Afghanistan Water, Agriculture, and Technology
Transfer (AWATT) Program
Fact Sheet: Forage Cowpea
Dr. Hamdy Oushy
Associate Professor
College of Agricultural, Consumer, and Environmental Sciences
New Mexico State University
Forage and Rangeland Management Specialist, USAID-NMSU/ AWATT
E-Mail: [email protected]
Cell: + (93) 0788-043-397
AWATT Forage Cowpea Fact Sheet
Afghanistan Water, Agriculture and Technology Transfer Program i
Authority Prepared for USAID/Afghanistan under Cooperative Agreement No. 306-A-00-08-00506
awarded 03 March 2008, entitled Afghanistan Water, Agriculture and Technology Transfer
(AWATT).
This document was completed in partial fulfillment of Clause 2a of the Award Document for
Cooperative Agreement No. 306-A-00-08-00506 awarded 03 March 2008, entitled Afghanistan
Water, Agriculture and Technology Transfer (AWATT). The views expressed and opinions
contained in this report are those of the NMSU AWATT team and are not intended as
statements of policy of USAID.
Prepared by:
NMSU-AWATT Team with CSU, UIUC, and SIUC
Credits The program referred to in this document is based on the NMSU-AWATT Technical Proposal, as
revised, submitted February 4, 2008 in response to USAID Request for Application No. 306-07-02
Disclaimer The opinions expressed in this document are those of the author and are not intended as statements of
policy of USAID or the United States Government.
AWATT Forage Cowpea Fact Sheet
Afghanistan Water, Agriculture and Technology Transfer Program ii
TABLE OF CONTENTS
Abbreviations and Terms ............................................................................................................................... iii
Forage Cowpea ................................................................................................................................................. 1
Introduction .............................................................................................................................................. 1
Soil Requirements ..................................................................................................................................... 1
Varieties .................................................................................................................................................... 1
Sowing ....................................................................................................................................................... 1
Sowing methods ........................................................................................................................................................ 1
Sowing rate ................................................................................................................................................................ 2
Sowing time ................................................................................................................................................................ 2
Nitrogen Fixation ...................................................................................................................................... 2
Fertilizer .................................................................................................................................................... 2
Irrigation Management ............................................................................................................................. 3
Cutting Management ................................................................................................................................ 3
Forage Production ..................................................................................................................................... 3
Seed Production ........................................................................................................................................ 4
Forage Mixture .......................................................................................................................................... 7
Position of Forage Cowpea in Crop Rotation ............................................................................................ 7
Forage Quality ........................................................................................................................................... 7
Crud Protein ............................................................................................................................................................... 7
Digestibility ................................................................................................................................................................. 7
Forage Preservation .................................................................................................................................. 7
Hay ............................................................................................................................................................................... 7
Silage............................................................................................................................................................................ 8
Acknowledgements ....................................................................................................................................... 11
AWATT Forage Cowpea Fact Sheet
Afghanistan Water, Agriculture and Technology Transfer Program iii
ABBREVIATIONS AND TERMS
AWATT Afghanistan Water, Agriculture and Technology Transfer
Canal In this and all AWATT documents, the word “canal” refers to either a
secondary or tertiary canal. 1
CSU Colorado State University
jerib Unit of land area approx. 0.2 hectare
karez Usually unlined sloping tunnels in the hills that access aquifers
MAIL Ministry of Agriculture, Irrigation and Livestock
MEW Ministry of Energy and Water
NMSU New Mexico State University
NVDA Nangarhar Valley Development Authority
SIUC Southern Illinois University Carbondale
UIUC University of Illinois at Urbana-Champaign
US United States
USAID United States Agency for International Development
USDA United States Department of Agriculture
1 This distinction is important because the new Afghan Water Law passed last year (2010) gives responsibility for
primary canals (diverted directly from the rivers) to the Ministry of Energy and Water (MEW), and for secondary canals (diverted from the primary canals to villages) and tertiary canals (diverted from the secondary canals for distribution to the farms) to be the responsibility of MAIL, specifically the newly established MAIL Department of Irrigation (DI). Similarly, the term “watercourse” is used interchangeably with the word “canal” in AWATT documents.
