form of solid precipitation. It consists of balls or irregular
lumps of ice, each of which is called a hailstone. Unlike graupel, which
is made of rime, and ice pellets, which are smaller and translucent,
hailstones – on Earth – consist mostly of water ice and measure
between 5 and 200 millimetres (0.20 and 7.9 in) in diameter.
The METAR reporting code for hail 5 mm (0.20 in) or greater is GR,
while smaller hailstones and graupel are coded GS. Hail is possible
within most thunderstorms as it is produced by cumulonimbi, and
within 2 nautical miles (3.7 km) of the parent storm. Hail formation
requires environments of strong, upward motion of air with the parent
thunderstorm (similar to tornadoes) and lowered heights of the
freezing level.
In the mid-latitudes, hail forms near the interiors of continents, while
in the tropics, it tends to be confined to high elevations.
Sumber: http://en.wikipedia.org/wiki/Hail
ANGIN
Wind is the flow of gases on a large scale. On
the surface of the Earth, wind consists of the
bulk movement of air.
Winds are commonly classified by their spatial
scale, their speed, the types of forces that
cause them, the regions in which they occur,
and their effect.
Sumber: http://en.wikipedia.org/wiki/Wind
General wind classifications
Tropical cyclone classifications (all winds are 10-minute averages)
Beaufort
scale[18]
10-minute
sustained
winds (knots)
N Indian
Ocean
IMD
General
term[21]
0
1
<1
1–3
Calm
Light air
2
4–6
Light breeze
3
7–10
Gentle breeze
4
11–16
Moderate breeze
5
17–21
Fresh breeze
6
22–27
Strong breeze
SW Indian
Ocean
MF
Australian
region
South Pacific
BoM, BMKG,
FMS, MSNZ
NW Pacific
JMA
NW Pacific
JTWC
NE Pacific &
N Atlantic
NHC & CPHC
Tropical low
Tropical
Depression
Tropical
depression
Tropical
depression
Tropical
depression
Tropical storm
Tropical storm
Low Pressure
Area
Tropical
disturbance
Depression
7
28–29
30–33
Moderate gale
8
34–40
Fresh gale
9
41–47
Strong gale
10
48–55
Whole gale
11
56–63
Storm
12
64–72
13
73–85
14
86–89
15
90–99
16
100–106
107–114
115–119
17
>120
Deep depression
Cyclonic storm
Severe cyclonic
storm
Very severe
cyclonic storm
Hurricane
Super cyclonic
storm
Tropical
depression
Moderate tropical Tropical cyclone
storm
(1)
Severe tropical
storm
Tropical cyclone
(2)
Tropical cyclone
Severe tropical
cyclone (3)
Intense tropical
cyclone
Very intense
tropical cyclone
Tropical storm
Severe tropical
storm
Severe tropical
cyclone (4)
Hurricane (1)
Hurricane (2)
Typhoon
Major hurricane
(3)
Typhoon
Major hurricane
(4)
Severe tropical
cyclone (5)
Sumber: http://en.wikipedia.org/wiki/Wind
Super typhoon
Major hurricane
(5)
ENERGI ANGIN
Wind energy is the kinetic energy of the air in motion.
Total wind energy flowing through an imaginary area A during the time
t is:
E = A·v·t·ρ·½ v2,
where v is the wind velocity and ρ is the air density. The formula
presented is structured in two parts: (A·v·t) is the volume of air
passing through A, which is considered perpendicular to the wind
velocity; (ρ·½ v2) is the kinetic energy of the moving air per unit
volume.
Total wind power is:
P = E/t = A·ρ·½ v3
Wind power is thus proportional to the third power of the wind
velocity.
Sumber: http://en.wikipedia.org/wiki/Wind
KELEMBABAN UDARA – PERTUMBUHAN TANAMAN
Relative humidity is the ratio of the partial
pressure of water vapor in an air-water
mixture to the saturated vapor pressure of
water at a prescribed temperature.
The relative humidity of air depends not only
on temperature but also on the pressure of the
system of interest.
Sumber: http://en.wikipedia.org/wiki/Relative_humidity
Air humidity as affecting plant growth.
