土壤水分对土壤中硝态氮水平运移的影响

对硝态氮示踪的风沙土和黄潮土中水分及其扩散率进行了研究.结果表明,硝态氮水平运移速率受土壤含水量的影响较大,并随土壤含水量增加而增加.硝态氮水平运移速率随土壤水分扩散率的变化呈指数曲线变化趋势.硝态氮水平运移浓度随土壤含水量的增加而减少,并呈幂函数曲线变化,硝态氮水平运移浓度与含水量的相关系数达到极显著水平.硝态氮水平运移浓度还受到土壤水分扩散率的影响,随土壤水扩散率的升高而下降,并在湿润锋(土壤干湿交界)面上达到最大值.

Influence of soil moisture on the horizontal transport of nitrate-N in the soil

The water moisture and its diffusivity in yellow fluvo-aquic and aeolian sandy soils traced by nitrate-N were studied. The transport velocities of nitrate-N was influenced greatly by and increased with the water content of soil. The transport velocities of nitrate-N tended to change with the soil moisture diffusivity, presenting index curve, nitrate-N transport concentration decreased with increase of water content of soil, presenting exponential function curve; and the correlative factors of the transport concentration of nitrate-N with the water content all reached very obvious level. The transport concentration was also influenced by the soil moisture diffusivity, and decreased with increase of the diffusivity and reached maximum value at the surface of wet spearhead, the interface of wet and dry soil.