秸秆还田下两种氮肥施用方式对夏玉米生长特性的影响

氮肥施用过量、肥效低下以及持续增产效果不显著一直以来制约着农业的发展。近年来，秸秆还田配施氮肥在农业生产中已经得到了广泛应用。本试验在向当地农户调查的基础上设置了传统施氮处理(300kg／hm^2)，依据叶片诊断技术所确定的玉米需肥量设置了优化施氮处理(60kg／hm^2)，以不施氮肥作为对照，研究了北京郊区秸秆还田下不同氮肥施用方式对夏玉米生长特性以及产量的影响。通过田间试验，得到如下结果：两种氮肥施用方式对夏玉米株高、叶面积、茎粗、节根等影响不明显；各指标均高于对照；传统施氮、优化施氮条件下夏玉米产量分别达到7297．65kg／hm^2、7385．1kg／hm^2，产量效应几乎没有差异；然而对照处理只有5485．65kg／hm^2，传统施氮、优化施氮增产达到了33．03％和34．63％；优化施氮大大减少了氮肥使用量，不仅具有良好的经济效益，而且具有良好的生态效益。

Effects of Two N-fertilization on the Growth of Summer Maize with Straw in the Field

Excessive using and low efficiency of N-fertilizer have long been the obstacles for agriculture development. Now, N-fertilizer using with straw has being used in large scales in summer maize. In this paper, two treatments were designed. The first was traditional N-fertilization which was designed by investigating the amount of N-fertilizer using in the village, that's 300 kg/ha. The second was optimized N-fertilization which was designed by the means of diagnosing the leaf, and the amount of N-fertilizer which the crop need in its growing stage was decided consequently. Comparing with the treatment of no N-fertilization, effects of two N-fertilization on the growth characteristics and yields of summer maize with straw in the field was studied. The results showed as fellows: There were no obvious differences between two types of N-fertilizer application on the plant height, leaf area, stem diameter and the number of root of the summer maize. These growth characteristics were better than those of control. To the traditional N-fertilizer application and optimized N-fertilizer application, the yields were 7 297.65 kg/ha and 7 385.1 kg/ha, which has no obvious yield difference, but increased 33.03% and 34.63% compared with the yield of control, it's 5 485.65 kg/ha. The optimized N-fertilizer application greatly reduced the N-fertilizer amount with good economic and ecological benefits.