RESPONSE OF MAIZE TO INTEGRATED USE OF COMPOST AND UREA FERTILIZERS

Abstract

The effect of integrated use of compost and urea on yield of and N uptake by maize was assessed in a field experiment in Peshawar valley of North West Frontier Province, Pakistan during summer 2005. Urea and compost were combined in various ratios in such a way that the total N supply from both sources was 120 kg ha -1 . The contributions of N from the two sources were in 0:0, 100:0, 75:25, 50:50, 25:75 and 0:100 ratios. The treatments were arranged in a RCB design with four replications. Maize (variety: Jalal) was planted in rows. Data on biological, grain and stover yields of maize were recorded. Samples of grain and stover were analyzed for total N to determine its uptake by the crop. The results indicated that maximum biological (12410 kg ha 1 ), stover (8200 kg ha -1 ), and grain (4210 kg ha -1 ) yields of maize were obtained in treatment receiving N from urea and compost in 75:25 ratio. The next higher yield was obtained in treatment receiving 50 % N from urea and 50 % from compost. Comparing with other fertilizer treatments, the yields were significantly lower in treatments where N from urea source was below 50 %. Similarly, the N uptake in grain (64.84 kg ha -1 ) and stover (34.44 kg ha -1 ) was also significantly (P<0.05) greater in treatments receiving 75 % N from urea and 25 % from compost. The data on crop yields and N uptake of maize in response to integrated use of urea and compost supported each other. The residual soil organic fertility after maize harvest was proportional to the level of compost used. Our data thus suggest that integrated use of urea and compost at 75:25 or 50:50 ratios (N basis) has produced maximum yields and is therefore recommended for profitable maize yield and sustainable soil fertility.