Evaluation of the Effects of Sole and Combined Applications of Organic Amendments on Soil Chemical Properties and Soybean Production in Southeastern Nigeria.

Abstract

In sustainable agricultural systems, recycling of nutrients is a major component of nutrient management. A pot experiment was carried out to study the effects of sole and combined applications of pig manure and cow dung at the rates of 0, 5, 10 and 15t/hafor sole application and 1t/ha + 1t/ha, 2.5t/ha +2.5t/ha, 5t/ha+ 5t/ha and 7.5t/ha +7.5t/hafor combined application on soil chemical properties and soybean performance in Owerri West, Imo State, Nigeria. The treatments were fitted in a complete randomized design (CRD) with each rate of application replicated three times. Results showed that combined application irrespective of rates, improved the soil chemical properties than the sole application. In sole application, cow dung at the rate of 5t/ha gave the highest significant (P < 0.05) plant height, leaf area, numbers of grains and pods. Over the sampling periods, 15t/ha of pig manure gave significant (p < 0.05) higher leaf area, number of leaves, grain and pod yields than other rates. In combined application, 5t/ha +5t/ha and 2.5t/ha+2.5t/ha of cow dung and pig manure gave superior growth rate and yield components compare to other rates with the control giving the least results. On the average, 2.5t/ha+2.5t/ha rate gave higher yield components and number of leaves compared to 15t/ha of pig manure and 5t/ha of cow dung that gave improved results in sole application. The study recommended 5t/haof cow dung and 15t/ha of pig manure for sole application, 5t/ha+5t/ha and 2.5t/ha+2.5t/ha for combined application.