AWATT Forage Cowpea Fact Sheet
Afghanistan Water, Agriculture and Technology Transfer (AWATT) Forage Program 1
FORAGE COWPEA
Common Name: Forage Cowpea Scientific Name: Vigna unguiculata
Local Name: لوبيا علفي
INTRODUCTION
Cowpea (Vigna unguiculata) is a leguminous forage crop. Cowpea (Vigna unguiculata) is a forage
legume, which can be grown in relatively infertile sandy soils with a minimum annual rainfall of
200mm. It is a fast growing, drought resistant crop, which also improves soil fertility by fixing
atmospheric nitrogen. Cowpea forage is usually superior to other forage legumes in terms of
both quantity and quality. Cowpea crop is grown as a green manure and also a cover crop to
increase soil fertility, retain moisture and reduce soil erosion (Koralagama, K. D. N. et al. 2002).
It is suitable for Afghanistan summer environmental conditions. Cowpea performed very well in
Kabul, Herat, and Balkh Provinces in the summer of 2010. It is a fast growing, annual, summer
forage legume. It is an excellent quality crop for fattening both sheep and cattle, and is also
regarded as good feed for milking cows. In a crop rotation program, cowpea can significantly
improve soil nitrogen levels by nitrogen fixation or by incorporation in the soil as a green
manure crop. Cowpea also offers an alternative for grain production. In addition, cowpea is
tolerant to drought and heat.
SOIL REQUIREMENTS
Cowpea does very well in a wide variety of soils from light, sandy soils to well-drained, heavier-
textured soils. Cowpea requires well-drained soils.
VARIETIES
The Cowpea Cream-1 variety, which originated in Egypt, is the main forage summer legume
variety grown, especially in Egypt, and was recently introduced in Afghanistan by Dr. Hamdy
Oushy, AWATT Forage and Rangeland Management Specialist, in May 2010. The first forage
demonstration and seed production sites for cowpea were established at MAIL-Badam Bagh
Agricultural Research Station in Kabul in June 2010 through a collaboration forage program
between the AWATT and ASAP projects.
SOWING
Sowing methods
Cowpea is best sown into a well-prepared and leveled seedbed that has a good depth of
subsoil. The seed should be sown at a depth of 3 to 4 cm into soil. Two sowing methods could
be used: 1) Sowing into plot on 35 cm row spacing with 25 cm plant spacing; 2) sowing into
furrows on 75 cm furrow with spacing of 20 cm between plants.
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Sowing rate
Sow cowpea at 10 kg per jerib on plots and 12 kg per jerib on furrows of good quality seed
under irrigation conditions.
Furrows suitable to sow forage cowpea at Dehdadi Agricultural Research Station, Balkh Province in June 2009
(Oushy, 2009); Cowpea, Cream-1 variety, planted on furrows at MAIL-Badam Bagh Agricultural Research Station
in Kabul, in July 2010 (Oushy, 2010).
Sowing time
Cowpea can be sown during the spring and summer seasons. In most Afghan provinces, cowpea
can be sown for forage from April to May. The earlier sowings usually produce the most feed
and the highest number of cuts.
NITROGEN FIXATION
The forage legume cowpea nodulate readily when naturally or artificially inoculated with the
correct strain of rhizobia. The production of nodules depends on the efficiency of inoculation,
soil moisture, soil temperature and soil acidity. Nodulation appears to improve with good soil
moisture and lower soil temperatures. Poor nodulation sometimes occurs with increasing soil
temperature and low soil moisture. When well-nodulated; cowpea can fix around 4 to 28 kg
residual nitrogen per jerib in the soil. Such levels of nitrogen fixation represent the equivalent of
around 10–60 kg urea fertilizer per jerib. The amount of soil nitrogen fixed varies widely, but
the effect on the following cereal crops is usually dramatic.
FERTILIZER
Location, soil type and history of fertilizer application will determine fertilizer needs. It is
preferable to add organic manure to the poor and sandy soil in organic matter. Phosphorus is
the main nutritional requirement and should be applied at soil preparation. Soils with low to
medium levels of phosphorus require 25 to 30 kg Di-Ammonium Phosphate (DAP) per Jerib.
After two weeks from germination, 20 kg of Urea should be applied per Jerib.
AWATT Forage Cowpea Fact Sheet
Afghanistan Water, Agriculture and Technology Transfer (AWATT) Forage Program 3
IRRIGATION MANAGEMENT
Cowpea plants should be irrigated according to the irrigation sequences. In addition, it requires
9-12 irrigations according to the soil type, soil and air temperatures. Lack of water irrigation
will negatively affect the fresh forage and seed yield.
Flexi Flume irrigation system was used to irrigate forage cowpea, Cream-1 variety from Egypt, at MAIL-Badam
Bagh Agricultural Research Station in July 2010 (Oushy, 2010).
