Sduty On The Laws Of Nitrogen Translation And Movement Under Drip-irrigation In The Greenhouse

The study on the rules of nitrogen translation and movement under drip irrigation in the greenhouse has both academic and practical values in the research field of nitrogen translation and movement in unsaturated soil. At the beginning, a two-dimensional mathematical model describing the rules of nitrogen translation and movement through the soil was built in this article. And then, field experiments were conducted to study the problem mentioned above. The experimental and analytical results indicated:1,Under drip irrigation, NH4+-N drived by the diffusion mechanism moves slowly through the soil and accumulates a lot in the area near and around the drip point because of the NHU+-N sorption on the soil stuied. Besides, It's very fast that NH4+-N translates into other forms of nitrogen, mainly NOa"-N in the soil under drip irrigation. For example, 80% NFLt"1"-N will be translated after a short time of two weeks.2,When the rule of movement is concerned, NOs~ - N determined by the convection-dispersion mechanism shows the same rule to water under drip irrigation. However, the concentration distribution patterns of nitrate and water are different. For nitrate, the concentration is much higher both at the boundary of the volume and near the drip point than in the inner region of the wetted volume while the water content in the whole wetted volume to a certain extent is uniform.3,Urea-N is quickly hydrolyzed and translated into NH/-N in less than 3 days after being fertilized to soil through drip irrigation system. In addition, whether the fertigation time is brought forward or be gotten behind will influence the distribution pattern and the rate of translation and movement of Urea-N in the soil under drip irrigation.