农业环境科学学报2024，Vol.43Issue(7)：1568-1579,12.DOI:10.11654/jaes.2023-0891
不同生草模式下降雨强度对土壤氮磷淋溶特性的影响
Effects of rainfall intensity on soil nitrogen and phosphorus leaching characteristics in different planting patterns
摘要
Abstract
In order to explore the effects of different planting patterns and rainfall intensities on the rate of N and P leaching as well as soil N and P content in Morella rubra L.forests,an indoor column experiment was performed to simulate the effects of different understory planting patterns(Medicago sativa cv.WL525HQ monocropping,Dactylis glomerata cv.Amba monocropping and mixed cropping).The effects of heavy rainfall on N and P loss through leaching was simulated in soil at 20,40,and 60 cm.The results showed that the differences in planting patterns had a significant effect on the fluxes of N loss from leaching,and considerable N loss occurred under M.sativa monocropping.The concentrations of total nitrogen(TN)and dissolved nitrogen(DN)from leaching at 60 cm increased by 27%and 29%compared with that from pore water at 40 cm.However,the D.glomerata monocropping effectively reduced the concentrations of TN and DN from leaching in pore water between 0-40 cm and 60 cm,and both the concentrations of TN and DN in the leachate were reduced by approximately 60%at 60 cm compared with that at 40 cm.The flux of P losses was significantly affected by planting pattern and rainfall intensity in the M.sativa-D.glomerata mixed cropping and was reduced 70%and 60%compared with the values obtained from the M.sativa monocropping and D.glomerata monocropping,respectively.The correlation analyses showed that TN,DN and TP contents in leachate were correlated with soil available nitrogen,and that the grassing pattern had a greater effect on quick-acting nitrogen as rainfall intensity increased.The results showed that AN content was highest(32.6 mg·kg-1)in the at 0-40 cm soil layer under M.sativa-D.glomerata mixed cropping under heavy rainfall,and there was no obvious difference among the three planting patterns at 60 cm.In conclusion,under heavy rainfall,D.glomerata monocropping had a significant effect on reducing N loss fluxes.In the mixed cropping pattern,the increase in the average diameter and total root volume of D.glomerata under heavy rainfall may be the reason for improved retention of soil AN at 20-40 cm and impeded migration of AN constituents from the topsoil to deeper depths.Based on these results,the M.sativa-D.glomerata mixed cropping pattern was determined to be an effective measure in reducing the N and P loss fluxes in conditions of extreme rainfall intensity.关键词
林下生草模式/降雨强度/淋溶/氮磷流失Key words
planting pattern/rainfall intensity/leaching/nitrogen and phosphorus loss分类
农业科技引用本文复制引用
徐翠,刀承娇,赵鹏程,邢赟,陈建军,李元,祖艳群..不同生草模式下降雨强度对土壤氮磷淋溶特性的影响[J].农业环境科学学报,2024,43(7):1568-1579,12.基金项目
云南省科技计划项目(202203AC100002)Science and Technology Plan of Yunnan Province,China(202203AC100002) （202203AC100002）
