秸秆还田及蚯蚓活动对小麦-玉米轮作下土壤水分运移的影响

Effects of straw returning and earthworm activity on soil water transport under wheat-maize rotation

为探讨关中平原小麦-玉米水分高效利用的栽培技术方式,采用田间定点观测方法,研究秸秆还田+接种蚯蚓处理对土壤含水量的影响。设置CK(对照)、S_(1)(秸秆还田3000 kg·hm^(-2))、S_(2)(秸秆还田6000 kg·hm^(-2))、E(接种蚯蚓)、S_(1)E(秸秆还田3000 kg·hm^(-2)+接种蚯蚓)、S_(2)E(秸秆还田6000 kg·hm^(-2)+接种蚯蚓)共6个处理。结果表明:各处理较CK处理均提高了土壤含水量,S_(1)、S_(2)、E、S_(1)E、S_(2)E处理下土壤含水量分别增加0.21%~27.47%、0.43%~32.85%、1.00%~15.53%、3.25%~36.52%、2.97%~51.24%。CK、S_(1)、S_(2)、E、S_(1)E、S_(2)E处理下土壤含水量分别为15.51%、17.14%、17.66%、16.33%、17.94%、18.91%;S_(2)E处理土壤蓄水保水效果最佳,S_(2)、S_(1)处理次之,E处理效果最差。由小麦扬花期、收获期到玉米抽雄期、收获期,不同处理下0~100 cm土壤含水量整体呈增长趋势,最大均值在玉米收获期(20.60%),最小均值在玉米抽雄期(8.63%)。相比于CK处理,其余处理均扩大了高含水区范围,且接种蚯蚓处理下土壤高含水区范围大于未接种蚯蚓处理。对小麦-玉米生长期土壤含水量影响因素相关分析结果显示,土壤含水量与>0.25 mm的大团聚体、SOC含量、TN含量呈显著正相关关系(P<0.05),与0.053~0.25 mm、<0.053 mm的土壤团聚体、pH值、毛管孔隙呈显著负相关关系(P<0.05)。可见,秸秆还田与蚯蚓活动有利于增加土壤含水量,扩大深层高含水区,提高土壤蓄水能力,进而提高降水利用效率。

To explore the cultivation techniques of wheat and maize water efficient utilization in Guanzhong Plain,the method of spot observation in the field was used to study the effect of straw returning and earthworn inoculation on soil water content.The treatments included CK(control),S_(1)(straw returned to the field 3000 kg·hm^(-2)),S_(2)(straw returned to the field 6000 kg·hm^(-2)),E(inoculated earthworms),S_(1)E(straw returned to the field 3000 kg·hm^(-2)+inoculated earthworms),S_(2)E(straw returned to the field 6000 kg·hm^(-2)+inoculated earthworms).The results showed that:compared with CK,the soil water contents under S_(1),S_(2),E,S_(1)E and S_(2)E treatments increased by 0.21%~27.47%,0.43%~32.85%,1.00%~15.53%,3.25%~36.52%and 2.97%~51.24%,respectively.The soil water contents under CK,S_(1),S_(2),E,S_(1)E,and S_(2)E treatments were 15.51%,17.14%,17.66%,16.33%,17.94%and 18.91%,respectively.S_(2)E treatment had the best water retention effect,followed by S_(2) and S_(1) treatment,and E treatment had the least obvious effect.From wheat flowering stage and harvest stage to maize despot stage and harvest stage,soil moisture content of 0~100 cm showed an overall increasing trend under different treatments,with the maximum mean value was 20.60%at maize harvest stage and the minimum mean value was 8.63%at maize despot stage.Compared with CK,other treatments expanded the range of high water cut areas,and the range of high water cut areas in soil treated with earthworms was larger than that without earthworms.The correlation analysis of factors affecting soil water content in wheat-maize growing period showed that soil water content was significantly positively correlated with large aggregates>0.25 mm,SOC content and TN content(P<0.05).It was significantly negatively correlated with soil aggregates,pH and capillary pores of 0.053~0.25 mm and<0.053 mm(P<0.05).In conclusion,the joint action of straw returning to field and earthworm activity increased soil water content and expands deep high water cut area.