Coupling characteristics of soil water and nitrogen under intermittent infiltration

Coupling characteristics of soil water and nitrogen under intermittent infiltration with different fertilization concentrations were analyzed to study the effect of fertilization concentration on intermittent infiltration characteristics under surge fertigation. The results indicate that intermittent infiltration and infiltration rate increase with the increase of the fertilizer concentration at the same infiltration time, and it is obvious at the first period and is slow with the increase of periods gradually. The mechanism that intermittent infiltration increased with fertilizer concentration was analyzed. The intermittent infiltration model based on　simplified Philip infiltration equation was suggested, and the relationships between intermittent infiltration parameters for different fertilizer concentrations and pure water continuous infiltration parameters were established, which could calculate intermittent infiltration under surge fertigation with continuous infiltration data and fertilizer concentrations. The example indicates that the method is simple and in effecte.