外源有机物料提升农田黑土抗机械扰动能力研究

Improving Resistance of Black Soil to Mechanical Disturbance with Added Organic Materials

【目的】为探明外源有机物料是否可以增强农田黑土抗机械扰动能力。【方法】以典型黑土区长期机械作业的农田土壤为研究对象,设置添加3种常见外源有机物料(秸秆、生物炭、猪粪肥)、3个含量梯度(少量、实际还田量、大量)10个处理的室内恒温恒湿培养试验,随后进行4个机械扰动强度(0、500、1500和4500 J)的模拟机械扰动试验,探讨在添加外源有机物料条件下机械扰动对土壤团聚体稳定性的影响。【结果】有机物料种类、添加量以及机械扰动强度显著影响平均重量直径、几何平均直径和团聚体破坏率,添加秸秆后的土壤团聚体平均重量直径分别是生物炭、猪粪肥的1.40、1.23倍;几何平均直径分别是生物炭、猪粪肥的1.22、1.12倍。【结论】添加秸秆可显著增强农田黑土团聚体抗机械扰动能力,添加猪粪肥效果次之,生物炭效果不显著;机械扰动以及有机物料修复均对>1 mm团聚体破坏率作用最为显著,>1 mm团聚体可作为农田黑土抗机械扰动能力以及有机物料添加效果的评价指标。

[Objective]To find out whether added organic materials can enhance the ability of Black soil to resist mechanical disturbance in cultivated land.[Method]Based on the farmland soil from typical black soil region under long-term mechanical operation,the constant temperature-humidity culture experiment were set up with 10 treatments after adding three different exogenous organic materials(straw,biochar,pig manure)with different content gradients(low amount,normal returning amount,high amount),and then mechanical disturbances of four intensities(0,500,1500 and 4500 J)were conducted to explore the effect of mechanical disturbance on the aggregates’stability in the treatments of adding exogenous organic materials.[Result]The mean weight diameter,geometric mean diameter and percentage of aggregate destruction were significantly influenced by the type and the amount of material,and the intensity of mechanical disturbance.The mean weight diameter of soil aggregate after adding straw was 1.40 and 1.23 times of biochar and pig manure,respectively.And geometric mean diameter was 1.22 and 1.12 times of biochar and pig manure,respectively.[Conclusion]Adding straw can significantly improve the ability of Black soil aggregate to resist mechanical disturbance,following by adding swine manure,and no significant improvement by adding biochar.Mechanical disturbance and organic material amendment both have the significant effect on>1 mm aggregate.Therefore,the>1 mm aggregate is suggested to be used to evaluate the ability of black soil to resist mechanical disturbance,and the effect of organic material amendment for cultivated land.