Project : USDA ARS

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Research Project: Sustainable Intensification of Crop and Integrated Crop-Livestock Systems at Multiple Scales

Location: Pasture Systems & Watershed Management Research

2022 Annual Report

Objectives
Objective 1: Assess and improve sustainable intensification strategies of crop and integrated crop-livestock systems for farm systems, watersheds, and landscapes. Sub-objective 1A: Quantify long-term sustainabilities of “business as usual” (BAU) and “aspirational” (ASP) dairy and beef production systems through farm simulation and life cycle assessment. Sub-objective 1B: Develop management and placement strategies for improving ecosystem service provisioning through diverse agricultural landscapes that integrate crop and livestock systems. Objective 2: Determine the sensitivity of farm systems, watersheds, and landscapes to climate variability and develop strategies for adapting agriculture to current and projected changes. Sub-objective 2A: Quantify effects of projected climate and potential adaptation strategies on long-term sustainabilities of “business as usual” (BAU) and “aspirational” (ASP) dairy and beef production systems through the use of farm simulation and life cycle assessment. Sub-objective 2B: Characterize the landscape-scale responses and trade-offs of agricultural ecosystem services, given projected climate and potential adaptation scenarios.

Approach
Agriculture faces increasing demands for productivity and efficiency that must be balanced against pressures to continually improve stewardship of natural resources. Climate models from 1950 through 2100 predict increases in temperature and precipitation in the Northeast, further complicating agricultural sustainability planning. Our research focuses on whole farms, watersheds, and landscapes to quantitatively evaluate both long-term sustainabilities and broader environmental impacts of various agricultural production systems under current and predicted climate. We will evaluate alternative production strategies based on economic viability, implementation feasibility, and impacts to ecosystem services and disservices. We are concerned with not only provisioning ecosystem services such as dairy, beef, and crop production but also supporting and regulating services like nutrient cycling and landscape diversity. Disservices from agriculture include greenhouse gas emissions and other nutrient losses to air and water. Our two objectives assess “business as usual” (BAU) and “aspirational” (ASP) agricultural production strategies for sustainable intensification at multiple scales. The (A) sub-objectives are farm-scale in detail and industry-wide in scope. The (B) sub-objectives focus on landscape-scale hydrology and ecology within the Northeast to inform both local and multi-regional research efforts. Objective 1 assesses strategies under recent climate conditions (1980-2005), and corroborates our modeling tools in representing BAU and ASP strategies. To be most valuable, however, developed strategies and tools must be successful under future climate conditions. Objective 2 corroborates our tools under historical climate (1960-1980) and applies them under future mid-century (2040-2060) and late-century (2080-2100) climate projections, assessing ASP strategies that most effectively meet the challenges and opportunities of future climate. 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 cropping and integrated crop-livestock systems that will be used to confirm results of the first objective and provide a basis for extrapolation of future systems for the second. We will analyze data using both simple and complex process-based simulation models, life cycle assessment, and advanced computational techniques. With an emphasis on sustainable intensification in accord with climate predictions, our research will support systems-level understandings of current and potential agricultural systems in the Northeast, and how these can continue to produce food and fuel in the future. 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
Progress was made on both objectives and their subobjectives, all of which fall under National Program Action Plan 216: Agricultural System Competitiveness and Sustainability and contributes to Component 1: Building agroecosystems for intensive, resilient production via GxExM; Component 2: Increasing efficiency for agroecosystem sustainability; and Component 3: Achieving agroecosystem potentials. Under Objective 1, subobjective 1A, a series of beneficial management practices were assessed for U.S. beef production systems, and a report was submitted to the National Cattlemen’s Beef Association. The Integrated Farm System Model (IFSM) was linked with life cycle assessment software to provide full system evaluation of multiple environmental impact categories. Archetypical production systems across the U.S. were constructed using the IFSM simulation platform to supply life cycle inventory flows. For many impact categories, electricity consumption and fertilizer production were notable drivers of environmental impact. The only direct action available to the beef sector to aid in mitigation of these impacts is to reduce electricity and fertilizer consumption or shift to renewable sources. In collaboration with the Southwest Beef Project and the Long-Term Agroecosystem Research network, representative beef cattle operations were modeled in the western region. Farm-gate life cycle assessments of cattle finishing on rangeland in the Southwest, pastureland in the Northern Plains, and feedlots in the Texas Panhandle were determined and a manuscript was prepared. Use of a decanter centrifuge to extract phosphorus from manure was evaluated on a 2000-cow dairy farm in central Pennsylvania, and a manuscript was published. Phosphorus extraction provided a better ratio of nitrogen and phosphorus contents for use on nearby cropland and reduced transport costs for nutrients applied to more distant cropland. In collaboration with Dairy Management Incorporated, a project was initiated to study the environmental benefits of implementing various technologies or strategies with the goal of obtaining net zero greenhouse gas emissions from dairy farms. As a follow up to our recent national assessment of the environmental impacts of current U.S. dairy farms, a project was initiated to model dairy farms in 1970 to quantify environmental improvements made over the past 50 years. This analysis is quantifying the rate of change in methane emissions from dairy farms, which enables the calculation of global warming using a new model referred to as GWP*. Under Objective 1, subobjective 1B, a detailed water quality model was modified from the Soil and Water Assessment Tool (SWAT) to simulate hydrology, nutrient, and sediment losses of agricultural fields in multi-year rotations. This model focuses on the effect of hillslope position and topography of the field in simulating infiltration- and saturation-based flows. Seasonal and annual results from each field were compared with similar outputs from Pennsylvania Phosphorus Index version 2. Because the Phosphorus Index provides an average annual risk assessment over a multi-year rotation, we found that its results minimized the actual year-to-year losses caused by temporal climatic variation. This result was more pronounced for row crop rotations without continuous soil cover and for more disruptive tillage practices. In addition to field losses of excess nutrients, the impacts of agricultural chemicals beyond their intended purpose can be costly, both environmentally and economically. Life cycle inventory (LCI) models were developed for pesticides in the National Agricultural Statistics Service (NASS) chemical use survey for corn, soybeans, wheat, and cotton in the United States and their impact was characterized using the Chemical Life Cycle Collaborative Tool (CLiCC). Finally, multiple axes of diversity -- physical, production (irrigated and rain-fed crops, and livestock), and socio-economic -- were used to characterize agriculturally-relevant landscape diversity for the conterminous United States. The regionalization thus developed is a key part of current Long-Term Agroecosystem Research efforts and is additionally used to provide a basis for climate change and ecosystem services modeling. Under Objective 2, subobjective 2A contained no specific milestones. Milestones for subobjective 2B involved development of models and model inputs to better understand how agriculture may be impacted by future climatic changes. Soil and Water Assessment tool projects were modified to incorporate the estimated impact of increased atmospheric carbon dioxide in accordance with climate change projections. Additionally, the long-term practicality of promoting a shift in manure application levels to not exceed agronomic phosphorus demands was simulated across the Susquehanna River Basin with several variations. Input modifications for grazing and crop growth were made to ensure simulated increases and decreases in biomass over time were realistic. Extending our look into climate change projections even more broadly, empirical models of climatic distribution were developed for forage species and for key crop species. These models were linked with climate change projections to produce maps of potential future agricultural scenarios for the northeastern United States, and consequences for ecosystem services including production, soil erosion, and pollination services.

Accomplishments

U.S. DEPARTMENT OF AGRICULTURE

Pasture Systems & Watershed Management Research: University Park, PA