California Agroecosystem Services: Assessment, Valuation and Policy Perspective - Proceedings from the Sept 2007 workshop
Combined pdf of all papers below (pdf, 3120 kb)

Making Policy to Achieve Sustainable Agriculture American Farmland Trust
Abstract, Ann Sorensen AAAS

In the past few decades, U.S. agriculture has steadily cleaned up “its footprint” on the landscape but major challenges remain. In 1999, USDA’s Economic Research Service looked at the sustainability of U.S. agriculture and concluded that “Environmental programs exist and the resource base is depreciating but the extent of the effects is in the range that can be adequately addressed by thoughtful policy.” Studies that look at agriculture’s impacts on the environment and the use of conservation practices to minimize those impacts are challenged by a continuing lack of qualitative and quantitative data. Nonetheless, they paint a complex picture. The policy options available to increase the environmental sustainability of farming are varied. Regulatory approaches, like expanding conservation compliance (i.e., tying eligibility for federal payments to conservation behavior) or enacting a national environmental law for farming could be very effective but may not be politically feasible. Incentive-based approaches to help farmers adopt more conservation practices are more palatable to lawmakers and landowners and have broad public support. These options include increasing funding for conservation programs, consolidating, refining and simplifying programs to make them easier to use and more focused on producing environmental benefits, and introducing conservation loan guarantees or encouraging more cooperative conservation partnerships. The most intriguing, and perhaps most promising long term approach, however, is the possibility of creating markets for the environmental services offered by agriculture--including cleaner water, mitigation of greenhouse gases and flooding, wildlife habitat, and restoration of wetlands. With global climate change and the search for alternative energy sources, agriculture could potentially become a potent environmental service provider. For this reason, we are cautiously optimistic that the political will and policies to help agriculture implement the necessary conservation practices, create the necessary infrastructures and become a net provider of environmental services for this country is within our reach.

The Science of Sustainability in U.S. Agriculture (Powerpoint, 11000 kb)
Kenneth G. Cassman Director, Nebraska Center for Energy Science Research, University of Nebraska

The sustainability of U.S. agriculture must be considered from a global perspective because U.S. agriculture accounts for the greatest share of world food exports. Agriculture must address the following global challenges: continued population increase, limited arable land and water resources, climate change, and rising prices for petroleum-based motor fuels. Of these, rising fuel prices are having the largest impact on agriculture because they are driving a rapid expansion of biofuel production from grain, sugar, and oilseed crops—both in the U.S. and globally. The benefits from biofuels are compelling: decreased reliance on imported petroleum, a reduction in greenhouse gas emissions, increased agricultural commodity prices and farm income, rural jobs and economic development, and reduced crop subsidies. High commodity prices will motivate farmers to increase crop yields and expand production area. A marked acceleration in the rate of yield gain for the major crops will be required to avoid conversion of marginal land not suited for crop production, and conservation of centers of biodiversity such as grassland savannahs, forests and wetlands. Crop and soil management practices used to achieve substantially higher yields must protect water and soil quality and contribute to a reduction in greenhouse gas emissions. Although it is possible to meet these challenges, the magnitude of scientific innovation required has been underestimated. A dynamic, real-time, site-specific, “ecological systems approach” will be needed. Biotechnology and transgenic crops are not a silver bullet. Eventually, development of cellulosic (biomass) ethanol will reduce the need to use food crops for biofuels, but large-scale deployment of cellulosic ethanol systems is 7-10 years away. During this period, grain-sugar-oilseed biofuel systems will build out to utilize a significant portion of global food crop production. There is an urgent need to focus research and technology development on ensuring the environmental sustainability of high-yield food-crop systems to meet demand for both food and biofuels. 