The relative humidity of an air-water mixture is defined as the ratio of
the partial pressure of water vapor (H2O) in the mixture to the saturated
vapor pressure of water at a given temperature.
Relative humidity is normally expressed as a percentage and is
calculated by using the following equation:
The humidity of an air-water vapor mixture is determined through the
use of psychrometric charts if both the dry bulb temperature (T) and the
wet bulb temperature (Tw) of the mixture are known. These quantities
are readily estimated by using a sling psychrometer.
Sumber: http://en.wikipedia.org/wiki/Relative_humidity
Psychrometric charts
Sumber: http://www.pinguicula.org/pages/culture/Overview.htm
Psychrometric charts
Sumber: http://philipmarshall.net/Teaching/rwuhp382/wood/psychrometric_chart_ex_1.htm
Measuring relative air humidity with dry and wet bulb temperatures
Difference
Between Dry
Bulb
and Wet Bulb
Temperatures
Tdb - Twb
(oC)
1
2
3
4
5
6
7
8
9
10
Relative Humidity - RH (%)
Dry Bulb Temperature - Tdb (oC)
15
18
20
22
25
27
30
33
90
80
71
62
53
44
36
28
21
13
91
82
73
65
57
49
42
34
27
20
91
83
75
67
59
52
45
38
31
25
92
84
76
68
61
54
47
41
34
28
92
85
77
70
64
57
51
45
39
33
92
85
78
71
65
59
53
47
41
36
93
86
79
73
67
61
55
50
45
40
93
87
80
74
69
63
58
53
48
43
Sumber:http://www.engineeringtoolbox.com/humidity-measurement-d_561.html
PERIDOE PERTUMBUHAN
The growing cycle is the period required for an annual crop to
complete its annual cycle of establishment, growth and production of
harvested part. Perennial crops have growing cycles of more than one
year.
The growing period for annual crops is the duration of the year when
temperature, soil. water supply and other factors permit crop growth
and development.
Thus, a growing cycle is a property of the crop (i.e. a crop requirement)
whereas a growing period is a condition of the land (i.e. a land quality
or land characteristic).
Growing periods can be constrained by wet or humid conditions that
limit opportunities for ripening and drying the crop, or which lead to
problems of quality (e.g. reduced sugar content of sugarcane, staining
of cotton, blemishes on fruits, etc.).
Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm
PERIODE KERING UNTUK PEMASAKAN TANAMAN
MAJOR CLIMATES
IKLIM
Tropics
All months with
monthly mean
temperatures,
corrected to sea
level, above 18°C
Major climates
during growing
period
No.
Descriptive
name
24 hr mean
(daily)
temperature (C)
regime during
the growing
period
1
Warm tropics
More than 20
II and III
2
Moderately cool
tropics
15-20
I and IV
3
Cool tropics
5/10 - 15
I
4
Cold tropics
Less than 5
Not suitable
Sumber: FAO 1980c, p. 355; Higgins and Kassam 1981.
Suitable for
consideration
for crop group
(Table 33)
DRYING PERIODS FOR RIPENING OF CROPS.
MAJOR CLIMATES
Subtropics
One or more months
with monthly mean
temperatures,
corrected to sea level,
below 18°C but all
months above 5°C
5
Warm/moderately cool
subtropics (summer rainfall)
More than 20
II and III
6
Warm/moderately cool
subtropics (summer rainfall)
15 - 20
I and IV
7
Warm subtropics (summer
rainfall)
More than 20
II and III
8
Moderately cool subtropics
(summer rainfall)
15 - 20
I and IV
9
Cool subtropics (summer rainfall)
5/10 - 20
I
10
Cold subtropics (summer rainfall)
Less than 5
Not suitable
11
Cool subtropics (winter rainfall)
5/10 - 20
I
12
Cold subtropics (winter rainfall)
Less than 5
Not suitable
Sumber: FAO 1980c, p. 355; Higgins and Kassam 1981.
