Otto C. Doering

Sustainable Biofuels Redux

Science-based policy is essential for guiding an environmentally sustainable approach to cellulosic biofuels.

Consequences of future climate change and changing climate variability on maize yields in the midwestern United States

Any change in climate will have implications for climate-sensitive systems such as agriculture, forestry, and some other natural resources. With respect to agriculture, changes in solar radiation, temperature, and precipitation will produce changes in crop yields, crop mix, cropping systems, scheduling of field operations, grain moisture content at harvest, and hence, on the economics of agriculture including changes in farm profitability. Such issues are addressed for 10 representative agricultural areas across the midwestern Great Lakes region, a five-state area including Indiana, Illinois, Ohio, Michigan, and Wisconsin. This region is one of the most productive and important agricultural regions in the world, with over 61% of the land use devoted to agriculture. Individual crop growth processes are affected differently by climate change. A seasonal rise in temperature will increase the developmental rate of the crop, resulting in an earlier harvest. Heat stress may result in negative effects on crop production. Conversely, increased rainfall in drier areas may allow the photosynthetic rate of the crop to increase, resulting in higher yields. Properly validated crop simulation models can be used to combine the environmental effects on crop physiological processes and to evaluate the consequences of such influences. With existing hybrids, an overall pattern of decreasing crop production under scenarios of climate change was found, due primarily to intense heat during the main growth period. However, the results changed with the hybrid of maize (Zea mays L.) being grown and the specific location in the study region. In general, crops grown in sites in northern states had increased yields under climate change, with those grown in sites in the southern states of the region having decreased yields under climate change. Yields from long-season maize increased significantly in the northern part of the study region under future climate change. Across the study region, long-season maize performed most successfully under future climate scenarios compared to current yields, followed by medium-season and then short-season varieties. This analysis highlights the spatial variability of crop responses to changed environmental conditions. In addition, scenarios of increased climate variability produced diverse yields on a year-to-year basis and had increased risk of a low yield. Results indicate that potential future adaptations to climate change for maize yields would require either increased tolerance of maximum summer temperatures in existing maize varieties or a change in the maize varieties grown.

Why Metrics Matter: Evaluating Policy Choices for Reactive Nitrogen in the Chesapeake Bay Watershed †

Despite major efforts, the reduction of reactive nitrogen (Nr) using traditional metrics and policy tools for the Chesapeake Bay has slowed in recent years. In this article, we apply the concept of the Nitrogen Cascade to the chemically dynamic nature and multiple sources of Nr to examine the temporal and spatial movement of different forms of Nr through multiple ecosystems and media. We also demonstrate the benefit of using more than the traditional mass fluxes to set criteria for action. The use of multiple metrics provides additional information about where the most effective intervention point might be. Utilizing damage costs or mortality metrics demonstrates that even though the mass fluxes to the atmosphere are lower than direct releases to terrestrial and aquatic ecosystems, total damage costs to all ecosystems and health are higher because of the cascade of Nr and the associated damages, and because they exact a higher human health cost. Abatement costs for reducing Nr releases into the air are also lower. These findings have major implications for the use of multiple metrics and the additional benefits of expanding the scope of concern beyond the Bay itself and support improved coordination between the Clean Air and Clean Water Acts while restoring the Chesapeake Bay.

Changes in Soybean Yields in the Midwestern United States as a Result of Future Changes in Climate, Climate Variability, and CO2 Fertilization

This modeling study addresses the potential impacts of climate change and changing climate variability due to increased atmospheric CO2 concentration on soybean (Glycine max (L.) Merrill) yields in theMidwestern Great Lakes Region. Nine representative farm locations and six future climate scenarios were analyzed using the crop growth model SOYGRO. Under the future climate scenarios earlierplanting dates produced soybean yield increases of up to 120% above current levels in the central and northern areas of the study region. In the southern areas, comparatively small increases (0.1 to 20%) and small decreases (–0.1 to–25%) in yield are found. The decreases in yield occurred under the Hadley Center greenhouse gas run (HadCM2-GHG), representing a greater warming, and the doubled climate variability scenario – a more extreme and variableclimate. Optimum planting dates become later in the southern regions. CO2fertilization effects (555 ppmv) are found to be significant for soybean, increasing yields around 20% under future climate scenarios.For the study region as a whole the climate changes modeled in this research would have an overall beneficial effect, with mean soybean yield increases of 40% over current levels.

Biofuel vs Bioinvasion: Seeding Policy Priorities

Desirable biofuel crops may amount to mass cultivation of potentially invasive species—How should policy keep these agroecosystems in check?

Domestic Farm Policy and the Gains from Trade

This paper assesses the extent to which the gains from agricultural trade are influenced by both U.S. domestic policy and tariff and nontariff trade barriers. It shows theoretically that the volume of trade can be substantial but the gains nonexistent. Empirical results, along with rent-seeking arguments, support the no-gains-from-trade hypothesis.

Mitigating the Compliance Cost of a Phosphorus-Based Swine Manure Management Policy

Regulatory changes by federal and state agencies portend a switch from nitrogen-based livestock manure disposal policies to phosphorus-based policies. This paper estimates the compliance costs of such a policy change for a hypothetical hog-grain farm in North Central Indiana. The farm includes 1,500 acres of cropland and has the capacity to raise 11,970 grow-finish hogs annually. The farm model also as the potential to produce four different crops on six different land types. A nonlinear math-programming model was developed to determine the optimal mix of management activities for a phosphorus-based regulation. The model allows mitigation of compliance costs via the choice between four different pig diets, three alternative methods of manure disposal, changes in timing of manure application, and crop pattern adjustments. This analysis concludes that the new regulation will result in a decrease in whole-farm returns above variable costs, the use of phytase enzyme in pig diets, and an increase in wheat acreage. The model also reveals that it is optimal for the farmer to hire a custom hauler to assist in application of manure in an effort to reduce the degree to which available field days constrain farming activities and land application of manure. The estimated cost to the farmer, as a result of the policy change, ranges between

Economic linkages driving the potential response to nitrogen over-enrichment

0.56 and

Crop models capture the impacts of climate variability on corn yield

21.74 per unit of pig production capacity.

Agriculture and Energy Use in the Year 2000

Most public decisions ultimately have economic content. Decisions that deal with externalities, such as pollution, carry costs as well as benefits for society. Actions that mitigate nutrient over-enrichment in the Gulf of Mexico would require actions throughout the Mississippi River Basin resulting in both direct and indirect economic impacts. This paper describes and explains the economic linkages and trade-offs involved in actions that could be cost effective and meet a public goal of reducing nitrogen over-enrichment within the Mississippi River Basin. The impacts of different approaches that reduce the major source of nitrogen flows to the Gulf, nonpoint pollution from agriculture, are simulated for both source reduction the major source of nitrogen flows to the Gulf, nonpoint pollution from agriculture, are simulated for both source reduction and interception of nitrogen. Lessons learned include the fact that any one approach by itself has increasing marginal cost. The approaches considered have modest direct and indirect costs when only required to mitigate 20% to 25% of the nitrogen losses. Simultaneous multiple approaches appear even more attractive to induce only moderate negative impact. The impacts of mitigation are not just confined to the Mississippi River Basin but spread beyond the basin and are themselves influenced by external factors such as commodity prices and import and export markets for agricultural commodities. Success in reducing excess nitrogen flows will depend on institutional factors as well as technical efficacy. Finally, the nature of soil system sinks and the resulting long lead time likely before results might be apparent present a special obstacle to enlisting cooperation, assessing efficacy, and designing adaptive behavior.