玉米整秆带状覆盖量对旱地冬小麦土壤水分利用的影响

Effects of Whole Maize Straw Mulching Amounts on Soil Water Use of Winter Wheat in Dry Land

为明确西北黄土高原半干旱雨养条件下,玉米整秆带状覆盖适宜的秸秆覆盖量,以露地种植为对照(CK),研究了4种覆盖量(T_1:6 750kg/hm^2,T_2:9 000kg/hm^2,T_3:11 250kg/hm^2,T_4:13 500kg/hm^2)对旱地冬小麦土壤水分和产量的影响。结果表明:4种覆盖量较CK显著增产12.1%~23.3%,提高水分利用效率13.4%~26.8%。产量与单位面积穗数呈显著正相关(r=0.937),整秆带状覆盖较CK可显著(除T_3)提高单位面积穗数10.4%~19.0%,以T_2单位面积穗数最高。全生育期0—200cm土层平均含水量4种覆盖量均显著高于CK,较CK高0.7~1.0个百分点,以T_1土壤水分状况最好。4种覆盖量可显著改善灌浆前0—200cm土壤墒情,但从灌浆期开始0—90cm土壤含水量普遍不如CK。4种覆盖量间,以T_2全生育期0—60cm土壤墒情最好,且其增产和提高水分利用效率效果也最显著。

In order to determine the appropriate mulching straw amounts of whole maize straw mulching in a semiarid rainfed area of the Loess Plateau,Northwest China,we studied the effects of four different mulching modes(T_1:6 750kg/hm^2,T_2:9 000kg/hm^2,T_3:11 250kg/hm^2,T_4:13 500kg/hm^2)on the soil moisture and winter wheat yield in dryland with the comparison of no muching(CK).T_he results show that,compared with CK,the wheat yield was increased by 12.1% ~23.3% and the water use efficiency was increased by 13.4%~26.8%.T_he production and number of spike were significantly positive correlated(r=0.937),compared with CK,the mulching whole maize straw can significantly improve the number of spike(in addition to T_3),and the number of spike of T_2 was highest.In the four mulching modes,the average soil water storage in 0—200cm layer was significantly higher than that of CK in the whole stages with an increase of 0.7%~1.0%,and the soil moisture condition of T_1 was the best.T_he soil moisture in 0—200cm layer was obviously improved before filling stage,but the soil moisture in 0—90cm layer was generally lower from start of filling stage.Among the four mulching modes,the soil moisture of T_2 in 0—60cm layer was the highest in the whole growth period,and the improvement of the production and water use efficiency of T_2 was also the most significant.