CROP ADAPTABILITY GROUPS, BASED ON PHOTOSYNTHETIC PATHWAY
AND RESPONSE TO RADIATION AND TEMPERATURE
Crop
adaptability
group
Photosynthetic
pathway
Optimum
temperature for
photosynthesis
(°C)
I
II
III
IV
V
C3
C3
C4
C4
CAM
15-20
25-30
30-35
20-30
25-35
Sugarbeet
Phaseolus
Wheat
Barley
Oats
Potato
Bean (TE)
Chickpea
Soybean (TR)
Phaseolus; Rice
Cassava
Sweet Potato
Yams; Bean (TR)
Groundnut
Cotton; Tobacco
Banana; Coconut
Rubber; Oil palm
Sorghum (TR)
Panicum
Sisal
Maize (TR)
Millet (TE, TH) Pineapple
Pearl millet
Sorghum (TE,
Panicum
TH)
Millet (TR)
Maize (TE, TH)
Finger millet
Setaria
Setaria
Sugarcane
TE = Temperate cultivars; TR = Tropical (lowland) cultivars; TH = Tropical (highland) cultivars. Source: Based on information
extracted from FAO 1978a and FAO 1980c.
GROWING PERIOD
Tipe Periode
Pertumbuhan
(Kondisi tadah hujan yg
dapat dimodifikasi
dnegan irigasi) –
Normal.
a - Beginning of rains and
growing period
b1 and b2 - Start and end of
humid period respectively
c - End of rains and rainy
season
d - End of growing period
P – Precipitation
PET - Potential
evapotranspiration
(after FAO 1978a)
Sumber:http://www.fao.org/docrep/X5648E/x5648e0e.htm
PERIODE PERTUMBUHAN
Tipe Periode
Pertumbuhan
(pada kondisi
tadah hujan yg
dapat
dimodifikasi
dengan irigasi) –
Intermediate
Sumber:http://www.fao.org/docrep/X5648E/x5648e0e.htm
GROWING PERIOD
Type of
growing period
(under rainfed
conditions
which might be
modified by
irrigation) –
Sepanjang
tahun basah
(humid)
Sumber:http://www.fao.org/docrep/X5648E/x5648e0e.htm
GROWING PERIOD
Type of growing
period (under
rainfed
conditions which
might be
modified by
irrigation) –
Sepanjang tahun
kering
Sumber:http://www.fao.org/docrep/X5648E/x5648e0e.htm
LAND QUALITIES RELATED TO DOMESTIC ANIMAL
PRODUCTIVITY
PRODUKTIVITAS LAHAN GEMBALAAN :
1.
2.
3.
4.
5.
6.
Climatic hardships affecting animals.
Endemic pests and diseases.
Nutritive value of grazing land.
Toksisitas lahan rumput gembalaan.
Resistensi thd degradasi vegetasi.
Resistance to soil erosion under grazing
conditions.
7. Ketersediaan Air Minum.
Sumber: FAO Land and Water Bulletin No. 5. 1997
KUALITAS LAHAN SEHUBUNGAN DENGAN
PRODUKTIVITAS HUTAN
Kualitas-lahan berikut berhubungan dnegan Hutan
Alam, Hutan Tanaman, atau keduanya.
Mean annual increments of timber species :
1.Types and quantities of indigenous timber species.
2.Site factors affecting establishment of young trees.
3.Hama dan Penyakit.
4.Bahaya Kebakaran.
Sumber: FAO Land and Water Bulletin No. 5. 1997
KUALITAS LAHAN YG BERHUBUNGAN
DNEGAN MANAJEMEN & INPUT
1. Kualitas lahan yg berhubungan dengan penggunaan
pertanian, peternakan dan kehutanan.
2. Faktor Terrain yg mempengaruhi mekanisasi ( trafficability ).
3. Terrain factors affecting construction and maintenance of
access-roads (accessibility).
4. Size of potential management units (e.g. forest blocks,
farms, fields).
5. Lokasi terhadap pasar dan suplai input produksi.
Sumber: FAO Land and Water Bulletin No. 5. 1997
Land qualities related to vertical components
of a natural land unit
KUALITAS ATMOSFERIK
1. Suplai air Atmosferik: Curah hujan, lamanya
musim pertumbuhan, evaporasi, pembentukan
embun.
