渭北旱塬不同秸秆覆盖量对土壤水分和春玉米产量的影响

Effects of different rates of straw mulch on soil moisture and yield of spring maize in Weibei Highland area of China

为了探明不同秸秆覆盖量对渭北旱塬土壤水分及春玉米产量的影响,于2008-2009年在陕西合阳县旱农试验站进行了3个水平的秸秆覆盖量(4500、9000和13500kg/hm2)试验,以不覆盖为对照(CK)。2a结果表明,3个处理0～200cm土层平均土壤贮水量较CK均显著提高,分别增加16.52、25.52和34.04mm(P<0.05);播后0～60d,农田蒸散量较CK分别减少4.43、8.23(P<0.05)和6.96mm(P<0.05);9000kg/hm2处理2年平均籽粒产量及水分利用效率表现最优,较CK分别提高11.03%(P<0.05)和9.25%(P<0.05),13500kg/hm2处理次之,4500kg/hm2处理最差。本研究表明,渭北旱塬春玉米生育期降水量低于390mm时,不同秸秆覆盖量处理蓄水保墒及增产效应明显,且以9000kg/hm2覆盖量为宜。

A field experiment（2008-2009） was conducted at the Heyang Dryland Farming Experimental Station in Shaanxi Province of China to determine the effects of straw mulch rates on soil moisture and spring maize（Zea mays L.） yield.Maize straw at rates of 0（CK）,4 500,9 000 and 13 500 kg/hm2 was placed on field plots.The results indicated that the average soil water storage in the 0-200 cm soil layers under the three different rates of straw mulch were 16.52,25.52 and 34.04 mm,respectively,significantly（P0.05） higher than that of CK,and the average field evapotranspiration（ET） in the 0-200 cm soil layers were 4.43,8.23 and 6.96 mm,respectively,significantly（P0.05） lower than that of CK during 0-60 days after sowing.Besides,the average grain yield and water use efficiency（WUE） of the treatment with 9 000 kg/hm2 of straw mulch were optimal among the treatments,its grain yield and WUE increased by 11.03%（P0.05） and 9.25%（P0.05） compared with the CK,while it was medium with the treatment of 13 000 kg/hm2,and lowest with the treatment with 4 500 kg/hm2.It is suggested that the treatment with 9 000 kg/hm2 of straw mulch is preferable for Weibei highland area in China,as the precipitation is below than 390 mm during the maize growing season.