Straw and nitrogen applications interactively affect maize yield and nitrogen utilization efficiency

In order to investigate the effect of straw return on nitrogen use efficiency in maize, split design was adopted.The main plot was with no stalk and stalk amendment (7 500 kg · hm^-2), and the subplot was with four nitrogen application levels, i.e., N0(0 kg · hm^-2), N135(135 kg · hm^-2), N180(180 kg · hm^-2) and N225(225 kg · hm^-2), respectively.The yield of maize was determined and nitrogen use efficiency was analyzed.The results showed that, compared with no stalk addition, the stalk application increased the content of soil alkali-hydrolytic nitrogen and soil organic matter.Soil total nitrogen was higher under N180 and N225 treatments than any other nitrogen treatments, but there was no significant difference among N treatments.The yield of maize under the stalk application and N180 treatment was with the highest value.Under the N225 treatment, the stalk application increased yield by 11.0% compared to the no stalk application.Nitrogen fertilizer agronomic utilization efficiency and nitrogen fertilizer utilization rate were with the highest values under stalk and N180 treatment; the N fertilizer bias productivity was with the highest value under N135 treatment, while decreased by 12.4% to 37.2% with the increase of N application.Addition of stalk plus N180 application was beneficial to maize production.