2. Energi Atmosfir untuk fotosintesis : temperature,
daylength, kondisi pencahayaan matahari.
3. Atmospheric conditions for crop ripening,
harvesting and land preparation: occurrence of
dry spells.
Sumber: FAO Land and Water Bulletin No. 5. 1997
Kualitas Lahan yg berhubungan dengan komponen vertikal suatu Unit
Lahan alamiah
KUALITAS TUTUPAN LAHAN
1. Nilai “the standing vegetation” sebagai “Tanaman", misalnya timber
(tegakan kayu hutan).
2. Nilai “the standing vegetation” sbg sumber plasma nutfah : Nilai
biodiversitas.
3. Nilai “the standing vegetation” sebagai agen perlindungan degradasi
tanah dan DAS.
4. Nilai “the standing vegetation” sbg regulator kondisi klimatik lokal dan
regional.
5. Regeneration capacity of the vegetation after complete removal.
6. Value of the standing vegetation as shelter for crops and cattle against
adverse atmospheric influences.
7. Hindrance of vegetation at introduction of crops and pastures: the land
"development" costs.
8. Incidence of above-ground pests and vectors of diseases: health risks of
humans and animals.
Sumber: FAO Land and Water Bulletin No. 5. 1997
KUALITAS PERMUAKAN LAHAN DAN TERRAIN
1.
2.
3.
4.
5.
Sifat permukaan sebagai “bedengan” : Kondisi sifat-olah tanah.
Sifat permukaan untuk diolah : daya dukung untuk hewan, mesin dll.
Pembatas permukaan untuk implementasi (adanya batu-batu, sifat kelekatan,
dll.): Arabilitas, kemudahan untuk digarap.
Keteraturan spatial tanah dan terrain, menentukan ukuran dan bentuk bidanglahan dengan kapasitas pengelolaan yg seragam
Deformasi permukaan lahan: adanya ancaman bahaya erosi tanah oleh air dan
angin.
6.
7.
8.
Accessibility of the land: the degree of remoteness from means of transport.
The presence of open freshwater bodies for use by humans, animals or fisheries.
Surface water storage capacity of the terrain: the presence or potential of ponds,
on-farm reservoirs, bunds, etc.
9. Surface propensity to yield run-off water, for local water harvesting or
downstream water supply.
10. Accumulation position of the land: degree of fertility renewal or crop damaging
by overflow or overblow.
Sumber: FAO Land and Water Bulletin No. 5. 1997
KUALITAS TANAH
1. Kesuburan Tanah secara Fisik : Kapasitas simpanan lengas-tanah
dalam zone perakaran.
2. Toksisitas tanah secara fisik: Adanya bayhaya genangan air dalam
zone perakaran (yaitu kekurnagan oksigen).
3. Kesuburan Tanah Kimiawi : Ketersediaan hara bagi tanaman.
4. Toksisitas Tanah kimiawi: Bahaya Salinitas atau salinisasi;
berlebihannya Na-tukar.
5. Biological soil fertility: the N-fixation capacity of the soil biomass;
and its capacity for soil organic matter turnover.
6. Biological soil toxicity: the presence or hazard of soil-borne pests
and diseases.
7. Substratum (and soil profile) as source of construction materials.
8. Substratum (and soil profile) as source of minerals.
9. Biological soil toxicity: the presence or hazard of soil-borne pests
and diseases.
Sumber: FAO Land and Water Bulletin No. 5. 1997
KUALITAS SUBSTRATUM ATAU UNDERGROUND
1. Tinggi muka-air dan kualitas Groundwater dalam
hubungannya dengan guna lahan (irrigasi).
2. Potensi Substratum intuk simpanan air-tanah
(penggunana lokal) dan penyaluran air
(penggunaan daerah bawahan).
3. Keberadaan “of unconfined freshwater aquifer”.
4. Kesesuaian Substratum dan profil tanah untuk
“pondasi” bangunan (gedung, jalan, saluran air
dll.)
