Effects of Different Nitrogen Applications on Soil Physical, Chemical Properties and Yield in Maize (<i>Zea mays</i> L.)

Abstract

Application of nitrogen (N) fertilizer is one of the most important approaches on improving maize grain yield. However, as is known to all, overuse N fertilizer not only leads to decline of N use efficiency and maize yield, but also leads to potential risk to environment pollution. This experiment was conducted to determine the effects of N fertilizer applications with nine different treatments on soil physical-chemical characters and maize grain yield using hybrid variety Zhengdan 958 in 2011 and 2012. Results indicated that the soil bulk densities of T 2 (CK) and T 1 were the lowest compared to other treatments in 2011 and 2012, respectively, whereas the soil bulk density of T 5 in 2011 and T 3 in 2012 were higher than other treatments. The soil porosity and field capacity of T 5 in 2011 and T 3 in 2012 were lower than other treatments, but those of CK in 2011 and T 1 in 2012 were higher than other treatments. The pH values of T 3 to T 7 were lower than other treatments. These results indicated that the soil bulk densities were increased, whereas the soil porosity, field capacity and values pH were decreased by N application at different stages. N application could increase the N contents of leaf and stem, whereas less or excess N application should not significant improve maize yield. Although the soil organic matter and total N contents of T 3 were the highest in both 2011 and 2012, the yield of T 4 is the highest in both 2011 and 2012. The application amount, period and times of N fertilizer were important to maize yield.