Effects of Rice-Bran Compost on Growth and Yield of Soybean (Glycine max) on an Alfisol in Ibadan, Nigeria.

Abstract

Farmers in the tropical environment face the acute problem of using mineral fertilizers due to their unsustainable attributes ranging from scarcity and high cost of the material to the adverse effects on tropical soil which resulted to soil acidity and pollution of underground water. This study evaluated the effects of rice-bran compost on the growth and yield of improved variety of soybean on an Alfisol, in Ibadan, Nigeria. The investigation involved a screen house experiment conducted at the Department of Agronomy, University of Ibadan. The experiment comprised five rates of compost (0, 2.5, 5.0, 7.5 and 10 t/ha) replicated four times with two pots per replicate in a Completely Randomized Design (CRD) using soybean (TGX 1740- 1F) variety with a total of 40 pots in all. The data collected were subjected to analysis of variance ANOVA and Duncan multiple range test was used to separate the means. The experimental results showed significant differences (p˂0.05) among the levels of compost on soybean; however, 10 t/ha gave the highest value on the number of leaves while 7.5 t/ha performed better in respect of plant height compared with the other treatments. Also, rice bran compost at 10 t/ha produced statistically highest root and grain yields followed closely by 7.5 t/ha. However, 10 t/ha of rice bran compost promoted shoot performance. Soybean yield increased with higher rates of rice-bran compost. Soybean growth and yield are improved with a compost of rice- bran and cattle dung up to 7.5 t/ha to supply 95 kg N, 169 kg P and 12 kg K.