Experiment on water and nitrogen transport characteristics of wetting body in bubbledroot irrigation
HE Zhenjia, FU Yuliang.
1. Shaanxi Provincial Land Engineering Construction Group Co., Ltd, Xi′an, Shaanxi 710075, China; 2. School of Water Conservancy, North China University of Water Resources and Electric Power, Zhengzhou, Henan 450045, China)
In the jujube micro irrigation demonstration base on Mizhi Mountain of northern Shaanxi, infiltration experiments of fertilizer solution were carried out in undisturbed soil in bubbledroot irrigation to study wetting soil body and nitrogen transport characteristics. The results showed that infiltration capacity of bubbledroot irrigation increased with increasing fertilizer concentration and the relationship between cumulative infiltration and infiltration time was in accord with Kostiakov model. The vertical and horizontal migration speeds of wetting front increase with increasing fertilizer concentration, and can be expressed as a power function of time. The greater the concentration of fertilizer solution, the deeper the wetting depth of wetting body in the same time, and the higher the soil moisture in the same position. The distribution of average water content of soil water in bubbledroot irrigation with different fertilizer concentrations was similar to the distribution of concentration of fresh water. The higher the concentration of fertilizer and the higher the water content in the same soil depth. Under a certain fertilization condition, the contents of NO-3-N and NH+4-N in the same infiltration depth of infused fluid by bubbledroot irrigation increase with increasing concentration of fertilizer solution. After water redistribution, the contents of NO-3-N and NH+4-N in the depth of 70 cm are near their back ground values in the soil.
HE Zhen-Jia,FU Yu-Liang-.. Experiment on water and nitrogen transport characteristics of wetting body in bubbledroot irrigation[J]. Journal of Drainage and Irrigation Machinery Engin, 2019, 37(1): 73-79.