Bahan kajian
MK. Pengelolaan Kesuburan Tanah
KEBUTUHAN HARA
dan
PEMUPUKAN
TANAMAN SAYURAN
Dihimpun dan diabstraksikan : Smno.jursntnh.fpub.Okt2012
Crop Rotation and Vegetable
Nutrient Relationship
Understanding the vegetable nutrient relationship between your
vegetables and your soil is an important aspect of organic
gardening crop rotation. This relationship of plant and nutrient
determines whether you have a successful long term, healthy
organic garden, or a short term pest ridden garden. The principle I
use to explain this comes from the world renowned biointensive
gardener and author John Jeavons and his incredible book How to
Grow More Vegetables.
http://www.organicgardeninfo.com/vegetable-nutrientrelationship.html
. Asian Journal of Crop Science Year: 2012 | Volume: 4 | Issue: 3 | Page
No.: 103-112
Effect of Nitrogen Fertilizer on the Levels of Some Nutrients, Antinutrients and Toxic Substances in Hibiscus sabdariffa
Amanabo Musa and Emmanuel O. Ogbadoyi
The presence of antinutrients and toxic substances in vegetables
limits the derivable benefits from vegetables. The levels of these
substances in vegetables are influenced by the nature of soil in
which the vegetables are grown.
The effect of applied nitrogen fertilizer on the levels of some
antinutrients and toxic substances is investigated with a view to
determine the appropriateness or otherwise of the application of
nitrogen fertilizer in growing vegetables.
Pot experiments were conducted to determine the effect of soil
nitrogen levels on soluble and total oxalates, cyanide, nitrate and
some micronutrients namely, vitamin C, β-carotene (precursor of
vitamin A) and mineral elements (Fe, Mg, Zn, Cu, Ca, Na and K) in
Hibiscus sabdariffa. The leaves of the vegetable were harvested and
analysed at market maturity (vegetative phase) and fruiting
(reproductive phase) of the plant development.
Results obtained showed that the applied nitrogen fertilizer
significantly elevated nitrate and β-carotene contents, while it
decreases the levels of vitamin C, soluble and total oxalates in the
vegetable. The levels of cyanide and mineral elements were not
significantly affected by the applied nitrogen fertilizer.
Diunduh dari: http://scialert.net/abstract/?doi=ajcs.2012.103.112 ..
NITROGEN LEVEL AND LIGHT INTENSITY CAN EFFECT VEGETABLE
AMARANTH LEAF NUTRIENTS
D.J. Makus
HortScience April 1993 vol. 28 no. 4 267
. Three-week-old transplants of Amaranthus tricolor cultivars
'RRC 241' (RC) and 'Hinn Choy' (HC) were given split applications
of supplemental N of 0, 100 and 200 kg/ha and in the 5th week
after sowing were exposed to 100, 70 and 50% of ambient solar
radiation for nine and ten days, respectively. Increased shading
had a linear (L) effect on leaf blade NO3, protein, K, Mg, S, P, Al, Fe
and Cu (dry wt basis).
There were L and quadratic (Q) increases in chlorophyll (chloro)
and carotenoids. Increasing supplemental N increased leaf blade
protein (L,Q), Na (L), Mn (L), chloro (L,Q), carotenoids (L,Q), but
decreased Mg (L), P (L,Q) and Zn (L,Q).
Nitrate levels showed L and Q increases in RC and HC,
respectively. HC was higher in leaf blade K, Mg, Na, Fe, Zn, Cu,
NO3, chloro and carotenoides, but lower in CA than RC. Shading
had no effect on leaf area or plant fresh wt, but decreased plant
dry wt while increasing plant water content.
Nitrogen application increased stem length, and plant fresh and
dry wt.
Diunduh dari: http://hortsci.ashspublications.org/content/28/4/267.1.abstract ..
. ISHS Acta Horticulturae 506: International Workshop on Ecological
Aspects of Vegetable Fertilization in Integrated Crop Production
NITROGEN EFFECTS ON VEGETABLE CROP PRODUCTION AND
CHEMICAL COMPOSITION
J. Sorensen
Concerns about human health in relation to the intake of food
have led to an increasing interest in the nutritional quality of
food products. A high intake of vitamins, dietary fibres and some
minerals, and a low intake of nitrate, is supposed to protect
against several life-style diseases which occur in many
industrialized countries.
Application of fertilizers may not only influence the yield and
quality of field vegetable crops, but also the chemical
composition of the marketable product. Therefore, application of
fertilizers may be used to control and improve the nutritional
quality of products used for human consumption. During the last
two decades the chemical composition of field vegetable crops
has been monitored in several fertilizer experiments at the
Danish Institute of Agricultural Sciences.
This paper shows that increased N supply decreased the
concentration of dry matter, potassium, sucrose, vitamin C, and
dietary fibre in leaf vegetable crops, but increased the
concentration of nitrate, nitrogen, and carotene.
Diunduh dari: http://www.actahort.org/books/506/506_4.htm..
Effect of nitrogen fertiliser on the nitrate contents of
field vegetables grown in Britain
Duncan J. Greenwood, John Hunt
Journal of the Science of Food and Agriculture
Volume 37, Issue 4, pages 373–383, April 1986
. The nitrate and percentage organic nitrogen contents of 14
vegetable and two arable crops were measured after they had been
grown with different levels of N-fertiliser. Foliage crops always
contained substantial quantities of nitrate which increased with
increase in the rate of N-fertiliser application.
Grain of legumes and cereals, storage roots of carrots, parsnips and
sugar beet, and onion bulbs and leeks contained no detectable
amounts of nitrate even when N-fertiliser application rates were
very high. Storage roots of red beet, swede and white turnip
contained more than 3 mg NON g−1 dry weight when grown with
exceptionally high levels of fertiliser-N but contained very little when
grown with the optimum amount of fertiliser-N or less. An equation
was developed that linked NON to percentage organic-N for those
parts of plants that could accumulate nitrate. It gave good fits to the
data from seven crop species grown at a range of different levels of
N-nutrition.
It is estimated from the foregoing data and a survey of household
food consumption that the average British person consumes about
60 mg NON week−1 in field vegetables. If N-fertilisers were withheld
consumption would be about 30 mg and if excess were applied it
would be about 120 mg NON week−1.
Diunduh dari: . http://onlinelibrary.wiley.com/doi/10.1002/jsfa.2740370407/abstract.
Effects of a catch crop and reduced nitrogen fertilization on nitrogen
leaching in greenhouse vegetable production systems
Authors: Min, Ju1; Shi, Weiming2; Xing, Guangxi1; Zhang, Hailin3; Zhu,
Zhaoliang1
Source: Nutrient Cycling in Agroecosystems, Volume 91, Number 1,
September 2011 , pp. 31-39(9)
Greenhouse vegetable cultivation has greatly increased productivity
but has also led to a rapid accumulation of nitrate in soils and
probably in plants. Significant losses of nitrate-nitrogen (NO3-N)
could occur after heavy N fertilization under open-field conditions
combined with high precipitation in the summer. It is urgently
needed to improve N management under the wide spread
greenhouse vegetable production system.
The objective of this study was to evaluate the effects of a summer
catch crop and reduced N application rates on N leaching and
vegetable crop yields. During a 2-year period, sweet corn as an N
catch crop was planted between vegetable crops in the summer
season under 5 N fertilizer treatments (0, 348, 522, 696, and 870 kg
ha−1) in greenhouse vegetable production systems in Tai Lake region,
southern China.
A water collection system was installed at a depth of 0.5 m in the soil
to collect leachates during the vegetable growing season. The sweet
corn as a catch crop reduced the total N concentration from 94 to 59
mg l−1 in leached water and reduced the average soil nitrate N from
306 to 195 mg kg−1 in the top 0.1-m soil during the fallow period of
local farmers' N application rate (870 kg ha−1). Reducing the amount
of N fertilizer and using catch crop during summer fallow season
reduced total N leaching loss by 50 and 73%, respectively, without
any negative effect on vegetable yields.
Diunduh dari: .
http://www.ingentaconnect.com/content/klu/fres/2011/00000091/00000001/00009441.
Effects of band placement and nitrogen rate on dry matter
accumulation, yield and nitrogen uptake of cabbage, carrot and onion
T. SALO
Agricultural and Food Science
Vol 8, Nro 2 (1999)
Adequate nitrogen (N) nutrition is essential for producing high vegetable yields of good quality.
Fertilizer N not taken up by the plants is, however, economically wasteful and can be lost to the
environment. Therefore the efficient use of N fertilizer, involving accurate estimation of crop N
demand, choice of application method and timing of N fertilization, is an important research
area. The effects of band placement and rate of N fertilization on inorganic N in the soil and the
dry matter accumulation, yield and N uptake of cabbage, carrot and onion were studied in a
three-year field experiment between 1993 and 1995. The plants were sampled during the
growing season to determine the dry matter accumulation and plant N concentration. The
inorganic N in the soil was determined during the growing period and after harvest. The N
uptake was 3.8 kg, 1.6 kg and 2.5 kg per ton of edible yield of cabbage, carrot and onion,
respectively. At the highest yield levels the N uptake including crop residues was 300 kg ha-1,
150 kg ha-1 and 120 kg ha-1 in cabbage, carrot and onion, respectively. In cabbage, almost 50%
of N was in crop residues, whereas in carrot and onion only about 30% of N was in crop
residues. Nitrogen uptake from non-fertilized soil varied from 29 to 160 kg ha-1, depending on
the growing season and the crop. Cabbage and carrot utilised soil N efficiently, usually taking
up more than 100 kg ha-1 from non-fertilized soil. Onion, on the contrary, utilised soil N
relatively poorly, usually less than 50 kg ha-1 from non-fertilized soil. The rate of N uptake was
low with all crops in early summer. After one month, N uptake increased in cabbage and onion.
