Intensive agriculture in the Upper Mississippi River Basin is a major contributor to the hypoxic zone in the Gulf of Mexico and excess nutrients from farming activities have been identified as the primary cause of degraded water quality. The empirical economic literature has explored the effects of conservation practices on retired lands (e.g., slippage and additionality), and their impacts on ambient water quality have been studied by integrating with engineering simulation models. However, econometric evidence of the effect of working land programs on ambient water quality remains largely unquantified. This study aims to isolate the impact of the Conservation Stewardship Program (CSP) on surface water quality (i.e., nitrogen). We find a ten percent increase in the percentage of land enrolled in CSP reduces ambient nitrogen concentration by 0.5 to 1.0 mg/l in the Illinois River Basin. This amount of abatement is 12 to 23% of the average nitrogen measurements.

Afforestation, which involves converting cropland to forestland, can provide multiple ecosystem services. Consequently, public incentive programs such as those administered by the U.S. Department of Agriculture (USDA), and, increasingly, private incentive programs, provide funding to farmers to convert their land to forest. However, the degree to which afforestation incentives provide greater ecosystem services depends on the degree to which afforestation is additional, both in the short- and long-term. Incentives are additional if they lead to forest growth that would not have occurred without payments. In this study, we assess the additionality of incentives for afforestation of cropland in USDA's Conservation Reserve Program over a twodecade time span. We estimate impacts using a regression discontinuity design that leverages the Conservation Reserve Program's General Signup auction mechanism. We use remote-sensing data to compare the extent of trees on land that had rejected and accepted offers to enroll in the program. We find that 32 to 65 percent of land enrolled is additional; and that impacts of incentives on tree cover remain steady from nine to twenty years after initial offers are made.

Agricultural production is the largest contributor of nitrogen and phosphorus pollution in lakes, rivers, and streams in the United States. The effectiveness of agricultural conservation programs that encourage farmers to adopt certain practices to reduce this water pollution, once implemented, is an open question. We develop a unique data set combining the spatial structure of the watershed river system, the timing of federal conservation contracts, water quality measurements, land use, land cover, and weather data to study the effect of conservation contracts on nitrogen and phosphorus levels in the Wabash River watershed, which drains Indiana and Illinois. We develop econometric models that generate a causal understanding of the effectiveness of these conservation contracts for reducing nitrogen and phosphorus levels in the surface water system. We find that at current treatment levels, these programs reduce surface water pollution only during relatively dry periods. The efficacy of these programs in the study area is highly sensitive to precipitation to the extent that average precipitation can eliminate the nutrient loss reduction benefits of conservation program installations at current treatment levels. Therefore, we find weak evidence to support ambient downstream water quality improvements resulting from program investment levels to date. We anticipate this work will motivate further inquiry into the manner in which these conservation programs have or have not been effective.

Diversifying the simplified landscape of corn and soybeans in the Midwest is an emerging priority in both the public and private sectors to reap a suite of climate, social, agronomic, and economic benefits. However, little research has documented the perspectives of farmers, the primary stakeholders in diversification efforts. This preliminary report uses newly collected survey data ( n = 725) from farmers in the states of Illinois, Indiana, and Iowa to provide descriptive statistics and tests to understand what farmers in the region think about agricultural diversification, including their perspectives on its benefits, barriers, and opportunities. For the purposes of the study, we define diversification as extended rotations, perennials, horticulture, grazed livestock, and agroforestry practices. We find that a majority or plurality of farmers in the sample believe that diversified systems are superior to non-diversified systems at achieving a range of environmental, agronomic, and economic goals, although many farmers are still forming opinions. Farmers believe that primarily economic barriers stand in the way of diversification, including the lack of affordable land, low short-term returns on investment, and lack of labor. Farmers identified key opportunities to increase diversification through developing processing capacity for local meat and specialty crops, increasing demand for diversified products, and providing more information on returns on investment of diversified systems. Different interventions, however, may be needed to support farmers who are already diversified compared to non-diversified farmers. Building on these initial results, future studies using these data will develop more detailed analyses and recommendations for policymakers, the private sector, and agricultural organizations to support diversification.

