河套灌区节水减肥对玉米不同生育期水分和养分的影响

Effects of Water Saving and Fertilizer Reducing on Water and Nutrients of Maize at Different Growth Stages in the Hetao Irrigated Area

为探究不同灌水和施肥条件对河套灌区不同生育期玉米生长的影响,以玉米“金苹628”为材料,分别研究了低水(1800 m^3/hm^2)、中水(2250 m^3/hm^2)、高水(2700 m^3/hm^2)3个灌水水平,低肥(300 kg/hm^2)、中肥(375 kg/hm^2)、高肥(450 kg/hm^2)3个施肥水平,并以当地一般灌水量和施肥量为对照(CK),共10个处理在苗期、拔节、抽雄、灌浆、成熟期对土壤水分、养分和玉米生长的影响。结果表明:拔节期以后,土壤平均含水率呈下降趋势;抽雄和灌浆期玉米耗水量最大,占整个生育期耗水量65%以上;拔节期土壤硝态氮累积量最小,植物吸收大量养分供玉米快速生长;高水水平下,玉米产量及水分利用效率随灌水和施肥量的增加呈先增后减趋势。通过多元逐步回归分析不同生育阶段土壤水分和养分对玉米生长的影响,筛选出不同生育期对玉米生长影响更为关键的要素,得出在抽雄、灌浆、成熟期土壤水分对玉米生长的影响比土壤养分大,拔节期土壤养分对玉米生长的影响比土壤水分大。研究结果可为河套灌区节水减肥,合理分配水资源,减少氮素面源污染,保障玉米稳定生长提供理论基础。

In order to investigate the effects of different irrigation and fertilization conditions on the growth of maize at different fertility stages in the Loop irrigation area,three irrigation levels of low water(1800 m^3/hm^2),medium water(2250 m^3/hm^2)and high water(2700 m^3/hm^2),and three fertilization levels of low(300 kg/hm^2),medium(375 kg/hm^2)and high(450 kg/hm^2)fertilization were investigated using maize“Jinping628”as the material,respectively.At the same time,the local irrigation and fertilization amount were used as the control group(CK).The effects of 10 treatments on soil moisture,nutrient and maize growth in the seedling stage,jointing stage,tasseling stage,filling stage and maturity stage were analyzed.Based on the results,it was found that the average soil water content tended to decrease after the pulling stage.Maize water consumption was highest during the pulling and filling stages,accounting for more than 65%of water consumption during the entire reproductive period.Soil nitrate-nitrogen accumulation was minimal during the pull-out stage,and plants absorbed large amounts of nutrients for rapid maize growth.Under high water levels,maize yield and water-use efficiency tended to increase and then decrease with irrigation and fertilization.Through multiple stepwise regression analysis,the effects of soil moisture and nutrients on maize growth in different growth stages were screened out.The results showed that soil moisture had a greater influence on maize growth than soil nutrients at tasseling,filling and maturity stages,and soil nutrients at jointing stage had a greater impact on maize growth than soil moisture.The results of the study can provide a theoretical basis for water conservation and reduction of chemical fertilizer use in the loop irrigation area,rational allocation of water resources,reduction of nitrogen surface pollution,and ensuring stable growth of maize.