氮水耦合对玉米产量和品质及氮肥利用率的影响

利用大型活动式防雨棚,设计了3个施氮水平和2个水分水平,研究了氮水耦合对玉米产量和品质及氮肥利用率的影响。结果表明:控释尿素处理开花前玉米的地上部干重、叶面积指数低于常规尿素处理,开花后开始赶超常规尿素处理,收获时其籽粒产量和生物产量均显著高于常规尿素。适宜的水分和施氮显著提高了玉米的籽粒产量、蛋白质产量及氮肥利用率。从产量上看,在田间持水量的50%±5%(W1)处理中常规尿素N 150 kg/hm2(NU)和控释尿素N 150 kg/hm2(CU)的籽粒产量分别比对照提高15.77%和29.97%;在田间持水量的75%±5%(W2)中二者分别提高35.60%和40.87%,处理间差异均达显著水平。因此,与常规尿素相比,不论在干旱或水分适宜条件下,控释尿素能更好地协调玉米的地上、地下部生长,利于获得高产,而适宜的水分可以显著提高这种效果。

Effects of Water-nitrogen Coupling on Yield, Quality and Nitrogen Use Efficiency of Summer Maize

Under the condition of mobile rain-proof shelter,three nitrogen application rates and two soil moisture rates were designed to investigate the effects of water-nitrogen coupling on the grain yield and quality and N use efficiency of summer maize.The results showed that the dry matter accumulation and leaf area index of maize applied with controlled release urea(CU) were lower than those applied with normal urea(NU) before anthesis,but the situation was just contrary after anthesis.And as a result,the grain yield and biomass of CU treatment were higher than those of NU treatment.Suitable soil moisture and application of controlled release urea could significantly increase the grain yield,grain protein yield and nitrogen use efficiency.However,grain protein was decreased significantly.Compared with the control,the grain yield of CU and NU was improved by 15.77% and 29.97% under 50%±5% soil water moisture(W1) and 35.60% and 40.87% under 75%±5% soil water moisture(W2) respectively.The differences between the treatments were significant.In conclusion,whatever under dry or wet soil,using controlled release urea could coordinate the growth of root and shoot better to get higher grain yield,and the suitable soil moisture was benefit to enhance this effect.