US agencies have long used the pay-the-polluter (PTP) approach in which government pays agricultural polluters to adopt conservation practices on a voluntary basis to address nutrient pollution. However, limited fiscal resources and continued poor water quality have led to calls for a new paradigm, the polluter-pays-principle (PPP), in which agricultural polluters must clean up their nutrient emissions. Whereas PTP relies on the public costsharing with farmers, PPP could induce food price increases that result from farm regulation. Little is known about the general public's preferences with respect to these paradigms. This paper addresses this gap using data from a randomized survey conducted in three US Corn Belt states that have significant agricultural nutrient pollution-Illinois, Indiana, and Iowa. We find that, overall, people favor the PPP approach over the existing PTP approach. Comparing PTP to PPP over a range of clean-up responsibilities, respondents are more likely to support PPP than PTP when given the choice of the most stringent PPP type. Examining specific PPP features, we find that assigning clean-up responsibilities equal to pollution source levels positively impacts support only PPP, while combining pollution trading with farm regulation has a negative impact on support for PPP.

We examine cover crop (CC) adoption to determine how this soil health practice has influenced agricultural non-point source pollution. We use remotely sensed data on practice adoption, and control for hydrological flow direction, weather, and land use to estimate the ex post impact of CC on total Nitrogen concentrations in surface water while controlling for pollutant spillovers from upstream. At the mean treatment level in the study area (3.2%), a 1% increase in CC adoption results in a 0.06 mg/L (2%) reduction in concentration in the study area. Results provide novel estimates based on observed data that can be compared to biophysical simulations of CC effectiveness.

Recent U.S. policies have promoted climate-smart farming practices. However, little is known about the costs of practice adoption or the regional allocation of support. The primary objective of this study is to identify cost-effective agricultural practices for climate mitigation and determine where practices might be targeted regionally. This study uses average regional abatement cost curves for six mitigation practices to analyze how conservation funding could incentivize adoption. Using a social benefit threshold of $51 per metric ton, we estimate that for all practices studied, except cover crops, there are regions where the average cost of reduction is less than the social benefit threshold, meaning that greenhouse gas could be cost-effectively mitigated or sequestered at regional levels given more adoption of these practices. For the purposes of conservation targeting, we outline the regions where the adoption of these practices is potentially the most cost-effective.

Interconnected food, energy, water systems (FEWS) require systems level understanding to design efficient and effective management strategies and policies that address potentially competing challenges of production and environmental quality. Adoption of agricultural best management practices (BMPs) can reduce nonpoint source phosphorus (P) loads, but there are also opportunities to recover P from point sources, which could also reduce demand for mineral P fertilizer derived from declining geologic reserves. Here, we apply the Integrated Technology-Environment-Economics Model to investigate the consequences of watershed-scale portfolios of agricultural BMPs and environmental and biological technologies (EBTs) for co-benefits of FEWS in Corn Belt watersheds. Via a pilot study with a representative agro-industrial watershed with high P and nitrogen discharge, we show achieving the nutrient reduction goals in the watershed; BMP-only portfolios require extensive and costly land-use change (19% of agricultural land) to perennial energy grasses, while portfolios combining BMPs and EBTs can improve water quality while recovering P from corn biorefineries and wastewater streams with only 4% agricultural land-use change. The potential amount of P recovered from EBTs is estimated as 2 times as much as the agronomic P requirement in the watershed, showing the promise of the P circular economy. These findings inform solution development based on the combination of agricultural BMPs and EBTs for the cobenefits of FEWS in Corn Belt watersheds.

We develop a choice experiment (CE) to estimate the benefits of nutrient reductions in the US Corn Belt. The study area covers Illinois, Indiana, and Iowa, the three states that contribute the largest amount of nutrients to the Gulf of Mexico and whose nutrient reductions are vital to achieving targets to reduce the hypoxic dead zone in the Gulf. We find that the public places large values on various local ecosystem services, including aquatic biodiversity, aesthetics of increased farm landscape diversity associated with conservation practices, and water-based recreational activities. Moreover, the results indicate that upstream residents have a strong preference for water quality far downstream in the Gulf of Mexico as characterized by reducing the size of the dead zone. Our analysis of observed taste heterogeneity indicates that public preferences vary depending on familiarity with nutrient pollution issues, users versus non-users of local ecosystem services, and different age groups. Our findings inform policies to improve water quality in the Gulf of Mexico and local water bodies in the US Corn Belt.

