Marcel P. Aillery

Manure Management for Water Quality Costs to Animal Feeding Operations of Applying Manure Nutrients to Land

Nutrients from livestock and poultry manure are key sources of water pollution. Ever-growing numbers of animals per farm and per acre have increased the risk of water pollution. New Clean Water Act regulations compel the largest confined animal producers to meet nutrient application standards when applying manure to the land, and USDA encourages all animal feeding operations to do the same. The additional costs for managing manure (such as hauling manure off the farm) have implications for feedgrain producers and consumers as well. This reports farm-level analysis examines on-farm technical choice and producer costs across major U.S. production areas for hauling manure to the minimum amount of land needed to assimilate manure nutrients. A regional analysis then focuses on off-farm competition for land to spread surplus manure, using the Chesapeake Bay region as a case study. Finally, a sectorwide analysis addresses potential long-term structural adjustments at the national level and ultimate costs to consumers and producers.

Water Conservation in Irrigated Agriculture: Trends and Challenges in the Face of Emerging Demands

This report relies on fi ndings from several national surveys and current literature to assess water resource use and conservation measures within the U.S. irrigated crop sector. U.S. agriculture accounts for 80-90 percent of the Nation’s consumptive water use (water lost to the environment by evaporation, crop transpiration, or incorporation into products. Expanding water demands to support population and economic growth, environmental flows (water within wetlands, rivers, and groundwater systems needed to maintain natural ecosystems), and energy-sector growth, combined with Native American water-right claims and supply/demand shifts expected with climate change, will present new challenges for agricultural water use and conservation, particularly for the 17 Western States that account for nearly three-quarters of U.S. irrigated agriculture. Despite technological innovations, at least half of U.S. irrigated cropland acreage is still irrigated with less effi-cient, traditional irrigation application systems. Sustainability of irrigated agriculture will depend partly on whether producers adopt more effi cient irrigation production systems that integrate improved onfarm water management practices with effi-cient irrigation application systems.

Agricultural Adaptation to a Changing Climate: Economic and Environmental Implications Vary by U.S. Region

Global climate models predict increases over time in average temperature worldwide, with significant impacts on local patterns of temperature and precipitation. The extent to which such changes present a risk to food supplies, farmer livelihoods, and rural communities depends in part on the direction, magnitude, and rate of such changes, but equally importantly on the ability of the agricultural sector to adapt to changing patterns of yield and productivity, production cost, and resource availability. Study findings suggest that, while impacts are highly sensitive to uncertain climate projections, farmers have considerable fl exibility to adapt to changes in local weather, resource conditions, and price signals by adjusting crops, rotations, and production practices. Such adaptation, using existing crop production technologies, can partially mitigate the impacts of climate change on national agricultural markets. Adaptive redistribution of production, however, may have signifi cant implications for both regional land use and environmental quality.

A dynamic model of soil salinity and drainage generation in irrigated agriculture: A framework for policy analysis

This paper presents a dynamic model of irrigated agriculture that accounts for drainage generation and salinity accumulation. Critical model relationships involving crop production, soil salinity, and irrigation drainage are based on newly estimated functions derived from lysimeter field tests. The model allocates land and water inputs over time based on an intertemporal profit maximization objective function and soil salinity accumulation process. The model is applied to conditions in the San Joaquin Valley of California, where environmental degradation from irrigation drainage has become a policy issue. Findings indicate that in the absence of regulation, drainage volumes increase over time before reaching a steady state as increased quantities of water are allocated to leaching soil salts. The model is used to evaluate alternative drainage abatement scenarios involving drainage quotas and taxes, water supply quotas and taxes, and irrigation technology subsidies. In our example, direct drainage policies are more cost-effective in reducing drainage than policies operating indirectly through surface water use, although differences in cost efficiency are relatively small. In some cases, efforts to control drainage may result in increased soil salinity accumulation, with implications for long-term cropland productivity. While policy adjustments may alter the direction and duration of convergence to a steady state, findings suggest that a dynamic model specification may not be necessary due to rapid convergence to a comon steady state under selected scenarios.

Agriculture and Ecosystem Restoration in South Florida: Assessing Trade-Offs from Water-Retention Development in the Everglades Agricultural Area

Agricultural production decisions can affect ecosystem function and environmental quality. Environmental restoration policies can, in turn, affect the profitability of the agricultural sector. A dynamic model of agricultural production, soil loss, and water retention in the Everglades Agricultural Area is developed to assess agricultural impacts under alternative water policy and land acquisition scenarios. Copyright 2001, Oxford University Press.

