Effect of organic amendments on the growth, yield and nutrient status of cowpea (Vigna unguiculata (L.) Walp.)

Indiscriminate use of inorganic fertilizer changes the physical, chemical and biological properties of soil as well as reduces soil fertility status. The decline in soil organic matter content is a major process of soil fertility reduction. Organic amendments can augment soil fertility. For this, a pot experiment was conducted to investigate the effects of various organic amendments (bagasse, bio-slurry, and kitchen waste compost) in comparison with chemical fertilizer on the growth, yield and nutrient status in the shoot and root of cowpea plant. Soil was treated with respective organic amendments at the rate of 5t/ha. Five cow pea seeds were sown in each pot. The experiment was laid down in a completely randomized design with three replications. Results indicated that all organic amendments influence the growth and yield attributes of cow pea plant. Fresh weight, dry weight and pod yield of the plant greatly enhanced by the application of bio slurry which accounted 2.5 times higher pod yield as compared to inorganic fertilizer. Root growth was improved with the application of bio slurry whereas kitchen compost had positive effects on root length, root diameter and root length density of cow pea plant. Nutrient (N, P and K) content and uptake in shoot of cow pea plant did not vary significantly with organic amendments except root. In addition, variable nutrient use efficiencies were recorded in shoot and root of the plant with the applied organic amendments. Sustainable agricultural production system requires improved soil health to increase crop production. Therefore, it is suggested to use these organic amendments with the attention given to the bio-slurry to achieve a long term sustainable agriculture system.