不同水氮处理对冬小麦生长及土壤硝态氮含量的影响

Effects of different water and nitrogen treatments on growth of winter wheat and soil nitrate content

【目的】研究不同施氮量、灌水量对覆膜冬小麦生长及土壤中硝态氮含量的影响。【方法】以"小偃22号"为供试材料,通过2010年和2011年2年的大田试验,研究了不同灌水量(750m3/hm2(冬前灌),1 500(冬前和返青期各灌750m3/hm2),2 250(冬前、返青期和拔节期各灌750m3/hm2),3 000m3/hm2(冬前、返青期、拔节期和灌浆期各灌750m3/hm2))和施氮量(75,150,225和300kg/hm2,70%基肥,30%追肥)处理对拔节期-成熟期覆膜冬小麦生长、产量及越冬期、返青期和拔节期土壤硝态氮含量的影响。【结果】在拔节期-成熟期,冬小麦的株高随着灌水量和施氮量的增大而增加,表现出明显的正相关性。在越冬期-拔节期,0～200cm土层的土壤硝态氮含量先降低后增加,高氮处理能提高表层0～60cm土壤硝态氮含量,高灌水会降低表层土壤硝态氮含量并增加深层土壤硝态氮含量。小麦产量随着灌水量和施氮量的增大而增加,但在氮肥高于150kg/hm2、灌水量高于2250m3/hm2时,产量增加不显著。【结论】灌水量和施氮量对小麦株高、地上部干质量、产量和土壤硝态氮含量都有一定的影响,灌水量和施氮量超过一定值后,小麦的生长指标则不会显著增加。在本试验条件下,灌水量2 250m3/hm2(冬前、返青和拔节期各750m3/hm2)和施氮量150kg/hm2(70%基肥,30%追肥)处理水氮利用效率最佳。

【Objective】 This paper studied the effects of watering and fertilizer coupling on growth and soil nitrate contents of winter wheat with film mulching.【Method】 Winter wheat ＂Xiaoyan 22 ＂was used as the test material during crop season in 2010 and 2011.Through providing different water supplements：750 m3/hm2（750 m3/hm2 water supplement before winter）,1 500 m3/hm2（750 m3/hm2 water supplement before winter and turning green stage,respectively）,2 250 m3/hm2（750 m3/hm2 water supplement before winter,turning green and jointing stage,respectively）,3 000 m3/hm2（750 m3/hm2 water supplement before winter,turning green,jointing stage and filling stage,respectively）and different nitrogen applications（75,150,225 and 300 kg/hm2）,the changes of growth and yield of winter wheat with film mulching during jointing to mature stage and soil nitrate content were studied.【Result】 During jointing to maturing stage,there was a significant positive correlation between plant height of winter wheat,water supply and nitrogen application.During overwintering to jointing stage,the soil nitrate contents increased firstly and then decreased in of the depth of 0-200 cm.High nitrogen treatment（300 kg/hm2） could improve the nitrate content in the depth of 0-60 cm.Irrigation decreased nitrate content in surface soil while increased it in deep soil.The yield increased with irrigation and fertilization until the irrigation quantity raised above 2 250 m3/hm2 and fertilizing amount was over 150 kg/hm2.【Conclusion】 Nitrogen application and water supplement had certain effects on plant height,dry matter quantity aboveground,yield of winter wheat and soil nitrate contents.However,when they reached a certain level,the growth of winter wheat would not significantly enhance.In the conditions of this study,the treatment with water amount of 2 250 m3/hm2 and nitrogen amount of 150 kg/hm2 would get the highest water and nitrogen use efficiency.