From an irrigated cropland perspective, what are the processes and mechanisms that contribute to water losses – and which can be managed or influenced to contribute to ag water conservation?
Not all water withdrawn from surface or ground water supplies for irrigation is ‘consumed’ by the irrigated crops, or lost from the immediate hydrologic cycle. In many instances, a portion of pumped, withdrawn, or irrigated water is returned to the immediate or near-immediate hydrologic cycle through conveyance losses, infiltration, drainage below the crop root zone, or field runoff. Some of these mechanisms are critical to long-term sustainability of agricultural crop land; for instance, leaching of salts below the crop root zone and adequate drainage are critical to sustainable crop production. In contrast, agricultural water conservation can be achieved through minimization of conveyance losses, scheduling irrigation timing and amounts to balance crop needs with soil water storage capacity and climatic conditions, by assuring uniform irrigation applications, by minimizing field-end runoff, and by adopting cropping system practices that maximize the capture and utilization of precipi
