The study has demonstrated that the crop water use model MOPECO can be adapted to many different scenarios
In a collaborative work between the Agricultural Research Service (ARS) Soil and Water Management Research, the University of Castilla-La Mancha (UCLM) in Spain, West Texas A&M University, and Texas A&M AgriLife, researchers have adapted a crop model for use in the Texas High Plains to simulate crop water use and corn yield to help producers adjust center-pivot irrigation strategies and maximise profitability with limited water.
Crop producers in this semi-arid region of the Texas High Plains largely depend on groundwater irrigation. Each season, crop producers in the region evaluate how much land area could be irrigated under the pivot with limited water. Addressing this is not straightforward because producers must consider reducing irrigated areas, which influences grain yield, input costs, and the timing of the irrigation applications.
To help producers with these decisions, researchers completed a study that uses 25 years of climatic data to simulate corn production using a range of irrigation capacities, the maximum amount of water that can be delivered to an irrigated acre in a day, to evaluate water allocation strategies that could increase profitability and improve the efficient use of water.
The model showed that for irrigation capacities representative of the region and a growing season with average rainfall, maximum profitability was achieved by irrigating about 75 per cent of entire pivot area with the remaining area in fallow or dryland cotton. Concentrating water generated greater net returns because of lower seed and fertiliser costs and greater corn yields that compensated for lack of production in fallow areas. In years with seasonal drought, the irrigated area would need to be further constrained to avoid crop failure and maximise profits.
“This study has demonstrated that the crop water use model MOPECO can be adapted to many different scenarios and is a useful tool for improving the environmental and economic sustainability of agricultural systems where water is limiting,” said Alfonso Domínguez researcher of the Centro Regional de Estudios del Agua (CREA) of UCLM.