CUTTING MANAGEMENT
Cowpea produces up to three cuts per season. Cutting should be started when plants reach 60
cm heights. The first cut should be implemented after 60-65 days from plantation; then, the
second cut after 45-55 days from the first cut; followed by the third cut after 50 days from the
second cut.
FORAGE PRODUCTION
Cowpea can produce a good yield of high quality dry matter. Forage yield ranges between 5 – 7
tons per jerib in the first cut. Then, it declines to 4 tons per jerib in the second and the third
cuts. In general, the leaf and leaf stalk portion should be considered in determining the feed
availability of the crop.
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Forage cowpea field and cowpea plant of Cream-1 variety from Egypt at MAIL-Badam Bagh Agricultural
Research Station, Kabul in July 2010 (Oushy, 2010).
SEED PRODUCTION
In case of seed production, cowpea plants should not be cut for forage at all. In addition, it
should be sown in furrows with good irrigation to assure high seed yield.
Cowpea seed production field of Cream-1 variety from Egypt; cowpea pods are in the maturity stage at MAIL-
Badam Bagh Agricultural Research Station, Kabul in October 2010 (Oushy, 2010).
The seed pods will become dry 4-5 months from plantation. Seed yield ranges between 400 –
500 kg per jerib according to the variety and the production conditions. Harvesting cowpea is
carried out on two picks. The first pick will take place when 70 - 80% of the pods are matured
and dried.
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Afghanistan Water, Agriculture and Technology Transfer (AWATT) Forage Program 5
Cowpea seeds were harvested by trained workers in plastic baskets and transferred from the field to the
collective site at MAIL-Badam Bagh Agricultural Research Station, Kabul in October 2010 (Oushy, 2010).
Training extension workers and farmers how and when to harvest the cowpea pods is essential
to ensure high quantity and quality cowpea seed production. At the MAIL-Badam Bagh
Agricultural Research Station, AWATT and ASAP programs have initiated a collaborative
training program for MAIL extension workers, farmers, faculty members, teachers and students
in cowpea seed and forage production.
Trained workers harvested the forage cowpea pods and transferred to the collective seed site at MAIL-Badam
Bagh Agricultural Research Station, Kabul in October 2010 (Oushy, 2010).
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Forage cowpea seeds produced at MAIL-Badam Bagh Agricultural Research Station in 2010 (Oushy, 2010).
It is important to know the right time to harvest the first pick of cowpea pods. Sometimes, if
you’ve missed the right time to pick them up, the pods will start shattering and the seeds will
fall down to the soil and be wasted. Therefore, the training of farmers and cowpea seed
producers is very important to produce high seed yield and high quality seeds of forage cowpea.
Training extension workers and farmers how and when to harvest the cowpea pods at MAIL-Badam Bagh
Agricultural Research Station, Kabul in October 2010 (Oushy, 2010).
Harvesting cowpea pods should be scheduled based on the maturity stage and the availability of
labor. Therefore, we recommend that cowpea growers and seed producers should plan ahead
of time for harvesting their seeds.
The cowpea seed harvesting is carried out through the following steps:
80% of the cowpea pods should be matured and dried;
Soil should not be wet and dry enough for laborers to work on it;
The first pick should be started and collected into containers;
Cowpea pods should be transferred to collective, clean and dry place;
When harvesting is completed, cowpea pods will be threshed and stored in plastic bags.
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FORAGE MIXTURE
Intercropping forage legume on warm season grasses is very common practices. When sowing
cowpea with forage sudangrass or pearl millet, use three quarters of the recommended seeding
rate for cowpea with one half of the recommended rates for forage sudangrass or pearl millet.
This mixture makes excellent balanced fresh diet for animals; in addition, it makes excellent
silage and hay.
POSITION OF FORAGE COWPEA IN CROP ROTATION
Apart from its high value as a forage crop, this legume is included in crop rotations to build up
soil nitrogen as well as to break weed and disease cycles. This is particularly useful for building
up fertility in a country like Afghanistan that has been run down from over cropping of wheat-
rice. Cowpea can fix 4 to 28 kg residual nitrogen per jerib into the soil. This can give a
significant bonus to later cereal crops in the rotation. The legume cowpea crop should be
rotated with a grass crop (i.e. wheat in winter) to minimize disease buildup and take advantage
of increased soil nitrogen.
FORAGE QUALITY
Cowpea provides high quality forage suitable for growing and fattening livestock, as well as
feeding lactating dairy cows.
Crud Protein
This legume generally produces forage very high in crude protein, low in fiber, high in
digestibility and high in metabolizable energy. Crude protein levels of leaves and shoots are
usually over 20 percent, depending on the crop's stage of growth and seasonal conditions.
