THE INFLUENCE OF SOIL CONFIGURATION OF RICE PADDY IN THE YELLOW RIVER BEACH ON THE RICE YIELD AND SOIL HYDRAULIC CHARACTERISTIC

摘要

Field experiment was conducted in Yellow River Beach and soil column experiment was conducted in lab to evaluate the optimal soil configuration suited for rice growth. Yellow River Beach soils were formed from sandy parent material with high air-filled porosity and poor water retention of the soil and cannot support the rice growth. Therefore, the artificial soil configuration was composed of the plow pan and the plough layer. The plough layer was formed by the covering loess, and the plow pan was constituted by the mixture of sand and FA (fly ash), which could be because that FA could amend soil by improving the soil water retention. In the field experiment, the influence of thickness of the plough layer on the rice yield and quality was explored. In the lab experiment, the influence of the constitution (i.e., ratio of FA to sand and compactness degree) of the plow pan on the hydraulic characteristic of the soil was studied. Based on our result, the optimal soil configuration in the yellow river beach appropriated for rice growth could be the constituted by the 30cm thickness of covering loess and plow pan with 1:2 ratio of FA to sand and 1.8g/cm3 bulk density, considering the engineering cost. In view of serious problem of arable land resources in China, the study of the optimal soil configuration of rice paddy soil in the Yellow River Beach was necessary, considering such remediation method could be applied in large area to improve the soil productivity in the Yellow River Beach.