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Evaluation of a Landscape‐Scale Approach to Cotton Modeling
Author(s) -
Booker J. D.,
Lascano Robert J.,
Evett Steven R.,
Zartman Richard E.
Publication year - 2014
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj14.0202
Subject(s) - loam , soil water , environmental science , groundwater recharge , irrigation , hydrology (agriculture) , soil science , spatial variability , aquifer , agronomy , groundwater , mathematics , geology , statistics , geotechnical engineering , biology
The Texas Southern High Plains is a semiarid region for cotton ( Gossypium hirsutum L.) production that uses irrigation water from the Ogallala Aquifer, where depletion exceeds recharge, prompting limits to pump water. Thus, there is a need for management strategies to optimize the diminishing water, and these could be modeled provided the spatiotemporal variability associated with irrigated cotton production is captured. The Precision Agricultural‐Landscape Modeling System (PALMS) is a grid‐based model that accounts for variability across complex landscapes but lacked a cotton model. Our objective was to integrate the Cotton2K model with PALMS to produce PALMScot and to compare calculated values of soil water storage obtained with PALMScot to field‐measured values for 2 yr and two irrigation treatments at two locations with contrasting soils, a fine sandy loam near Lamesa, TX, and a clay loam near Bushland, TX. Two statistics, mean absolute difference (MAD) and modified coefficient of efficiency ( E 1 ) were used to compare differences between measured and calculated values of soil water content. In both years, MAD was <5% in the Amarillo and <10% in the Pullman soils and E 1 was 0.2 in the Amarillo and 0.4 in the Pullman soils, supporting the accuracy of the calculated values. Within the 1.4‐m profile of both soils, however, the model overestimated root water uptake in the surface horizon and underestimated it in deeper ones. Our evaluation implied that PALMScot is a tool that can be used to track spatial and temporal variability of soil water storage across a complex landscape.