Sumber: FAO Land and Water Bulletin No. 5. 1997
KRITERIA GLASOD untuk derajat degradasi lahan untuk
menspesifikasikan daya tahan:
1. DEGRADASI RINGAN: The terrain has somewhat reduced
agricultural suitability, but is suitable for use in local farming
systems. Restoration to full productivity is possible by modifications
of the management system. Original biotic functions are still largely
intact.
2. DEGRADASI MODERAT: The terrain has greatly reduced agricultural
productivity but is still suitable for use in local farming systems.
Major improvements are required to restore productivity. Original
biotic functions are partially destroyed.
3. DEGRADASI KUAT: The terrain is non-reclaimable at farm level.
Major engineering works are required for terrain restoration.
Original biotic functions are largely destroyed.
4. DEGRADASI EKSTRIM: terrain tidak dapat direklamasi atau
direstorasi. Fungsi biotik originalnya telah rusak.
Sumber: FAO Land and Water Bulletin No. 5. 1997
Some concepts of resilience of land and its productivity, comparing the
situation in some industrialized countries (A) with that of most
developing countries (B). (Sombroek, 1993).
Sumber: FAO Land and Water Bulletin No. 5. 1997
LQI
LAND QUALITY
INDICATOR
Sumber: FAO Land and Water Bulletin No. 5. 1997
PSR – PRESSURE STATE RESPONSE
Sumber: FAO Land and Water Bulletin No. 5. 1997
Three groups of LQIs have been developed to reflect the PSR
structure:
Group 1. TEKANAN PD SUMBERDAYA LAHAN
Indicators in this group include those activities that relate to the
degree of intensification and diversification of agricultural land
uses, and result in increased pressure on land quality.
1.
2.
3.
4.
5.
Indikator ini meliputi :
Banyaknya tanaman dalam sistem-tanam setiap tahun atau
hektar,
Tipe dan Intensitas pengolahan tanah,
Derajat panen biomassa,
Integrasi dnegan sistem ternak,
Jumlah produk pangan dan serat yg dihasilkan setipa tahun,
dll.
Sumber: FAO Land and Water Bulletin No. 5. 1997
Tiga kelompok LQI dikembangkan untuk mencerminkan
struktur PSR : Group 1. Tekanan pd Sumberdaya Lahan
Indikator ini harus dilihat dalam konteks kondisi sosiodemografis yang ada, seperti tekanan-penduduk, land
tenure, dll., tetapi hal-hal ini tidak dapat dimasukkan
sebagai LQI.
This is because these major forces do not influence land
quality directly, but rather through the land practices that
are adopted by farmers as a consequence.
It is these management systems and their impacts that we
wish to capture as LQIs, although changes in the major
driving forces may provide some "early warning" signals .
Sumber: FAO Land and Water Bulletin No. 5. 1997
Group 2. Keadaan Kualitas Lahan
State indicators reflect the conditions of the land as well as its
resilience to withstand change as a consequence of sector pressures.
Ini meliputi indikator yang mencerminkan :
1. Perubahan produktivitas biologis (aktual dan potensial),
2. Luas dan parahnya dampak degradasi tanah, termasuk erosi-tanah,
salinisasi dll.
3. Annual and long-term balance of nutrients (exported and imported
by the cropping systems),
4. Degree and type of contamination or pollution (by direct
application, atmospheric transport, etc.),
5. Perubahan kandungan BOT, WHC dll.
Perubahan “keadaan” mungkin positif akibat pengelolaan yg buruk,
atau positif akibat pengelolaan yg baik.
Sumber: FAO Land and Water Bulletin No. 5. 1997
Group 3. Societal response(s)
The response mechanisms are normally achieved through direct
actions by the farmers themselves in evolving or adopting improved
land management systems, or through complementary activities
whereby adoption of conservation technologies is stimulated by
general economic, agricultural and conservation policies and
programmes. In rare instances, environmental regulations may be
necessary to effect proper control of land resource degradation.
Response indicators may include number and types of farmer
organizations for soil conservation, extent of change in farm
technologies, risk management strategies, incentive programmes for
adoption of conservation technologies, etc.
