残膜对土壤氮排放和氮肥利用效率的影响

Effect of Plastic Film Residue on Soil Nitrogen Emissions and Nitrogen Use Efficiency

[目的]为探明不同残膜量对氮素利用效率及损失的影响。[方法]试验设置5个不同残膜量(0,180,360,720,1440 kg/hm^(2))和2种残膜类型(聚乙烯和生物降解残膜),通过盆栽试验,研究不同残膜含量对土壤全氮、氮素气态损失、氮肥利用效率及番茄生长等指标的影响。[结果]随着残膜含量的增加,土壤氨气和氧化亚氮的累积排放量呈先增大后减小的趋势,当残膜含量达到720 kg/hm^(2)时,氨气累积挥发量显著减少11.31%~13.70%,氧化亚氮累积排放量减少4.74%~5.13%;土壤中氮素残留量无显著差异。当残膜含量低于180 kg/hm^(2)时,地膜残留促进番茄的生长;当残膜含量高于180 kg/hm^(2)时,地膜残留抑制番茄的生长。低残膜含量对氮肥利用效率无显著影响,当含量高于360 kg/hm^(2)时,氮肥利用效率与残膜含量呈负相关关系。通过综合分析,土壤残膜含量应控制在180 kg/hm^(2)内才不会对作物生长造成不利影响。此外,由于可降解地膜的降解特性,其对植株氮素吸收和氮肥利用效率的不利影响弱于聚乙烯残膜。[结论]降解地膜替代聚乙烯地膜具有一定的可行性。

[Objective]The aim of this study is to investigate the effects of different residue amounts on nitrogen utilization efficiency and losses.[Methods]The experiment involved five different residue amounts(0,180,360,720,1440 kg/hm^(2))and two types of residues(polyethylene and biodegradable residues).Through pot experiments,the study examined the impact of different residue contents on soil total nitrogen,nitrogen gas losses,nitrogen fertilizer utilization efficiency,and tomato growth indicators.[Results]The research indicates that with an increase in residue content,the cumulative emissions of ammonia and nitrous oxide in the soil show a trend of first increasing and then decreasing.When the residue content reaches 720 kg/hm^(2),the cumulative ammonia emission significantly decreases by 11.31%to 13.70%,and nitrous oxide emission decreases by 4.74%to 5.13%.There was no significant difference in nitrogen residue in the soil.When the residue content is below 180 kg/hm^(2),the residue promotes tomato growth;when the residue content is above 180 kg/hm^(2),it inhibits tomato growth.Low residue content has no significant effect on nitrogen fertilizer utilization efficiency.However,when the content is higher than 360 kg/hm^(2),nitrogen fertilizer utilization efficiency shows a negative correlation with residue content.Through comprehensive analysis,it is suggested that soil residue content should be controlled within 180 kg/hm^(2) to avoid negative effects on crop growth.Furthermore,due to the degradable nature of biodegradable residues,their adverse effects on nitrogen absorption by plants and nitrogen fertilizer utilization efficiency are weaker than those of polyethylene residues.[Conclusion]Therefore,replacing polyethylene residues with biodegradable residues is considered feasible.