This uptake continued until harvest, i.e. mid-August for onion and early September for cabbage.
Nitrogen uptake by carrot started rapidly only two months after sowing and continued until
harvest at the end of September. High N rates often resulted in high N concentrations and N
uptakes, but growth was not necessarily increased. One month after fertilization, most of the N
placed was still near the original fertilizer band and at the depth of 5-10 cm. At that time,
broadcast N was at a depth of 0-5 cm. After harvest the soil mineral N content was generally
low, i.e. below 25 kg ha-1 at the depth of 0-60 cm. Onion was an exception with poor growth in
1994, when soil mineral N after the highest N rate was 80 kg ha-1 at a depth of 0-60 cm after
harvest. The placement distance in the cabbage experiment, 7.5 cm in the side and 7 cm below
cabbage transplants, resulted in lower plant growth and N uptake than broadcasting of N at the
beginning of the growing periods 1993 and 1994. Towards harvest differences between
application methods decreased, although in 1993, placement of N still led to 6% lower cabbage
yields than broadcasting of N. In 1993, high N rates increased cabbage dry weight and N uptake
towards harvest, and this effect was more pronounced when N was broadcast. In 1994, soil N
mineralisation was high, and only non-fertilized cabbages took up less N than fertilized plants.
Carrot was remarkably insensitive to N fertilization. Carrot yields were similar with and without
N fertilizers. Band placement and N rate did not affect carrot growth and N uptake. In 1993,
band placement and high rates of N increased onion growth and bulb yield more than
broadcasting. In 1994, onion growth was poor and treatments did not affect plant N
concentrations or growth. Apparent recovery of fertilizer N was increased in 1993 by low N
rates or band placement. This result that band placement of N does not much affect vegetable
growth is in agreement with most previous studies. With onion, probably due to the sparse
root system, positive effects of N placement are most likely to be found.
Diunduh dari: http://ojs.tsv.fi/index.php/AFS/article/view/5624..
. Effects of different fertilization modes on vegetable growth, fertilizer
nitrogen utilization, and nitrogen loss from vegetable field. HUANG
Dong-feng;WANG Guo;LI Wei-hua; QIU Xiao-xuan
Chinese Journal of Applied Ecology 2009, Vol. 20 Issue (03): 631-638
A field experiment with Chinese cabbage, water spinach, and threecolored amaranth cropped three times in one year was conducted to
study the effects of seven fertilization modes, i.e ., none
fertilization, basal application of chemical fertilizers, 1/2 basal
application and 1/2 top-dressing of chemical fertilizers, basal application
of chemical fertilizers and dicyandiamide, 1/2 basal application and 1/2
top-dressing of chemical fertilizers and dicyandiamide, 1/2 basal
application and 1/2 top-dressing of chemical fertilizers and organic
manure, and basal application of organic manure, on the plant height,
yield, nitrogen accumulation, and fertilizer nitrogen utilization of the
vegetables, and the loss of NO3--N and NH4-N from vegetable field
under natural rainfall condition.
The results showed that comparing with none fertilization, the
fertilization modes ‘1/2 basal application and 1/2 top-dressing of
chemical fertilizers and organic manure’ and ‘basal application of
chemical fertilizers and dicyandiamide’ improved the agronomic
properties of test vegetables, increased their yields by 103%〖KG-*2〗-〖
KG-*7〗219% and 93%〖KG-*2〗-〖KG-*7〗226%, and nitrogen accumulation
by 153%〖KG-*2〗-〖KG-*7〗216% and 231%〖KG-*2〗-〖KG-*7〗320%,
respectively, and enhanced fertilizer nitrogen utilization rate.
They also decreased the surface runoff loss of NO3--N and NH4-N by 48
1% and 46 5%, respectively, compared with the mode ‘basal
application of chemical fertilizers’, and hence, reduced the risk of
agricultural non-point pollution. Therefore, these two fertilization
modes could be popularized in vegetable production.
Diunduh dari: http://www.cjae.net/EN/abstract/abstract10555.shtml ..
Effects of nitrogen on development and growth of the leaves of
vegetables. 3. Appearance and expansion growth of leaves of spinach
H. Biemond
NJAS Vol. 43 No.2 1995
In a series of greenhouse and field trials, spinach cv. Trias plants
were supplied with different amounts of N fertilizer in various split
applications. Rates of leaf emergence and expansion were recorded,
as well as final leaf size.
The rate of leaf appearance varied between 0.16 and 0.57/day
across experiments, but was hardly affected by N treatment. The
rate of leaf expansion and mature leaf area increased with leaf
number, reaching maximum values at leaf pair 3+4 or 5+6 and
decreasing subsequently. Both characteristics were positively
correlated with N supply. The duration of expansion was not
influenced by N treatments and varied between 15 and 30 days in
most experiments.
The rate of leaf expansion was the main factor determining mature
leaf size. Specific leaf area over all green leaves slowly decreased
with time in most experiments and was around 300 cmsuperscript
2/g.
As the differences in the number of leaves were small, the
differences in total green leaf area per plant resulted from
differences in the areas of individual mature leaves.
Diunduh dari: ..
. ISHS Acta Horticulturae 745: VI International Solanaceae Conference :
Genomics Meets Biodiversity EFFECTS OF NITROGEN LEVELS ON
GROWTH AND YIELD OF BROAD-LEAFED AFRICAN NIGHTSHADE
(SOLANUM SCABRUM)
Authors: M.O. Abukutsa-Onyango, J. Karimi
African nightshade (Solanum scabrum) is an important indigenous
vegetable in many African countries, yet factors affecting leaf yields
have not been fully investigated. A market survey conducted in
Kakamega Municipal market in Kenya revealed that broad-leafed
African nightshade was among the preferred African vegetables in
the region. Besides being rich in micronutrients, it has several
medicinal properties and is less bitter than other vegetable
nightshades. For the potential of this crop to be exploited, there is a
need to look at factors that would contribute to optimal leaf yields.
Nitrogen affects growth and development of many leafy vegetables
through its effect on cell division and hence leaf expansion. Little
work has been reported on nitrogen effects on this emerging crop.
The objective of the study was therefore to investigate effects of
nitrogen rates on growth and yield of Solanum scabrum. A pot and
two field experiments were conducted at Maseno University,
Western Kenya, between June 2003 and December 2005. The pot
experiment was laid out in a completely randomized design with
four treatments and four replications.
The treatments included 0, 25, 50, and 75 mg of N per kg. The field
experiments were set up in a randomized complete block design
with six nitrogen rates and three replications. The treatments
included 0, 10, 20, 40, 80 and 100 kg of N per hectare.
Nitrogen levels significantly (p ≤ 0.05) affected plant growth and leaf
yields in both pot and field experiments with optimal levels at 25 mg
N/kg and 40 kg N/ha respectively.
Diunduh dari: http://www.actahort.org/books/745/745_23.htm ..
Effects of Nitrogen Fertilization and HPS Supplementary Lighting on
Vegetable Transplant Production. II. Yield
Jean Masson, Nicolas Tremblay1 and André Gosselin
JASHS July 1991 vol. 116 no. 4 599-602
Transplants of celery (Apium graveolens L.), lettuce (Lactuca
sativa L.), broccoli (Brassica oleracea italica L.), and tomato
(Lycopersicon esculentum Mill.) grown in multicellular trays
under natural light or with supplementary lighting of 100 μmol·s1·m-2 (PAR) in factorial combination with four rates of N
fertilization (100, 200, 300, and 400 mg•liter-1) were tested for
productivity under field conditions.
Celery was seeded once, lettuce twice, and broccoli and tomato
three times. Broccoli and tomato were transplanted at two sites,
celery and lettuce at one.
Supplementary lighting had no effect on yields of celery, lettuce,
and broccoli, but significantly increased yields of early seeded
tomato.
High rates of N fertilization (300 and 400 mg·liter-1) applied at
the transplant stage improved yields for all the species.
Diunduh dari: http://journal.ashspublications.org/content/116/4/599.abstract..
LIGHT AND NITROGEN LEVELS AFFECT THE AGRONOMIC
PERFORMANCE OF VEGETABLE AMARANTH
D. J. Makus
HortScience May 1993 vol. 28 no. 5 519
Three-week-old transplants of Amaranthus tricolor cultivars `RRC
241' and `Hinn Choy' were given split applications of supplemental N
(0, 100 and 200 kg/ha). Five weeks after sowing both cvs. were
exposed to 100, 70 and 50% of ambient solar radiation for nine and
ten days, respectively.
During shading, avg. daily photosynthetic irradiance was reduced
from 11.6 to 7.7 and 5.0 KW/m2, respectively. Soil, air, and leaf
temperatures were reduced by shading. Plants were harvested in the
seventh week.
Cultivars differed in leaf number and area, yield, height, mineral
uptake, and stem fresh and dry weight. Increasing shade levels
decreased the dry wt. of stems, leaf blades, and plants.
Shading had no effect on leaf area, plant fresh wt. or yield, but
increased stem length, plant water content and leaf blade pigments.
Photosynthetic fixation rates were reduced by 50% shade.
Leaf blade protein and most leaf blade mineral nutrients, including
nitrates, were increased by shading.
Nitrogen application increased stem length, stem, leaf blade and
plant fresh and dry wt., leaf blade pigments and yield.
Diunduh dari: http://hortsci.ashspublications.org/content/28/5/519.1.abstract..
