Effect of nitrogen rate on okra and tomato in Gliricidia alley cropping system in South-western Nigeria

Abstract

The effect of nitrogen rate with hedgerow primings applied as mulch in Gliricidia sepium alley cropping system on weed control and growth and yields of okra and tomato was studied in an on-farm experiment in South-western Nigeria in 1993 and 1994. The growth of the vegetables was increased by increasing nitrogen fertilizer rate up to 90 kg ha'1 with total hedgerow primings applied as mulch, but this was not accompanied by a significant increase in fruit yields beyond 60 kg ha'1. When averaged over the two years, however, application of 30 kg N ha'1 gave more economical yield than application of 60 kg ha'1. With total foliage from hedgerow pruning applied as mulch, weed dry weight decreased significantly by 70-75% and 60-66% under okra and tomato, respectively, with and without fertilizer. It is concluded that application of small amount (about 30 kg ha'1) of nitrogen fertilizer with hedgerow primings applied as mulch can suppress weed growth and increase fruit yield of okra and tomato under Gliricidia sepium alley cropping system.