ABSTRACT
The aim of this work was to test the influence of cowpea on micronutrients in the soil. The field study was conducted at experimental field behind the new Faculty of Agriculture, Ugbowo Campus, University of Benin, Benin City.
Cowpea (vigna unguiculate L. Walp) is a popular legunm e crop formed primarily in Africa and used for human livestock diets all over the world. It is a water deficiency tolenrant crop that could be used as food for humans and feed for livestock with the bulk of their macro and micronutrients.
The soil became more acidic after the planting of cowpea because the pH was reduced, therefore, planting of cowpea had an effect on the soil as well as the micronutrients.
The experience was laid out in a randomized complete block design and the five(5) replications with a spacing of 60cm x 30cm.
The results showed that the pH of the soil decreased from 5.74 to 5.32 and for the micronutrients, (Boron, Iron, Copper, Zn) they decreased after harvest. From 4.33 to 3.84, 112.0 to 107.3, 34.6 to 30.8, 25.8 to 21.6 for Boron, Iron, Copper, Zinc respectively.
The percentage reduction of the micronutrients after harvest were 12.76% reduction for Boron, 4,.38% reduction for iron, 12.41% reduction for copper and 19.44% reduction for zinc. The tolerance limit of these micronutrient are 0.48mg/kg for Boron, 4.8mg/kg for iron, 100mg/kg for copper and 300mg/kg for zinc.