Effects of nitrogen on accumulation and partitioning of dry matter and
nitrogen of vegetables. 2. Leek
H. Biemond
NJAS Vol. 43 No. 4 1995
Two greenhouse and 2 field trials were carried out on leeks cv.
Albana with different N fertilizer rates and application dates.
Observations included frequent measurements of DM and N
accumulation in leaf blades, leaf sheaths and, if present, scapes.
Both the amount of N applied and the time of application affected
the total accumulation of DM and N in the plant.
The relative partitioning rates of DM increase to the shaft were
affected in such a way that the final harvest indices for DM (which
ranged from 0.32 to 0.53) were significantly lower at higher N
application rates.
The final harvest indices for N (0.21-0.35) were not significantly
affected by amount or timing of fertilizer applications.
The total N concentrations of leaf blades and leaf sheaths
decreased with increasing leaf age. Average nitrate N
concentrations over all plant parts were always below 40%.
Diunduh dari: http://library.wur.nl/ojs/index.php/njas/article/view/565..
Effects of nitrogen on development and growth of the leaves of
vegetables. 2. Appearance, expansion growth and life span of
leaves of leek plants
H. Biemond
NJAS Vol. 43 No.. 2 1995
In greenhouse pot experiments and field trials, leek cv. Albana
plants were supplied with different amounts of N fertilizer at
various growth stages. Leaf emergence, expansion, size and
senescence were monitored.
The rate of leaf appearance was not affected by N treatments
and almost constant across experiments at 0.15/day. The rate of
leaf expansion and the mature leaf area increased with leaf
number, reaching maximum values between leaf numbers 11
and 14 and decreasing with higher leaf numbers. Both variables
increased with increasing N application rate.
The duration of leaf expansion was more or less constant across
leaf numbers and not influenced by N treatments; the leaf
expansion rate was the main factor determining mature leaf
area.
The rate of leaf senescence was not influenced by N treatments.
Differences in total green leaf area per plant were caused by
differences in the area of individual mature leaves and not by
differences in the number of leaves. The specific leaf area of all
leaves was more or less constant at 100 cmsuperscript 2/g.
Diunduh dari: http://library.wur.nl/ojs/index.php/njas/article/view/579..
EFFECT OF NITROGEN ON GROWTH AND YIELD
OF RADISH
Muhammad Saleem Jilani, Tariq Burki and Kashif Waseem*
J. Agric. Res., 2010, 48(2)
Effect of different levels of nitrogen on growth and yield of
radish was studied at Gomal University, D. I. Khan, Pakistan
during winter season 2007.
Five N levels (50, 100, 150, 200 and 250 kg/ha) alongwith a
control (no nitrogen) were tried. The results showed that higher
N levels gave better results for all parameters studied.
Maximum number of leaves (18.70, 18.17 and 18.10), leaf length
(33.33, 32.80 and 31.10 cm), weight of leaves (160.67, 132.83
and 140.82 g), root length (23.77, 22.10 and 22.23 cm), root
diameter (4.43, 4.87 and 4.15 cm), root weight (139.28, 122.73
and 127.16 g) and yield (99.88, 85.10 and 89.24 t/ha) were
recorded when N was applied @ 200, 250 and 150 kg per
hectare, respectively.
Diunduh dari: http://www.jar.com.pk/admin/upload/34__219Paper-No.11.pdf..
Effects of nitrogen on development and growth of the leaves of
vegetables. 1. Appearance, expansion growth and life span of
leaves of Brussels sprouts plants
H. Biemond, J. Vos, P.C. Struik
NJAS Vol. 43 No.2 1995
n greenhouse pot trials, Brussels sprouts cv. Icarus SG2004 plants
were supplied with various amounts of N at different stages
during growth.
The rate of leaf emergence ranged from 0.39 to 0.72 per day
and was significantly increased by increasing N application rate.
Leaf expansion rate and mature leaf area increased with leaf
number, reaching maximum values between leaf number 10 and
20 and decreasing subsequently.
Plants receiving more N had a higher total green leaf area per
plant, due to more and larger green leaves.
Specific leaf area of all leaves declined gradually from 130-230
cmsuperscript 2/g (depending on experiment) at about 30 days
after planting to 60 cmsuperscript 2/g at the end of the
experiments and was usually significantly increased by increasing
N application rate.
Diunduh dari: http://library.wur.nl/ojs/index.php/njas/article/view/578..
. ISHS Acta Horticulturae 506: International Workshop on Ecological
Aspects of Vegetable Fertilization in Integrated Crop Production
NITROGEN EFFECTS ON VEGETABLE CROP PRODUCTION AND
CHEMICAL COMPOSITION
Author: J. Sorensen
Concerns about human health in relation to the intake of food have
led to an increasing interest in the nutritional quality of food
products. A high intake of vitamins, dietary fibres and some
minerals, and a low intake of nitrate, is supposed to protect against
several life-style diseases which occur in many industrialized
countries.
Application of fertilizers may not only influence the yield and quality
of field vegetable crops, but also the chemical composition of the
marketable product. Therefore, application of fertilizers may be used
to control and improve the nutritional quality of products used for
human consumption. During the last two decades the chemical
composition of field vegetable crops has been monitored in several
fertilizer experiments at the Danish Institute of Agricultural Sciences.
This paper shows that increased N supply decreased the
concentration of dry matter, potassium, sucrose, vitamin C, and
dietary fibre in leaf vegetable crops, but increased the concentration
of nitrate, nitrogen, and carotene.
Diunduh dari: http://www.actahort.org/members/showpdf?booknrarnr=506_4..
. African Journal of Biotechnology Vol.10 (48), pp.9857-9863, 29 August,
2011
The effects of applied nitrogen fertilizer and leaf positions on levels of
micronutrients, anti-nutrients and toxic substances in Amaranthus
cruentus
Amanabo Musa, Johnson A. Oladiran, Matthew I.S. Ezenwa, Helmina
O. Akanya and Emmanuel O. Ogbadoyi
The presence of antinutrients and toxic substances in vegetables
limits the nutritional benefits of vegetables. The effects of age of
plant and application of nitrogen fertilizer on the bioaccumulation of
antinutrients (oxalate), toxic substances (cyanide and nitrate),
micronutrients (vitamin C, β-carotene -provitamin A) and mineral
elements (Fe, Mg, Cu, Zn, Ca Na and K) in Amaranthus cruentus were
investigated using pot experiment. Leaves were harvested at market
maturity (vegetative phase) at three different leaf positions, basal
(oldest), middle (younger) and upper (youngest) and were subjected
to chemical analysis.
Results obtained showed that cyanide, nitrate and oxalate were
concentrated significantly in the basal and middle positions. The
concentration of β-carotene, vitamin C and Zn were significantly
higher in the leaves in the middle part than in the basal and upper
leaves. Similarly, Fe, Mg, Cu and Na contents were significantly
higher in the basal leaves than in the middle and upper leaves, while
the concentration of K was higher in the younger leaves.
We concluded that consumption of the vegetable leaves from the
upper leaf position will provide the dietary requirements of the
analysed micronutrients with significant reduction in the levels of
oxalate, cyanide and nitrate and associated health problems.
Diunduh dari: .
http://www.academicjournals.org/AJb/full%20text/2011/29Aug/Musa%20et%20al.htm.
. Pakistan Journal of Nutrition Year: 2010 | Volume: 9 | Issue: 11 | Page
No.: 1039-1042
Effects of Effective Microorganisms on Yield and Quality of Vegetable
Cabbage Comparatively to Nitrogen and Phosphorus Fertilizers Kwizera
Chantal, Shao Xiaohou, Wang Weimu and Basil T. Iro Ong`or
The misuse and excessive use of fertilizers resulted in the loss of soil
sustainability and a declined productivity, have increased the need
of use of Effective Microorganisms Technology (EM) as an alternative
to such practices to meet the future nutritional requirements of the
people.
This study aimed at appraising the effects of EM on Leaf Area (LA)
and Photosynthesis (PH) of vegetable cabbage comparatively to
Nitrogen (N) and Phosphorus (P) fertilizers. Results showed an
increased leaf area for treatments with EM, while others
demonstrated its reduction.
Significant among treatments was recorded with p<0.05. Likewise,
EM has improved photosynthesis. This suggested that EM improve
plant yield and quality, resulting in a fulfillment of a sustainable
agriculture.
Diunduh dari: http://scialert.net/abstract/?doi=pjn.2010.1039.1042..
. The Journal of Horticultural Science & Biotechnology November
2000 — Vol. 75 No: 6
Changes in chlorophyll, ribulose bisphosphate carboxylase-oxygenase,
glycine betaine content, photosynthesis and transpiration in
Amaranthus tricolor leaves during salt stress
Y. WANG and N. NII
pp: 623-627
We examined changes in leaf growth and chemical composition, including
chlorophyll content, ribulose bisphosphate carboxylase-oxygenase (RuBisCO), and
glycine betaine (GB) in relation to photosynthesis and transpiration responses to
salt stress in Amaranthus tricolor leaves. To induce salt stress, plants were
transferred to a growth medium containing 300 mM NaCl for 7 d followed by 7 d
of relief from salinity. A decrease in leaf enlargement began 3 d after salt stress,
and leaves subsequently showed the same degree of regrowth as controls after
relief in non-salt medium.
Chlorophyll content expressed on a leaf-area basis increased under conditions of
salinity due to a reduction in leaf tissue water content. The decrease in
chlorophyll content continued throughout the 7 d of relief from salinity. The
RuBisCO and soluble protein contents when expressed on a leaf dry-weight basis
decreased in response to salinity, and then gradually increased during the relief
period. GB content increased slightly up to 3 d of salt stress, and showed typical
accumulation during salt stress.
