Substituting urea by organic wastes for improving maize yield in alkaline soil

Abstract

Nitrogen (N) deficiency is a very common problem of alkaline soils. Incorporation of organic residues with urea could be promising practice for improving soil properties and crop yield. This study was aimed, to evaluate the responses of two maize cultivar (Azam and Jalal) to organic wastes and Urea (sole organic residues i.e. seed cake (SC), poultry manure (PM), press mud (PrM) and mineral nitrogen (urea) and their combinations with urea (25%, 50% or 75%) applied at 150?kg N ha^?1 under field conditions. Significant differences were recorded for leaf area index, plant height, number of grains ear^?1, 1000 grain weight, biological and grain yield to N sources. Maize cultivar Jalal performed significantly better than Azam for all tested traits. The performance of both cultivars was significantly better when N was applied as either SC/PM with urea at 25:75, SC and PM with urea at 25:25:50, 100% sole urea, SC/PrM with urea at 50:50, or all organic N sources (25%) with urea (75%). Integration of organic wastes with urea gave the higher maize yield however, it was similar to the yield obtained from sole urea but due to allied environmental and health hazards, the sole use of urea could not be encouraged.