Urgent calls for actions to slow climate change have stimulated new interest in actions to harness the potential for carbon sequestration on agricultural lands. The private sector has established corporate goals for reducing contributions to climate change and there has been much decentralized market activity to develop voluntary markets for agricultural soil carbon sequestration to meet this demand from companies and consumers wishing to offset emissions. This brief conducts a critical assessment of the nature of the market opportunity today for farmers and for those who would benefit from the opportunity to incentivize real increases in net carbon sequestered in agricultural lands of the U.S. We discuss how the potential success of these markets is currently limited by important factors related to contract design and land tenure, with suggestions for how to address the challenges and unlock the opportunities.

Conservation practices (CPs) are integral to maintaining the long-term viability of agro-ecological systems. Because farming systems and farmers' values and attitudes are heterogeneous, factors that consistently predict conservation behaviors remain elusive. Moreover, heterogeneity is present among studies regarding the type of CPs examined, and whether behavioral intentions or actual behaviors were measured. This study considers the characteristics of each CP, and whether a given study measured behavioral intention or actual behavior, to better understand farmers' adoption of CPs. We reviewed and analyzed 35 years (1982-2017) of quantitative conservation adoption literature in the United States. We categorized CPs based on their primary purpose, the type of benefit they provide, and whether they are operational or structural. We also examined the following five CPs: conservation tillage, buffers or borders, soil testing, grassed waterways, and cover crops. In our behavioral intention and actual behavior analysis, we found that attitudinal factors predicted both conservation intention and action (actual behavior), whereas current or previous use of practices only influenced actions, not stated conservation intentions. In our analysis focusing on CP characteristics, we found that having specific knowledge about and positive attitudes toward the CP, adoption of other CPs, seeking and using information, larger farm size, and vulnerable land predicted actual adoption across nearly all CP categorizations. Nuances emerge when comparing predictors of CPs that share a particular characteristic. For example, we found farm characteristics to be comparatively more important in predicting adoption of soil management CPs than nutrient and livestock management CPs, and farmers' stewardship identity to be more important for permanent practices than operational practices.

Canada and the United States have a rich history of policy interventions aimed at improving environmental outcomes from agricultural production. We review the agri-environmental programs in these two countries as well as the related economic literature. Despite the impacts of agriculture on land, water, and climate quality, the literature on agri-environmental programs has largely focused on a few major programs or the adoption of specific management practices. Far less research evaluates programs on active farmland, environmental regulation of agriculture, and the interactions of these policies and programs. Further research is also needed on how the heterogeneity of environmental characteristics and processes affects the outcomes of management practices and how these outcomes might be affected by climate change. Given the continued substantial impacts of agriculture on environmental outcomes, the increased interest of agricultural processors and consumers in these outcomes, and the potential for new models and data to inform research, we conclude that this is an ideal time to examine and apply lessons learned from past program successes and failures as we seek to improve the performance of the next generation of agri-environmental policy interventions.

This study scrutinizes spatial econometric models and specifications of crop yield response functions to provide a robust evaluation of empirical alternatives available to researchers. We specify 14 competing panel regression models of crop yield response to weather and site characteristics. Using county corn yields in the US, this study implements in-sample, out-of-sample, and bootstrapped out-of-sample prediction performance comparisons. Descriptive propositions and empirical results demonstrate the importance of spatial correlation and empirically support the fixed effects model with spatially dependent error structures. This study also emphasizes the importance of extensive model specification testing and evaluation of selection criteria for prediction.

The long-term viability of United States (US) agriculture and food systems is contingent upon sustainable soil and water conservation. Currently, the majority of conservation practices rely on voluntary adoption by farmers. However, a large and growing proportion of farmland is rented, thereby presenting a conservation decision-making context where tenant farmers have less control over conservation behavior than farmers who own the land they operate. For decades, social science scholarship has examined whether and how land tenure affects farmers’ conservation behavior. The overall effect of tenure on conservation behavior has been found to be inconclusive in quantitative studies, whereas qualitative studies suggest that it hinders conservation behavior. This article draws upon reviews of quantitative and qualitative studies examining conservation adoption in the US between 1982 and 2017 to highlight gaps in and opportunities for understanding the relationship between land tenure and conservation behavior. Highlighting the multidimensional nature of land tenure, we propose that future research on conservation adoption in agriculture use the following eight dimensions: within-farm tenure heterogeneity, tenure stability, market dynamics, type of lease arrangements, lease negotiation timelines, relational aspects, non-operating landowner characteristics, and operator characteristics. We invite scholars to operationalize and measure these dimensions to evaluate their effects on conservation behavior on rented farmland.

