机械耕作对水田土壤的破坏与防止措施的调查研究——Ⅰ.机械耕作对水田土壤的破坏现象和原因

两年来,我们对水田土壤的机械耕作问题,进行了广泛的系统调查研究,并对与农机没计运用和土壤管理有密切关系的土壤物理性质、机械行走机构在水田土土壤中的性能,进行了田间试验和测定。观测证实:机械耕作条件,引起土壤破坏的有机械、土壤和人为等三个因素,在不同地区、不同土壤和不同的管理措施,破坏表现有差异。粘质田为扩大泥脚变化幅度和深度,引起打滑、陷车。而砂质田使耕作层变浅,犁底层加深且压实。使土壤退化原因,与其说是机械耕作反复作用,破坏犁底层,不如说是人为搅动和不合理的土壤管理作用。

INVESTIGATIONS ON THE DESTRUCTION OF MECHANICAL TILLAGE IN PADDY SOIL AND ITS PREVENTIVE MEASURES Ⅰ. THE APPEARANCES AND CAUSES OF DESTRUCTION WITH MECHANICAL TILLAGE IN PADDY SOIL

Systematic and wide investigations in the mechanical tillage of soil and simulatcd tests to determine the physical properties of soil and the perfermances of the mechanical walking devices in paddy fields were made in 1979-1980. The study confirms that there are three factors resulting in the destruction of soil. namely, the machinery, the soil and the human activity, The expression of destruction is different in various areas and soils. In a claycy field the soil depth and its fluctuation are increased, causing tractor to slip and get stuck in the mud. while in a sandy field the cultivated soil is shallowed with the hard pan compacted and deepened. The reasons for soil deterioraction are from human disturbance and unreasonable soil management rather than repeated action of mechanical tillage.