滴灌条件下秸秆覆盖和土壤含水量对冬小麦灌浆特性的影响

为阐明滴灌条件下秸秆覆盖和土壤含水量以及两因素交互作用对冬小麦籽粒灌浆、产量形成的影响,以冬小麦矮抗58为试验材料,设计了秸秆处理(覆盖T、不覆盖T0)与土壤相对含水量(40%(W1)、50%(W2)、60%(W3)、70%(W4)4个水平)两因素裂区试验。结果表明:Richards方程拟合秸秆覆盖和水分调控下冬小麦籽粒灌浆过程的决定系数在0.977 5~0.999 6,达到极显著水平。秸秆覆盖和水分调控间的交互作用对除最大灌浆速率和平均灌浆速率(V)外其他冬小麦籽粒灌浆特征参数的影响达到显著或极显著水平。其中,秸秆覆盖下土壤相对含水量60%(TW3)处理组合具有最长的灌浆持续期T(51.91 d),最长的灌浆中期持续期T_2(15.230 d)和灌浆后期持续期T_3(26.556 d),最大的灌浆中期灌浆速率R_2(0.897 mg/d)和灌浆后期灌浆速率R_3(1.365 mg/d)。产量、水分利用效率和耗水量的二次曲线关系表明,在耗水量240~270 mm可达到产量与水分利用效率双高的效果。本试验中以秸秆覆盖与土壤相对含水量60%(TW3)处理组合水分利用效率最高(29.02 kg/(mm·hm~2)),较秸秆覆盖下土壤相对含水量的70%(TW4)提高了5.30%;产量为7 097.7 kg/hm~2,与TW4处理组合差异不显著。

Effects of Straw Mulching and Soil Water Content on Grain Filling Characteristics of Winter Wheat under Drip Irrigation

The objective of this study was to explore the effect of straw-mulching, soil water content and their interaction under drip-irrigation condition on grain-filling characteristics and winter wheat yield.Taking wheat cultivar AK58 as test material, a split-plot experiment was conducted with non-mulching (T0) and straw mulching (T) as main plot, with four irrigation levels (W1, field capacity 40%, W2, field capacity 50%, W3, field capacity 60%, W4,field capacity 70%) as sub-plot.The results showed that,the decision coefficient of grain filling characteristics of winter wheat was studied with Richards model under straw-mulching and soil water regulation conditions was 0.977 5-0.999 6,which was reached extremely significant level.The differences of winter wheat grain-filling characteristics parameters in the interactive effect of straw-mulching and relative soil moisture reached significant or extremely significant level but the maximum filling rate and the average filling rate, V;TW3 treatment had the maximum values of filling duration T, 51.91 d,medium-term duration of grain filling T2,15.230 d,late duration of grain filling T3,26.556 d,medium grain filling rate R2, 0.897 mg/d and late grain filling rate R3,1.365 mg/d.Yield, water use efficiency and water consumption of quadratic curve relationship indicate that crop yield and water use efficiency achieve the highest level at the same time in the water consumption of 240-270 mm.What is more, TW3 obtained the maximum WUE, 29.02 kg/(mm·hm2), increasing by 5.30% relative to TW4, while grain yield was 7 097.7 kg/ha with no significant difference with TW4.