[Effects of heavy machinery operation on the structural characters of cultivated soils in black soil region of Northeast China].
With the cultivated soils in black soil region of Northeast China as test objects, this paper measured their structural characters such as soil strength, bulk density, and non-capillary porosity/capillary porosity (NCP/CP) ratio before and after heavy and medium-sized machinery operation, aimed to study the effects of machinery operation on the physical properties of test soils. The results showed that after machinery operation, there existed three distinct layers from top to bottom in the soil profiles, i.e., plowed layer, cumulative compacted layer, and non-affected layer, according to the changes of soil strength. Under medium-sized machinery operation, these three layers were shallower, and there was a new plow pan at the depth between 17.5 and 30 cm. Heavy machinery operation had significant positive effects on the improvement of topsoil structure (P < 0.05). After subsoiling and harvesting with heavy machinery, the bulk density of topsoil decreased by 7.2% and 3.5%, respectively, and NCP/CP increased by 556.6% after subsoiling, which would benefit water infiltration, reinforce water storage, and weaken the threat of soil erosion. The main action of heavy machinery operation was soil loosening, while that of medium-sized machinery operation was soil compacting.
Wang
En-Heng
EH
College of Forestry, Northeast Forestry University, Harbin 150040, China. erxin222@163.com
Chai
Ya-Fan
YF
Chen
Xiang-Wei
XW
D000383:Agriculture / Q000379:methods*; D002681:China; D004784:Environmental Monitoring; D016062:Porosity; D012987:Soil / Q000032:analysis*; D014867:Water / Q000032:analysis*
D012987:Soil; D014867:Water