| In this paper, experimental field data based on Tianjin Agricultural laboratory wasanalyzed. Nitrogen transport transformation model was discussed, and different cropirrigation mode settings were obtained so that wastewater irrigation can be betterutilized.This article includes two parts: field trials section and laboratory experimentssection. The field trials section set outdoors in different parts of the irrigation watertreatment; each water treatment has nine partitions. And irrigation experiment wasconducted. Meanwhile, according to the growth characteristics, the plants werefertilized. During the growing period, the plants needed to be irrigated and takensamples at different depths of water. The samples were used for analysis to exploretrends of nitrogen content in Tianjin groundwater at a depth of about1.6meters andgive out irrigation mode in the real crop growth environment and obtain the fitirrigation schemes, which didn·t lead to the groundwater and soil pollution.In the laboratory experiments section, five soil columns of2m high were set.Under the condition of soil of the same physical parameters and the same volume rate,irrigation test was conducted, using the different irrigation modes. According todifferent water quality and different time, they were irrigated and taken the samples indifferent depth. Without the external factors condition such as precipitation andfertilizer, samples were analyzed. Then the trends of nitrogen content at a depth ofabout1.6meters would be collected. Under the condition of no crop growth, theirrigation schemes didn·t lead to the groundwater and soil pollution.According to the diffusion equation about NH4-N and NO3-N, the parameterespecially soil moisture are simulated. Under particular boundary conditions, analogconversion of concentration of surface water nitrogen will be achieved in particularenvironmental conditions and soil conditions, which can obtain the concentrationchanges of the simulated values for critical groundwater. According to the model andthe measured results, irrigation scheme will be finished, which have certain guidingproduction capacity. |
