一级全黄少妇免费录像片,亚洲国产一区在线,日日操夜夜摸,都市激情久久,日日夜夜操av,国产视频在线一区二区,国产777777线观看视频

Phosphorus export by runoff from agr

時間:2023-04-29 15:28:59 環(huán)境保護論文 我要投稿
  • 相關推薦

Phosphorus export by runoff from agricultural field plots with different crop cover in Lake Taihu watershed

Runoff and soil losses from agricultural fields are investigated as major nonpoint sources of phosphorus (P) entering lakes of Eastern China. There is relatively little information on P transport from ricefield and cropland of Lake Taihu watershed in Eastern China. Soil and P in surface runoff from a series of plots in the watershed were evaluated under simulated rainfall conditions. The objectives of this study were to evaluate theeffects of crop cover, slope, and fertilizer application on P concentrations in surface runoff and eroded soil. Accumulated sediment yields varied from 7.1 to 300 g/m2 for croplands, depending on management practices. For all experiment plots, weighted average concentrations of total-P (TP), dissolved P (DP) and particulate P (PP) are much higher than 0.02 mg/L, the limiting concentration in lake water. This result showed the potential contamination of lake water from agricultural surface runoff. Accumulated TP losses were 3.8 and 18.8 mg/m2 for ricefield and cropland, respectively. The estimated annual loss of TP was 0.74 kg/(hm2鷄) for cropland. Most of P loss is in PP form, which accounts for more than 90% of TP loss for cropland.

作 者: YAN Wei-jin HUANG Man-xiang Zhang Shen TANG Yi-jian   作者單位: Department of Environmental Biogeochemistry, Institute of Geographic Science and Natural Resources Research, Chinese Academy of Sciences,  刊 名: 環(huán)境科學學報(英文版)  ISTIC SCI 英文刊名: JOURNAL OF ENVIRONMENTAL SCIENCES  年,卷(期): 2001 13(4)  分類號: X59  關鍵詞:  

【Phosphorus export by runoff from agr】相關文章:

Phosphorus release from phosphate rock and iron phosphate by low-molecular-weight organic acids04-26

Effects of land-use pattern change on rainfall-runoff and runoff-sediment relations:a case study in Zichang watershed of04-26

learn from steven spielberg05-24

Determination of operational parameters of anaerobic phase for enhanced phosphorus removal in MBR04-26

Chapter 26: Writing from Reading05-04

How Does the Partitioning of Evapotranspiration and Runoff between Different Processes Affect the Variability and Predic04-27

Effect of carbon source and nitrate concentration on denitrifying phosphorus removal by DPB sludge04-26

Preliminary study on particulate organic carbon export fluxes in the Bering Sea04-27

Study on synthesis of polylactide from kitchen garbage04-25

Immunosuppressive Activities of Fucoidan from Laminaria japonica04-27