• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Leaching and denitrification losses of nitrogen from corn fields as influenced by conventional- and no-till practices in soils of the Chesapeake Bay area.
【24h】

Leaching and denitrification losses of nitrogen from corn fields as influenced by conventional- and no-till practices in soils of the Chesapeake Bay area.

机译：切萨皮克湾地区土壤中常规耕种和免耕做法影响了玉米田氮素的淋失和反硝化损失。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Research was conducted in soils of the Chesapeake Bay area primarily to determine the combined effects of tillage practice and N fertilizer application rates on N leaching and denitrification losses from corn fields. Three well known models--the NTRM, CERES-Maize, and VT-MAIZE--were also tested to determine their predictive ability of N distribution in soil and crop, the various components of the N cycle, and corn yields.; To accomplish the above objectives, two field sites were located (in 1986) for a 3 year study on agronomically important and representative soils that are used for corn production in the Chesapeake Bay drainage basin. The main plot treatment consisted of no-till and conventional-till. The subplot treatments consisted of 6 levels of N application rates with 4 inorganic and 2 organic (sewage sludge) N fertilizers. Denitrification experiments were also conducted on the Groseclose silt loam soil by applying the accetylene inhibition technique. Nitrogen leaching losses were determined by applying the principle of N mass balance.; Denitrification N loss during the corn growing season was less than 2% of the applied N fertilizer. The N loss from the two tillage systems was not significant at p {dollar}>{dollar} 0.10. Fick's law may be applied for predicting N loss subsequent to accetylene application, only if N sampling takes place following a minimum present critical time.; During the growing season, conventional tillage gained generally more N than no-till. During winter, however, N loss due to leaching was proportional to the amount of N retained at the end of the growing season. Thus, conventional tillage lost more N by leaching during the winter months.; Mineralization of N was higher in conventional till, while denitrification was higher in no-till. Split application has shown less N loss due to leaching than the preplant. Mineralization, denitrification, and leaching took place from the upper as well as the lower zones of the soil profile.; The model performances varied from year to year and from one tillage practice to another. The models did not make satisfactory predictions under the severe moisture stress conditions experienced during this study. Thus, they need a great deal of readjustment.
机译：在切萨皮克湾地区的土壤中进行的研究主要是确定耕作实践和氮肥施用量对玉米田氮淋失和反硝化损失的综合影响。还测试了三个众所周知的模型-NTRM，CERES-玉米和VT-MAIZE，以确定它们在土壤和农作物中氮分布的预测能力，氮循环的各个组成部分以及玉米产量。为了实现上述目标，在切萨皮克湾流域内两个田间地点（1986年）进行了为期3年的农业重要和代表性土壤研究，这些土壤用于玉米生产。主要地块处理包括免耕和常规耕作。该子样地处理包括6种水平的氮肥施用量，4种无机和2种有机（污水污泥）氮肥。还通过应用乙炔抑制技术在Groseclose淤泥质壤土上进行了反硝化实验。氮的浸出损失是通过应用氮质量平衡原理确定的。玉米生长期的反硝态氮损失少于所施用氮肥的2％。两个耕作系统的氮损失在p {dollar}> {dollar} 0.10时不显着。仅当在最短的当前临界时间后进行N采样时，才可以使用菲克定律来预测乙炔添加后的N损失。在生长季节，常规耕作通常比免耕获得更多的氮。然而，在冬季，由于浸出导致的氮损失与生长季节结束时保留的氮量成正比。因此，传统的耕作在冬季通过淋洗损失了更多的氮。常规耕作中N的矿化度较高，而免耕法中的反硝化度较高。分次施用已显示出比预种植更少的氮浸失。在土壤剖面的上部和下部发生矿化，反硝化和浸出。该模型的性能每年不同，从一种耕作实践到另一种耕作实践也各不相同。在此研究中遇到的严重水分胁迫条件下，模型未能做出令人满意的预测。因此，他们需要大量的调整。

著录项

  • 作者

    Menelik, Ghezai.;

  • 作者单位

    Virginia Polytechnic Institute and State University.;

  • 授予单位 Virginia Polytechnic Institute and State University.;
  • 学科 Agriculture Agronomy.; Environmental Sciences.
  • 学位 Ph.D.
  • 年度 1990
  • 页码 548 p.
  • 总页数 548
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 农学（农艺学）;环境科学基础理论;
  • 关键词

相似文献

  • 外文文献
  • 中文文献
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号