不同耕作方式对黑土区农田土壤物理特性的影响

为探讨耕作方式对黑土区农田土壤物理特性的影响,2016年6—9月在内蒙古自治区呼伦贝尔市阿荣旗试验区设置3种耕作方式深松(SS)、免耕(MG)及常规耕作(CK)],分别采集0~10、10~20、20~30 cm土层的土样,对土壤容重、含水量、土壤渗透速率及土壤孔隙度进行调查。结果表明：3种耕作方式土壤容重及含水量均表现为SS>CK>MG;土壤入渗特征表现为初始入渗率>平均渗透率>稳定入渗率;土壤入渗速率及累计入渗量表现为SS>CK>MG;土壤孔隙度以SS处理下最高且随着月份的增加土壤孔隙度降低。主成分分析表明,初始入渗速率和渗透总量对不同耕作方式最为敏感,可以作为考察东北黑土区农田耕作效应与缓解黑土地退化的评价指标。由综合得分可知,不同耕作方式下土壤性能优劣表现为SS>MG>CK。综上,深松耕作可以有效降低土壤容重,提高土壤含水量,促进土壤渗透能力;免耕更有利于水分的保持,降低土壤的无效蒸发。

Effect of Tillage Management Modes on Farmland Physical Properties in Black Soil Region

To understand the effects of different tillage management on black soil area of farmland physical properties,a field experiment was conducted at the Arong Banner of lnner Mongolia from June to September 2016.Three tillage modes including subsoiling(SS),no-tillage(MG),and conventional tillage.By the collect of the soil samples from 0-10 cm,10-20 cm and 20-30 cm respectively,the soil permit heaviness,soil moisture and soil permeability were investigated.The results showed that the soil permit heaviness and soil moisture of three tillage modes were in the order of SS>MG>CK;The eigenvalues of soil infiltration were in the order of initial infiltration rate>average infiltration rate>stable infiltration rate.The soil infiltration rate and cumulative infiltration were in the order of SS>MG>CK.Soil total porosity was the highest under SS treatment, and soil porosity decreased with the increase of month.Principal component analysis showed that the initial infiltration rate and total infiltration amount were most sensitive to different tillage management, and could be used as an evaluation index to investigate farmland tillage effect and mitigate black soil degradation in the black soil region of Northeast China. According to the comprehensive score, the performance of soil under different tillage management is SS>MG>CK. In conclusion, subsoiling tillage can effectively reduce soil bulk density, increase soil water content, and promote soil permeability; no-tillage is more conducive to water conservation and reduce soil evaporation.