GB content decreased sharply immediately after plants were transferred to nonstress medium, but remained at a higher level throughout the relief period. A
decrease in photosynthetic activity and transpiration rate preceded any changes
in leaf area, RuBisCO or GB content. During relief from salinity, photosynthesis
and transpiration rates gradually recovered to control levels with restoration of
stomatal conductance.
The above findings suggest that the increase in GB content is important in
adaptation to salt stress in Amaranthus plants, although photosynthesis and
transpiration responses occurred immediately after salt-stress.
Diunduh dari: http://www.jhortscib.org/Vol75/75_6/1.htm..
Alleviating phosphorus stress of chile ancho pepper (Capsicum
annuum L. 'San Luis') by arbuscular mycorrhizal inoculation
F.T. DAVIES, JR, V. OLALDE-PORTUGAL, M.J. ALVARADO, H.M. ESCAMILLA,
R.C. FERRERA-CERRATO and J.I. ESPINOSA
The Journal of Horticultural Science & Biotechnology November
2000 — Vol. 75 No: 6 . pp: 655-661
Chile ancho pepper (Capsicum annuum L. 'San Luis') is a primary source of
vitamin C in the Mexican diet. It is important to select indigenous mycorrhizal
fungi from Mexico that will utilize nutrients and water more efficiently in the
production of this commercially valuable, native crop. In a greenhouse study,
Chile ancho pepper plants were either non-inoculated (NonAMF), or inoculated
with arbuscular mycorrhiza (AMF): Glomus fasciculatum, or a mixed species
inoculum from Mexico (ZAC-19) containing Glomus albidum, Glomus claroides
and Glomus diaphanum.
Under reduced phosphorus (P) conditions, AMF enhanced plant vegetative and
reproductive growth. Growth of AMF plants at low P was comparable with
NonAMF plants at moderate P. At low P, only plants inoculated with ZAC-19 had
greater leaf tissue P than NonAMF plants, while both groups of inoculated
plants had greater leaf tissue P at moderate P fertility.
AMF plants generally had greater Fe, Mn, Zn and Cu, but lower N and K (ZAC-19)
than NonAMF chile ancho plants. Formation of extraradical hyphae was greatest
in ZAC-19 at low P, and was reduced at higher P levels. This corresponded with a
2.9 fold reduction in spores recoverable in soil by ZAC-19 at high P; however
spore production and development of extraradical hyphae by Glomus
fasciculatum was not affected by P fertility.
At low P, G. fasciculatum had greater arbuscule and vesicle formation than ZAC19. While both AMF isolates enhanced vegetative and reproductive growth of
chile ancho under reduced P conditions, G. fasciculatum was generally more
effective than ZAC-1.
Diunduh dari: http://www.jhortscib.org/Vol75/75_6/index.htm..
The effect of nitrogen application on nitrogen utilization by white
cabbage (Brassica oleracea var. capitata) and on nitrogen in the soil at
harvest
A.P. EVERAARTS and R. BOOIJ
The Journal of Horticultural Science & Biotechnology November 2000 —
Vol. 75 No: 6 pp: 705-712
During two seasons and at four locations the effect of the rate of nitrogen
application and the method of application on the nitrogen uptake by white
cabbage (Brassica oleracea var. capitata) was studied. Maximum nitrogen
uptake by white cabbage was around 400 kg ha-1. Split application had no
effect on nitrogen uptake. Band placement incidentally stimulated nitrogen
uptake by the crop.
The efficiency of nitrogen utilization for product dry-matter production
decreased with increasing nitrogen rates. With increasing amounts of nitrogen
applied the dry matter concentration of the heads decreased linearly with
increasing nitrogen concentration. The nitrogen harvest index, the amount of
nitrogen removed from the field with the product as a percentage of the total
uptake by the crop at harvest, was not influenced by the rate or method of
nitrogen application and varied between experiments from 54 to 60%. The
amount of nitrogen in crop residues increased with increasing amounts of
nitrogen applied and, in two experiments, was higher with band placement of
nitrogen.
At the optimum nitrogen application rate (= 330 - 1.5Nmin 0-60 cm kg ha-1;
Everaarts and De Moel, 1998) an average of 113 kg of nitrogen ha-1 would have
been left in the field in crop residues at harvest. The amount of nitrogen left in
the soil at harvest was low and amounted to a maximum of around 40 kg ha-1
for the soil layer 0-90 cm. Leaching of nitrogen during growth is probably
limited. High amounts of nitrogen band placed resulted in a horizontally
unequal distribution of soil nitrogen at harvest.
The amount of nitrogen unaccounted for at harvest was proportional to the
amount of nitrogen available and for all experiments could be described by
one linear equation. The method of fertilizer application had no effect on this
relationship. The amount of nitrogen in crop residues is the largest single
source of potential loss of nitrogen with white cabbage cultivation.
Diunduh dari: http://www.jhortscib.org/Vol75/75_6/15.htm..
The Journal of Horticultural Science & Biotechnology Vol. 75 No: 6
Effect of humidity and nutrient feed K/Ca ratio on physiological
responses and the accumulation of dry matter, Ca and K in tomato
B.J. MULHOLLAND, M. FUSSELL, R.N. EDMONDSON, I.G. BURNS, J.M.T.
McKEE and J. BASHAM
pp: 713-722
Two levels of humidity, high, 0.1 kPa vapour pressure deficit (vpd) and control 0.5
kPa vpd, and four nutrient feed K/Ca mM ratios (4/7, 10/7, 4/2 and 10/2) were
applied in all factorial combinations to a nine-week old tomato (Lycopersicon
esculentum Mill.) crop for 63 d.
The effect on gas exchange, water relations, vegetative growth, yield and
accumulation of Ca and K in the shoot was examined. High humidity had a
deleterious effect on leaf expansion, delayed truss and fruit maturity and reduced
fruit yield. Water uptake was reduced and the Ca concentration of leaf and fruit
tissue was increased under high humidity compared with plants grown under
control humidity; K accumulation was unaffected.
The accumulation of K and Ca in the shoot appeared to be poorly related to the
rate of transpiration. The high (10/2 mM) K/Ca ratio nutrient feed had little effect
on vegetative growth and yield compared with the low (4/7 mM), but restricted
Ca uptake to the fruits at both the high and the control humidity. During the
measurement period, 0900-1300 hours, stomatal conductance and leaf water
status remained high at elevated humidity, compared with a progressive
reduction in leaf water status and low stomatal conductance in the control
humidity.
A/ci gas exchange analysis where A is the net CO2 assimilation rate and ci is the
intercellular partial pressure of CO2 suggested that, at high humidity, the
photosynthetic capacity of the leaves was reduced because of a lower in vivo
carboxylation efficiency. However, the mechanism(s) responsible for reduced leaf
expansion remains unclear.
The complex interrelations between physiological responses, leaf expansion and
the uptake and distribution of K and Ca to the shoot, are discussed.
Diunduh dari: http://www.jhortscib.org/Vol75/75_6/16.htm..
The Journal of Horticultural Science & Biotechnology Vol. 75 No: 6
Apparent nitrogen mineralization and recovery of nitrogen supply in
field trials with vegetable crops
M FINK and H.C. SCHARPF
pp: 723-726
A major cause of uncertainty in predicting the demand of nitrogen
(N) fertilizer by means of mathematical models is the treatment of
apparent net N mineralization (ANM) and apparent recovery rate
(REC) of mineral N supply (N fertilizer plus soil mineral N at planting).
REC and ANM were analysed in 29 multi-level N fertilizer trials
conducted with a range of vegetable crops over a period of 11 years.
REC differed substantially between experiments (0.29 to 1.24). ANM
ranged from -110 to 140 kg N ha-1; it decreased with an increasing N
supply, and increased with the time between planting and harvest.
A simple regression model was used to predict ANM. The model
consisted of both a N supply-dependent and supply-independent
term, and used N supply and growing time as input parameters.
Whereas the model significantly reduced the variance in measured
ANM (r2 = 0.45, n = 129), the residuals showed a considerable
variation (standard deviation (SD) = 37 kg N ha-1).
It is not feasible to predict N fertilizer demand without predicting
net N mineralization and fertilizer recovery. Therefore, the
regression model is recommended despite its inaccuracy, which is
taken into account by adding a security margin to the fertilizer
recommendation.
Diunduh dari: http://www.jhortscib.org/Vol75/75_6/17.htm ..
Agron. Sustain. Dev. 30 (2010) 763–768Research article
Efficient urea-N and KNO3-N uptake by vegetable plants using
fertigation
Constantinos Ehaliotis, Ioannis Massas and Georgios Pavlou
Vegetable production demands high nitrogen inputs. Fertigation is a
means to increase fertilizer-N use by plants. However, the effect of
different N sources and doses, and how they relate to the total
available N in soils are poorly known.
In this study we applied 15N-labeled fertilizers to green pepper in
the field using a drip irrigation system during the dry summer. KNO3N and urea-N were applied at a total of 6, 12 and 18 g plant−1. Our
results show that urea was as effective as KNO3 as a N source.
The fertilizer-N utilization efficiency was dramatically reduced at
higher N doses, from 48% for the 6 g N plant−1 dose to 36% and 26%
for the 12 and 18 g N plant−1 doses, respectively. However, the N in
plants derived from fertilizer consistently exceeded 60%, indicating
high availability of fertilizer-N even at the lowest dose. Negative
added nitrogen interactions – the effect of added N on the fate of
soil-N – were observed, particularly at high fertilizer-N doses. The
fertilizer-N utilization efficiency calculated by the difference method
was lower compared with the 15N enrichment method.
