深松和施氮对夏玉米产量及氮素吸收利用的影响

于2010年和2011年通过田间裂区试验，研究了在旋茬和旋茬后深松条件下常规尿素分次施用和控释尿素对郑单958夏玉米的花后氮素积累、 分配、 利用及产量的影响。结果表明，在相同的耕作措施下，氮素积累及其向子粒的分配量均表现为控释尿素＞普通尿素两次施用＞普通尿素一次施用＞不施氮处理；在相同施氮水平下，玉米氮素积累及其向子粒的分配量均表现为深松大于旋茬处理。深松并施用控释尿素处理的夏玉米在两年试验中的子粒产量和氮素利用率均为最高，与其他处理相比差异显著。可见，与传统的旋茬耕作和施肥方式相比，深松耕作和施用控释尿素均能显著提高郑单958夏玉米的氮素利用率和产量。二者的有机结合可为玉米的氮素高效利用和产量的提高提供新的思路。

Effects of subsoiling and N fertilizer application on dry matter accumulation,nitrogen use efficiency and yield of summer maize

To provide the basis for the high yield summer maize cultivar, field experiments were conducted to study the effects of subsoiling and controlled release urea on nitrogen accumulation, distribution and use efficiency and yield of summer maize in 2010 and 2011．Two sets of treatments were arranged in a split plot design．The whole plot treatment factor was two tillage methods, rototilling for stubble breaking and subsoiling after rototilling for stubble breaking, and the sub subplot treatments are the N 225 kg/ha controlled release urea treatment, the N 225 kg/ha conventional urea for two applications treatment (40% was used as basal application and 60% was used at the beginning of male tetrad stage)，the N 225 kg/ha conventional urea treatment for one application and no nitrogen fertilizer treatment used as control．The maize cultivar, Zhengdan 958, was chosen as experiment material．The results show that in the same cultivation measure conditions，the trends of the nitrogen accumulation and distribution into the grains of all treatments are the controlled release urea treatment the conventional urea for two applications treatment the conventional urea treatment for one application the no urea treatment．Compared with the rototilling for stubble breaking, the subsoilling could increase the dry matter accumulation, nitrogen accumulation and distribution into the grains under the same nitrogen level．The yields and nitrogen use efficiencies of Zhengdan 958 in the two years are highest under the subsoiling and controlled release urea treatment, and are significantly higher than those of the other treatments．It is thus clear that the combination of subsoiling and the application of controlled release urea could provide an approach for using the nitrogen efficiently and getting higher maize yield．