The effects of nitrogen fertilization strategies on the productivity of maize (Zea mays L.) hybrids

Nitrogen (N) is one of the major limitations to crop productivity. Therefore, afield study was conducted to examine the impacts of N application strategies: N-1 - 20% of N at sowing through broadcast + 79%N at mid-season through fertigation + 1% of N at flowering through foliar application, N-2 - 40% of N at sowing through broadcast + 59% of N at mid-season through fertigation + 1% of N at flowering through foliar, N-3 - 60% of N at sowing through broadcast + 39% of N at mid-season through fertigation + 1% of N at flowering through foliar, N-4 - 80% of N at sowing through broadcast + 19% of N at mid-season through fertigation + and 1% of N at flowering through foliar and N-5 - 100% of N at sowing through broadcast, on the productivity of maize hybrids (H) single cross-6142 (H-1) and double cross-4444 (H-2) over a 2-year period, 2010-2011. During both years, N strategies and maize hybrids differed significantly for all the observed traits of yield and quality. The highest biological yield (16.99-17.62 t ha(-1)) and grain yield (6.83-7.16 t ha(-1)) were recorded by using the strategy N-3. Similar trends were also observed for other traits except the grain oil content which was the maximum (3.38-3.98%) at N-5. However, in both years, maximum biological yield (14.83-15.69 t ha(-1)) and grain yield (5.01-6.02 t ha(-1)) were evident in Hp The interactive effect of H-1 x N-3 gave maximum biological yield (17.55-20 t ha(-1)) and grain yield (7.53-8.83 t ha(-1)). In 2010 and 2011, the highest net income (1220-1272 USD ha(-1)) and benefit cost ratio (2.52-2.56) was also attained at H-1 x N-3(.) In conclusion, our results suggested that maize productivity (grain yield up to 5.01-6.02 t ha(-1)) could be improved on economic basis (benefit cost ratio up to 2.52-2.56) by growing the single cross hybrid-6142 (H-1) with N application strategy N-3.