夏玉米不同施肥水平下土壤水分动态与氮素淋溶损失研究

Effect of Different Fertilizer Applications on the Dynamic Change of Soil Water and Nitrogen Leaching Losses for Summer Maize

基于模拟降雨与自然降雨的田间试验,分析了不同施肥处理下水分渗漏与氮素淋溶过程。结果表明,夏玉米生长期间,南小区土壤剖面含水率较北小区小,且土壤水分运动主要以向下为主;北小区不同处理水分渗漏占降水量的5.4%～8.9%,而南小区则高达12%～37%。土壤硝态氮与铵态氮质量浓度随着时间的推进而降低,且铵态氮质量浓度下降速率远高于硝态氮。南小区氮素质量浓度变化较北小区快,且略小于北小区。南小区氮素淋溶量占施肥量的1%～1.8%;而北小区不足1%,且氮素流失量随着施肥量的增大而增多。

Field experiments under simulated rainfall and natural rainfall were conducted to analyze the processes of soil water and nitrogen leaching losses under different fertilizer applicatons. The results indi- cated that during the growth stage of summer maize, soil water contents in profiles in south zone were lower than those in north zone, and soil water moved mainly downward; Soil water leaching losses in north zone and in south zone were about 5.4%-8.9% and 12%-37% of precipitation, respectively. Concentra- tions of soil nitrate nitrogen and ammonium nitrogen decreased with the time, and the declining rate of soilammonium nitrogen concentration was higher than soil nitrate nitrogen. Soil nitrogen concentration in south zone changed faster and was slightly higher compared to those in north zone. Leaching losses of ni- trogen in north zone were below 1% of fertilizer application and increased with the increase of fertilizer ap- plication while leaching losses of nitrogen in south zone were 1 %-8% of fertilizer application.