半干旱区秸秆覆盖量对土壤水分保蓄及作物水分利用效率的影响

2007～2008年在宁夏南部半干旱地区旱作春玉米播前设置了4种不同秸秆覆盖量(0、0.45、0.9、1.35万kg/hm2)处理,分析了该区秸秆覆盖量对土壤水分保蓄及水分利用效率的影响.两年定点试验表明,不同秸秆覆盖量对土壤含水量影响存在季节性、层次性差异;0.9 kg/hm2覆盖量处理,在玉米大喇叭口期以前,对保持0～40 cm土层的土壤含水量有显著效果(P< 0.05),较对照土壤水分含量提高了14.2%;秸秆覆盖量达到1.35万kg/hm 2时,土壤含水量不再显著增加.0.9～1.35万kg/hm2覆盖量处理较对照增产显著(P<0.01),幅度达16.9%;玉米水分利用效率较对照增加了4.3～5.6 kg/(mm*hm2),达到了极显著水平(P<0.01).

Effects of different straw mulching quantity on soil water and WUE in semiarid region

The study on the effects of different straw mulchi ng quantity (0, 4 500, 9000 and 13 500 kg/hm2) on soil water and water use eff iciency of spring maize was conducted in semiarid area of Ningxia from 2007 to 2 008. The results showed that the effects of straw mulching treatments on soil wa ter varied in different crop growth stages and soil layers. Straw mulching treat ment of 9 000 kg/hm2 had significant effect on soil water content of 0～40 cm soil layer compared with CK (P<0.05), and the soil water content increased b y 14.2%. The treatment of 13 500 kg/hm2 raised soil water content insignifi cantly compared with treatment of 9 000 kg/hm2. 9 000～13 500 kg/hm2 treatme nts could increase the yield by 16.9% (P<0.01), water use efficiency of sp ring maize increased by 4.3～5.6 kg/(mm*hm2) compared with CK (P<0.01).