| Irrigation facilities the nitrogen fertilizer rainfall (rehydrated) is more common in agricultural production and irrigation after fertilization rainfall (rehydrated) easily lead to the re-distribution of the nitrogen in the soil and leaching, so that not only will reduce nitrogen utilization The rate of serious pollution and loss of nitrate in the nitrogen fertilizer causes environmental.In order to clear irrigation the complex water (precipitation) impact on the distribution of water and nitrogen in the soil, as well as choose the reasonable irrigation embodiments, this article by water complex multi-pit irrigation water test, respectively, studied the migration of water and nitrogen in the soil after rehydration changes in different multiplexing water (1.06L,1.75L,3.03L) and different rehydration time interval (1d,5d,10d) rewatering migration of water and nitrogen, and analysis of the comparison of the same rehydration conditions under single pit irrigation and the similarities and differences of the distribution of multi-pit irrigation soil water and nitrogen, concluded as follows: 1.After irrigation water is mainly concentrated in the vicinity of water storage pit, the moisture content decreases with the radial distance, with vertical distance increases first and then decreases.Increased soil moisture and humid range rehydration moisture more evenly distributed, and the complex water the greater the greater the soil moisture content after rehydration, moist greater the scope, the more uniform moisture distribution.In the case of the same complex of water, r≤35cm rehydration time interval, the longer the greater the moisture content after rehydration; r>35cm rehydration time, the longer the interval, the smaller the moisture content after rehydration.2.Soil nitrate distribution moist body has internal concentration is smaller in a higher concentration of the edge of the moist body.The irrigated soil nitrate concentration with increasing radial distance increases with the vertical distance increases decreases and then increases.Rehydration, radial r=20to40cm range nitrate did not change significantly, radial r=40to45cm range nitrate content of water movement and the combined effect of the denitrification increased dramatically at first and then with the time increases gradually reduce the nitrate pooled regional vertical offset to the upper and lower sides, respectively.Complex water the greater the nitrate distribution wider the range of nitrate at the edge of the moist body bringing together the more obvious.Rehydration intervals no significant effect on the nitrate content of the moist body, and at the edge of the moist body rehydration interval the longer, the higher the concentration of nitrate in the deep soil, rehydration time interval longer the nitrate nitrogen with water into deep migration phenomenon is more obvious. 3.Ammonium nitrogen content in the soil after irrigation at the same depth as the radial distance increases and decreases, ammonium nitrogen content in the same radial direction with the increase in the vertical distance first increases and then decreases.With increasing time after rehydration, moist inside ammonium nitrogen content gradually reduced, a slight increase in the moist body at the edge of the ammonium nitrogen content, soil ammonium nitrogen more evenly distributed.Complex the greater the amount of water, the wider the range of ammonium nitrogen distribution in the soil, the greater the impact of the complex distribution of water in the deep soil ammonium nitrogen.The rehydration time interval shorter the ammonium nitrogen content increases.The rehydration time interval longer the smaller, the impact of the distribution of rehydration of ammonium nitrogen.4.Same irrigation and rehydration conditions, a broader multi-pit irrigation water distribution, moist body more internal soil moisture, water distribution more uniform depth z=30to80cm overall range of soil moisture content Artillery soil saturated moisture of80%.Nitrate in the soil at the edge of the moist body collection obvious rehydration,7days a single pit soil box with multi-pit the soil box nitrate pooled phenomenon both mitigate moist body edge of the nitrate content decreased, nitrate to migrate to the bottom of the moist body, multi-soil pit box baffle at the nitrate content decreased in the lower half of the moist body points, when the multi-pit irrigation nitrate distribution range is reduced nitrate to the the soil depths migration phenomenon lighter.Rehydration, ammonium nitrogen in the soil box single pit soil box with multi-pit concentrated around the water chamber from the pit closer at the most obvious single pit soil box, multi the pit soil box ammonium nitrogen distribution broader, moist inside ammonium nitrogen content is more evenly distributed. |
