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Modeling fate and transport of nitrogen and phosphorus in crop fields under tropical conditions.

机译：模拟热带条件下作物田中氮和磷的命运和运输。

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摘要

Modeling is a very important tool for developing nonpoint source (NPS) pollution control plans. Current NPS models were developed for temperate conditions and, thus, do not appropriately represent tropical conditions. The objective of this research was to develop or adapt a nonpoint source pollution model to simulate transformations and losses of nitrogen (N) and phosphorus (P) in leachate and runoff from crop fields under humid tropical conditions.; An extensive literature synthesis identified appropriate relationships for representing hydrologic and NPS processes in the tropics, as well as soil and climate conditions that differ from temperate conditions and impact NPS pollution. The GLEAMS model was selected for adaptation. Changes to the model included calculation of potential evapotranspiration (ET); changes in initial and default values of N and P pools, C:N ratio of soil organic matter, and soil P sorption; changes in simulation of transformations between N and P pools, along with the effect of temperature; and inclusion of a nitrate retardation factor (Ncrit) and pH in the calculation of N transformation and movement.; The adapted model, called TROPGLEAMS, was evaluated through model verification, application, and sensitivity analysis. Model verification comprised a mass balance of nutrients and analysis of the variation of variable values in time. Model validation included application of the GLEAMS and TROPGLEAMS to three sites in Brazil: a set of lysimeters planted with sugarcane in Piracicaba, SP; a set of plots planted with sugarcane in Piracicaba; and a set of plots planted in a wheat-soybean rotation in Lages, SC. Model sensitivity to temperature, Ncrit and pH were evaluated in the sensitivity analysis.; Model evaluation indicated that TROPGLEAMS is more accurate than GLEAMS in simulating fate and transport of nutrients under tropical conditions. Prediction of actual ET, effect of tillage on losses of N and P in runoff, and N and P kinetics was improved with TROPGLEAMS compared to GLEAMS. However, based on data from the Lages study, TROPGLEAMS did not simulate losses of nutrients in runoff well. Improvements in the model, especially related to losses in runoff, and application of TROPGLEAMS to different areas of the humid tropics are recommended.
机译：建模是开发非点源（NPS）污染控制计划的非常重要的工具。当前的NPS模型是针对温带条件开发的，因此不能适当代表热带条件。这项研究的目的是开发或改编一种非点源污染模型，以模拟潮湿热带条件下渗滤液和农田的径流中氮（N）和磷（P）的转化和损失。大量文献综述确定了代表热带地区水文和NPS过程以及与温带条件不同并影响NPS污染的土壤和气候条件的适当关系。选择了GLEAMS模型进行调整。对模型的更改包括潜在蒸散量（ET）的计算；氮和磷库的初始值和缺省值，土壤有机质的C：N比和土壤P吸收的变化; N和P池之间转换模拟的变化以及温度的影响；在计算氮的转化和运动中包括硝酸盐阻滞因子（Ncrit）和pH。经过调整的模型称为TROPGLEAMS，通过模型验证，应用和敏感性分析进行了评估。模型验证包括营养物质的质量平衡和变量值随时间变化的分析。模型验证包括将GLEAMS和TROPGLEAMS应用于巴西的三个地点：在巴西皮拉西卡巴（Piracicaba）种植甘蔗的溶渗仪。皮拉西卡巴的一组甘蔗种植地；以及在南卡罗来纳州拉格市以小麦-大豆轮作方式种植的一组地块。在敏感性分析中评估了模型对温度，Ncrit和pH的敏感性。模型评估表明，TROPGLEAMS在模拟热带条件下营养的命运和运输方面比GLEAMS更为准确。与GLEAMS相比，TROPGLEAMS改善了实际ET的预测，耕作对径流中N和P损失的影响以及N和P动力学。但是，根据拉格斯研究的数据，TROPGLEAMS并未模拟径流井中养分的流失。建议改进模型，尤其是与径流损失有关的模型，并建议将TROPGLEAMS应用于热带湿润地区的不同区域。

著录项

  • 作者

    Caiado, Marco Aurelio Costa.;

  • 作者单位

    Virginia Polytechnic Institute and State University.;

  • 授予单位 Virginia Polytechnic Institute and State University.;
  • 学科 Engineering Agricultural.; Engineering Environmental.
  • 学位 Ph.D.
  • 年度 2005
  • 页码 231 p.
  • 总页数 231
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 农业工程;环境污染及其防治;
  • 关键词

  • 入库时间 2022-08-17 11:42:11

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