Page 10 - Azerbaijan State University of Economics

XiaolinQu, M.S., Lal K. Almas: The water requirement and profitability analysis of corn using irrigation
management approaches including evapotranspiration and weather data

The data used in this study are obtained from Texas Cooperative Extension’s

ten-year (1998-2007) program called Panhandle Agripartners Demonstration

Program. 129 demonstrationsare extracted including the information of yield of

corn, amount of irrigation applied, irrigation methods, total water availability, and

PPET to analyze the yield-water relations.

Methods

In order to find out the relationship between water approaches including total

available water (TW), irrigation application, as well as Percent of Potential

Evapotranspiration (PPET) and the yields of corn, three models are developed. The

first model describes the corn yield as a function of TW. The second model defines

the corn yield as a function of the amount of irrigation applied. The third model

uses the PPET requirement of each crop to predict corn yield. Regression analysis

in Excel is used to evaluate the models under each approach and the models that fit

best will be chosen to represent the production functions for the four crops in the

Texas Panhandle area.

Based on the production functions under the three water approaches, the

corresponding Marginal Physical Product (MPP) could be determined. Combining

with the price of corn, which is a range of $3/bushel - $7.5/bushel, Marginal Value

Product is determined. On the cost side, Marginal Factor Cost (MFC) is obtained

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