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首页> 外文学位 >Relationships between yield variability and variability in soil hydraulic and physical properties in a tomato production system.
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Relationships between yield variability and variability in soil hydraulic and physical properties in a tomato production system.

机译：番茄生产系统中产量变异性与土壤水力和物理性质变异性之间的关系。

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摘要

To address variability in crop yield caused by the soil moisture status, the soil hydraulic and physical properties must be quantified at geo-referenced locations and mapped. The variability map can also help in the development of soil management practices that might reduce leaching of essential plant nutrients, minimize potential ground and surface water contamination, and soil degradation.; An infiltration model was developed and used to estimate infiltration rates at geo-referenced locations within the field based on the volume balance technique, using flow rate into a furrow, flow cross sectional area, and the water front advance time along a furrow. Daily soil moisture tension and equivalent daily volumetric soil moisture content of the soil, in a referenced soil profile consisting of three layers, were used to estimate the daily moisture depletion in the layered soil profile. Evapotranspiration (ETc) was estimated from infiltration depth and daily depletion of measured soil moisture profile at geo-referenced locations.; Variability in soil hydraulic conductivity (coefficient of variation = 151%), initial infiltration rate (coefficient of variation = 89%), final infiltration rate (coefficient of variation = 70%), ETc for the duration of the study (coefficient of variation = 84%), daily ETc (coefficient of variation = 63%), were found for the field. Yield (coefficient of variation = 12%), and the soil compaction level (coefficient of variation = 7–22%) were also, found be variable in the field. High correlation exited between yield and hydraulic conductivity (coefficient of determination, R2, = 0.79); initial infiltration rate (coefficient of determination, R2, = 0.83), final infiltration rate (coefficient of determination, R2, = 0.92), daily ETc (coefficient of determination, R2, = 0.98), TCI (coefficient of determination, R2, = 0.86), SCP (coefficient of determination, R2, = 0.90), and bulk density (coefficient of determination, R2, = 0.97) in the field.; A power function was found to best describe the quantitative relationship between saturated hydraulic conductivity and force measured by the TCI and SCP whilst a linear function best described its relationship with bulk density.; Extensive field tests were conducted on a 20-acre furrow-irrigated plot planted to processing tomato to quantify and map variability in crop yield, soil hydraulic conductivity, infiltration rate, crop evaportranspiration (ET c), soil compaction level measured by TCI, SCP and bulk density. (Abstract shortened by UMI.)
机译：为了解决由土壤水分状况引起的农作物产量的变化，必须在地理参考位置对土壤的水力和物理性质进行量化并绘制地图。变异图还可以帮助开发土壤管理方法，以减少必需的植物养分的淋洗，使潜在的地下水和地表水污染以及土壤退化最小化。开发了一种渗透模型，并基于体积平衡技术，使用进入犁沟的流量，水流截面积和沿着犁沟的水前移时间，来估算田间地理参考位置的渗入率。在由三层组成的参考土壤剖面中，土壤的每日土壤水分张力和当量土壤的等效土壤水分含量被用来估算分层土壤剖面中的每日水分消耗。蒸发蒸腾量（ET c ）是根据地理参考位置的渗透深度和土壤水分剖面的日耗竭来估算的。土壤水力传导率的变化（变异系数= 151％），初始入渗率（变异系数= 89％），最终入渗率（变异系数= 70％），ET c 在这项研究中（变异系数= 84％），该领域的每日ET c （变异系数= 63％）被发现。还发现在田间，产量（变异系数= 12％）和土壤压实度（变异系数= 7–22％）是可变的。屈服强度与水力传导率之间存在高度相关性（测定系数，R 2 ，= 0.79）；初始渗透率（测定系数，R 2 ，= 0.83），最终渗透率（测定系数，R 2 ，= 0.92），每日ET c （测定系数，R 2 ，= 0.98），TCI（测定系数，R 2 ，= 0.86），SCP（测定系数，R 2 ，= 0.90）和现场密度（测定系数，R 2 ，= 0.97）。发现幂函数最能描述饱和水力传导率与TCI和SCP测量的力之间的定量关系，而线性函数最能描述其与堆积密度的关系。在种植用于加工番茄的20英亩的沟灌地上进行了广泛的田间试验，以量化和绘制作物产量，土壤水力传导率，入渗率，作物蒸发蒸腾量（ET c ），土壤压实的变化并绘制地图通过TCI，SCP和堆积密度测量的水平。 （摘要由UMI缩短。）

著录项

  • 作者

    Josiah, Malcolm Nuertey.;

  • 作者单位

    University of California, Davis.;

  • 授予单位 University of California, Davis.;
  • 学科 Engineering Agricultural.; Agriculture Soil Science.
  • 学位 Ph.D.
  • 年度 2002
  • 页码 173 p.
  • 总页数 173
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 农业工程;土壤学;
  • 关键词

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