秸秆覆盖量对土壤水分利用及春玉米产量的影响

为了探明半干旱区秸秆覆盖栽培中适宜的秸秆覆盖量,在宁南旱区进行了春玉米栽培试验。试验设1.35、0.9、0.45和0万kg/hm24个覆盖量处理,分析了不同覆盖量对土壤水分、玉米产量及水分利用效率的影响。结果表明,4年玉米生育期覆盖量从高到低0～200 cm土层平均土壤贮水量分别较CK(无覆盖)高15.47、10.79 mm和6.26 mm(P<0.05)。试验期间,2009年玉米生育期降雨量最低(为266.1 mm),各处理依次较CK增产13.10%、17.37%和5.40%(P<0.05);2010年玉米生育期降雨量最高(为433.6 mm),各处理依次较CK增产3.91%、7.58%(P<0.05)和1.70%。0.9～1.35万kg/hm2覆盖量增产效果明显,4年平均比CK增产14.23%～12.03%,水分利用效率提高了10.64%～8.87%。宁南旱区,0.9万kg/hm2秸秆覆盖量能更好地蓄水保墒,促进农田土壤水分良性循环,且对提高玉米产量和水分利用效率有显著效果。

Effects of straw mulching quantity on soil water use and spring maize yield

In order to determine the appropriate straw mulching quantity in semiarid areas,a cultivation experiment of spring maize with straw mulching was conducted in the semiarid area of Ningxia.Four different treatments of straw mulching quantities(0 kg/hm2,4 500 kg/hm2,9 000 kg/hm2 and 13 500 kg/hm2) were adopted in field experiment,and an analysis of soil water,spring maize yield and water use efficiency(WUE) was made.In the maize growth period of 4-year experiment,compared with CK(no coverage),average soil water storage amount in 0~200 cm soil layers under all straw mulching treatments(follow the amount of straw mulching from high to low) increased by 15.47 mm,10.79 mm and 6.26 mm(P<0.05) respectively.During the experiment,the lowest precipitation of growth period was in 2009(266.1 mm),when maize production increased by 13.10%,17.37% and 5.40%(P<0.05) respectively;and the highest precipitation of growth period was in 2010(433.6 mm),when maize production increased by 3.91%,7.58%(P<0.05) and 1.70% respectively.The treatments of 9 000~13 500 kg/hm2 had distinct yield-increasing effect,and the average yield of 4 years increased by 14.23%~12.03% and water use efficiency increased by 10.64%~8.87%.In the semiarid area of southern Ningxia,the use of straw mulching amount of 9 000 kg/hm2 could play an active role in the preservation of soil moisture,promote a virtuous cycle of soil moisture,and increase maize yield and maize water use efficiency significantly.