Crop-livestock Systems for Sustainable High Plains Agriculture

Crop-livestock Systems for Sustainable High Plains Agriculture

Summary

Over the past 100 years, the Texas High Plains grasslands evolved into a $20+ billion agricultural industry centered largely on cotton and finishing beef cattle in feedlots. Agriculture was made possible with fertile soils, cheap energy and fertilizers, and irrigation water from the Ogallala aquifer. Today, energy and related costs are escalating rapidly, and water in the Ogallala is declining at a rate of over 1 foot per year. Recharge is negligible, and water demand is expected to exceed supply within the next 10 to 20 years. With marginal profits, cotton acres are now declining and new industries, including dairies and ethanol plants are proliferating causing increased acres of corn, a crop that dramatically increases irrigation water demands. Sorghum could replace corn silage for the dairy industry and reduce water use. Moreover, with limited cropping of minimally irrigated, water-use efficient plants and a perennial grass grazing-based beef industry, integrated systems could be sustained indefinitely, but alternatives must be energy efficient and economically viable. Current trends cannot be continued. Our SARE-funded research, begun 10 years ago, showed that an irrigated, integrated, cotton-forage-beef stocker cattle system reduced irrigation water (24%) and nitrogen fertilizer (40%) with similar profitability to a cotton monoculture. Despite such promising results, these systems need refocusing to address emerging issues. Additional SARE-funded comparisons of a dryland, integrated cotton-native grass-stocker cattle system and a deficit-irrigated perennial grass-stocker cattle system remain relevant. With state funding, monitoring of 26 producer sites is further testing monocultures and integrated systems under irrigation and dryland conditions. With this historic and ongoing platform of replicated research and on-farm producer systems, we can generate information on energy use and energy economics so urgently needed to design efficient agricultural systems. Furthermore, by redesigning the original irrigated integrated systems to compare perennial forages for finishing beef cattle with a sorghum monoculture, we can further reduce water use and meet a growing market demand for forage-fed beef. Additionally, sorghum may flexibly meet needs for grazing, silage, or biofuels. These systems will be compared for system and component water and energy use and efficiencies, plant and animal product quantity and quality, input requirements, economic profitability, and soil conservation and quality. A Farming Systems Research and Extension approach will be used to increase awareness, knowledge sharing, and adoption of appropriate technologies within the region and beyond using participatory methods with producers and industry as full partners to establish true Communities of Practice.

Objectives/Performance Targets

Our hypothesis is that more energy, water, and soil can be conserved, profitability and sustainability of agriculture can be increased, and the changing priorities and opportunities for agriculture in the semi-arid region of the Texas High Plains can be better addressed through an integrated systems approach than through existing monoculture agricultural systems.

The overall objective is to conserve energy, water, and soil and maintain an agricultural industry that is economically and environmentally sustainable.
Specific objectives are:

1. To compare integrated crop and beef cattle (stocker and forage finishing) systems (both irrigated and dryland) and a forage sorghum monoculture for dependence on water (irrigation + precipitation) and energy, and impact on soil quality and erosion, and economic returns.
2. To determine energy use, energy efficiency, and energy economics of integrated systems and monocultures, representing both dryland and irrigated agriculture, using both new and long-term, replicated field-scale systems and 26 on-farm producer managed systems.
3. To translate results from Objectives 1 and 2 into practices incorporated in agriculture in the High Plains and other applicable ecosystems.

Accomplishments/Milestones

Conversion of the original 3-paddock irrigated crop/forage/livestock system to a perennial grass/legume system for finishing stocker steers is near completion and grazing will begin in 2010.
This 3-paddock was revised as follows. The perennial warm-season grass pasture composed of WW-B. Dahl old world bluestem was overseeded with alfalfa and yellow sweetclover in the spring of 2010. The intent is to include sufficient legume to contribute nitrogen to the system and improve forage quality for the grazing steers without increasing water requirements. Seeding rates were based on our previous research. Following unusually high winter precipitation, establishment success is anticipated. Cattle will begin grazing these paddocks when legumes have become established and to reduce over growth of the grass.

The 2-paddock rotation with cotton and small grains was converted to 1) a paddock containing warm-season native grasses (blue grama, sideoats grama, and green sprangletop); and 2) a paddock containing a mixture of Jose tall wheatgrass and alfalfa. These forages have been established during the past year and are ready for grazing to begin in 2010.

Stocker steers will begin grazing these forages in late spring 2010 and will be supplemented with DDG’s from the ethanol industry to supplement energy and crude protein to increase daily gains. If steers are not finished by the end of the grazing season, they will be placed in the feedlot and finished on a conventional diet to determine the additional length of time required post pasture to finish cattle. At harvest, carcass quality will be evaluated.
Data continues to be collected from the ongoing dryland integrated crop/livestock system and the irrigated perennial grass grazing system for stocker steers. Beginning in 2010, steers from these two systems will also be feedlot-finished and carcass quality will be evaluated at harvest.

Data collected is contributing to publications, field days, and to efforts to secure future funding. Our goal is to establish this research site as a long-term Agroecosystem site for semi-arid regions where water resources are declining.

Impacts and Contributions/Outcomes

Data collected from this long-term integrated systems research has resulted in 20 graduate students trained, 11 papers published in peer-reviewed journals, over 50 national and international talks, more than 10 field days, and has lead to additional grant successes. In 2004, the State of Texas funded ($6.2 M) the Texas Alliance for Water Conservation which is a producer-led demonstration of 27 producer sites across 2 counties to document water savings and profitability of integrated systems. This provides the ground-truthing of the research component and resulted directly from the SARE-funded research platform. Together, the replicated SARE-funded systems research and the state-funded demonstration project provide an absolutely unique opportunity to test, demonstrate, and incorporate sustainable agricultural practices in this semi-arid region. Results have global implications and are leading the changes that are inescapable in this region where water for irrigation will not be there in the future as it has been in the past. Whether water is reduced by government regulation, increasing costs of pumping, or absolute loss of this resource, water will be increasingly restricted in the future. This research is leading the way in finding practices that will allow agriculture to be sustained in this region.

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