Irrigation Technology Transitions in the Mid-plains States: Implications for Water Conservation/Water Quality Goals and Institutional Changes

A Parks modified multinomial logit model is used to examine the influence of the agricultural economic environment on irrigation technology transitions in the mid-plains states. Simulation analyses assess expected agricultural water conservation and its implications for water quality/environmental goals and water institutional reform. Under baseline agri-economic assumptions, regional agricultural water use efficiency could improve from 2.3% to 9.8%. Technology-specific elasticities show that crop price effects on irrigation technology transitions are relatively inelastic. Results for the mid-plains states differ from those obtained for the Pacific north-west (an earlier study), implying that differentially endowed resource regions will likely require different resource conservation policy and institutional approaches.

Agricultural Production under Climate Change: The Potential Impacts of Shifting Regional Water Balances in the United States

General circulation models predict significant and accelerating changes in local patterns of precipitation and temperature during the twenty-first century. Agricultures vulnerability to climate change will depend on both the biophysical impacts of climate change on crop yields and on the agricultural systems ability to adapt to changing production conditions. Shifts in the extent and distribution of irrigated and dryland production are a potentially important adaptation response. Farmer flexibility to adapt may be limited, however, by changes in the availability of irrigation water under future climate conditions. This study uses a suite of models to explore the biophysical and economic impacts of climate change on U.S. fieldcrop production under several potential future climate projections, and to explore the potential limits and opportunities for adaptation arising from shifting regional water balances. The study findings suggest that, while irrigation shortages attributable to climate change have varying effects on cropland use, the aggregate impacts on national production are small relative to the direct biophysical impacts of climate change on yield.

Integrating Commodity and Conservation Programs: Design Options and Outcomes

Can a single program support farm income and encourage producers to adopt environmentally sound farming practices? While simple in concept, attempting to roll the farm income support features of existing commodity programs and conservation payments into a single program raises questions. Exactly how would farm commodity and conservation payments be combined? What difference would it make for environmental gain and farm income support? This report approaches the questions in two ways. First, spending patterns in existing commodity and conservation programs are analyzed to determine the extent to which producers who are currently receiving commodity payments also receive conservation payments. Then, a number of hypothetical program scenarios are devised and analyzed to estimate how emphasis on current income support recipients would differ from a combined program that focuses on achieving cost-effective environmental gain. The results show that policymakers face significant tradeoffs between environmental conservation) objectives and farm income support objectives in designing a program that provides both income support and environmental gain.

AGRICULTURE IN AN ECOSYSTEMS FRAMEWORK

By broadening the definition of an ecosystem to include economic activities, can we better characterize the interactions and relationships among agricultural activities and important indicators of ecological system health? This paper addresses research approaches for assessing the role of agriculture in an ecosystems context. Environmental regulation and resource management policies have heightened the interest in understanding interactions among agricultural activities and the natural resource base, including the impacts of agriculture on environmental quality and the impacts on agriculture of ecosystem restoration efforts. What are the most meaningful indicators of environmental quality? Which agricultural practices and policies should be considered, along with which nonagricultural resource uses? Finally, does the evolving thinking about ecosystems permit us to link agricultural practices and policies more directly and meaningfully to conceptions of sustainability, of both natural and socioeconomic systems? This paper presents a brief synopsis of ecosystem management, drawing from several recent governmental initiatives. It then provides an overview of the economics of ecosystem management from the perspective of the role of agriculture; discusses two specific cases, the Pacific Northwest and South Florida; and concludes with a discussion of promising economic approaches, data needs, and caveats to those engaged in policy analysis involving ecosystem restoration.

Regional Modeling and Economic Incentives to Control Drainage Pollution

Management of quantity and quality of irrigation water—both as an on-farm production input and as an off-farm agricultural drainage residual—is an increasing concern in many parts of the world, including the arid western United States. Agricultural drainage water often carries salts, pesticides, nitrates, selenium, and other trace elements that contaminate soil and water resources. As a nonpoint source of pollution, drainage discharges directly and indirectly affect agricultural productivity, wildlife, public health, and amenity resources. In addition to the quality aspects, strong competition exists for water among urban, industrial, environmental, and agricultural users in the western United States. Irrigation water conservation may achieve the dual goal of extending fresh water supplies and improving environmental quality.