Project : USDA ARS

ARS Home » Northeast Area » University Park, Pennsylvania » Pasture Systems & Watershed Management Research » Research » Research Project #437022

Research Project: Sustainable Intensification of Integrated Crop-Pasture-Livestock Systems in Northeastern Landscapes

Location: Pasture Systems & Watershed Management Research

2021 Annual Report

Objectives
Objective 1: Develop novel, and improve existing, pasture and crop management strategies to improve agricultural productivity and environmental sustainability in integrated crop-pasture-livestock systems. Sub-objectives include: Sub-objective 1.A. Develop cover crop management strategies to enhance plant and animal productivity and soil health. Sub-objective 1.B. Evaluate plant and animal performance using alternative forages to extend the grazing season to compensate for periods of low perennial cool-season pasture production. Sub-objective 1.C. Evaluate soil health benefits achieved when a confinement dairy is converted to grazing-based forage production. Objective 2: Incorporate novel and existing management strategies into farm- and landscape-scale agricultural planning tools to foster sustainable intensification. Sub-objectives include: Sub-objective 2.A. Quantify the effects of managed riparian grazing on water quality, invasive species, grazing behavior, and plant and animal productivity. Sub-objective 2.B. Develop precision management strategies for perennial forage and biomass crops to increase production and profitability and minimize environmental impacts. Sub-objective 2.C. Synthesize the results of farming system and statistical modeling to develop adaptive decision support tools and to quantify the regional consequences of incorporating the novel practices evaluated in other sub-objectives into integrated crop-pasture-livestock systems.

Approach
Agriculture in the Northeastern U.S. contributes greatly to the regional economy, but is constrained by complex topography, soils, hydrology, and land use patterns, and now faces challenges due to climate change. Strategies for sustainable intensification of characteristic small farms must incorporate crop, pasture, livestock, and biomass production to efficiently use the diverse resources available. Such integration has the potential to not only increase production, but also to improve nutrient cycling, carbon storage, and soil health. This integration and optimization require improved production systems, precision management, and new tools for assessment and decision-making. At the field scale, integrative strategies will result in more efficient utilization of cropland in space and time through cover crops and interseeding. These practices can improve soil health and water quality, while also providing additional forage and increasing crop yields. Conversion from annual to perennial crops benefits soil health and mitigates climate change. At the farm scale, managed grazing of riparian areas increases forage availability and reduces invasive plants without impacting water quality. Precision agriculture techniques adapted to this region improve targeting of management practices and reduce unnecessary inputs. Simulation modeling synthesizes new knowledge of farm and regional effects of these practices on production and ecosystem services and extrapolates these effects to future climates to better plan adaptation efforts. Results at all scales will be integrated into an adaptive decision support system. Explicit guidance on management strategies for sustainable intensification of diverse farms in the northeastern U.S. will benefit farmers through increased production efficiency, will contribute to the prosperity of rural communities, and will improve environmental quality across the entire region. We will collaborate with larger USDA-led research networks, including the Long-Term Agroecological Research network (LTAR), Conservation Effects Assessment Project (CEAP), and Dairy Agroecosystems Working Group (DAWG). Such networking provides expertise and data on outcomes from management strategies for integrated crop-pasture-livestock systems that will be used to complete the objectives of this project. With an emphasis on sustainable intensification in accord with climate predictions, our research must be approached not just on individual farms, but at landscape and regional scales. Because of the impossibility of performing experiments on multiple farms across the entire northeastern US, modeling is required to extrapolate on-farm research to a wider area, and to facilitate the development of broadly applicable decision support tools and management recommendations. To meet this objective, we will combine both on-farm studies and modeling. Outcomes of this research will support farmers directly through management strategies and decision support tools, and will provide scientifically-valid data to federal and state programs aimed at improving nutrient management, conservation, and resource use efficiency.