Response indicators should be distinguished into those categories
promoted by governments, those undertaken by individual farmers
and those supported by agri-business.
Sumber: FAO Land and Water Bulletin No. 5. 1997
Erosion Productivity Impact Calculator (EPIC):
EPIC was developed by the United States Department of Agriculture
(USDA) and Agricultural Research Service (ARS) originally as a tool to
analyse the impacts of soil management and erosion on crop yields,
but more recently it has been expanded to include assessments of
water quality, pesticides, etc.
EPIC consists of ten major subroutines, namely, weather, hydrology,
wind and water erosion, nitrogen and phosphorus transformations,
soil temperature, crop growth, tillage, plant environment control
(irrigation, lime, etc.), pesticide routines and economic crop budgets.
Interim and final output is available from each subroutine, either in
daily, monthly or annual increments. Although the model inputs are
flexible through the use of many data defaults (for missing data), the
model requires reliable data on soil properties, crop inputs and tillage
management (weather is generated through a weather generator).
Sumber: FAO Land and Water Bulletin No. 5. 1997
Erosion Productivity Impact Calculator
(EPIC):
EPIC menghasilkan beberapa output yang berguna
untuk LQI, yaitu:
1. Hasil tanaman, for several economically
important crops;
2. Erosi tanah, wind and water, rate (t/ha) dan
dampaknya pada hasil tanaman;
3. Perubahan N-tanah dan P-tanah (estimasi kasar).
Sumber: FAO Land and Water Bulletin No. 5. 1997
Erosion Productivity Impact Calculator (EPIC):
Laju perubahan dihitung dengan EPIC melibatkan berbagai
skenario pengelolaan lahan selama bertahun-tahun
(biasanya 30 tahun).
Metode EPIC ini semakin banyak digunakan di daerah iklim
temperate dan tropis sebagai alat bantu untuk evaluasi
praktek pengelolaan lahan, terutama pengolahan tanah dan
pengelolaan residu.
It also has been integrated with large economic optimizing
models to provide analytical systems for evaluation of
environmental impact prior to implementation of
agricultural policies and programmes.
Sumber: FAO Land and Water Bulletin No. 5. 1997
CENTURY
The CENTURY model simulates the effects of erosion on
long-term storage of soil organic carbon under field
conditions. Briefly, soil organic matter is divided into pools
with active (1.5y), slow (25y) and passive (1 000y) turnover
rates.
A plant production subroutine simulates the allocation of carbon into
shoots and roots, dividing plant residue into a metabolic (0.1-1y) and a
structural (1-5y) pool based on the lignin:nitrogen ratio. The model
then transfers the carbon to the soil, and simulates carbon stability
through interactions with clay and organic molecules. Estimates of soil
carbon change are obtained by running CENTURY under initial (usually
current) conditions, then again for future scenarios under new
management technologies.
Sumber: FAO Land and Water Bulletin No. 5. 1997
CENTURY
Output yg berguna untuk LQI meliputi:
1. Total C-tanah, used to estimate carbon
sequestration;
2. Fraksi BO yang mudah lapuk, a surrogate for
microbial biomass
Dalam konteks kualitas lahan, fraksi karbon yg
mudah lapuk menjadi LQI yg lebih baik daripada
total carbon.
Sumber: FAO Land and Water Bulletin No. 5. 1997
NUTMON
This is a recently developed model for estimating regional losses or
gains of nutrients as a consequence of nutrient inputs (mineral
fertilizers, organic manures, wet and dry deposition, nitrogen fixation,
sedimentation), compared to nutrient losses (harvested product, crop
residue removal, leaching, erosion, denitrification) (Smaling, 1993).
Data for nutrient inputs and nutrients removed by harvest are
gathered for various land use systems, and estimates for the other
variables are calculated using various available models.
NUTBAL menghitung apakah sistem mengalami “penambahan” atau
“kehilangan” hara makro. Hasilnya dapat diekstrapolasi untuk daerah
yug lebih luas dengan teknik-teknik GIS.
