Impact of Integrated Nutrient Management on Yield and Nutrient Uptake by Maize under Rain-Fed Conditions

A field study was conducted to determine the effect of Zinc (Zn) application as well as interactive effect of organic and mineral fertilizer sources of nitrogen (N) on maize productivity and nutrient uptake during 2008 at NARC, Islamabad. Four combinations of N sources, viz. control; 100 % recommended dose of N from Chemical Fertilizer (CF); 75% N from CF + 25% N from Farm Yard Manure (FYM) and 50% N from CF + 50% N from FYM and three levels of Zn fertilizer, viz. 0, 4, 8 kg Zn/ha were applied. Maximum maize grain yield, viz., 5.18 t/ha was obtained with 75% + 25% (CF + FYM) and 4 kg Zn/ha. It was statistically at par with treatment having 50% + 50% (CF + FYM) and 4 kg Zn/ha as well as 75% + 25% and 8 kg Zn/ha. Zinc application also enhanced maize grain yield by 12% over treatment where no Zn was applied i.e. 4.08 t/ha. Highest N uptake, viz., 98.7 kg/ha was observed with 50% + 50% (CF + FYM) and 8 kg Zn/ha application. Similarly, maximum Zn uptake, viz., 250.7 g/ha was observed with 75% + 25 % (CF + FYM) and 4 kg Zn/ha application. The study revealed that substitution of 25 or 50% N with FYM + 4 kg Zn/ha performed better than 100% N fertilizer alone, with respect to leaf area index, grain and straw yield, soil organic matter content and nutrient uptake.