Characteristics of residual plastic film and effect on soil physical properties of continuous cropping field for maize seed in Zhangye
[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.
maize seedplastic film residuedistribution characteristicssoil physical properties
万方数据
维普