This clearly indicates luxury N applications and excess N availability
brought about by precise localized placement of fertilizer-N that
leads to limited uptake of the available soil-N. N leaching risks in the
following rain period should therefore be based on both the residual
fertilizer-N and the increased amounts of residual soil mineral-N.
Diunduh dari: http://www.agronomyjournal.org/index.php?option=com_article&access=doi&doi=10.1051/agro/2010016&Itemid
=129 ..
Effects of vertical distribution of soil inorganic nitrogen on root
growth and subsequent nitrogen uptake by field vegetable crops
H. L. Kristensen, K. Thorup-Kristensen
Soil Use and Management
Volume 23, Issue 4, pages 338–347, December 2007
Information is needed about root growth and N uptake of crops
under different soil conditions to increase nitrogen use efficiency in
horticultural production. The purpose of this study was to investigate
if differences in vertical distribution of soil nitrogen (Ninorg) affected
root growth and N uptake of a variety of horticultural crops. Two
field experiments were performed each over 2 years with shallow or
deep placement of soil Ninorg obtained by management of cover
crops. Vegetable crops of leek, potato, Chinese cabbage, beetroot,
summer squash and white cabbage reached root depths of 0.5, 0.7,
1.3, 1.9, 1.9 and more than 2.4 m, respectively, at harvest, and
showed rates of root depth penetration from 0.2 to
1.5 mm day−1 °C−1. Shallow placement of soil Ninorg resulted in greater
N uptake in the shallow-rooted leek and potato. Deep placement of
soil Ninorg resulted in greater rates of root depth penetration in the
deep-rooted Chinese cabbage, summer squash and white cabbage,
which increased their depth by 0.2–0.4 m.
The root frequency was decreased in shallow soil layers (white
cabbage) and increased in deep soil layers (Chinese cabbage,
summer squash and white cabbage). The influence of vertical
distribution of soil Ninorg on root distribution and capacity for
depletion of soil Ninorg was much less than the effect of inherent
differences between species. Thus, knowledge about differences in
root growth between species should be used when designing crop
rotations with high N use efficiency.
Diunduh dari: http://onlinelibrary.wiley.com/doi/10.1111/j.14752743.2007.00105.x/abstract..
. ISHS Acta Horticulturae 852: IV International Symposium on
Ecologically Sound Fertilization Strategies for Field Vegetable
Production EFFECT OF NITROGEN AND SULPHUR FERTILISATION ON
YIELDS, NITRATES AND CYSTEINE AND METHIONINE CONTENT IN
ONION (ALLIUM CEPA L.)
Authors: T. Lošák, J. Hlušek, S. Kráčmar, Mårtensson
This study explored the interactive effects of two doses of nitrogen
and two levels of soil sulphur on onion yields, nitrate content and
concentration of the amino acids cysteine and methionine under
accurately controlled conditions. Onions were cultivated in
Mitscherlich pots with 6 kg of soil with a low content of S-SO42- (5
ppm, S0) or a high content (30 ppm, S1) with added doses of 0.6 (N1)
and 1.2 (N2) g N pot-1 as (NH4) 2SO4 and NH4NO3.
There were no significant differences (P<0.05) in onion yields
between the two N doses. The higher sulphur content (S1) increased
yields by 7.0-8.4% compared with S0 for both doses of nitrogen. The
nitrate content in fresh onion increased with nitrogen dose (225 and
566 mg NO3- kg-1 for N1 and N2 respectively).
High sulphur reduced the nitrate content of onions by 19.3-20.5%
depending on nitrogen dose. The contents of cysteine and
methionine increased by on average 39.1% and 25%, respectively,
with increasing nitrogen dose. Soil sulphur content did not change
the cysteine content but higher sulphur content in combination with
higher nitrogen dose (N2) significantly increased the methionine
content, by 18.7-40.7% compared with the other treatments. Joint
fertilisation with nitrogen and sulphur is thus a suitable measure to
increase onion yield and quality since it stabilises or increases the
content of sulphur amino acids and reduces the level of undesirable
nitrates.
Diunduh dari: http://www.actahort.org/books/852/852_37.htm..
EFFECT OF NITROGEN SOURCE AND LEVEL ON VEGETABLE AMARANTH
D. J. Makus
HortScience May 1994 vol. 29 no. 5 444
On 3 Aug. 1993, 20-day-old `Hinn Choy' plants (Amaranthus tricolor
L.) were-planted on 15 × 15 cm spacings in 4-row beds at 1.3 m row
spacings in a Leadvale silt loam soil. Nitrogen sources of NH4, NO3
and NH4 NO3 were used at rates of 0, 100 and 200 kg/ha, and were
split-applied at and 1 week after transplanting. All treatments
received both supplemental K and P at the rate of 90 kg/ha at
planting.
Plants were harvested 31 days after transplanting. Plants given the
NH, source were taller, and were higher in yield, leaf chlorophyll,
total carotenoids and Mn (dry wt basis) than were plants given other
N-sources. NO3-N fertilizer increased leaf Fe and Cu, and residual soil
K and NO3, but reduced Mn levels.
Leaf blade Ca was highest when NH4NO3 fertilizer was used.
Increasing N-rates decreased both soil pH linearly and leaf blade Ca
but linearly increased soil EC, NO3, and S and leaf blade N, K, S, P,
NO3, Fe, chlorophyll and carotenoids.
Diunduh dari: http://hortsci.ashspublications.org/content/29/5/444.6.abstract ..
The effect of nitrogen and the method of application on
yield and quality of broccoli
A.P. EVERAARTS1,* AND P. DE WILLIGEN2
Netherlands Journal of Agricultural Science 47 (1999) 123-133
The effects of the amount and the method of nitrogen application on
yield and quality of broccoli were studied during three seasons.
Different amounts of nitrogen fertilizer were applied broadcast or
band placed at planting. Band placement of fertilizer increased the
yield in five out of eight experiments.
Application of nitrogen results in larger heads. No relationship was
found between mineral nitrogen at planting and optimum nitrogen
applications because of the narrow range of amounts of mineral
nitrogen at planting.
Split application had no or a negative effect on yield and therefore is
not recommended. For optimum yields it is recommended to apply
270 kg of nitrogen per hectare, minus the mineral nitrogen in the soil
layer 0–60 cm at planting, band placed at planting.
For broadcast application 275 kg of nitrogen minus mineral nitrogen
applied at planting is recommended, but yield will be lower as
compared with band placement of fertilizer.
Diunduh dari: ..
Middle Eastern and Russian Journal of Plant Science and Biotechnology
©2007 Global Science Books
Effect of Different Levels of Nitrogen Fertilizer and Cultivars
on Growth, Yield and Yield Components of
Romaine Lettuce (Lactuca sativa L.)
Maryam Boroujerdnia* • Naser Alemzadeh Ansari
Middle Eastern and Russian Journal of Plant Science and Biotechnology
1(2), 47-53 ©2007 Global Science Books
In order to determine the effect of nitrogen fertilizer rates and
cultivars on growth and critical yield of lettuce, an experiment was
conducted at Shahid Chamran University of Ahwaz, Iran during 20052006. This study was arranged in a spilt plot experiment based on a
randomized complete block design, in three replications. The
treatments included four nitrogen rates (0, 60, 120, and 180 kg N ha1) as the
main plot and two lettuce cultivars (‘Pich Ahwazi’ and ‘Pich
Varamini’) as the sub-plot. Sampling was done in 86, 100, 114, 126,
142, and
156 days after sowing. The criteria measured were plant length,
fresh and dry weights of leaves, leaf area, number of leaves, crop
growth
rate (CGR), leaf area index (LAI) and yield. Results indicated that
different levels of nitrogen fertilizer on all growth characteristics
were
significant at P<0.01. Nitrogen fertilizer caused head formation to
accelerate and delayed the bolting date of lettuce. Cultivar had a
significant effect on growth characteristics, on fresh and dry weights
of leaves and on leaf number but not on plant length and leaf area.
The highest yield was obtained with 120 kg ha-1 treatment by ‘Pich
Ahwazi’. Also, it took ‘Pich Varamini’ longer to form a head and to
flower than ‘Pich Ahwazi’.
Diunduh dari:
Effects of Photoperiod, Nitrogen Nutrition and Temperature on
Inflorescence Initiation and Development in Onion (Allium cepa L.)
J. L. BREWSTER
Ann Bot (1983) 51 (4): 429-440.
The effects of photoperiod, nitrogen nutrition and temperature on
inflorescence initiation and development in onion cv. Rijnsburger
and cv. Senshyu Semi-globe Yellow were studied in controlled
environments.
Rates of inflorescence initiation were estimated using the data for
leaf numbers formed prior to flower formation and the rates of leaf
initiation. At 9 °C inflorescence initiation was accelerated by long
photoperiods particularly for cv. Rijnsburger where the average time
for initiation was 86 days in 8 h and 38 days in 20 h photoperiods.
Initiation was as rapid at 12 °C as at 9 °C but was slower at 6 °C.
A reduction in the nitrate concentration in the nutrient solution from
0.012 to 0.0018 M greatly accelerated inflorescence initiation
particularly in photoperiods and temperatures not conducive to
rapid initiation. Cv. Senshyu initiated more slowly than cv.
Rijnsburger and was less sensitive to photoperiod and nitrogen level.
The development rate of inflorescences after initiation was
accelerated by long photoperiods and increases in temperature from
6 to 12 °C but was retarded by the lower nitrogen level.
Diunduh dari: . http://aob.oxfordjournals.org/content/51/4/429.short.
