不同厚度地膜连续覆盖对玉米田土壤物理性状及地膜残留量的影响

为了探明不同厚度地膜对土壤物理性状及地膜残留量的影响,采用大田定位试验,连续4年对玉米田分别进行0.006 mm、0.008 mm(CK)、0.010 mm、0.012 mm厚地膜覆盖处理。结果表明:10~40 cm土层,随着地膜厚度的增加,土壤紧实度和土壤容重降低。0.010 mm、0.012 mm处理土壤容重比0.008 mm(CK)分别降低了1.25%、2.43%,而0.006 mm处理比CK提高0.76%。2玉米播种至大喇叭口期,0.006 mm、0.010 mm、0.012mm处理0~5 cm土层分别日均土壤温度比CK提高-0.90℃、0.23℃和0.40℃;5~10 cm比CK提高-0.50℃、0.19℃和0.28℃。且随玉米生育进程的推进,增温效应逐渐弱化。3在灌水第25 d,0~100 cm土层,0.006mm、0.008 mm、0.010 mm、0.012 mm处理土壤储水量分别为166.73 mm、170.42 mm、190.00 mm、195.97 mm,比灌水第5 d分别下降46.81%、45.75%、39.32%、37.62%。4在0~30 cm土层,残留地膜量浅层显著多于深层,面积小于4 cm2小块膜片数显著多于面积为4~25 cm2和≥25 cm2的中、大膜块。0.006 mm、0.008 mm、0.010mm、0.012 mm处理4年累计残膜量分别为79.03 kg/hm2、57.68 kg/hm2、50.32 kg/hm2、53.58 kg/hm2,0.006 mm处理残留量显著高于CK。综合分析连续覆盖不同厚度地膜对土壤物理性状及地膜残留量的影响,建议在农业生产中推广使用厚度0.008 mm以上的地膜。

Effects of Continued Mulching of Plastic Film with Different Thickness on Soil Physical Properties and Film Residues in Maize Field

To investigate the effects of different thickness plastic film mulching on soil physical properties and plastic film residues in soil, this paper carried out 4 continuouse years studies by adopting a field trial. The results showed that: ①soil compactness and soil bulk density decreased in 0~40 cm soil layer as the thickness of plastic film increased. The soil bulk density for treatments of 0.010 mm and 0.012 mm decreased by 1.25% and 2.43%, respectively, while, that of 0.006 mm increased by 0.76% compared to 0.008 mm（CK）. ②From planting to bellbottom, daily average soil temperature for treatments of 0.006 mm, 0.010 mm and 0.012 mm increased by -0.90℃, 0.23℃ and 0.40℃ in 0~5 cm and -0.50℃, 0.19℃ and 0.28℃ in 5~10 cm soil, compared to that of the CK. The temperature increasing effect gradually weakened with the maize growing. ③In 25 d after irrigation, the soil water contents for treatments of 0.006 mm, 0.008 mm, 0.010 mm and 0.012 mm were 166.73 mm, 170.42 mm, 190.00 mm and 195.97 mm, respectively, decreased by 46.81%, 45.75%, 39.32% and 37.62%, respectively, compared to that irrigation after 5 d in 0~100 cm soil layer. ④In 0~30 cm soil layer, the amount of film residue in shallow soil was significantly more than that in deep soil, the film blocks with area of less than 4 cm2 were significantly more than that with area of 4~25 cm2 and above 25 cm2. The total accumulative film residues reached 79.03 kg/hm2, 57.68 kg/hm2, 50.32 kg/hm2, 53.58 kg/hm2 in 4 years for treatments of 0.006 mm, 0.008 mm, 0.010 mm and 0.012 mm. The residues for treatment of 0.006 mm were significantly higher than that of the CK. The plastic film with more than 0.008 mm of thickness was suggested to be used widely in crop production by comprehensive analysis of soil physical properties and influence of film residues.