不同施肥量对旱作沟垄集雨种植农田土壤水分及玉米产量的影响

Effects of fertilization on soil moisture and maize yield in rainfed farmland with ridge mulching-furrow planting system

【目的】沟垄集雨种植是西北旱作农田广泛运用的高效节水栽培模式。研究不同施肥处理对旱作沟垄集雨种植农田土壤水分及玉米产量的影响,为优化施肥配置,进一步提升其增产效能提供科学依据。【方法】以玉米为供试作物,在宁夏回族自治区固原市进行了连续5年的田间定位施肥试验。试验玉米栽培采用集雨沟垄栽培技术,设置4个施肥水平处理:无肥对照(CK),低肥(N 150 kg/hm^(2)、P2O575 kg/hm^(2)),中肥(N 300 kg/hm^(2)、P2O5150 kg/hm^(2)),高肥(N 450 kg/hm^(2),P2O5225 kg/hm^(2))。在玉米生长关键期,取0—200 cm深土壤不同层次的土壤样品,测定了土壤含水量、农田耗水量、水分利用效率,调查了玉米产量。【结果】无论缺水年、平水年还是丰水年,随施肥量的增加,农田耗水量、玉米干物质累积量均呈提高趋势,高、中、低水平施肥处理的农田耗水量较CK分别平均提高了8.8%、7.7%和5.3%,玉米干物质累积量分别显著(P<0.05)提高了38.3%、35.8%和31.2%。在各年份,各处理土壤含水量从四叶期到抽雄吐丝期均随施肥量的增加呈降低的趋势,而在收获期,各施肥处理土壤含水量均显著(P<0.05)低于CK,高、中、低水平施肥处理分别平均降低24.7%、24.2%和17.7%。综合来看,中肥处理5年平均籽粒产量最高(11.4 t/hm^(2)),产量变异系数最小(12.9%)。在丰水年,低肥处理玉米产量及籽粒水分利用效率均高于高肥和中肥处理,而在平水年和干旱年,中肥处理可获得较高的籽粒产量和水分利用效率。【结论】在半干旱地区,施肥量对沟垄集雨种植模式春玉米产量及水分利用效率的影响受制于降雨量。在丰水年,较低的施肥量(N 150 kg/hm^(2)、P2O575 kg/hm^(2))即可获得理想产量和水分利用效率,而在平水年和干旱年,中量施肥水平(N 300 kg/hm^(2)、P2O5150 kg/hm^(2))获得的产量和水分利用效率最高。高施肥量(N 450 kg/hm^(2)、P2O5225 kg/hm^(2))会造成土壤水分的大量消耗。

【Objectives】Ridge mulching-furrow planting is a high-efficiency and water-saving cultivation mode widely used in arid northwest China.To understand the effects of fertilization on crop yield,we conducted a fiveyear field experiment in Guyuan of Ningxia Hui Autonomous Region and analyzed the effects of different fertilization treatments on soil moisture and maize yield.【Methods】Ridge mulching-furrow planting system,as a rainwater harvesting system,was adopted in this experiment.The four different fertilization levels in this study were:no fertilizer control(CK);low fertilizer rate(N 150 kg/hm^(2),P2O575 kg/hm^(2));medium fertilizer rate(N 300kg/hm^(2),P2O5150 kg/hm^(2))and high fertilizer rate(N 450 kg/hm^(2),P2O5225 kg/hm^(2)).During the key growing stages of maize,soil samples were collected in 0-200 cm depth for determination of water content,water consumption of farmland,water use efficiency(WUE),while maize yield was assessed at maturity stage.【Results】The water consumption of farmland and dry matter accumulation(DM)of maize increased with the increase in fertilizer amount,regardless of annual rainfall.Compared to CK,high,medium and low fertilizer treatments increased water consumption by 8.6%,7.7%and 5.3%,respectively,while they increased dry matter accumulation by 38.3%,35.8%and 31.2%,respectively.In general,the medium fertilizer treatment had the highest average grain yield(11.4 t/hm^(2))with the lowest yield variation coefficient(12.9%).In wet year,low fertilizer treatment had higher maize yield and water use efficiency than high and medium fertilizer treatments did,while in median water year and drought year,medium fertilizer treatment had higher grain yield and water use efficiency.【Conclusions】In semi-arid area,the effects of fertilizer application rate on yield and water use efficiency under the ridge-furrow rainfall harvesting planting relies on rainfall.In wet year,lower fertilizer rate(N 150 kg/hm^(2),P2O575 kg/hm^(2))could achieve higher yield and WUE,while in normal and drought year,middle level of fertilization rate(N 300 kg/hm^(2),P2O5150 kg/hm^(2))is recommended.High fertilizer rate(N 450 kg/hm^(2),P2O5225 kg/hm^(2))could reduce soil water.