. ISHS Acta Horticulturae 852: IV International Symposium on
Ecologically Sound Fertilization Strategies for Field Vegetable
Production IDENTIFICATION OF CROP ROTATIONS INCLUDING
NITROGEN CATCH CROPS WHICH CAN DECREASE NITROGEN LOSSES IN
GERMAN FIELD VEGETABLE PRODUCTION SYSTEMS
Authors: L. Nett, C. Feller, M. Fink
Nitrogen (N) use efficiency in field vegetable production systems has
to be increased in order to avoid negative environmental impacts,
meet legal regulations and guarantee the farmers’ competitiveness.
The use of catch crops has been shown to have a great potential in
reducing N losses by retaining N in the plant-soil system. However,
the effects of catch crops on the N nutrition of the succeeding crop
vary from positive to negative and numerous possible combinations
exist of different crop rotations, management practices and soil and
weather conditions.
To find appropriate crop rotations for every individual location by
means of field trials is too time-consuming, laborious and costly. A
modelling approach was therefore adopted using the DAISY model
which was validated with data from a field experiment. The results
of the crop rotation experiment in the field (main crop–catch crop–
successive crop) indicated that N recovery at harvest of the
successive crop in aboveground plant biomass and soil mineral N
(Nmin) ranged between 42% and 84% of the N input at harvest of the
main crop in crop residues and Nmin. As compared to fallow, the
catch crop had a small positive effect on N recovery (64% vs. 49%) in
one out of four cases and negative effects in all other cases. The
agreement between simulated and measured plant dry masses was
good with an R2 (linear regression) for all dry mass data pooled of
0.83 (n=48) whereas there were still systematic deviations for Nmin
and plant N uptake.
Diunduh dari: http://www.actahort.org/books/852/852_29.htm..
. CURRENT MANAGEMENT PRACTICES FOR WHEAT PRODUCTION IN A
RAINFED AGRO-ECOLOGICAL ZONE IN NORTHERN PUNJAB
Abdur Razzaq, M. Munir, N.I. Hashmi*, P.R. Hobbs ** and A. Majid
Pakistan Journal of Agricultural Research, Vol, 17 No. 3
This study is based on the surveys undertaken during wheat harvest
in the rainfed areas of Rawalpindi District of northern Punjab. Wheat
yields were estimated by crop cut and data regarding management
practices adopted by farmers for wheat in the same plots was
collected. Eighty nine percent of the sample farmers were owner
operators, only 11% tenants.
Land type was classified as lepara land, near the homestead which
receives farm yard manure and mera land further from the village.
The most common cropping system is called Dosala where wheat
and kharlf crops are grown in one year followed by the same land
remaining fallow for the next whole year.
On lepara land, double cropping every year was practiced on 46% of
the sample fields. The average number of ploughings was 8.2 and
varied from 1 to 20.
There was a significant increase in the use of tractor ploughing in the
4 years of study from 35% to 70%. The average harvest date varied
from April 15 to May V depending on temperature which was
influenced by rainfall. Planting by drill on contract has risen from
20% in 1983 to 59% in 1986 replacing the pora method. About 7% of
the farmer prefer the high quality variety C-591. Lyp-73 was the
most popular variety but this is being replaced with the new variety
Pak-81. Pak-81 increased from 26% to 55% during the study period
at the expense of Lyp73. The average yield of wheat was 1.98 t/ha.
Diunduh dari: http://www.parc.gov.pk/Pjar/Journal-17-3.html..
Producing Nitrate-free Endive Heads: Effect of Nitrogen Form on
Growth, Yield, and Ion Composition of Endive
Pietro Santamaria
Antonio Elia
JASHS January 1997 vol. 122 no. 1 140-145
In a growth chamber, endive (Cichorium endivia L. var. crispum Hegi) plants were
grown using a solution culture method to evaluate the influence of four
ammonium : nitrate (NH4-N : NO3-N) percentage ratios (100:0, 70:30, 30:70, and
0:100) on growth (leaf area, dry mass, crop growth rate, relative growth rate, and
net assimilation rate), yield characteristics (head and root fresh mass and root
length), quality (dry matter, nitrogen, and nitrate), and inorganic ion content.
No symptoms of NH4+ toxicity were detected in endive plants 8 weeks after
beginning nutrient treatments. Moreover, by feeding N in mixed form, the growth
indices increased compared to indices from feeding with any of the two N forms
alone. Ammonium-fed plants produced nitrate-free heads with a fresh mass (171
g) similar to nitrate-fed plants. Compared to the other treatments, the heads of
NH4+-fed plants were darker green and more succulent.
Mixed N improved yield but caused a remarkable accumulation of nitrate in
heads. Following an increase in NO3-N from 30% to 70% in the nutrient solution,
head fresh mass rose from 196 to 231 g and NO3- concentration more than
doubled (from 2.4 to 6.1 g·kg-1 fresh mass). With 100% of NO3-N, NO3concentration was 5.5 g·kg-1 fresh mass. With higher NO3-N percentages in the
nutrient solution, the difference in the concentration of inorganic cations and
anions increased, but K+ concentration was also high in ammonium-fed plants (on
average 77 g·kg-1 dry mass).
Head total N accumulation was increased by the presence of NH4+ in the nutrient
solution and decreased with 100% NO3-N. From the commercial viewpoint, the
produce obtained from 100% NH4-N was good, with the value-added factor of the
absence of nitrate.
This may be an extremely remarkable factor because of the commercial limits on
the allowable nitrate content in leafy vegetables already enforced by many
European countries and those the European Union is going to adopt in a directive.
Diunduh dari: ..
Yield response of African leafy vegetables to nitrogen,
phosphorus and potassium: The case of Brassica rapa L.
subsp. chinensis and Solanum retroflexum Dun.#
W van Averbeke*, KA Juma and TE Tshikalange
Water SA Vol. 33 No. 3 (Special Edition) 2007
In this study the growth and yield response of Solanum retroflexum
Dun. (nightshade) and Brassica rapa L. subsp. chinensis
(non-heading Chinese cabbage) to N, P and K availability in the soil
and the interaction effects of these three nutrients were
determined by means of pot experiments in a greenhouse.
S. retroflexum was most sensitive to the availability of nitrogen
in the soil. Sufficient nitrogen needed to be available to achieve
optimum growth but adding too much adversely affected
biomass production, suggesting a fairly narrow optimum range for
nitrogen availability.
The production of the crop was also
dependent on the adequate availability of phosphorus and
potassium but any adverse effects due to excess availability were
less distinct than for nitrogen. In the case of B. rapa subsp. chinensis,
an optimum availability range was identified for N and
K and a critical level of availability for P.
The decline in biomass production caused by adding N in excess of
the optimum was reversed by applying both P and K at rates that
were in excess of the respective optima.
Diunduh dari: http://www.ajol.info/index.php/wsa/article/viewFile/49116/35461 ..
EFFECTS OF NITROGEN FORMS ON THE GROWTH AND POLYAMINE
CONTENTS IN DEVELOPING SEEDS OF VEGETABLE SOYBEAN
Authors: Chen, Lei; Liu, Qian-Qian; Gai, Jun-Yi; Zhu, Yue-Lin; Yang, LiFei; Wang, Cong
Source: Journal of Plant Nutrition, Volume 34, Number 4, January 2011 ,
pp. 504-521(18)
A pot culture experiment of nitrogen forms [nitrate (NO-3):
ammonium (NH+4)] with four ratios (100:0, 75:25, 50:50, and 25:75)
in nutrient solutions was conducted to examine the effect of
nitrogen forms on the growth and polyamine contents of developing
seeds of vegetable soybean [Glycine max (L.) Merr. cv. 'Li-xiang 951'].
Results showed that the best plant growth vigor was observed in
[image omitted] (75%), and then in [image omitted] (50%). However,
the fresh and dry weight of biomass decreased when a high
concentration of either [image omitted] (100%) or [image omitted]
(75%) was the primary nitrogen source in the nutrient solution. The
numbers of flowers and pods in [image omitted] (75%) were
significantly decreased compared with other ammonium-nitrate
ratios in which the numbers of flowers and pods were not influenced
by nitrogen forms.
During the development of seeds, levels of free Put and Spd
decreased, and the decrease extents were more marked in 100:0
and 25:75 ([image omitted]:[image omitted]), but the change of free
Spm was opposite. Levels of conjugated and bound polyamines in all
nitrogen forms increased, but the increases in 75:25 and 50:50
([image omitted]:[image omitted]) were not so obvious as in 100:0
and 25:75 ([image omitted]:[image omitted]) treatments. The
possible roles of polyamines in the adaptive mechanism of vegetable
soybean seeds to different nitrogen forms were discussed.
Diunduh dari:
http://www.ingentaconnect.com/content/tandf/lpla/2011/00000034/00000004/art00003..
. ISHS Acta Horticulturae 247: Research and Development Conference
on Vegetables, the Market and the Producer
OPTIMIZING NITROGEN FERTILIZATION OF VEGETABLE CROPS BY DRIP
IRRIGATION
Authors: C.R. Gastaldi, B.G. Sutton
. Nitrogen nutrition requirements of lettuce seedlings in recirculating
solution culture were investigated.
The effects of different NH4-N/ NO3-N ratios on growth of the plants
were measured. A growth technique, in which additions of nitrogen
increase with time as a result of electrical conductivity and pH
titrations was tested.
The results obtained showed that a stable internal nutrient status
was achieved after 2 weeks. Linear regressions were found between
accumulated nitrogen addition and growth, accumulated nitrogen
addition and accumulated nitrogen uptake.
This information can be employed in establishing conditions for
efficient use of N fertilizer in drip irrigation.
