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虽然氮是集约耕作农业系统的重要营养物,但是充分发挥其效率并减少损失非常困难,原因之一是影响土壤残留硝态氮和硝态氮淋失潜力的空间和时间变异性。1999~2001年美国土壤学家Delgado使用氮素淋洗经济分析(NLEAP)模型评价精细管理地区的氮管理效益。氮淋失随管理地区变化,低生产力地区淋失量最大。研究发现生产力是决定硝态氮淋失的重要空间变量,低生产力地区硝态氮淋失量随施肥量增加而增加。除了氮,可以限制产量以减少硝态氮的生长季淋失和土壤残留硝态氮非生长季的有效淋失。基于生产力地区的空间变量施肥比统一施肥的硝态氮淋失量少,且维持最高产量,使用精细管理后第一年可减少硝态氮的淋失率为25%。
Although nitrogen is an important nutrient for tillage agricultural systems, one of the reasons that it is very difficult to give full play to its efficiency and reduce losses is one of the reasons for the spatial and temporal variability affecting the potential for leaching residual nitrate and nitrate in soil. From 1999 to 2001, American soil scientist Delgado used nitrogen leaching economic analysis (NLEAP) model to evaluate nitrogen management efficiency in finely managed areas. Nitrogen leaching changes with the management of the region, the largest loss of low productivity areas. The study found that productivity is an important spatial variable that determines the leaching of nitrate nitrogen. The leaching loss of nitrate nitrogen in low productivity area increases with the increase of fertilizer application. In addition to nitrogen, the yield can be limited to reduce the leaching of nitrate during the growing season and the effective leaching of the soil during the non-growing season. The spatial variability of fertilization based on spatial variability in the productivity area was less than the leaching loss of nitrate by uniform fertilization and the highest yield was maintained. The leaching rate of nitrate nitrogen was reduced by 25% in the first year after using fine management.