Evaluation of Plant Populations of Velvet Bean (Mucuna cochinchinensis) for Soil Fertility Improvement in Yam (Dioscorea rotundata) Production at Makurdi, Southern Guinea Savanna, Nigeria
1Shave, P. A.; S. T. Wuese2 & 1Hiiorga, H. P.
1 Department of Crop and Environmental Protection, University of Agriculture, Makurdi
2Department of Soil Science, University of Agriculture, Makurdi, Makurdi
Corresponding author: S. T. Wuese2Email:kumedula@gmail
ABSTRACT
Field trials were conducted in 2013 and 2014 on a fallow field at the Teaching and Research Farm of the University of Agriculture, Makurdi (070411N, 080371E and 106m above mean sea level) using Velvet bean (Mucuna cochinchinensis) to improve soil fertility for yam production. Four Mucuna populations were used: 400 plants/ha, 800 plants/ha, 1600 plants/ha and 0 plants/ha (control). The experiment was set up using the Randomized Complete Block Design (RCBD). The physico-chemical properties of the soil before and after planting Mucuna as well as after yam harvest and number of earthworm cast were evaluated. Yam (Dioscorea rotundata) was planted the following year after Mucuna was ploughed-in into the heaps. The residual effect of Mucuna, yam germination percentage, number of leaves, leaf area index and yam yield were assessed. All the Mucuna populations influenced the physico-chemical properties of the soil. 1600 plants/ha had the highest number of earthworm cast while 800 plants/ha had the highest germination percentage, number of leaves, leaf area index and yam yield compared with the control (0.00 plants/ha). 800 plants/ha population decreased the pH by 4.09%, increased organic matter by 25.22%, Cation Exchange Capacity by 13.87%, Total Exchangeable Bases by 15.25% and Base saturation by 1.59% as compared with the control. Thus, it is recommended that planting Mucuna at 800 plants/ha will positively influence the soil properties and lead to higher yield of yam.
Keyword: Evaluation, Populations, Velvet bean, Soil fertility and Guinea savanna
