秸秆覆盖量对土壤水分利用及春玉米产量的影响

摘要

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、10.79mm和6.26mm(P＜0.05).试验期间,2009年玉米生育期降雨量最低(为266.1mm),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433.6mm),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.%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 un-der 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.