On-farm trials to investigate the effect of manure and basal fertilizer quantity and application method on maize yield, and glasshouse trials on the effect of heaping cattle manure on weed seed survival and mineral nutrient release were conducted during the 1993/94 and 1994/95 rainy seasons. Station placement of manure achieved the highest yield (6383 kg/ha) and was superior to broadcasting (farmer practice) by 1480 kg/ha, but achieved similar yield to dribbling in the planting furrow during the 1993/94 season. Dolloping of inorganic basal fertilizer at planting and 2 weeks after crop emergence (WACE) achieved higher yields than dribbling in the planting furrow during the 1994/95 season at sites where moisture was not limiting. Where moisture was limiting at planting, dribbling yielded more than both dolloping at planting and at 2 WACE. There was a significant decrease (65-70%) in weed seed density in manure heaped for one to five months. Total N availability increased from 0.86% in unheaped manure to 1.38% in manure heaped for four months. K2O increased from 0.03% in unheaped manure to 2.04% in manure heaped for three months. P2O5 dropped from 1.84% in unheaped manure to 0.82% in manure heaped for five months. The limited quantities of cattle available in the smallholder sector can be stretched through station placement or dribbling. Manure heaping for at least two to three months before field application is a cheap and effective way of reducing weed seed viability and it enhances N and K release from the manure. The preliminary results on basal inorganic fertilizer indicate that fertilizer application method significantly affects maize grain yield.

English

9801|AGRIS 9702

Jose Juan Caballero

CIMMYT Publications Collection