Effects of N and P rates and proportional timing of N application on rainfed wheat in Zambia

A study was carried out to establish the optimum rates of N and P fertilizers, optimal ratio of basal to top dressed N and time for top dressing the balance of total N in rainfed wheat in the high rainfall zone of northern Zambia. Grain yield, number of spikes per unit area and number of kernels per spike increased with both N and P rates. Except for kernel weight, the other yield components were positively correlated with grain yield. Split application with a ratio favouring top dressing, and applied four weeks after seeding gave higher yields than ratios favouring basal dressing. Initial fertility levels and rainfall distribution influence on the effects of these factors are discussed. Part of M.Sc. Thesis by S.P. Mooleki submitted to the College of Graduate Studies and Research, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 0W0, Canada Part of M.Sc. Thesis by S.P. Mooleki submitted to the College of Graduate Studies and Research, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 0W0, Canada