Farmers in the Nigerian state of Sokoto are increasingly growing cowpeas for animal feed, not just for human food, and it offers diversity in arid regions where food supplies are uncertain.
In Sokoto in the northwest of the West African state, the leaves and stems of the cowpea have been a popular livestock feed for a long time. Known locally as harawa, this material is sufficiently valuable in terms of its nutritional content for animals that cowpeas have been grown for this purpose alone, according to Daily Trust.
Cowpea growers employ local people — often women and youngsters — to harvest the plants, paying them in cash or with a share of crop. The workers separate the seeds, and the harawa stems and leaves are bundled together and dried for later use or sale when other forage sources are unavailable.
Another cowpea product used by livestock farmers is the chaff, which is left when the cowpea seeds are separated from the pods.
Actually a member of the bean family, the cowpea (Vigna unguiculata) is a food and animal feed crop widely grown in semi-arid tropical areas of the world.
It is thought to have originated and been first domesticated in southern Africa, and later moved to East and West Africa, and to Asia, according to the International Institute for Tropical Agriculture (IITA).
The plant’s high protein content — around 25 percent — and ability to tolerate a wide variety of soils, drought and even shade have led to the wide popularity of the cowpea. Furthermore, as a legume, its roots contribute to soil fertility, and its rapid growth helps reduce soil erosion.
More than 5.4 million metric tons of dried cowpeas are produced worldwide, according to IITA, mostly in Africa. Just over half is consumed as food — as young leaves, immature pods and seeds, and mature seeds — and 30 percent as animal feed.
Since 2015, IITA and other institutions in West Africa have been collaborating with Monsanto to improve cowpea breeding programs.
This work had led to the development of higher-yielding varieties of cowpea that have been released to 68 countries, according to a recent report in Open Access Government.
As head of the IITA Genebank, Michael Abberton stressed the importance of this genetic diversity in important food and feed crops such as cowpeas to enable plants to adapt to new pests and diseases and climate change. IITA holds 17,000 types of cowpeas in its Genebank.
Cowpeas are particularly valuable in West Africa because they grow well during the “hungry season” (June to October), when other crops are not producing. The seeds are a very important source of protein for human consumption, according to Abberton.
In the U.S., cowpea was recently recommended as suitable for inclusion in a complex cover crop seed mix by the Sustainable Farming Association of Minnesota. Such a mix can help prolong the grazing period for pastured livestock in areas of low rainfall or at high risk of drought where grass alone does not thrive.