Effects of different nitrogen sources on maize intercropped with soybean on an Alfisols.

Abstract

A pot experiment was carried out at the screenhouse of the School of Agriculture and Agricultural Technology, Gidan Kwano campus, Minna in the cropping season of 2020. The experiment aimed to evaluate growth and nodulation of soybean intercropped with maize. Two seeds of each crop were planted per pot containing 14 Kg of Gidan Kwano soils. A week after sowing, plants were thinned to a seedling per crop genotype per pot, before basal application of N,P , K , Mg and micronutrients (B, Mo, Zn). Thereafter, the following cropping systems (sole maize, sole soybean, intercropped maize and intercropped soybean) were fertilized as follows: -N as 0 kg N ha-1 (control), + inorganic N (urea) as 20 Kg N ha-1, +organic N (poultry dropping) as 20 Kg N ha-1 and the United States Department of Agriculture (USDA 110) as 5mls per plant of rhizobium inoculant. Subsequently, treatments were then arranged in a Completely Randomized Design with three replicates. Watering of plants was done daily till harvest at 6 weeks. Data collected were subjected to ANOVA. Means were separated using Duncan Multiple Range Test (DMRT). Results showed that averagely, sole maize was better than intercropped maize in plant height, the number of leaves and root weight but was significantly higher than intercropped maize in leaf area and shoot weight. Averagely, with the exception of days to 50% flowering and nodule weight, sole soybean was better than intercropped soybean in all the growth and nodulation characteristics measured. The sole soybean performed better when inoculated with elite strains of USDA 110 while the intercropped soybean was better when in association with indigenous rhizobium and 0 Kg N ha-1. Organic nitrogen of poultry source produced the best maize growth trait that was not significantly different as a result of inoculation of soybean with rhizobia.