文献类型： 外文期刊

第一作者： Li, JS

作者： Li, JS;Zhang, JJ;Ren, L

作者机构：

期刊名称：IRRIGATION SCIENCE （ 影响因子：2.94； 五年影响因子：3.214 ）

ISSN： 0342-7188

年卷期： 2003 年 22 卷 1 期

页码：

收录情况： SCI

摘要： The simultaneous distribution of water, nitrate, and ammonium from a point source discharging an ammonium nitrate (NH4NO3) solution was measured using the gravimetric method. A 15degrees wedge-shaped plexiglass container was used to represent one twenty-fourth of the complete cylinder. The variables affecting water and solute distributions, including application rate, input concentration, and applied volume were investigated and their effects are presented on a basis of a completely cylindrical system. In the experiments, the apparent cylindrical application rate was varied from 0.6 to 7.8 l/h, the apparent cylindrical applied volume from 6 to 15 l, and the input concentration from 100 to 700 mg/l. Monitoring of the water movement revealed that the ultimate saturated entry radius on the surface increased with the application rate. Surface wetted radius and vertical wetted depth were proportional to the applied water volume with power values of about 0.3 and 0.5, respectively. The shape of the wetted soil zone was clearly related to the application rate and the applied volume. An increase in rate resulted in an increase in the wetted horizontal area and a decrease in the wetted soil depth, while an increase in volume resulted in an increase in wetted horizontal and vertical areas. A uniform distribution of nitrate concentration in the soil was found 15 cm around the point source for a given input concentration. For any input concentration, the accumulation of nitrate at the boundary of the wetted volume was observed. The nitrate concentration in the soil was primarily affected by the input concentration; there was an increased nitrate concentration with a higher input concentration. The results of ammonium distribution measurements indicated that there existed an extremely high ammonium concentration in the proximity of the point source (about 2.5-7.5 cm from the source). An increased input concentration produced a higher ammonium concentration around the point source. Results also demonstrated that the influence of fertigation on the ammonium distribution was restricted in a small volume, about 10 cm around the point source. Beyond this range, input concentration, application rate, and total applied volume had insignificant effects on ammonium distribution. The information obtained from this research is useful in the design, operation, and management of a fertigation system with drip irrigation.

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