Diunduh dari: http://www.actahort.org/members/showpdf?booknrarnr=247_40..
Effect of Planting Date and Nitrogen Fertilization Rates on No-till
Pumpkins
E. Ryan Harrelson, Greg D. Hoyt1, John L. Havlin, David W. Monks
HortScience June 2008 vol. 43 no. 3 857-861
. Vegetable growers in the Mountain region of North Carolina are faced with
increased land prices resulting from urbanization and reduced farm income from
low-commodity prices. Local consumer use of pumpkin (Cucurbita pepo) for jacko-lanterns and baking provides a fall market for growers to increase production
and profitability on-farm.
Most soils in these regions are highly erodible and susceptible to drought during
the growing season. Little information is available on cultural practices for no-till
pumpkin production in this region. Field studies were established to evaluate the
yield response of no-till pumpkin to planting date and nitrogen (N) fertilization.
Experiments were conducted at the Mountain (MRS), Upper Mountain (UMRS),
and the Mountain Horticultural Crops Research Stations (MHCRS) in Summer
2003 and 2004 using no-till cultural practices.
Three planting dates were established at 2-week intervals and 0, 40, 80, and 120
kg·ha−1 N treatments were applied at each planting date in a randomized
complete block design.
The 80 and 120 kg·ha−1 N fertilization rates produced greater yields and larger
fruit size than the 0 and 40 kg·ha−1 N rates. Pumpkins planted earliest produced
the greatest marketable and total yields for all N rates at all three locations. The
latest planting date (9 July) and highest N rate yielded more cull fruit compared
with marketable pumpkins with the earlier planting date at the Upper Mountain
Research Station. This location has a shorter growing season and cooler summer
temperatures than the two other locations. Although the third planting date was
late for pumpkin planting, higher N rate treatments at that timing produced
marketable yields comparable to earlier planting dates at the two warmer
summer locations (MRS and MHCRS).
In these experiments, the highest rate applied (120 kg·ha−1 N) maximized
pumpkin yield. This observation would indicate that higher yields might be
possible with even greater N rates.
Diunduh dari: http://hortsci.ashspublications.org/content/43/3/857.abstract..
Nutrient management
for organic vegetable production
http://compost.tamu.edu/dem
Average rates of N, P2O5 and K2O applied to
vegetable crops in the US
(lbs/acre)
Nitrogen
Phosphorus
Potassium
Why are these rates so high ?
http://www.ers.usda.gov/publications/sb969/sb969c.pdf
~ 16 elements have been identified as
essential for the growth of all plants
Soil
C OH
N K Ca Mg P S Cl Fe Mn Zn B Cu
Mo
air & watermacronutrients micronutrients
V
Co
Ni
Needed by
some
plants
Na
Si
Micronutrients are critical components of enzymes
Soil water contains nutrients
H20
H20
H20
K+
H20
Humus
---
Ca+2
Mg+2 H20
H+
-
H20
exchangeable
ions
H20
Clay
--
H20
H20
-
H20
Soil
H20 soup
Na+
K+
Ca+2
H20
H20
H20
H20
H20
H20
What’s in the soil soup ??
Cu+3
Ca+2
DOM
Ca+2
NO3-
+2
Mg
NO3
-
Ca+2
H2PO4-
Zn+2
DOM
K+
K+
NO3-
Ca+2
Mg+2Fe+3
Mg+2
NO3-
DOM
Ca+2
SO4-2
Adapted from Brady and Weil (2002)
Which forms of nutrients are available to
plants ?
solution
exchangeable
“active” OM
passive “OM”
weatherable minerals
Re-seasoning the soup
Modified from Havlin et al. (1999)
……
Crop yield
Deficiency
Symptoms
Nutrient availability
http://www.extension.umn.edu/distribution/horticulture/components/M1190fig1.htm
Understanding nutrient uptake
H20
Root exudates
activate soil
microbes
Transpirational
stream
H20
Root growth
Feed the soil vs. Feed the crop ?
Both strategies are important !
?
Healthy roots need available nutrients !
Unhealthy roots use nutrients inefficiently…
Chronic root
malfunction
Acute
root
disease
Nutrient availability varies with pH
Understanding aluminum toxicity
Toxic forms of Al are bioavailable at low pHs
Aluminum
toxicity is
minimal
above
pH 5.5
http://www2.ctahr.hawaii.edu/tpss/research_extension/rxsoil/alroot.gif
100%
Percentage of maximum cation exchange capacity
75%
50%
25%
Exchangeable
Al+3
0%
Brady and Weil (2002)
http://hubcap.clemson.edu/~blpprt/acid2-chart1.gif
. The effect of different rates of nitrogen fertilizer application on the
growth, yield and postharvest life of cauliflower.
Kodithuwakku, D. P.; Kirthisinghe, J. P.
Journal Tropical Agricultural Research 2009 Vol. 21 No. 1 pp. 110-114
A Field experiment was conducted to compare the effect of urea as a
fertilizer on growth, yield and post harvest life of cauliflower
(Brassica oleracea L). Four levels of urea were compared with the
recommendation of the Department of Agriculture (DOA), using a
Randomized Complete Block Design. Other cultural practices and
crop protection were done according to the recommendations of the
DOA.
The plant height at one week after transplanting and 50% flowering,
number of leaves at 50% flowering, total leaf area at time of
flowering, total number of days to flowering, and time period for
curd maturity were recorded in each treatment. The average
cauliflower curd yield in the field varied between 90-125 g/plant
(3.6-5.0 t/ha). The results revealed the possibility of increasing N
dosage up to 125% of the DOA recommendation for obtaining larger
curds and a higher curd yield.
Significant difference was not observed (p>0.05) among the
treatments in any of the curd quality parameters measured. Even
though no significant difference was observed among the post
harvest quality, curds of the 50% nitrogen fertilizer treatment stored
at room condition and in polythene bags could be kept 6 days & 9
days longer than other treatments, without decay.
Diunduh dari:
http://cabdirect.org/abstracts/20103110134.html;jsessionid=1D56339477B5629D5993784
EDDEDAE37?start=300..
Estimating Nitrogen Mineralization of Composted Poultry Manure,
Organic Fertilizers, and Green Manure Crops for Organic Sweet Corn
Production on a Sandy Soil Under Laboratory Conditions
Heidi J. Johnson, Jed B. Colquhoun, Alvin J. Bussan1 and Carrie A.M.
Laboski
HortTechnology February 2012 vol. 22 no. 1 37-43
Organic sweet corn (Zea mays) production is challenging for growers because of
the high nitrogen (N) requirements of sweet corn and the relatively low N content
of organic soil amendments.
Total N supplied and rate of mineralization throughout the growing season are
two important aspects in determining the optimal N management program.
Green manure (GrM) crops, composted manures, and commercially available
organic fertilizers are used to manage N in organic production systems. Using a
combination of these tactics can optimize N while minimizing cost.
In this study, we used combinations of composted poultry manure (CPM) and two
organic fertilizers (one high N and one with a balance of nutrients) with three
GrM crops [rye (Secale cereale), alfalfa (Medicago sativa), and pea (Pisum
sativum)] in a loamy sand soil for a 112-day laboratory incubation study. Total
plant available N (PAN) was quantified at six times throughout the 16 weeks to
determine total N mineralized and rate of N release from each of the
management programs.
The CPM and the high N organic fertilizer mineralized completely within the first 6
weeks of the study, while only 65% of the other organic fertilizer mineralized by
the end of the study. Total N mineralized from pea grown as a GrM for 48 days
was comparable to the amount of N mineralized from rye suggesting that pea as a
GrM crop should not receive an N credit in field production on a sandy soil.
Significant quantities of PAN were mineralized from alfalfa residue, the equivalent
of 80 lb/acre, although this is not sufficient for sweet corn production.
The combination of alfalfa and the high N organic fertilizer provided sufficient N
for sweet corn production and the mineralization rate closely matched sweet corn
need. The release of N from CPM, even in combination with GrM crops, was
asynchronous with sweet corn crop need.
Diunduh dari: ..
Can Cover Crop-based Systems Reduce Vegetable Crop Fertilizer
Nitrogen Requirements in the Southeastern United States?
Laura Avila1,
Johannes Scholberg2,
Lincoln Zotarelli2 and
Robert McSorely3
HortScience July 2006 vol. 41 no. 4 981
Poor water- and nutrient-holding capacity of sandy soils, combined with intense
leaching rainfall events, may result in excessive N-fertilizers losses from vegetable
production systems.
Three cover cropping (CC) systems were used to assess supplemental N-fertilizer
requirements for optimal yields of selected vegetable crops. Fertilizer N-rates
were 0, 67, 133, 200, and 267; 0, 131, and 196; and 0, 84, 126,168, and 210 kg
N/h for sweet corn (Zea mays var. rugosa), broccoli (Brassica oleracea), and
watermelon (Citrullus lanatus), respectively. Crop rotations consisted of sunn
hemp (Crotalaria juncea) in Fall 2003 followed by hairy vetch (Vicia villosa), and
rye (Secale cereale) intercrop or a fallow. During Spring 2004, all plots were
planted with sweet corn, followed by either cowpea (Vigna unguiculata) or pearl
millet (Pennisetum glaucum), which preceded a winter broccoli crop. Hairy vetch
and rye mix benefited from residual N from a previous SH crop. This cropping
system provided a 5.4 Mg/ha yield increment for sweet corn receiving 67 kg N/ha
compared to the conventional system. For the 133 N-rate, CC-based systems
produced similar yields compared to conventional systems amended with 200 kg
N/ha. Pearl millet accumulated 8.8 Mg/ha—but only 69 kg N/ha—and potential
yields with this system were 16% lower compared to cowpea system.
