地膜残留量对河西绿洲灌区玉米田土壤理化性状的影响

Effects of Film Residual Levels on Soil Physical and Chemical Properties of Maize Fields in Hexi Oasis Irrigated Area

为探究残留地膜对土壤理化性状的影响,以玉米品种沈单16为指示品种,在半膜覆盖平作栽培条件下,于2015年4月至2020年10月在河西绿洲灌区模拟设置5个地膜残留量水平(0、110、220、440、660 kg/hm^(2)),测定不同残膜水平下土壤容重、土壤紧实度、土壤水分、土壤养分含量等指标。结果表明,随地膜残留量增加,0~30 cm土层土壤容重呈逐渐增加趋势,且玉米拔节前0~10 cm土层土壤温度提高0.14、0.25、0.28、0.43℃。残膜的存在能够减少土壤表层水分蒸发,提高播前土壤含水量,但在玉米苗期由于残膜阻碍水分的下渗,导致30~40 cm土层土壤含水量分别比地膜残留量为0 kg/hm^(2)降低0.11%、1.89%、6.07%、5.93%。当地膜残留量为660 kg/hm^(2)时,土壤有机质、全氮、矿质氮、Olsen-P养分含量显均著低于地膜残留量为0 g/hm^(2),降幅分别为15.57%、10.53%、18.89%、36.32%。长期残膜作用使土壤容重增加、通透性降低,并会降低土壤有机质、全氮、矿质氮及Olsen-P含量,引起土壤质量退化。

To investigate the effects of residual plastic film on soil physical and chemical properties,Shendan 16 was chosen as indicator variety with semi-film mulching and flatten cultivation applied,5 residual levels(0,110,220,440 and 660 kg/ha)were mimicked,soil bulk densities,soil compaction degrees,soil moisture and soil nutrient contents were determined for different residual levels.Results showed that compared with that of the control,with the increase of residual level,soil bulk densities at the depth of 0 to 30 cm were increased,soil temperatures before jointingat the depth of 0 to 10 cm were increased by 0.14,0.25,0.28 and 0.43℃,respectively.Film residues were able to reduce the evaporation from soil surface which would increase the soil water content before sowing,but water infiltration was obstructed by film residues during the seedling stage which led to reduction of soil water content at the depth of 30 to 40 cm,with the increase of residues,the reduction levels,compared with the soil water of level 0 kg/ha at the depth of 30 to 40 cm,were 0.11%,1.89%,6.07%and 5.93%,respectively.At the residual level of 660 kg/ha,contents of soil organic,soil total nitrogen,soil mineral nitrogen and soil Olsen-P were significantly lower compared with that of the level 0 kg/ha,with reduction levels of 15.57%,10.53%,18.89%and 36.32%,respectively.Long-term utilization of film mulching could lead to increased soil bulk density,reduced soil perviousness,reduced contents of soil organic,soil total nitrogen,soil mineral nitrogen and soil Olsen-P,which would lead to soil degradation.