The Simulation Research On The Nitrogen Transport Rule In The Soil Under Re-use Water Irrigation

It is the long and hard work to resolve our country's problem of the water pollution and water resources short. It is an important way to make reused water available that use the reused water to irrigate. It has two effects: one is increasing the water supply, and another is decreasing the sewage water discharge. It will cut down the cost of treating sewage water, make the soil more fertilized.The main pollution in the sewage water is nitrogen. It is absolutely necessarily nutrition for crop growing. Studying on nitrogen's transport and transformation rule in the soil-plant system is very meaningful to reasonablely use the reused water resources, furthest improve the using efficiency and reduce the water environment pollution of the nitrogen's evluviation.Since opening and reformation, our country's drove and fowl'plant keeps development fast. It improves the structure of the agricultural production and the rural economic development. But on the other hand, it restricts the area's sustainable economic development, because of the large discharge of the waste, the high pollution content, the deficiency of the treat utility, the environment deterioration. So, it has become an important problem to improve the treatment and using as resources of brove and fowl plant's sewage water. This paper conjecting the Beijing city's important science and technology project"The demonstrating research on the reused water irrigation in Beijing"(H030730040230), uses the reused water from the fowl plants to irrigate, and has a research on the netrogenous fertilizer resolved distribution rule in the soil. In this paper, it was using the advanced model Hydrus-2D to simulate the nitrogen concentration distribution along the depth with different time in the root zone. The climate, crop, soil's parameters were determined by investigated and tested methods, and built a simulate nitrogen transport model for reused water irrigation, and improved the simulated computers agreed well with the experiment's. After 12d from irrigation, the absolute error of the nitrogen along the depth 20cm, 40cm, 60cm are 0.0001, 0.0003, 0.0012.The result of the simulate indicated that, during the irrigation, the nitrogen concentration in the soil will increased with the concentration in the irrigation water, increased with the quantity of water, and make accumulation with the interval-time of irrigation in 10d.So, the model in this paper, has simulated nitrogen transport under different irrigation conditions, and simulated the nitrogen distribution under the wheet and corn grown. It has important meaning to make reasonable irrgation systerm and use reused water for irrigation scientificly and reasonably.