NUTBAL masih di-ujicobakan, tetapi telah digunakan dengan sukses
dalam kajian-kajian di Kenya.
Sumber: FAO Land and Water Bulletin No. 5. 1997
SUSTAINABILITY REFERENCE SYSTEMS (SRS)
Barometer-Sustainabilitas dari Prescott-Allen (1996)
Prescott-Allen (1996) has proposed a "sustainability barometer" based
on a graphical representation of the location of an exploited
ecosystem on an orthogonal system in which the two axes represent
indexes of human well-being and of ecosystem well-being, considered
as the two fundamental dimensions of sustainability.
The aim of the barometer is to (a) give a picture of the whole system;
(b) treat ecosystem and human well-being as equally important; (c)
facilitate a rigorous and transparent progress towards sustainability.
Used as orthogonal axes, the human and ecological dimensions, with a
scale normalized between 0 and 1, provide an orthogonal system of
reference in which the position of an exploitation system (e.g., a
fishery) can be located if the corresponding values on the two axes can
be estimated.
Sumber: FAO Land and Water Bulletin No. 5. 1997
Penyajian Sustainabilitas secara Statis. Suatu SRS yg sedikit
dimodifikasi dari "Sustainability Barometer" konsepnya Prescott-Allen
(1996)
Sumber: FAO Land and Water Bulletin No. 5. 1997
SUSTAINABILITY REFERENCE SYSTEMS (SRS)
The scales of the barometer include also "value judgements"
corresponding to the various intervals on the axes, e.g. the 0.00.2 interval is considered "Bad" while the 0.8-1.0 interval is
considered "Good". Prescott-Allen stresses the importance of the
"scaling" of the barometer and the amount of case-specific
judgement involved in it.
The paper does not explain how the numerical value of the
coordinates is arrived at but examples are given in this paper in the
specific case of fisheries. Prescott-Allen called it a "sustainability
barometer“ used to "measure" exploitation pressure, by analogy with
the instrument used to measure atmospheric pressure.
Because this device does not provide a "measure" of sustainability but
helps representing it, locating an exploited ecosystem in a system of
reference, in the rest of this paper I shall refer to it and to other similar
devices as "Sustainability Reference Systems“ (SRSs).
Sumber: FAO Land and Water Bulletin No. 5. 1997
Indikator Perubahan. Empat kuadran menyajikan area-area Tidak
sustainable (U), Sustainable (S), Instabilitas sosial dan Instabilitas
ekologis (SU, EU).
Sumber: FAO Land and Water Bulletin No. 5. 1997
SUSTAINABILITY REFERENCE SYSTEMS (SRS)
Bagan-bagan berikut mengilustrasikan konsepkonsep tambahan ini.
Assuming that a fishery could be located on a SRS,
the direction in which (and the rate at which) the
situation is changing would be as important as the
position on the SRS.
Arah dan kecepatan perubahan memang
menyediakan informasi yang sangat penting.
Sumber: FAO Land and Water Bulletin No. 5. 1997
Dynamic representation of sustainability:
combination of the SRS and the IC. The strings of white squares illustrate different
“trajectories” of the fishery in the SRS.
Sumber: FAO Land and Water Bulletin No. 5. 1997
Diagram Layang-layang untuk Sustainabilitas
Diagram bintang sering digunakan untuk menyajikan sifat
multivariate suatu SISTEM, misal. Untuk mengikhtisarkan
performan suatu komputer dengan skor-skor untuk menilai
kecepatan prosesornya, kapasitas RAM, kapasitas hard disk,
kecepatan transfer file, efisiensi energi, kemudahan
pengguna, dll.
A theoretical example of such a diagram and illustrates the
fact that it can be used to compare the profile (the
"signature") of different systems including the "ideal" one
with optimal values for all parameters.
Sumber: FAO Land and Water Bulletin No. 5. 1997
Contoh teoritis Diagram Bintang
Sumber: FAO Land and Water Bulletin No. 5. 1997
Contoh Teopritis SRS isometrik empat sumbu. Situasi perikanan yg
sangat khusus yg disajikan pada suatu bagan “layang-layang”.
