Integrated Crop and Livestock Systems: Dryland Crop Rotations to Improve Economic and Ecological Sustainability in the Central High Plains
This project focuses on developing additional dryland cropping options for producers in southeastern Wyoming, northeastern Colorado and western Nebraska to improve economic sustainability while reducing erosion and improving soil quality. This would not only enhance profitability for landowners and producers but also increase viability of rural, agricultural-based communities. This 3-year project looks at integrating alternative forages such as winter pea, spring pea and medic as alternative cropping system rotations compared to the traditional dryland rotations of wheat/fallow. Soil quality, production (both livestock gain and crop production) and economic analysis will be used to evaluate and compare the sustainability of these practices vs. conventional farming.
The objectives of this project are to establish integrated dryland cash-crop/forage/livestock systems and evaluate the impacts on soil quality and profitability. This project represents the initial three years of a multi-year study evaluating dryland cropping system opportunities in southeastern Wyoming.
Sub-objectives are: 1. Establish and evaluate the use of both annual and regenerative legumes (peas & medic) in an integrated crop, forage and livestock system. 2. Evaluate profitability of each of the proposed alternative crop, forage and livestock systems. 3. Measure and compare soil quality for the alternative crop, forage and livestock systems vs. traditional wheat-fallow and perennial pasture. 4. Compare long-term sustainability of permanent pastures vs. sustainable cropping and livestock systems on existing wheat-fallow dryland fields.
Year 1 Goals identified in proposal, followed by actual accomplishments:
1. The perimeter of proposed site will be fenced. Twelve pastures and the perennial grass paddock will be established based on soil type, soil testing and terrain to minimize differences in crop production potential
First year establishment of farm scale experimental blocks: In accordance with the proposal objects, 370 acres of dryland wheat fallow cropland at the University of Wyoming Sustainable Agriculture Research and Extension Center near Lingle, WY was chemical fallowed over the spring and summer of 2006. The conversion to the experimental commenced in the manner as shown in figure 1 starting in mid September 2006 when the first winter annual crops were sown. A John Deere 1560 no-till drill with 7.5 inch row spacing was used to seed winter wheat, Austrian winter pea and medic at a seeding rate 60, 60 and 13.5 lbs/acre, respectively. Despite the extremely dry conditions, autumn emergence of the winter wheat and peas was acceptable. This was because of the special effort to sow these crops into soil moisture at 1.5 to 2 inches of soil depth.
Medic, because of its small seed size (the seed is roughly only twice the size of alfalfa), required shallow (¼ to ½ inch) sowing. As a consequence of the extreme dry conditions that persisted into December, the medic emergence in the autumn was poor. Sampling for sown seed on 26 January indicates that medic seed that did not germinate has not yet imbibed moisture. Seed has been retained for a bench-top germination test. The outcome from this test will indicate what the potential may be for early spring germination and establishment of more medic now that soil moisture conditions have finally improved.
It is anticipated that the sowing of the final experimental treatment, the perennial pasture, will take place in April or May depending on weather related field conditions.
2. Effects of treatments on soil quality will be tracked by Gary Hergert. Dr Hergert will establish baseline conditions on both quantitative and qualitative factors including soil organic matter, total organic carbon, organic nitrogen and C:N ratio. Sampling will be done when the treatment plots are established to reflect spatial variability (soils, slope, landscape position) plus average conditions within the larger experimental units. These points will be logged with GPS/GIS technology and the plots re-sampled at the same points after three years.
All pastures were sampled during the fall of 2006, resulting in 8 samples per pasture (as indicated by the dots on figures 1 and 2). Laboratory analysis has started on all samples, but is not complete at the time of this report.
Planned work for this spring:
Pastures will be fenced off separately, and replacement heifers, provided by cooperating producer James Sedman, will be used to determine livestock gain and plant response to grazing. Heifers will remain on grazed pastures from early May until early to mid-June. Forage quality and standing dry matter estimates will be taken systematically throughout the grazing period. Under the direction of Steve Paisley, stocking rates for each pasture will be managed to provide similar grazing pressure across all treatments, and samples of selected pea lines will be subjected to laboratory tests known to provide information regarding potential nutritive value for livestock. Forage and grain samples will be analyzed for dry matter and ash, crude protein (Leco FP-528) and digestibility (Filter bag technique; DaisyII digestion system). Forage samples will be analyzed for neutral and acid detergent fiber (Filter bag technique; Ankom200 analyzer).
