Assessing Water Use Efficiency, Soil Health, and Pollinators within a Transition from Irrigation to Dryland Management in the Texas High Plains

This Research and Education Grant project was awarded a 2021 James Harrison Hill, Sr. Young Scholar Enhancement Grant award in the amount of $2,009. The award provides high school and undergraduate college students the opportunity to conduct sustainable agriculture research, as part of an existing Research and Education Grant project.

View the project final report

Commodities

Practices

• Crop Production: irrigation, pollination, water management
• Production Systems: agroecosystems, dryland farming, integrated crop and livestock systems
• Soil Management: soil quality/health

The rapid decline in water supply for irrigation in the Texas High Plains is encouraging some growers to convert their irrigated cropland to production of dryland crops and low water requiring forages. Reduced irrigation will directly depress crop yields and financial security. Research on the impacts of transitioning toward reduced water input can reveal soil and crop management practices that build up the soil’s health. Switching to more diverse cropping systems can enhance numbers and activities of introduced and native bees, which are potential pollinators. We propose to study changes in soil health indicators, ground-nesting bees (as an indicator of pollinator habitat), and water use by annual crops and perennial forages in the context of transition from high irrigation to low irrigation to dryland management. Water use efficiency measurements of crops will serve as an integrator management practices aimed at building soil water storage and effective water use in crop rotations. The forage component concentrates on alfalfa growing in monoculture (but at modest water input), in mixture with old world bluestem grass, and compared to grass alone. Studies will be done on four commercial farms in the South Plains of the Texas High Plains, and the Texas Tech University pasture research facility near New Deal, TX. Three of the growers are already part of long-term studies by a cooperating agency (USDA-ARS) for soil health; hence three more years of data will extend those trends. Crops on those farms comprise cotton, corn, sorghum, and rye cover crop. Results will reveal whether transitioning part of the producers’ field to dryland management improves habitat for soil microbes, wild bees, and water retention, in turn will inform decisions on crop type and water management.

1) Estimate the water use and water-use efficiency of annual crops and perennial forages transitioning to limited irrigation and dryland production.

2) Evaluate soil health indicators under different transitions to dryland including changing annual crops from irrigated to dryland production, and interseeding alfalfa into established perennial grassland.

3) Compare irrigated and recently transitioned dryland croplands, alfalfa, grass-alfalfa, and grass pastures on ground-nesting bee communities as indicators of insect pollinator health and abundance.