When Can Intelligent Design of Crops by Humans Outperform Natural Selection?
R.F. Denison, University of Minnesota
Abstract (download full paper, pdf, 100kb)

Natural selection operated on the wild ancestors of crop plants for millions of years. Many seemingly intelligent design changes that we could make to enzyme structure or gene expression would duplicate (at least in phenotypic effect) variants already rejected by past natural selection. These variants died out because they decreased individual plant survival or reproduction under preagricultural conditions. Many of the variants rejected by past natural selection would also reduce crop yield or quality today, so it would be a waste of time to duplicate them using molecular methods. For example, most changes to rubisco will decrease photosynthesis (and crop yield) under current conditions, just as they would have decreased photosynthesis (and individual plant fitness) under preagricultural conditions. A few of natural selection’s ‘rejects’, however, would be genuine improvements by human criteria. Can we identify these promising rejects? Opportunities for crop genetic improvement that were missed by past natural selection are likely to fall into three major categories. First, and most important, conflicts of interest among competing plants, or between plants and their microbial symbionts, can cause trade-offs between individual plant fitness (favoured by past natural selection) and the collective performance of the crop community. Therefore, we can sometimes increase yield by reversing the effects of past natural selection for individual competitiveness. Second, changes in climate, soil fertility and pest populations mean that some variants that were less fit in the past will be more fit today. In this case, crop genetic improvement may accelerate changes that are already favoured by ongoing natural selection in an agricultural context. Third, eventually molecular methods may produce genotypes so different from anything that existed in the past that we cannot assume they were tested and rejected by natural selection. C4 photosynthesis has evolved repeatedly, however, so a proposed innovation would have to be more radical than C4 photosynthesis before we can assume it was missed by past natural selection. The relative importance of these three kinds of opportunity is likely to change over the next few decades. Some trade-offs between individual competitiveness and the yield of the crop community have already been exploited, as in dwarf wheat and rice, but other opportunities may remain. Our ability to design radical new enzymes from scratch, or to predict the consequences of major changes in gene expression patterns, may improve over coming decades. Even after most significant opportunities to improve yield potential (yield in the absence of pests and diseases) have been fully exploited, ongoing evolution of pests and pathogens will create a continual need for ‘Red Queen Breeding’, generating a stream of new cultivars to keep up with the latest biotic threats.

Role of Farm Programs in Environmental Sustainability of Agriculture Briefing (pdf, 240k)
Daniel Sumner and Antoine Champetier de Ribes

Environmental Sustainability of Agriculture and U.S. Farm Programs
Daniel A. Sumner

The main U.S. farm subsidy programs transfer between $10 billion and $25 billion per year to farms that produce wheat, rice, oilseeds, feed grains and cotton. These programs have evolved since the 1930s, but the basics remain. Subsidies stimulate additional production of the supported crops and thereby suppress market prices for those crops. Estimated production and price impacts range from just a few percent (for soybeans in recent years) to 10 to 15 percent or more (for cotton and corn in years when market prices are expected to be low). These impacts depend on the expected share of revenue from subsidy, the share of the U.S. crop in relevant markets and the price elasticities of supply and demand. These price impacts have been the basis for WTO complaints by trading partners. Although there are “conservation compliance” rules designed to reduce negative environmental consequences of commodity programs, subsidies continue to encourage use of additional resources and purchased inputs for these crops (i.e. more land, water, fertilizer, pesticides, etc.). Farm subsidies distribute most benefits roughly in proportion to production or land base in the program crops. That means that bigger farms get more, but there is no solid evidence that programs are biased towards larger farms or that they stimulate larger farm size. Payments benefit owners of farmland and suppliers of inputs and resources, whether they are farm operators or not. These benefits come at the expense of taxpayers and economic efficiency. In addition to commodity subsidies, farm programs include long-term land retirement (such as the Conservation Reserve Program) and so-called “working lands” programs (such as the Environmental Quality Incentive Program and the Conservation Security Program). Complex technical and economic issues surround effective targeting of such programs. One challenge is tying measured environmental outcomes to on-farm practices; another is designing schemes to maximize environmental benefits given limited funds. Some current programs allow farmers to bid for the lowest payment they would accept for undertaking certain practices (including land idling) on their farms. These bids are ranked by an estimate of environmental benefit per dollar and bids are accepted to achieve the most cost-effective outcome. It is challenging to design programs that facilitate more accurate measurement of environmental impacts and pay farms not for practices but directly for environmental or ecological services, either in the form of positive benefits from farmland use (such as carbon sequestration or wildlife habitat) or reduced negative environmental consequences of farming. Farm programs are scheduled for renewal, reformulation or removal with the 2007 Farm Bill that is now being developed in Congress. New legislation provides an opportunity to reconsider how farm programs contribute to national objectives and gauge if alternative roles for government might be better tuned to current realities and goals.