Long-term AgroEcosystems Research and Adoption in the Texas Southern High Plains – Phase II

View the project final report

• 2014 annual report
• 2015 annual report

Commodities

• Agronomic: general hay and forage crops, grass (misc. perennial), hay
• Animals: bovine

Practices

• Animal Production: grazing - continuous, grazing management, grazing - rotational, stocking rate, stockpiled forages, feed/forage
• Crop Production: fertigation, irrigation
• Education and Training: decision support system, demonstration
• Farm Business Management: budgets/cost and returns
• Natural Resources/Environment: carbon sequestration
• Pest Management: biological control, field monitoring/scouting
• Production Systems: agroecosystems, holistic management, integrated crop and livestock systems
• Soil Management: soil analysis, soil microbiology, organic matter, soil quality/health
• Sustainable Communities: sustainability measures

This project funds the maintenance of the long-term field site at the Texas Tech New Deal Research Station in support of sustainability objectives pertaining to the integration of forages and livestock into a predominant row-crop region. Doctoral research was finished on analysis of legume composition and responses of cattle growth and water-use efficiency of Old World bluestem (OWB) ‘WW-B.Dahl’ growing alone or with legume (mainly alfalfa). Other doctoral research continued on 1) growth analysis and calibration of a computer model of Old World bluestem (OWB) ‘WW-B.Dahl’, 2) relation between OWB and insects in pastures and on cattle, 3) introduction of alfalfa into dryland native pastures, and 4) the impact of winter cover crops and tillage on water response of a summer grass (teff). In the finished grazing trial, averaged over 2014-2016, rate of weight gain of steers was 1.74 lbs/day in the grass-alone system and 2.06 lbs/day in the grass-legume system, and gain per area was 118 lbs/acre and 188 lbs/acre, respectively, over 4 months. We expressed efficiency of water use for steer weight gain as a ‘water footprint’ to put emphasis on water input per unit of beef liveweight gain. The water footprint (groundwater used/lb of gain) was 287 gal/lb on the grass-legume system and 395 gal/lb on the grass-alone system, when considering grazing only (not hay production). Fly density on steers tended to be lower when grazing OWB alone compared with bluestem-alfalfa mixtures, but not significantly so on any one date. Fire ants and harvester ants were strongly deterred from pastures containing OWB and were most numerous in the native-grass pastures (containing mostly blue grama and sideoats grama). Beneficial pollinators were not deterred by the presence of OWB. The computer models ALMANAC and APSIM were greatly improved in modeling growth of OWB, which will make them useful for predicting effects of drought on pasture supply. We established alfalfa into four out of six native-grass pastures despite major dry periods, in the initiation of a multi-year trial to test the longevity of this method of improving the nutritional quality of native pastures. A major field day was held in 2015 demonstrating improvements in soil health, pasture establishment, integration of low-water-input grazing into cropping systems, and dryland pasture options, and a smaller field tour was organized in 2017 (but rained out on two attempts). We continued to integrate our efforts with the Texas Alliance for Water Conservation to broaden the impact of grassland water use efficiency.

The overall objectives of crop-livestock research and demonstration projects at Texas Tech University are to (1) understand the biological, environmental, social, economic, and policy issues impacting agricultural sustainability in the Southern High Plains, and (2) to translate research into adoption of more sustainable practices. The Large-Systems SARE grant contributes a critical piece of this effort by funding the maintenance of the long-term field research site at the New Deal Research Station, which is the basic platform for our collaborative research and education efforts. The research arm of our effort (Texas Coalition for Sustainable Integrated Systems, TeCSIS) focuses on the integration of forage-based beef production into the region’s predominantly row-crop agriculture as a means of reducing water extraction from the Ogallala Aquifer, building soil organic matter, stabilizing soil from wind erosion, and diversifying income. The outreach arm of our effort (Texas Alliance for Water Conservation, TAWC) partners with 20-30 producers to demonstrate improved irrigation practices on 30-34 fields in over 9 counties in the South Plains. TAWC produces field days, field walks, an annual Water College, radio and TV reports, Twitter and Facebook messages, e-newsletters, and web-based management tools to reach a diverse rural and urban populace on using practical technologies to sustain agriculture and communities. Research at the New Deal Research Station is a source of information pertaining to grazing systems that help meet producers’ goals of stretching water supplies and reverting cropland to perennial grasses in ways that meet their economic goals.

We visualize the following trends in Southern High Plains agriculture in the coming decades in the context of transitioning to low-irrigation management: (1) fewer acres of irrigation overall and increased acres of limited-acreage high-value crops, (2) continual improvements in water use efficiency of major row crops such as cotton and corn, (3) partial replacement of irrigated row crops with perennial grasses and legumes and with dryland crops, (4) greater use of precision water management technologies such as ultra-low and variable-rate irrigation, (5) greater dependence on online decision aides for guiding inputs, and (6) warmer temperatures leading to greater evaporative demand and more droughts. These trends will require constant testing of forage systems across the range of weather conditions experienced to offer options to landowners on how to maintain profitability. The benefit of long-term support by Southern SARE has been the sharing with local producers a growing knowledge pool of how climate, soil, crops, and cattle production interact in using the key limiting resource of water.