Modeling Soil Salt and Nitrogen Transport under Different Fertigation Practices with Hydrus-1D

摘要

In this study the effects of different fertigation practices on salt and nitrogen dynamics were analyzed in the Hetao District, China by using the Hydrus-ID model. The results indicated that the soil electrical conductivity increased gradually with depth after irrigation and the electrical conductivity of 0～60 cm depth changed faster than that of 60～100 cm depth. However, the soil ammonium nitrogen concentration decreased with depth and high irrigation intensity could promote the increase of ammonium nitrogen while reducing the differences of their distributions in soil profile. In addition, when the initial urea application was in a small amount (10 g), the nitrate nitrogen concentration increased with soil depth while decreased with irrigation intensity after irrigation. Furthermore, both ammonium and nitrate nitrogen content of soil profile rose with increasing initial urea application amount, which played a more important role in the changes of soil ammonium (0～100 cm) and nitrate (0～80 cm) nitrogen content than irrigation intensity.