秸秆还田下保水剂用量对砂性土性状与玉米产量的影响

为探讨宁夏盐环定扬黄灌区秸秆还田条件下保水剂用量对砂性土保水保肥效应及玉米产量的影响,通过3年大田试验,以不施保水剂为对照,研究保水剂施用量（30、60、90、120kg/hm2）对砂性土壤容重、水分、养分及玉米生长、产量和水分利用效率的影响,并对经济效益进行分析。结果表明,与对照相比,施用保水剂可有效降低0~40cm层土壤容重,改善土壤孔隙状况,以保水剂施用量90、120kg/hm2处理效果较优。在玉米整个生育期,施用保水剂60、90、120kg/hm2时0~100cm层土壤贮水量较高,其3年平均分别较对照显著提高18.3%、21.6%和23.5%。施用保水剂60、90kg/hm2处理耕层（0~40cm）土壤有机质、有效磷和速效钾含量较对照显著增加,其改善土壤养分状况效果最佳。施用保水剂可提高玉米植株株高、茎粗和地上部生物量,施用保水剂60、90kg/hm2处理的效果最为显著。与对照相比,施用保水剂60kg/hm2处理对提高作物水分利用效率、玉米增产和增收效果最佳,其3年平均玉米水分利用效率、产量和纯收益分别较对照显著增加30.4%、26.0%和20.7%。施用保水剂60kg/hm2时能有效改善砂性土壤理化性状,实现玉米的增产增收,可在宁夏盐环定扬黄灌区秸秆还田条件下的滴灌玉米田推广应用。

Effect of Super Absorbent Polymer Rate on Sandy Soil Property and Maize Yield under Straw Returning

With the aim to explore effect of super absorbent polymers (SAP) on sandy soil moisture and fertilizer conservation and maize yield under straw returning condition in Yellow River pumping irrigation area of Yanhuanding, Ningxia, a three-year field study was conducted to investigate effects of different rates (30kg/hm2, 60kg/hm2, 90kg/hm2, and 120kg/hm2) of SAP under straw returning condition on sandy soil bulk density, water storage, nutrient, maize growth, yield, water use efficiency and economic benefit, and the treatment without SAP was used as the control. The results showed that the soil bulk density of different SAP rates in the 0~40cm soil layer was decreased compared with the control, while the total soil porosity was greatly improved, and the effects of SAP with 90kg/hm2 and 120kg/hm2 treatments were the best. The soil water storage capacity at 0~100cm soil layer under SAP with 60kg/hm2, 90kg/hm2 and 120kg/hm2 was better than that of other treatment in the whole growing season of maize. The mean soil water storage capacity of SAP with 60kg/hm2, 90kg/hm2 and 120kg/hm2 was increased by 18.3%, 21.6%, and 23.5% compared with the control, respectively. The application of SAP with 60kg/hm2 and 90kg/hm2 obviously increased the soil organic matter, available P and available K contents in 0~40cm soil layer, resulting in the best results compared with the control. The application of SAP significantly increased the maize plant height, stem diameter, and above-ground biomass, especially the application of 60kg/hm2 and 90kg/hm2 of SAP was the most significant. The mean maize yield, water use efficiency and net income with 60kg/hm2 of SAP was the best among the treatments, which were 30.4%, 26.0%, and 20.7% higher than that of the control. Therefore, the application of SAP with 60kg/hm2 under straw returning condition could effectively improve sandy soil physic-chemical properties, promote the growth, and bring an increase in maize yield and income of farmers. The research results could be recommended to apply in maize field in the Yellow River pumping irrigation areas of Yanhuanding, Ningxia.