Converting to alternative annual and perennial forage based systems for sustainable grazing in semi-arid environments

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Commodities

• Agronomic: wheat

Practices

• Animal Production: feed/forage, grazing management
• Crop Production: cover crops
• Production Systems: integrated crop and livestock systems

Soil degradation is a 21st century global problem that has been estimated to have decreased soil ecosystem services by 60% between 1950 and 2010 (Lal, 2015; Leon et al., 2014). Lal (2015) noted that once the process of soil degradation is set in motion, often by land misuse and soil mismanagement along with extractive farming, it feeds on itself in an ever-increasing downward spiral. Such processes are particularly severe in rain-limited environments, where rainfall variability exacerbates crop failure and resource degradation (Tittonell et al., 2012). Incorporating livestock into cropping systems can reduce chemical inputs, decrease weed abundance, and enhance nutrient cycling, while maintaining or even increasing crop yields (MacLaren et al. 2019). However, grazing can increase soil compaction, decrease infiltration, and increase the potential of soil erosion depending upon management decisions (Wheeler et al., 2002).  Continuous, conventionally tilled, dual-purpose wheat systems are the norm across much of the southern U.S. Great Plains, where wheat is grazed as conditions allow with the option to remove cattle in late winter and subsequently harvest grain. However, this system has led to degraded soil resources and inconsistency from year to year due to variable climatic conditions in this harsh semi-arid environment.  Annual wheat systems have been utilized for grazing due to the resilient nature of wheat as well as the lack of a viable alternative. The renewed interest in cover crops has sparked interest in the feasibility of using cover crops as a viable grazing option. Research in the Texas Rolling Plains has shown that warm-season cover crops can provide alternative grazing outside of the typical winter wheat season. In addition, a summer-dormant tall fescue has been developed in the region to provide a viable cool-season perennial. Cover crop mixtures and perennial forage systems have been shown to rapidly increase soil organic matter through liquid carbon pathways, which ultimately improves soil function and improves crop production while decreasing the need for chemical inputs (Jones, 2015). We propose to build upon project LS16-271, which indicated that warm-season cover crop mixes and legume crops can improve soil function in continuous wheat systems compared to summer fallow in semi-arid environments. In addition, this project also found that profit gains were realized through the intensified systems implementing summer crops when fall and/or winter droughts decimated wheat production. In this study, we will evaluate a range of integrated crop-livestock intensity, ranging from annual wheat systems with summer fallow to year-round multi-species mixes to perennial forage-based systems. The assembled team, including cooperating farmers, will quantify impacts of alternative grazing systems on soil function and health, agronomic production, economic viability, and consumer behavior in integrated crop-livestock systems of the southern Great Plains. We hypothesize that systems which provide diversity and armor throughout the year will restore degraded farmlands and provide a more sustainable agricultural strategy.

1. Determine the effects of cover crop/forage mixes, crop rotation, and perennial forage-based systems on overall production and soil function.
2. Evaluate over-seeding of annual forages in warm-season and cool-season perennial systems to expand sustainable grazing options and soil function.
3. Conduct economic analysis of above systems and evaluate social and economic barriers to adoption of alternative integrated crop-livestock systems to restore soil function in semi-arid environments. Document the cost of production and profitability analysis of adopting these integrated systems.  Evaluate the adoption barriers highlighting economic and noneconomic considerations.  
4. Measure ecological services on producer farms that have implemented alternative grazing systems and provide information to stakeholders through educational programs and on-farm tours of evaluated integrated crop-livestock grazing systems.