Stems contain only about 10 percent crude protein. Crude protein levels can be equal to that
of alfalfa and greatly superior to most tropical grasses and forage sudangrass and pearl millet.
Digestibility
The digestibility of cowpea is about 50 to 56 percent on a whole-plant basis, and appears to
vary little with the crop's age or with changes in environment. The leaf is much more digestible
than the stem. Leaf parts have 60 to 75 percent digestible dry matter (DDM %) while stems
have been analyzed as 50 to 55 DDM %. Animal intake declines as leaf availability declines. This
highlights the importance of the leaf component for yield, quality and animal production.
FORAGE PRESERVATION
Hay
Cowpea makes excellent quality hay that compares favorably with alfalfa hay. A balanced hay
diet could be produced from mixed cowpea with pearl millet or with Sudan grass.
AWATT Forage Cowpea Fact Sheet
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Silage
Cowpea can produce good quality silage, particularly when mixed with forage sudangrass or
pearl millet. Like all legumes, this crop has a very low soluble sugar level which can prevent
good fermentation and production of silage. To produce good quality silage from pure crop of
cowpea, it is necessary to cut and wilt the crop to 30 to 35 percent DM before harvesting for
ensiling. Cutting and wilting 18 to 24 hours before ensiling will allow the concentration of
soluble sugars in the plants to increase and therefore ensure satisfactory fermentation of silage.
Forage cowpea plants after harvesting the pods, is suitable to produce high quality silage and hay at MAIL-
Badam Bagh Agricultural Research Station in Kabul, in October 2010 (Oushy, 2010).
Excellent silage can be made by sowing cowpea with forage sudangrass or pearl millet. These
mixtures will also need to be wilted before ensiling. When sowing cowpea with forage
sudangrass or pearl millet, sow three quarters of the recommended seeding rate for cowpeas
or lablab with one half of the recommended rates for forage sudangrass or pearl millet. This
mixture also makes excellent hay. For good quality hay, cowpea is best cut around mid-
flowering.
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CONCLUSION
Forage Cowpea is a summer forage legume. It is very palatable forage producing high yields with
outstanding crude protein content. It provides a good alternative crop for hay, silage, or
pasture. It makes an excellent annual pasture legume.
It is a forage legume, which can be grown in relatively infertile sandy soils with a minimum annual rainfall of 200mm. It is a fast growing, drought resistant crop, which also improves soil
fertility by fixing atmospheric nitrogen. Cowpea forage is usually superior to other forage
legumes in terms of both quantity and quality. Cowpea crop is grown as a green manure and
also a cover crop to increase soil fertility, retain moisture and reduce soil erosion. Forage
Cowpea tends to be more productive on sandy and infertile soils than other annual forages, but still
performs best on fertile, moist soils. Cowpea, Kareem-1 variety from Egypt, proves high yielding performance and high adaptability under Afghanistan farming system and environmental conditions.
It always be mixed with pearl millet or Sudan grass to produce high quality balanced diet for
livestock in which enhance livestock production substantially without requiring additional inputs
from resource-poor livestock farmers.
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REFERENCES
Koralagama, K. D. N. et al. 2002. Cowpea (Vigna unguiculata) as a human food and ruminant
forage crop for small holders in Ethiopia. www.smallstock.info/reference/BSAS/078.pdf.
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ACKNOWLEDGEMENTS
I would like to acknowledge the contributions, collaboration and support of the following
groups and individuals to the development of my cowpea forage and seed production at MAIL-
Badam Bagh Agricultural Research Station fact sheet: USAID/Afghanistan, MAIL, Afghanistan,
Water and Agricultural Technology Transfer (AWATT) and Accelerating Sustainable
Agriculture Program (ASAP).
I would like also to acknowledge the contributions of Mr. Don Dwyer, DCOP ASAP, who
helped me with his team to establish the cowpea seed and forage production program at MAIL-
Badam Bagh Agricultural Research Station.
This collaborative forage field work has been carried out through an MOU between AWATT
and ASAP program on forage technology transfer at MAIL-Badam Bagh Agricultural Research
Station in Kabul, Afghanistan through the period from May to February 2011.
I would also like to acknowledge the support of the contribution of the MAIL researchers and
extension workers, faculty members of different universities in Afghanistan who participated in
team efforts to implement the forage Cowpea program in Herat, Balkh and Kabul Provinces
through 2010. These efforts enabled me to produce this fact sheet for forage Cowpea for the
good of the Afghan extension workers, researchers, farmers and livestock production in
Afghanistan.
- Hamdy Oushy