SA-10343 Medic is currently in seed increase under the direction of Jim Krall. Dr. Krall will coordinate sowing of all annual crops and use standard research methodologies in the collection of data and analysis to measure annual crop performance and livestock utilization. It is expected that winter wheat protein content and yield, grain pea yield and medic and forage pea DM production (prior to and after grazing, using grazing exclosures) will be measured. Grain production, forage production and livestock weight gain data will be collected each year, and production data, as well as all inputs, will be included in the final economic analysis. Perennial pasture will also be established as one of the treatments, representing a common practice in the area. The perennial pasture treatment will just be established within the 3-year timeframe, potentially requiring re-submission. At the end of the 3-year period, Paul Meiman will evaluate all perennial pastures, providing estimates of forage production and conservative stocking rates. Species composition by weight will also be determined. Within the perennial pasture, an appropriate number of plots will be randomly established. Within each plot, all current year’s aboveground vegetation will be clipped to ground level, separated by species or functional group, oven dried at 50-60 degrees C to a constant weight and then weighed. Clipped material will also be used to determine total standing crop (current year’s aboveground production). Ground cover will be determined by randomly establishing an appropriate number of transects in the perennial pasture. Along each transect, ground cover will be determined using the point intercept method.
The economic analysis comparing the traditional dryland wheat/fallow system vs. alternative legume crop and cattle grazing rotations will be conducted by James Sedman and James Jacobs. This will be accomplished by developing enterprise budgets, showing per unit costs and returns for alternative crop and livestock enterprises. Specifically, input and machinery costs for respective field operations will be computed throughout the production cycle. At the next stage, individual enterprise budgets will be combined to evaluate each system with respect to single-point estimates of profitability for year-to-year product price and yield variation. These results will be examined in the context of appropriate probability distributions with a monte carlo @RISK simulation approach. The economic analysis comparing the alternative crop and cattle grazing rotations to the traditional winter wheat/fallow system will cover the 3-year grant period. An economic analysis will also provide the framework for future evaluation of the established pasture that will be compared to the traditional and alternative crop rotation systems.
Impacts and Contributions/Outcomes
Impact on producers, communities and farming practices: Regional producers will have access to results via visual assessment during field tours, grower meetings and publications. Knowledge gained will guide Central High Plains producers in the adoption of new legume crop/pasture plants and conversion to more intense and integrated crop/livestock production systems.
The measurable number of acres or animals that will be impacted may both be measured in the hundreds of thousands. Today, alternative crops such as sunflowers and proso millet replace 20-25% of fallow in Wyoming. Annual legumes might exceed this level of production.
The integrated crop/livestock systems will increase crop diversity over traditional wheat/fallow dryland cropping systems, introducing the use of medic (annual Medicago spp.) pastures, as well as winter and spring pea varieties to a traditional single crop system will also improve soil quality through the incorporation of legumes and livestock grazing in crop rotations. These systems will also help to reduce soil erosion and farming inputs compared with the traditional wheat-fallow system by providing livestock grazing opportunities.
This research is designed to generate data to more precisely measure economic impact. So far, an economic analysis of grazed Austrian winter pea (AWP) in place of fallow indicates a return of an extra $12/acre. Based on a 50% fallow replacement this means an additional $1.1 million/yr for the agricultural economy of southeastern Wyoming alone. Adoption of these practices in adjacent states would result in substantially larger returns, as estimated below in the economic impact.
Positive economic impact (in dollars): Over the last 10 years, approximately 189,000 acres of dryland wheat were planted in Wyoming, with an average yield of 25.4 bushels per acre. Current planted dryland wheat acreages in eastern Colorado and the Nebraska Panhandle are 1,670,000 and 689,000, respectively. The total planted wheat acreage in the high plains region is approximately 2.5 million acres.
Yields for dryland wheat production have remained fairly consistent for the past 20 years, indicating that alternative cropping systems may be needed to increase revenue per acre. With recent increases in fuel, seed, fertilizer and chemical prices, a lower cost, higher revenue alternative cropping system becomes desirable. Use of an alternative cropping system that includes legume grazing could significantly reduce variable costs in terms of fuel, machinery and labor when compared to wheat fallow systems. For example, previous research suggests that adding an alternative forage crop such as AWP to a wheat/fallow rotation could increase average revenue per acre by as much as $12. This could mean a $2.2 million dollar increase in revenue for Wyoming dryland wheat producers (projected over the entire state wheat acreage). Results from the proposed research will provide data needed to more accurately evaluate the economic impacts of producers adopting integrated dryland crop/forage/livestock systems in the high plains region.