Sumber: FAO Land and Water Bulletin No. 5. 1997
SRS - SUITABILITY REFERENCE SYSTEM
Contoh teoritis suatu diagram (bagan) untuk perikanan,
hanya menggunakan empat sumbu (diagram layang-layang)
untuk menyederhanakan.
Parameter yg digunakan disusun dalam dua domain sesuai
dengan ekosistemnya dan kemanusiaan (dalam rangka
untuk tetap sesuai dnegan konsep Prescott-Allen (1996).
Each axis can be scaled from 0 to 1 and the grey scale refers to the
assessment categories used in the preceding SRS (black= Bad, light
grey= Good). A fishery can be re-presented on this referential system
by a polygon and two fisheries can be compared by comparing their
polygons. In addition, the position of the polygon in relation to each
axis indicates in which sphere action might be required to improve the
situation.
Sumber: FAO Land and Water Bulletin No. 5. 1997
SEKALA SUMBU SRS
Prescott-Allen memberikan berbagai contoh perhitungan detail
tentang pen-sekala-an sumbu-sumbu dari SRS.
Scaling memerlukan penentuan batas-batas sekala (0-1 atau 0-100)
dan pembagian sekala yg relevan sesuai dengan “value judgement”
(misalnya, apakah kriteria "Bad" setara dengan 0 - 0.2 atau 0 - 0.5).
The latter could sometimes be arbitrary or conventional, but should in
most instances refer to the target and limit reference points.
In the example given by Prescott-Allen for the sustainability barometer
the two axes are scaled from 0 to 1 and the value judgements (i.e.,
Good to Bad) are evenly distributed on both axes.
Sumber: FAO Land and Water Bulletin No. 5. 1997
SEKALA SUMBU SRS
Dalam banyak kasus, nilai-nilai sebenarnya dari indikator
sustainabilitas (mis. Ukuran biomasa ‘spawning’) tidak berada di
antara 0 dan 1, tetapi di antara nilai Bv dan nol. Dalam hal seperti ini
diperlukan perhitungan kembali, misalnya dg menggunakan indikator
rasio (contohnya B/Bv).
In the section on "Indicators of level", above, an attempt has been
made to scale, from 0 to 1, the degree of people’s participation in a
management system and arbitrary value judgements were given.
Penggunaan SRS, memerlukan indikator-indikator yang bermanfaat,
menggunakan metode kuantitatif untuk estimasi dan menetapkan
kriteria ‘value judgements’.
Sumber: FAO Land and Water Bulletin No. 5. 1997
Contoh teoritis SRS an-isometrik empat sumbu.
Sumber: FAO Land and Water Bulletin No. 5. 1997
Penyajian Stochastik dan Dinamik Layang-layang sustainabilitas.
Sumber: FAO Land and Water Bulletin No. 5. 1997
LAND QUALITY
Tiga tipe indikator kunci dari “KUALITAS LAHAN” yg dianggap paling
penting :
a. Indikator di atas permukaan tanah, berhubungan dnegan hasil:
1. Cover close to the ground: its density, distribution, duration,
timing.
2. Stress in plants: growth rates; timing and frequency of wilting;
visible nutrient deficiencies or imbalances.
b. Indikator di permukaan tanah, mempengaruhi ketersediaan lengastanah, runoff dan erosi:
Porosity of at least topsoil layers, in millimetric bands: proportions of
incident rainfall becoming infiltrated;
Sumber:
Sumber: FAO Land and Water Bulletin No. 5. 1997
LAND QUALITY
c. Indikator di bawah permukaan tanah:
Kandungan BOT dan aktivitas biologis , mempengaruhi berbagai sifat
tanah lainnya:
Arsitektur Tanah:
. structural stability;
. gas exchange
. water movement and retention/release;
Kapasitas Tukar Kation (KTK) :
. nutrient capture and retention;
. pH buffering;
. nutrient availability;
. source of small amounts of recycled nutrients.
Sumber:
Sumber: FAO Land and Water Bulletin No. 5. 1997
EVALUASI KUALITAS LAHAN