To facilitate understanding and decision making in the food-energy-water (FEW) nexus context, we develop an integrated technology-environment-economics model (ITEEM) at a watershed scale. ITEEM is built as an integration of various models, including models for grain processing, drinking water treatment, and wastewater treatment (technology); a watershed model for hydrology, water quality, crop production, and nutrient cycling (environment); an economics model assessing total benefit, including non-market valuation of environmental benefits. Different data techniques are applied to develop suitable surrogates for computer-based models, including a response matrix method, artificial neural networks, and lookup tables. Empirical equations are applied to develop models of economics and drinking water treatment. The input-output relationships between the models are formulated in a unified computational framework. ITEEM, a spatially semi-distributed dynamic simulation model, can be used to quantify the environmental and socioeconomic impacts of various management practices, technologies, and policy interventions on FEW systems in the Corn Belt.

We study a situation in which a multi‐feedstock cellulosic biofuel plant can procure stover from productive cropland and switchgrass from marginal land, where growing corn for stover is typically not profitable. We calibrate our model to growing conditions in a promising area of Indiana, USA. We find that cost‐minimizing biorefineries are likely to include switchgrass in the mix of feedstocks despite their high cost of production relative to corn stover. This is because the biorefinery can reduce cost by buying switchgrass grown on marginal land near the plant instead of paying to cover high transportation costs to procure stover from more distant suppliers. Moreover, the share of switchgrass will rise further if the procurement region is constrained by transaction costs or natural barriers. This is because procuring switchgrass can alleviate the cost of paying to induce land conversion to corn to procure additional stover from the intensive margin. Under the assumption that switchgrass is grown on marginal land, inclusion of switchgrass in the feedstock mix not only reduces the cost of producing biofuels but also their carbon footprint without displacing food crops. A key caveat is that high transaction costs of contracting for switchgrass and/or farmers’ reluctance to grow switchgrass on marginal land can severely undermine its inclusion in the feedstock mix. However, these forces may be countervailed by a differential subsidy for biofuels that include a higher share of switchgrass, which would be warranted because of their lower carbon footprint.

Conservation tillage has been widely recommended for implementation in the U.S. for its environmental benefits. The effect of conservation tillage on crop yield is a subject of continued concern amongst farmers who have not adopted the practice. Previous empirical research on the yield performance of conservation tillage is largely limited to field trials, while observational studies remain scant. This article estimates the effects of conservation tillage on county average corn and soybean yields using remotely-sensed tillage practice adoption data in 646 counties across 12 Corn Belt states from 2005 to 2018. Exploiting deviations from county-specific means in the data, we find no evidence that conservation tillage negatively affects corn or soybean yields. We also find that it can mitigate the impact of drought on soybean yields. We explore how wider use of conservation tillage might offset the increase in drought-induced downside risk to soybean yields under climate change projections from five global climate models.

While all sectors of the economy can be impacted by climate variability and change, the agricultural sector is arguably the most tightly coupled to climate where changes in precipitation and temperature directly control plant growth and yield, as well as livestock production. This paper analyzes the direct and cascading effects of temperature, precipitation, and carbon dioxide (CO 2 ) on agronomic and horticultural crops, and livestock production in Indiana through 2100. Due to increased frequency of drought and heat stress, models predict that the yield of contemporary corn and soybean varieties will decline by 8–21% relative to yield potential, without considering CO 2 enhancement, which may offset soybean losses. These losses could be partially compensated by adaptation measures such as changes in cropping systems, planting date, crop genetics, soil health, and providing additional water through supplemental irrigation or drainage management. Changes in winter conditions will pose a threat to some perennial crops, including tree and fruit crops, while shifts in the USDA Hardiness Zone will expand the area suitable for some fruits. Heat stress poses a major challenge to livestock production, with decreased feed intake expected with temperatures exceeding 29 °C over 100 days per year by the end of the century. Overall, continued production of commodity crops, horticultural crops, and livestock in Indiana is expected to continue with adaptations in management practice, cultivar or species composition, or crop rotation.