The effects of time of applying basal dressing fertilizers on maize yield under varying rainfall regimes and inherent soil fertility in Malawi
1999
Kabambe, V.H. | Kumwenda, J.D.T. | Sakala, W.D. | Ganunga, R.P. (Chitedze Agricultural Research Station, Lilongwe (Malawi))
Due to widespread delays in basal dressing fertilizer application in Malawi, a trial was conducted in 1990/91 and 1991/92 seasons at 3 sites to determine maize yield response to delayed applications of basal fertilizers and split applications. A 50:30:0 kg ha-1 N:P2O5:K fertilizer package (from diammonium phosphate and urea) was applied once at 0, 2,3 and 4 weeks after planting (WAP), and compared to no fertilizer application and split application. There were significant yield reponses to fertilizer application at all sites in 1990/91 and at Mbawa only in 1991/92. Yield losses of up to 1000 kg ha-1 (25-74%) were recorded at Mbawa and Chitedze in 1990/91 and at drought stricken Chitedze in 1991/92, where grain yields without fertilizer were less than 2000 kg ha-1, due to delaying the application.of basal fertilizers by 2-4 weeks. Split applications produced similar yield to basal dressing at 0 WAE. At Meru in both seasons and Mbawa in 1991/92, where yield of maize without fertilizer was over 3t ha-1, there was no yield loss due to delayed basal fertilizer application. Split application significantly increased yield over single basal dressing at 0 WAE at Meru in 1990/91. Nitrogen use efficiency factors were generally higher in high yield potential sites. The results indicate potential to increase maize yield and optimise labour in Malawi by applying basal fertilizers at planting or soon after maize emergence, especially on depleted soils and under low and erratic rainfall conditions.
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