Variability of yield of an irrigated crop and its causes: 1. Statement of the problem and methodology
Variability of yield of an irrigated crop and its causes: 1. Statement of the problem and methodology
复制标题
灌溉作物产量的变化及其原因： 1. 问题和方法的陈述
DOI：
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发表时间：
1988
期刊：
影响因子：
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通讯作者：
G. Dagan
中科院分区：
文献类型：
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作者：
E. Bresler;G. Dagan
农作物产量取决于大量与土壤、水和大气有关的参数。其中一些参数在空间上是可变的，大多数参数具有不确定性。因此，产量也是空间可变的，其预测是不确定的。本研究的目的是：(1)估计产量变异性作为各种参数变异性的函数的程度，(2)试图挑出那些参数，这些参数的变异性估计对灌溉作物产量的变异性影响最大。研究的第一部分介绍了为实现这些目标而开发的一般方法。它由一个数字确定性模型组成，该模型预测作物产量相对于特定灌溉制度和水质以及特定土壤和大气条件下的潜在产量。然后，利用该模型推导出灌溉作物相对产量的期望值和方差作为各参数值的函数。
Crop yield depends on a large number of soil-, water-, and atmosphere-related parameters. Some of these parameters are spatially variable and most of them are subject to uncertainty. Consequently, the yield is also spatially variable and its prediction is uncertain. The aims of this study were to (1) estimate the degree of yield variability as a function of variability of various parameters and (2) attempt to single out those parameters, the variability of which are estimated to have the largest impact upon the variability of yield of an irrigated crop. The first part of the study presents the general methodology developed in order to achieve these aims. It consists of a numerical deterministic model which predicts crop yield relative to its potential yield for a given irrigation regime and quality of water and for given soil and atmospheric conditions. Subsequently, the model is used to derive the values of expectation and variance of the relative irrigated crop yield as functions of these values of the various parameters.