甘肃中东部旱区秸秆还田量对土壤水分、玉米生物性状及产量的影响

Effects of straw returning on soil water,biological traits and yield of maize in the eastern arid region of Gansu

在甘肃省安定区凤翔镇的旱川地上通过大田试验研究了不同秸秆还田量对玉米关键生育期土壤水分、生物性状及产量的影响。试验设计为三个秸秆还田量水平,分别为100%玉米秸秆（10 500 kg·hm-2）粉碎还田、75%玉米秸秆（7 875 kg·hm-2）粉碎还田、50%玉米秸秆（5 250 kg·hm-2）粉碎还田,对照为秸秆不还田。每个处理设3次重复,随机区组排列,玉米秸秆粉碎后均匀翻埋至0~25 cm的土层。结果表明：播前各还田处理0~200 cm土层土壤含水量均较CK有所提高,秸秆还田量由高到低,土壤含水量平均分别提高2.0%、2.8%和1.9%,但不同还田量之间差异不显著;玉米株高、茎粗和叶面积较对照显著增加（P〈0.05）;100%、75%和50%等三个不同秸秆还田量处理的玉米产量较对照分别提高10.3%、5.7%和3.7%,玉米水分利用效率（WUE）较对照分别提高9.2%、4.9%和3.1%。秸秆还田措施可提高土壤的保墒贮水能力,促进作物生长,增加产量,提高水分利用效率。

To investigate the effects of different straw returning treatments on the yield,soil water,and growth characteristics of corn during key growth period,a field experiment was conducted in the area of eastern Gansu province. The experiment of corn straw returning was implemented by three levels including 10 500 kg · hm- 2（ G）,7 875 kg·hm- 2（Z）,and 5 250 kg·hm- 2（D）. The control treatment had no straw returning. Each treatment contained three replicates. With a completely randomized block arrangement,straw was chopped at the length about 5 cm and was uniformly buried in the 25 cm soil layer. The results showed that compared with the control treatment,the average soil moisture in the 0 ~ 200 cm soil layer was significantly increased by 2. 0 %,2. 8 % and1. 9 % by G,Z and D treatments,respectively. The differences were not significant between different straw returning treatments. Compared with CK,maize height,stem diameter and leaf area had been significantly increased（ P 〈0. 05） by 100 % to 50 %. Also,grain yield of corn was increased by 10. 3 %,5. 7 % and 3. 7 %,respectively;WUE of corn was increased by 9. 2 %,4. 9 % and 3. 1 %,respectively. The results indicated that straw returning treatments in the area of eastern Gansu province can increase WUE,ability of soil water storage and soil microbial content,improving soil physical and chemical properties and thereby increasing the yield of corn.