RESUMEN
With pot experiment and soil nitrogen desorption model, this paper studied the characteristics of nitrogen desorption in vegetable garden soil, and their effects on the NO3- -N concentration of soil leachate. The results showed that soil leachate NO3- -N concentration had a non-linear relationship with the parameters Q, Cli and C1/lamda of soil nitrogen, but the relationship became linear when these eigenvalues were relatively low. A conception of hi-curve cross point was put forward to assess the soil NO3- -N loss potential. When the eigenvalues were higher than the hi-curve cross point X0, the NO3- -N concentration in soil leachate would be increased rapidly in non-linear form, while on the contrary, the increase would be maintained at a lower level.