秸秆还田和有机肥对宁夏银北盐碱地改良效果研究

Effect of Straw Returning and Organic Fertilizer Measures on Remediation of Soil in Ningxia Saline-alkali Land

研究旨在评估农艺改良措施对宁夏银北灌区盐渍化土壤速效养分、土壤酶活性、土壤物理结构的影响。通过施用有机肥、秸秆还田2种改良措施,并与单施化肥的处理进行对比。结果表明,采取的有机肥(OM)和秸秆还田(RS)2种措施,土壤碱解氮、有效磷和速效钾含量得到有效提高,土壤脲酶和碱性磷酸酶活性显著增强。OM处理>5 mm粒径机械稳定性团聚体占比提高了22.3%,0.5~0.25 mm粒径机械稳定性团聚体占比降低了3.8%;RS处理>5 mm粒径机械稳定性团聚体占比提高了19.1%,0.5~0.25、<0.25 mm粒径机械稳定性团聚体占比分别降低了3.1%、3.2%;OM和RS处理>5 mm粒径水稳性团聚体占比分别提高了29.0%和43.3%,0.5~0.25 mm粒径水稳性团聚体占比分别降低了23.1%和30.1%;OM和RS处理平均重量直径(MWD)分别提高了105.9%和139.7%,团聚体水稳系数(K)分别提高了136.4%和150.5%,团聚体破坏率(PAD)分别降低了28.2%和31.1%,土壤物理结构得到有效改善。这些结果表明,有机肥和秸秆还田是改善宁夏银北灌区盐渍化土壤质量的有效措施。

To study the effects of agronomic improvement treatments on soil available nutrients,enzyme activities and physical structures of Yinbei saline-alkali land in Ningxia,this experiment adopted two treatments of applicating organic fertilizer(OM)and straw incorporation,with application of chemical fertilizer as control.The results showed that OM and straw return(RS)effectively increased the content of soil alkaline hydrolyzable nitrogen,available phosphorus and available potassium,and significantly enhanced the activities of soil urease and alkaline phosphatase.The proportion of mechanical stability aggregates with particle size over 5 mm treated with OM increased by 22.3%,while particle size ranging from 0.5 to 0.25 mm decreased by 3.8%;the proportion of mechanical stability aggregates with particle size over 5mm treated with RS increased by 19.1%,while particle size ranging from 0.5 to 0.25 mm and under 0.25 mm decreased by 3.1%and 3.2%,respectively.The proportion of water-stable aggregates with particle size over 5 mm treated with OM and RS increased by 29.0%and 43.3%,respectively,while particle size ranging from 0.5 to 0.25 mm treated by OM and RS decreased by 23.1%and 30.1%,respectively.The mean weight diameter(MWD)increased by 105.9%and 139.7%,the soil water stability coefficient(K)increased by 136.4%and 150.5%,and the percentage of aggregate destruction(PAD)decreased by 28.2%and 31.1%,respectively,under OM and RS treatments.The soil physical structure was also effectively improved with OM and RS treatment.The results indicate that organic manure and straw returning are effective measures to improve the quality of salinized soil in the Yinchuan Irrigation Area of Ningxia.