摘要
[目的]研究张掖市玉米制种田地膜残留的时空分布特征及对土壤物理性状的影响.[方法]通过分层采集不同连作年限(1、5、10、15、20 a)玉米制种田残留地膜和土壤样品,测定其单位面积残膜数量、质量、残膜面积变化和分布特征,以及残膜对土壤容重、孔隙度等物理性状的影响.[结果]随着覆膜连作年限的增加,土壤中残膜数量与质量呈增加趋势,每年分别以136.79×104片/hm2和13.416 kg/hm2的速度增加,主要分布在0～20 cm耕作层.随着覆膜连作时间的延长,残膜有向深层土壤迁移的空间分布变化特征.残膜主要以面积为0～5 cm2和5～25 cm2的碎片为主,连续覆膜5～20 a面积<25 cm2地膜碎片占总地膜残留量的51.79%～98.21%.随着残膜累积量的增加,土壤容重呈增加趋势,孔隙度呈降低趋势.[结论]张掖市玉米制种田连续覆膜5 a以上,田间地膜残留量超过国家标准限值,应加强残膜回收、生物降解膜替代等措施,以缓解该区域制种玉米产业发展中残膜污染问题.
Abstract
[Objective]To study the spatial and temporal distribution characteristics of mulch residue in seed maize field and its effect on soil physical properties in Zhangye.[Method]Residual film and soil samples were collected from maize seed plots that had been cultivated continuously for different years(1 a,5 a,10 a,15 a,20 a).The quantity,quality,variation and distribution of residue film per unit area and the ef-fects of residue film on soil bulk density,porosity and other soil physical properties were measured.[Result]With the extension of continuous cropping years,the quantity and quality of residual film in soil also in-creased,at the rate of 136.79×104 pieces/hm2 and 13.416 kg/hm2,respectively.The residual film was mainly distributed in the 0～20 cm tillage layer.However,with the extension of continuous mulching time,the residual film had a change of distribution characteristics:spatially migrating to deep soil.Mainly,mulch film residues consisted of debris residues of 0～5 cm2 and 5～25 cm2,after 5～20 years of continuous mulch-ing,the film fragments with an area of<25 cm2 accounted for 51.79%～98.21%of the total mulch film residues.With the accumulation of film residues,the bulk density of the soil increased while the porosity de-creased.[Conclusion]In Zhangye,under the premise of continuous mulching for more than 5 years,the re-sidual film in the seed maize field was far above our government standard.Therefore,for the prosperity of maize seed production in this area,measures such as film recycling or biodegradable film replacement should be emphasized and strengthened to control residual film pollution.
维普
万方数据