For a subsequent watermelon crop, trends were reversed, possibly due to a delay
in mineralization for pearl millet. Because of its persistent growth after mowing,
hairy vetch hampered initial growth and shading also delayed fruit development.
Although CC may accumulate up to 131 kg N/ha actual N benefits, N-fertilizer
benefits were only 67 kg N/ha, which may be related to a lack of synchronization
between N release and actual crop demand.
Diunduh dari: ..
Broadcast vs. Band Applications of Fertilizer for Vegetable Crops
Richard L. Parish,
Regina P. Bracy and
Hershel F. Morris Jr.,
HortScience July 1997 vol. 32 no. 4 599
A study was conducted to evaluate the effect of banding or
broadcasting fertilizer on yield and quality of turnip (Brassica rapa L.
Rapifera group), sweetcorn (Zea mays var. rugosa Bonaf), and
cabbage (Brassica oleracea L. Capitata group).
Preplant fertilizer was applied broadcast prior to bedding, broadcast
after bedding, or banded after bedding. Sidedress applications were
broadcast or banded on the beds.
Strong visual differences were noticed early in the season in the
spring turnip crop with the growth in the broadcast-then-bed
treatment appearing superior. The yield at first harvest and total
yield were lower for turnip growth with the bed-and-broadcast
treatments. No differences in yield of cabbage and sweetcorn
resulted from the treatments. Few differences in turnip stem to leaf
ratio were noted due to fertilizer treatment.
Few differences in yield due to sidedress method were noted with
any of the crops. Since broadcasting can be done with a faster, wider
applicator, growers could reduce costs by broadcasting fertilizer and
obtain yields that are at least equivalent to the yields from banding.
Diunduh dari: http://hortsci.ashspublications.org/content/32/4/599.4.abstract ..
Burns, Ian G., Hammond, John P. and White, Philip J. (2010)
Precision placement of fertiliser for optimising the early nutrition of
vegetable crops : a review of the implications for the yield and quality of
crops, and their nutrient use efficiency.
Acta Horticulturae, Vol.852 . ISSN 0567-7572
The research outlined in this paper highlights the importance of the
early nutrition of vegetable crops, and its long-term effects on their
subsequent growth and development.
Results are also presented to demonstrate how the nutrient supply
during the establishment stages of young seedlings and transplants
can be enhanced by targeting fertiliser to a zone close to their
developing roots. Three different precision fertiliser placement
techniques are compared for this purpose: starter, band or sideinjected fertiliser.
The use of each of these methods consistently produced the same
(or greater) yields at lower application rates than those from
conventional broadcast applications, increasing the apparent
recovery of N, P and K, and the overall efficiency of nutrient use,
while reducing the levels of residual nutrients in the soil. Starter
fertilisers also advanced the maturity of some crops, and enhanced
produce quality by increasing the proportions of the larger and/or
more desirable marketable grades.
The benefits of the different placement techniques are illustrated
with selected examples from research at Warwick HRI using different
vegetable crops, including lettuce, onion and carrot.
Diunduh dari: http://wrap.warwick.ac.uk/4442/ ..
Can Sunn Hemp Decrease Nitrogen Fertilizer Requirements of
Vegetable Crops in the Southeastern United States?
Laura Avila1, Johannes Scholberg2, Nancy Roe3 and Corey Cherr1
HortScience July 2006 vol. 41 no. 4 1005
Increased dependency of conventional agriculture on inorganic
fertilizers and fossil fuels may hamper long-term sustainability of
agricultural production. Sunn hemp (Crotalaria juncea) was tested
during summer in a Community Supported Agriculture vegetable crop
operation located in Southeast Florida, from 2003 to 2005. Farm system
components included sunn hemp (SH) vs. a conventional fallow during
summer, tomato (Lycopersicon esculentus) and pepper (Capsicum
annum) during winter and spring sweet corn (Zea mays). Tomato and
pepper were fertilized with 0, 67, 133, 200 kg N/ha (2003) vs. 0,100, 200
kg N/ha (2004/05). Sweet corn received 133 or 200 kg N ha (2003) vs.
100 kg N/ha (2004/05). Average SH biomass was 3.7 Mg/ha. In 2003
tomato yields following SH without supplemental N were similar to
fallow, with 200 kg N/ha. By the third year, tomato and pepper yields in
SH plots were 25% and 26% higher, respectively. Conventional pepper
amended with 200 kg N/ha had only 8% higher yields than treatments
amended with 100 kg N ha and CC.
Overall, sweet corn had low yields, but yields increased if the preceding
tomato/pepper crop received higher N rates. In 2003, sweet corn
fertilized with 200 kg N/ha following a SH-fall vegetable crop produced
17% higher marketable yields compared to the fallow treatment. During
2004 and 2005, sweet corn within the SH-non-fertilized tomato system
produced 29% higher yields compared to a similar conventional system.
Results show that, in this rotation, both fall vegetable crops and sweet
corn yield benefit from residual N fertilizer. Mineralization of SH may
thus not only benefit the immediately following crop, but its effects can
be seen later during the year.
Diunduh dari: http://hortsci.ashspublications.org/content/41/4/1005.4.abstract ..
COVER CROP AND NITROGEN FERTILIZER RATE INFLUENCES ON YIELDS
OF SEQUENTIALLY PLANTED VEGETABLES
Owusu A. Bandele, Marion Javius, Byron Belvitt and Oscar Udoh
HortScience June 1992 vol. 27 no. 6 570
Fall-planted cover crops of hairy vetch (Vicia villosa Roth), Austrian
winter pea (Pisum sativum subsp. arvense L. Poir), and crimson
clover (Trifolium incarnatum L.) were each followed by springplanted 'Sundance' summer squash [Cucurbita pepo var. melopepo
(L.) Alef.] and 'Dasher' cucumber (Cucumis sativus L.). Squash and
cucumber crops were followed by fall 'Florida Broadleaf mustard
green [Brassica juncea (L.) Czerniak] and 'Vates' collard (Brassica
oleracea L. Acephala group), respectively.
The same vegetable sequences were also planted without benefit of
cover crop. Three nitrogen (N) rates were applied to each vegetable
crop.
Squash following winter pea and crimson clover produced greater
yields than did squash planted without preceding cover crop.
Cucumber following crimson clover produced the greatest yields. No
cover crop effect was noted with mustard or collard. Elimination of N
fertilizer resulted in reduced yields for all crops, but yields of crops
with one-half the recommended N applied were generally
comparable to those receiving the full recommended rate.
Diunduh dari: http://hortsci.ashspublications.org/content/27/6/570.3.abstract..
Slow-release Nitrogen Fertilizers in Vegetable Production: A Review
E.A. Guertal1
HortTechnology January-March 2009 vol. 19 no. 1 16-19
Slow-release nitrogen (N) fertilizers offer many potential benefits for
vegetable production. In sandy soils, their use may lessen N
leaching. If the slow-release fertilizer has a release pattern that
matches crop needs, N uptake by the growing crop may become
more efficient. Additionally, if slow-release fertilizers can be applied
as a preplant application, production costs could be lessened,
eliminating the need for multiple applications of soluble N fertilizer.
Synthetic slow-release fertilizers can be separated into two general
groups: those that are slow release as a byproduct of a chemical
reaction (such as urea-formaldehyde), and those that are slow
release via a sulfur, wax, or resin coating around the fertilizer prill.
In vegetable crop research, much of the available literature has
focused on use of sulfur coat urea and urea-formaldehyde, as they
have been in the fertilizer market for 40 years. Newer research has
evaluated resin-coated products.
In most studies, use of slow-release N fertilizers as a preplant
treatment did not decrease crop yield, but yield was rarely increased
when compared with standard split applications of soluble N.
Based on available research, the benefits of using slow-release N
fertilizers in vegetable crop production will come from reduced
environmental risk and savings in production costs.
Diunduh dari: http://horttech.ashspublications.org/content/19/1/16.abstract..
Broadcast versus Band Fertilizer Applications on Vegetable Crops
R.L. Parish, R.P. Bracy, H.F. Morris Jr.
HortTechnology October-December 1997 vol. 7 no. 4 389-395
A study was conducted to evaluate the effect of banding or
broadcasting fertilizer on yield and quality of turnip (Brassica rapa L.
Rapifera group), sweetcorn (Zea mays var. rugosa Bonaf.), and
cabbage (Brassica oleracea L. Capitata group).
Preplant fertilizer was applied broadcast before bedding, broadcast
after bedding, or banded after bedding. Sidedress applications were
broadcast or banded on the beds. Differences in plant size and vigor
were noticed early in the season in the spring turnip crop, with the
growth in the broadcast-and-bed treatment appearing superior.
The yield at first harvest and total yield were lower for turnip grown
with the bed-and-broadcast treatment. No differences in yield of
cabbage or sweetcorn resulted from the treatments. Few differences
in turnip stem-to-leaf ratio were noted due to fertilizer treatment.
Few differences in yield due to sidedress method were noted with
any of the crops.
Analysis of soil samples in a grid pattern across the beds showed
that the location of the fertilizer after the broadcast-and-bed
treatment was similar to the placement of the banded fertilizer.
Since broadcasting can be done with a faster, wider applicator,
growers could reduce costs by broadcasting fertilizer and obtain
yields that are at least equivalent to the yields obtained by banding
the fertilizer.
Diunduh dari: http://horttech.ashspublications.org/content/7/4/389.abstract ..
…..best management practices ………..
…..foto:smno.kampus.ub.okt2012…...