Empirical Assessment of Baseline Conservation Tillage Adoption Rates and Soil Carbon Sequestration in the Upper Mississippi River Basin

The study proposes a methodology for developing a carbon sequestration baseline attributable to the current use of conservation tillage. An integral component of the methodology is the explicit acknowledgment that there is an uncertainty in the baseline because of the uncertainty associated with the use of econometrically estimated models. The results of applying the method to a major crop production area, the Upper Mississippi River Basin in the central United States, are reported for two major crops in the region, corn and soybeans. The approach to estimation of the baseline should be readily transferable to other geographic areas and conservation practices.Environmental Economics and Policy,

TARGETING AND THE ECONOMICS OF CUMULATIVE WATERSHED EFFECTS

This study empirically investigates environmental benefits at the watershed level from conservation practices, which are typically non-linear. A conservation tillage adoption model is linked to the Soil and Water Assessment Tool model to examine the effectiveness of various conservation policies aimed at improving water quality in an Iowa watershed.Environmental Economics and Policy,

Institutions and the Value of Nonpoint Source Measurement Technology: Carbon Sequestration in Agricultural Soils

The development of technologies for accurate field-scale carbon assessment allows the implementation of more efficient policies than can be implemented in their absence. We estimate the value of accurate measurement technology by estimating the gains from implementing a more efficient policy, one that targets carbon reductions at the field scale but requires accurate field-scale measurement technology, relative to a practice-based policy that can be implemented in the absence of such technology. We find large cost savings due to improved targeting of conservation tillage subsidies for the state of Iowa. The cost savings depend significantly on the choice of baseline carbon, while the ability of the government to cost discriminate has little impact on the value of accurate measurement technology.carbon sequestration, green payment policy, value of measurement technology.

THE SUBSIDY FOR ADOPTING CONSERVATION TILLAGE: ESTIMATION FROM OBSERVED BEHAVIOR

Due to payoff uncertainties combined with risk aversion and/or real options, farmers may demand a premium in order to adopt conservation tillage practices, over and above the compensation for the expected profit losses (if any). We propose a method of directly estimating the financial incentives for adopting conservation tillage and distinguishing between the expected payoff and the premium of adoption based on observed behavior. We find that the premium may play a significant role in farmers' adoption decisions. Even for non-adopters, conservation tillage provides a higher payoff than does conventional tillage on average, as agronomists have argued. However, non-adopters do not use conservation tillage because the expected profit gain alone does not fully compensate them for the uncertainties. To induce additional adoption, subsidies could be used. We find that in Iowa on average, the mean subsidy needed is $2.40 per acre per year for corn and$3.50 per acre per year for soybeans.Land Economics/Use,

Avoiding biases from data-dependent specification search: an application to a tillage choice model

The study evaluates the gains of avoiding data-dependent specification search on an estimation sample in an application to discrete choice models. We incorporate data splitting, the process by which the total available sample is randomly split in two or more sub-samples with the first (specification) sub-sample used for specification search, and the second (estimation) sub-sample used for obtaining clean estimates using the model chosen on the specification sub-sample according to a set criterion. We estimate 14 binary Logit models of the adoption of conservation tillage corresponding to the major sub-watersheds of the Upper Mississippi River Basin. For each of the sub-watershed models, we use the specification sub-sample to choose the explanatory variables that lead to the highest number of correct predictions provided that estimated coefficients are in conformity with economic theory. To evaluate the gains of avoiding specification search on the estimation sub-sample, we follow Gong (1986)[8] and calculate the expected excess error, which is a measure of excess optimism concerning model fit on the specification sample. We find that the excess optimism varies with the sub-watersheds and has a tendency to be larger for the sub-watersheds with smaller samples.Research Methods/ Statistical Methods,

Multiple Benefits of Carbon-Friendly Agricultural Practices: Empirical Assessment of Conservation Tillage in Iowa

In this study, we estimate empirically the multiple benefits of a subsidy policy that would offer payments to farmers in return for the adoption of conservation tillage and compare the outcomes of alternative targeting designs for such a policy. Using data for roughly 12,000 National Resource Inventory (NRI) points, we simulate for the state of Iowa the least-cost policy schemes for offering payment incentives. We use an economic model of conservation tillage adoption to evaluate the costs of adoption, and we use a model that simulates physical processes (Environmental Policy Integrated Climate, or EPIC) to estimate the environmental benefits of adoption at each of the NRI points. We assess the costs and environmental consequences of two targeting options. The first is a practice-based policy instrument that maximizes the acres of land in conservation tillage, regardless of the level of environmental benefits achieved. The second is a performance-based instrument that yields the highest amount of environmental benefits per dollar spent. We consider four performance-based benefits: carbon sequestration in agricultural soils, reduction in nitrogen runoff, reduction of erosion of soil by wind, and reduction of erosion of soil by water. We find that the practice-based instrument provides high proportions of the four benefits relative to the performance-based instrument, especially at higher budget levels. Similarly, we estimate that targeting one of the four benefits provides high percentages of the other benefits compared to the amounts obtainable if they were targeted directly.conservation tillage, multiple benefits, subsidy policy, targeting.

Cac Versus Incentive-Based Instruments in Agriculture: The Case of the Conservation Reserve Program

In this paper, we examine command-and-control (CAC) policies and market-based instruments (MBI) in the context of the Conservation Reserve Program (CRP). The CRP, an MBI in the form of subsidies, is by far the largest agro-environmental policy implemented to date. We compare the environmental performance of the CRP as implemented to a few counterfactual CAC polices using EPIC (Environmental Policy Integrated Climate), a bio-physical simulation model. In the context of multiple environmental indicators, no policy alternative emerges as a clear winner. The importance of the choice and design of CAC policies is emphasized. Keywords: command-and-control policy, Conservation Reserve Program, market-based instrument.

Efficiency of Sequestering Carbon in Agricultural Soils (The)

Agricultural tillage practices are important human-induced activities that can alter carbon emissions from agricultural soils and have the potential to contribute significantly to reductions in greenhouse gas emission (Lal et al., 1998). This research investigates the expected costs of sequestering carbon in agricultural soils under different subsidy and market-based policies. Using detailed National Resources Inventory data, we estimate the probability that farmers adopt conservation tillage practices based on a variety of exogenous characteristics and profit from conventional practices. These estimates are used with physical models of carbon sequestration to estimate the subsidy costs of achieving increased carbon sequestration with alternative subsidy schemes.

Environmental Conservation in Agriculture: Land Retirement Versus Changing Practices on Working Land

The study develops a conceptual framework for analyzing the allocation of conservation funds via selectively offering incentive payments to farmers for enrolling in one of two mutually exclusive agricultural conservation programs: retiring land from production or changing farming practices on land that remains in production. We investigate how the existence of a pre-fixed budget allocation between the programs affects the amounts of environmental benefits obtainable under alternative policy implementation schemes. The framework is applied to a major agricultural production region using field-scale data in conjunction with empirical models of land retirement and conservation tillage adoption, and a biophysical process simulation model for the environmental benefits of carbon sequestration and reduction in soil erosion.

Privatizing Ecosystem Services: Water Quality Effects from a Carbon Market

Resource /Energy Economics and Policy, Q25,