Economic and environmental evaluation of precision farming practices in irrigated cotton production

Increased use of fertilizers, pesticides, and other chemicals has been an important development in agriculture over the past several decades. Currently, production agriculture is facing significant challenges, especially increased public concerns about the impacts of agricultural production practices on the environment. Traditionally, optimal fertilizer input use in agriculture has assumed spatial and temporal field homogeneity with respect to soil fertility, pest populations, and other characteristics. That is, optimal fertilizer input decision rules do not account for these differences within fields. Precision farming, precision agriculture, or site-specific management recognizes the variability within fields and seeks to optimize variable input use under these conditions.;The primary objective of this study is to evaluate the economic and environmental implications of precision farming practices with respect to nitrogen use in irrigated cotton production in the Southern High Plains of Texas (SHPT). This research addresses the impacts of nitrogen application and residual on crop yields under different levels of soil fertility. Hence, a dynamic optimization model is developed to evaluate optimal decision rules of nitrogen use and nitrogen residual levels. The primary source of data is from an experiment conducted at the Texas Agricultural Experiment Station at Lamesa, Texas in 1998.;To evaluate the economic significance and the environmental implications of precision input application technology under non-homogeneity of fields, the dynamic optimization model was solved under two scenarios. The first scenario represents the optimality conditions under conventional input application technology, i.e., whole-field farming. The second scenario represents the optimality conditions under the precision input application technology. Once solutions for these two scenarios were found, comparisons of the results were made to evaluate the economic and environmental impacts of precision farming practices.;Analysis and evaluation of the results revealed that precision farming practices, as compared to "uniform" nitrogen application used in 1998, would result in an increase in both cotton yield and net returns on a per acre basis. Also, the analysis indicated that precision farming can improve fertilizer-use efficiency.