玉米秸秆还田对砂姜黑土水分动态及冬小麦水分利用效率的影响

为给冬小麦水分高效利用提供科学依据,根据土壤-植物-大气连续体(SPAC)原理,利用野外小型蒸渗仪,以不施肥为对照(CK),原位研究了配方施肥(PF)以及配方施肥+秸秆还田(PF+JG)处理对砂姜黑土水分动态和冬小麦水分利用效率的影响.结果表明,秸秆还田主要影响0～40 cm土层土壤剖面水分含量,而40～80 cm土层土壤水分含量基本保持稳定.在小麦出苗期和拔节期,PF+JG处理的0～40 cm土层土壤含水量较PF处理分别提高50.9％和34.6％.土壤水分最大有效库容在小麦全生育期呈单峰变化趋势,峰值在返青期;PF+JG处理的出苗期土壤水分最大有效库容较CK和PF处理增加了8.25％和20.82％,拔节期增加8.07％和10.95％,且均差异显著(P＜0.05).PF+JG处理的土壤水分入渗量分别是CK和PF处理的4.53和3.55倍;小麦耗水量较PF处理降低9.2％;小麦产量和水分利用效率分别比CK和PF处理增加124.1％、18.8％和144.0％、30.8％,且差异达显著水平(P＜0.05).说明秸秆还田对冬小麦产量和水分利用效率的提高作用与增加土壤水分有效库容、水分入渗量和减少总耗水量有关.

Effects of Maize Straw Returning on Water Dynamics and Water Use Efficiency of Winter Wheat in Lime Concretion Black Soil

In order to provide the scientific proof of improving the water use efficiency (WUE) of winter wheat in lime concretion black soil, the influences of maize straw returning on water dynamics and WUE were studied in the Wudaogou hydrology water resource experimental station in Bengbu, China. The in situ micro lysimeter experiments were conducted to investigate the impacts of non fertilization (CK), soil testing and formulated fertilization (PF) and soil testing and formulated fertilization & maize straw returning (PF + JG) treatments on the water dynamics and WUE of winter wheat in lime concretion black soil based on the soil plant atmosphere continuum (SPAC) principle .The results indicated that the influences of maize straw returning to soil on water content were mainly concentrated in 0~40 cm soil layer, and it was kept relatively stable in 40~80 cm soil layer in the soil profiles. The soil water content (0~40 cm) at seeding and jointing stage in the PF + JG treatment was 50.9% and 34.6% higher than that in PF treatment after the maize straw returning to soil, respectively. A single peak trend of the soil maximal available water capacity was found during the whole stage of winter wheat, and the highest peak was detected at reviving stage. Compared with the control and the PF treatments, straw returning to soil (PF+JG) treatment could significantly increase the soil maximal available water capacity by 8.25%, 20.82% and 8.07%, 10.95% at seeding and reviving stage (P <0.05), respectively. The amount of water infiltration in lysimeter after maize straw returning was 4.53 and 3.55 times higher than that in the control (CK) and soil testing and formulated fertilization (PF) treatments, respectively. The quantities of water consumption in the whole winter wheat stage were 9.2% lower in PF+JG than that in PF treatment. The wheat yield and water use efficiency were 124.1%, 18.8% and144.0%, 30.8% higher than that in CK and PF experiments in the maize straw returning to soil and soil testing and formulated fertilization treatment. The straw returning to soil could increase both winter wheat yield and water use efficiency in lime concretion black soil, and also increase soil available water capacity, water infiltration and decrease total water consumption.