**Abstract**

Cowpea is the common legume crop plant widely cultivated in all over the world for human consumption and animal feed. The global biological name of cowpea is *Vigna unguiculta* (L.) Walp. The crop is cultivated globally in all warm-seasons, semiarid or specifically tropical regions by even poor farmers but originated from anciently to Africa. Cowpea able to grow in even variety of polluted soils and able to grow vigorously withstand in both biotic and abiotic stress conditions. Morphologically herbaceous dicotyledonous plant, grow annually. The entire plant parts of *Vigna unguiculata* (L) Walp such as dry seeds, leaves, roots and pods consumed by all humans and animals Cowpea has rich in nutrition, vitamins and minerals so preferred by many farmers cultivated as intercrop with other cereals. In this review able to discuss the nutritional, medicinal as well as ecological significance. The seeds of cowpea have high content of proteins, fiber foods like carbohydrates, low cholesterol, minerals and vitamins. The nutrient value is higher and delay hungry sense in cowpea when compare to other cereals or pulses. The cowpea used for various medical aspects to lower cholesterol, promote body growth, iron source to increase blood cells, improve gall bladder function, maintain good circulatory system, increase insulin production, decrease body weight and do excellent antioxidant mechanism. The black eye pea also maintains good health to reduce both communicable and non-communicable diseases. Cowpea to form symbioses with variety of beneficial soil microorganisms to increase soil fertility, soil-root aeration, improve humidity and do fix atmospheric nitrogen to reduce global warming, climate change and also increase activity of biogeochemical cycle in the environment. In future people focus on to cultivate cowpea with to increase global production in all countries.

**Keywords:** legume, tropical, biotic & abiotic, intercrop, nutrition, Fiber food, Symbiosis and biogeochemical cycle

## **1. Introduction**

Legumes are third largest family of flowering plants which consist of over 20,000 species, under the family of Fabaceae, amoung them *Vigna unguiculata* (L.) Walp is an annual, herbaceous, commonly cultivated throughout the landscape of the earth, with high values in its nutrients, medicinal value and also helps in ecological balances. This crop is cultivated worldwide. The cultivar group such as *Sesquipedal* is wildly known as long or sneak or asparagus bean with have sixteen ovules present and the seeds arranged within the pod compactly and it is suggested as a sub species in Ref. with molecular level [1].

It is an important crop in the semiarid regions across India, Africa and Russia, naturally it is the farmers friendly crop due to crop survival, yield, resistance towards pest, tolerance in sandy soil, low rainfall, whole plant is used as cattle feed and also well-suited to intercropping with other crops as the plant fixes nitrogen with *Agrobacterium*.

There are many species can exist but the common sub-species are includes as *V. unguiculata, Viola biflora, V. textilis and V. Sesquipedalis* are recognized. Among the subspecies, the *V. unguiculata, V. biflora* and *V. textilis* are cultivated worldwide. The bean plants have more morphological difference and found in same species with high differences in the shape, structure and size, shape, and structure. Cowpeas are growing by in semi-erect, erect and climbing manner.

The bean crop is cultivated for the purpose of cattle feed and its seeds have high nutrient values, in terms of rich protein, carbohydrates, vitamins and minerals. The cow pea plant green stems and leaves and seed coats are high nutrients, so consider as cattle feed which increase cattle milk production for many application for in the dairy industry. Many varieties cowpeas were traditionally cultivated in some states India, but in Africa consider as primary cultivar. The countries such as United States of America, United Kingdom, Europe and some parts of Asia.

The cowpea was emerging crop for food and Nigeria considered as largest production country approximately 3.67 million tons and the second largest cultivar Niger global production of cowpea are approximately 2.6 million tons and other countries cowpea production is approximately 2 million tons in 2020. The production of cowpea is marginally reduced in globally approximately 8.2 million tons in 2020. Cow pea seeds are usually cooked and made into stews and curries, or ground into flour or paste.

Most cowpeas are grown on the African continent, particularly in Nigeria and Niger and also in India which account for 66% of world production. Recently the estimate suggests that cowpeas are cultivated on 12.5 million hectares of land. The cowpea has been cultivated in tons of three million and two hundred million humans consume in everyday. The large number of production of cowpea in many places should drastically reduction by the involvement of many pests and insects, particularly causing over ninety percentage loss in crop yield.

