调亏灌溉和施氮对春玉米根区土壤水分、硝态氮分布及产量的影响

Effects of regulated deficit irrigation and nitrogen application on soil moisture,nitrate nitrogen distribution and yield of spring maize root zone

为探明调亏灌溉对黄土高原区典型作物的适用性,本文以春玉米为例,设置不同水氮处理的田间小区试验,研究调亏灌溉和施氮对根区土壤水氮和产量的影响。结果表明:调亏灌溉显著影响根区土壤水分和硝态氮含量,随施氮量增加,能削弱调亏灌溉对根区土壤水分的影响,但也增加了硝态氮淋失的风险;调亏灌溉会显著降低黄土高原区春玉米产量,但在不施氮条件下,苗期和灌浆期亏水会严重影响玉米产量,而随着施氮量的增加,苗期和灌浆期亏水对产量的影响减弱,但中氮和高氮处理下抽穗期亏水将显著降低玉米产量。该研究可为提出北方地区春玉米合理灌溉模式提供依据。

In order to find out the applicability of regulated deficit irrigation to typical crops in the Loess Plateau,this paper takes spring maize as an example,and sets up field plot experiments with different water and nitrogen treatments to study the effects of regulated deficit irrigation and nitrogen application on soil water and nitrogen and yield in root zone.The results showed that regulated deficit irrigation significantly affected soil moisture and nitrate nitrogen content in root zone.With the increase of nitrogen application rate,the effect of regulated deficit irrigation on soil moisture in root zone could be weakened,but the risk of nitrate nitrogen leaching increased.Regulated deficit irrigation can significantly reduce the yield of spring maize in Loess Plateau,but under the condition of no nitrogen application,water deficit at seedling stage and filling stage will seriously affect the yield of maize.With the increase of nitrogen application,the effect of water deficit at seedling stage and filling stage will weaken,but water deficit at heading stage will significantly reduce the yield of maize under medium and high nitrogen treatments.This study can provide a basis for putting forward a reasonable irrigation model for spring maize in northern China.