Progress Report
Under Sub-objective 1.A, plant species mixtures were established, and species biomass yield and quality measurements, hyperspectral, and Light Detection and Ranging (LiDAR) data were collected (1.A.1). Interseeded corn project was grazed with beef cattle in Nov 2020; forage yield and quality and soil data were collected. Grazing occurred again in May 2021 with the same measurements taken. Soil samples were taken on all plots in November 2020. Corn was planted in May 2021, with annual ryegrass to follow in early July in preparation for fall 2021 grazing. (1.A.2). Under Sub-objective 1.B, warm-season grasses (teff, pearl millet, sorghum-sudangrass) were planted as monocultures or interseeded into previously established orchardgrass pastures in June 2021. These species will be monitored for biomass productivity and persistence during the remainder of the 2021 growing season (1.B.1). Sub-objective 1.B.2 has been delayed. Due to restrictions as a result of the COVID pandemic and FY2021 Maximized Telework, the University of New Hampshire (UNH) was not able to conduct the research, and ARS personnel were not able to travel to UNH to assist with data collection. The future of this sub-objective is unknown, as cow availability in the future is uncertain due to commitments to other UNH research projects (including grant-funded projects). ARS researchers may end up substituting additional forage plot work to evaluate additional forage options for future grazing studies. Under Sub-objective 1.C, due to travel restrictions due to the FY2021 Maximized Telework, ARS personnel were not able to travel to UNH to collect the soil samples (1.C.1). Under Sub-objective 2.A, the riparian grazing sub-objective is on indefinite delay. FY2021 Maximized Telework prevented ARS researchers from traveling to potential farms to identify a suitable site for this research. In addition, the lead scientist on this project took another position (at another location) within ARS and is no longer able to lead this project. Commitments by other researchers and current vacancies prevent anyone else from taking the lead on this project (2.A.1). Under Sub-objective 2.B, miscanthus and switchgrass fields established in the Mattern watershed were maintained, and soil moisture network, biomass yield, hyperspectral, and LiDAR data were collected. (2.B.1). Nitrous oxide emission from agricultural soils may be much lower than assumed. Although much attention has been given to the potential for agricultural soils to store carbon, the 100-year global warming potential (GWP) of nitrous oxide (N2O) is 265-298 times higher than carbon dioxide. ARS researchers in Columbia, Missouri, Tifton, Georgia, and University Park, Pennsylvania, long term agroecosystem research (LTAR) network sites, working in collaboration with scientists at the City University of New York, measured potential soil denitrification rates (grams per hectare per day) that ranged from 46-783 at the Pennsylvania site, 227-763 at the Missouri site, and 1246-1448 at the Georgia site. Of these totals, conversion to nitrogen gas (N2), which has no GWP, was consistently greater than 90% of the denitrification product. Topographic position, deep soil layers that trap water, and soil rewetting after dry periods affected N2 and N2O production. These results provide information targeting areas of high denitrification which can be incorporated into N management tools to improve the ability of farmers to manage N for soil fertility, water quality, and reduced N2O emissions. (2.B.1) For Sub-objective 2.C, the representative farming systems were designed based on the previous discussion with land managers across the region and augmented with information on state-specific differences from the USDA National Agricultural Statistics Service (NASS) Census of Agriculture (2.C.1). For Sub-objective 2.C.2, improved methods were developed to model forage species abundance in a more statistically rigorous fashion, and models were developed for 31 species common in pastures of the northeastern U.S. New techniques for augmenting ARS field surveys with citizen science records were developed; this additional dataset improves coverage for species distribution models.

Accomplishments
1. Filling forage gaps in spring grazing systems. Traditional pasture forage species do not provide sufficient growth in early spring, resulting in farmers feeding more expensive harvested forages such as hay. Winter annual forages may provide high-quality, lower-cost pasture in early spring to offset this forage deficit. ARS researchers at University Park, Pennsylvania, and the University of New Hampshire collaborators evaluated five winter annual forages (cereal rye, barley, triticale, wheat, and hairy vetch) for spring productivity and forage quality. Barley showed the most potential for supplementing spring pastures with the fewest tradeoffs to maximize harvest yield and nutrient value for grazing cattle. These results show that winter annual forages complement traditional pastures to help grazing cattle herds decrease feed costs through an extended grazing season to improve farm profitability.

2. Assessing research needs for organic, grassfed dairy farms. Specialty milk markets, such as grass-fed and organic, are gaining popularity with dairy farmers and consumers. However, there is a lack of research outlining dairy production practices, producer-identified research needs, or social factors that affect these production systems. ARS researchers at University Park, Pennsylvania, and collaborators at the University of Vermont and University of New Hampshire conducted a nationwide survey of organic, grass-fed dairy farmers to self-assess farmer knowledge of production practices and identify areas needed for future research and outreach efforts. This innovative study identified several critical needs defining financial and production benchmarks, developing more effective communication strategies to reach and educate organic, grass-fed farmers (particularly those in the Plain community); and identifying methods to improve milk production through improved forage quality. These results will improve research and outreach efforts meet the needs of organic, grass-fed dairy farmers and improve the economic sustainability of this rapidly growing market sector.

U.S. DEPARTMENT OF AGRICULTURE

Pasture Systems & Watershed Management Research: University Park, PA