The Water Balance as Affected by Conservation and Conventional Tillage Practices on Slope Fields in the Drylands of North China

摘要

Soil erosion by water is a severe problem in the eastern loess belt of Northern China, particularly on agricultural land. The erosion problems are to a large extent associated with improper soil tillage practices. Changing the current tillage practices could therefore reduce soil loss. This will, however, also affect the water balance and hence the available water for crop growth, particularly in dryland farming systems. A field study was carried out on five plots on a slope field near Luoyang, Henan province, China, in order to compare the water balance under different soil tillage practices. The terms of the water balance were determined from August 1999 until April 2001. From October to June all plots were under winter wheat. After harvesting, four soil tillage practices were applied: conventional tillage, no tillage, subsoiling and reduced tillage. A two-crop rotation of winter wheat and summer corn or peanuts was applied as well. Analysis of the different components of the soil water balance enabled to determine the most suitable practice for crop growth. The results, though preliminary at this stage of the study, show that subsoiling resulted in the highest increase in moisture storage and lowest evaporation during the fallow period. The two-crop rotation with peanuts also showed promising results, mainly due to decreased evaporation of the soil surface. The no-tillage and conventional tillage gave intermediate results, whereas the reduced tillage was the worst alternative.