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ARS Home » Pacific West Area » Kimberly, Idaho » Northwest Irrigation and Soils Research » Research » Research Project #441338

Research Project: Improving Water Productivity and Quality in Irrigated Landscapes of the Northwestern United States

Location: Northwest Irrigation and Soils Research

Project Number: 2054-13000-010-000-D
Project Type: In-House Appropriated

Start Date: Nov 16, 2021
End Date: Nov 15, 2026

The research in this project includes a series of studies conducted under three broad objectives of improving water use efficiency and water quality in irrigated crop production. Water use efficiency research focuses on a variety of crops and conditions that occur in the northwestern U.S. Much of the water quality research focuses on the Upper Snake Rock (USR) watershed which is part of the ARS Conservation Effects Assessment Project (CEAP). Objective 1: Characterize plant-climate-management interactions to optimize water productivity in intensively irrigated systems. Subobjective 1A. Determine the effect of barley cultivar type (food and malt) on water use efficiency under full and deficit irrigation. Subobjective 1B. Quantify the relationships between irrigation level and barley grain and straw yields under optimum and sub-optimum N supplies. Subobjective 1C. Evaluate crop water use and agronomic response of sorghum-sudangrass hybrids under multiple management practices. Subobjective 1D. Develop an IoT canopy temperature measurement system for crop stress monitoring. Objective 2: Clarify climate and management impacts on water quantity and quality at the field edge and beyond the vadose zone. Subobjective 2A. Evaluate the impact of tillage, cover crop, and fertilization management on surface and groundwater processes under linear-move irrigation system. Subobjective 2B. Evaluate subsurface water quality dynamics under sprinkler and furrow irrigation at the field scale. Subobjective 2C. Develop a furrow irrigation-induced erosion prediction tool. Subobjective 2D. Develop a soil parameterization database for a center pivot infiltration model. Subobjective 2E. Evaluate the impact of variable soil depth on water balance and nutrient leaching. Objective 3: Identify environmental conditions and adaptive management strategies that improve water quality in surface and subsurface drainage networks in irrigated landscapes. Sub-objective 3A: Develop a machine learning technique to detect and map in-field irrigation methods. Sub-objective 3B: Evaluate the effect of long-term changes in irrigation methods and interannual variations in crop area on water availability and quality. Sub-objective 3C: Evaluate the SWAT model for highly managed irrigated watersheds of the Northwest. Sub-objective 3D: Determine P sorption capacity and equilibrium P concentration (EPC0) for a range of agricultural and canal soil/sediments in Idaho.

This project involves a combination of experimental field studies, watershed studies, model developments and tool development. The overall objective to optimize water productivity in intensively irrigated systems will be achieved through four field studies. A three-year study will measure the response of two barley cultivars to four irrigation levels ranging from full irrigation to 25% of full irrigation. A second study will further clarify the interrelation between irrigation level and barley straw and grain yield under optimum and sub-optimum nitrogen. This study will provide valuable data on evapotranspiration requirements under a variety of barley management scenarios. A third study will evaluate the performance and the viability of sorghum-sudangrass as an alternative forage crop while a fourth study will apply state-of-the-art sensing and wireless networking technologies (Internet-of-Things) to develop a canopy temperature measurement system to monitor crop water stress. This system will provide a practical canopy temperature measurement platform for the application of the crop water stress index (CWSI) to manage deficit irrigation for a wine grape cultivar. In a second objective cover crop and no-till practices will be evaluated to devise sustainable and climate-resilient management systems by monitoring runoff, erosion, infiltration, soil water content and surface and groundwater quality on experimental fields. Another study will compare furrow irrigation to sprinkler irrigation on surface and subsurface water quantity and quality using field-installed lysimeters, soil moisture sensors and runoff measurements. A third study will develop a furrow irrigation soil erosion model by contrasting a machine learning approach with a process-based approach to erosion prediction in eroding furrows. In a fourth study, a database to parameterize an infiltration model for center pivot irrigation will be developed to more accurately account for surface sealing in infiltration prediction. A fifth study will apply a combination of field monitoring of soil processes, in-situ remote sensing, cutting-edge imaging and 3D reconstruction technologies including Ground Penetrating Radar to model soil depth and its impact on water and nutrient dynamics. The third objective will be accomplished through watershed research. Irrigation water diverted into the 82,000 ha Upper Snake Rock watershed and water returning to the Snake River will be monitored for water quantity and quality to determine water, sediment, and nutrient balances for the watershed. Watershed research will evaluate potential associations between the extent of specific crops in a watershed and water quality outcomes. A methodology will be developed by applying deep learning techniques and computer vision to map the types of irrigation used on agricultural fields of the watershed. One study will parameterize the SWAT model for highly managed irrigated areas and evaluate improved irrigation routines developed for this model. A final study will use carefully designed benthic sediment sampling strategies to determine equilibrium phosphorus concentration in irrigation return flow drainage systems.