Nitrogen fertilizer management for nitrous oxide (N2O) mitigation in intensive corn (Maize) production: an emissions reduction protocol for US Midwest agriculture (original) (raw)
Related papers
2010
Nitrous oxide (N 2 O) is a potent agricultural greenhouse gas (GHG). More than 50% of the global anthropogenic N 2 O flux is attributable to emissions from soil, primarily due to large fertilizer nitrogen (N) applications to corn and other non-leguminous crops. Quantification of the trade-offs between N 2 O emissions, fertilizer N rate, and crop yield is an essential requirement for informing management strategies aiming to reduce the agricultural sector GHG burden, without compromising productivity and producer livelihood. There is currently great interest in developing and implementing agricultural GHG reduction offset projects for inclusion within carbon offset markets. Nitrous oxide, with a global warming potential (GWP) of 298, is a major target for these endeavours due to the high payback associated with its emission prevention. In this paper we use robust quantitative relationships between fertilizer N rate and N 2 O emissions, along with a recently developed approach for determining economically profitable N rates for optimized crop yield, to propose a simple, transparent, and robust N 2 O emission reduction protocol (NERP) for generating agricultural GHG emission reduction credits. This NERP has the advantage of providing an economic and environmental incentive for producers and other stakeholders, necessary requirements in the implementation of agricultural offset projects.
Nitrous oxide emission reductions from cutting excessive nitrogen fertilizer applications
Climatic Change, 2015
On average, U.S. farmers choose to apply nitrogen fertilizer at a rate that exceeds the ex post agronomically optimal rate. The technology underlying the yield response to nitrogen rewards producers who over apply in years when rainfall is excessive. The overapplication of nutrients has negative environmental consequences because the nitrogen that is not taken up by the plant will typically volatilize causing N2O emissions, or leach causing water pollution. We present a nonlinear offset program that induces farmers to reduce their nitrogen applications to the level that will be consumed by the plant in a typical year and, as a result, reduce N2O emissions from agriculture. The offset program is nonlinear because of the nonlinear relationship between N2O and nitrogen application rates. We assume that the farmer solves an expected utility maximization problem, choosing the optimal nitrogen application rate. The key contribution is a set of simulations that shows that modest offset payments will induce participation in the program and will have a significant impact on both expected and actual N2O emissions without having a significant impact on actual or expected yields. We also find that more risk-averse farmers will reduce emissions by a greater amount than less risk-averse farmers. Finally, we show the distribution of emission reductions induced by this nonlinear offset scheme.
Preliminary Assessment of Nitrous Oxide Offsets in a Cap and Trade Program
SSRN Electronic Journal, 2012
Nitrous oxide is a powerful greenhouse gas that is emitted from cropland treated with nitrogen fertilizer. Reducing such emissions through nutrient management might be able to produce offsets for sale in a cap and trade program aimed at reducing greenhouse gases. We use the Nitrate Leaching and Economic Analysis Program (NLEAP) model and data from the Agricultural and Resource Management Survey to examine what changes in rate, timing, or method of application a farmer would take to produce offsets. We find that reducing the application rate is the most favored approach for producing offsets. We also find that some management choices may increase nitrate losses to water.
The potential cost of methane and nitrous oxide emissions regulation in U.S. agriculture
2020
Most studies on the impacts of agriculture on the environment have devoted efforts to measure the environmental impacts of the sector rather than to assess its ability to reduce or mitigate such impacts. Some have addressed the environmental efficiency of the sector (Reinhard, et al., 1999, Ball et al., 1994 and 2004; Rezek and Perrin, 2004 and Serra et al., 2011) but only few have examined greenhouse gas emissions (Njuki and Bravo-Ureta, 2015; Dakpo, Jeanneaux and Latruffe, 2016) from the sector. This paper analyzes the agricultural performance of states in the U.S. in terms of their ability to reduce emissions of methane and nitrous oxide, two major greenhouse gases (GHGs) with important global warming potential. The analysis evaluates Färe's PAC (pollution abatement cost) for each state and year, a measure of the opportunity costs of subjecting the sector to GHG emissions regulation. Using both hyperbolic and directional distance functions to specify the technology with good ...
The potential cost of regulation of methane and nitrous oxide emissions in U.S. agriculture
CABI Agriculture and Bioscience, 2022
Most studies on the environmental impacts of agriculture have attempted to measure environmental impacts but have not assessed the ability of the sector to reduce or mitigate such impacts. Only a few studies have examined greenhouse gas emissions from the sector. This paper assesses the ability of states in the U.S. to reduce agricultural emissions of methane and nitrous oxide, two major greenhouse gases (GHGs) with important global warming potential. The analysis evaluates Färe’s PAC (pollution abatement cost) for each state and year, a measure of the potential opportunity costs of subjecting the sector to GHG emissions regulation. We use both hyperbolic and directional distance functions to specify agricultural technology with good and bad outputs. We find that such regulations might reduce output by an average of about 2%, although the results for individual states vary quite widely.
Quantifying On‐Farm Nitrous Oxide Emission Reductions in Food Supply Chains
Earth's Future, 2020
Reducing nitrous oxide (N 2 O) emissions from agriculture is critical to limiting future global warming. In response, a growing number of food retailers and manufacturers have committed to reducing N 2 O emissions from their vast networks of farmer suppliers by providing technical assistance and financial incentives. A key challenge for such companies is demonstrating that their efforts are leading to meaningful progress toward their climate mitigation commitments. We show that a simplified version of soil surface nitrogen (N) balance-or partial N balance-the difference between N inputs to and outputs from a farm field (fertilizer N minus crop N), is a robust indicator of direct N 2 O emissions from fields with maize and other major rainfed temperate-region crops. Furthermore, we present a generalized environmental model that will allow food-supply-chain companies to translate aggregated and anonymized changes in average N balance across their supplying farms into aggregated changes in N 2 O emissions. This research is an important first step, based on currently available science, in helping companies demonstrate the impact of their sustainability efforts. Plain Language Summary As a powerful greenhouse gas, nitrous oxide that is emitted from agriculture contributes to climate change. Reductions in these emissions are not only possible-they are critical to addressing climate change. Food companies and others wanting to reduce nitrous oxide emissions in their food supply chains are looking for a way to show evidence of progress. Our research shows that a simple calculation of nitrogen (N) balance in crop fields (N in fertilizer minus N in the harvested crop) can be used as an indicator of nitrous oxide emissions. At the large scale, reducing high N balances will reduce overall emissions. We demonstrate the strong relationship between N balance and nitrous oxide emissions and show how this simple model can be used at scale to bring about positive environmental change.
Frontiers in Environmental Science
In the carbon market, greenhouse gas (GHG) offset protocols need to ensure that emission reductions are of high quality, quantifiable, and real. Lack of consistency across protocols for quantifying emission reductions compromise the credibility of offsets generated. Thus, protocol quantification methodologies need to be periodically reviewed to ensure emission offsets are credited accurately and updated to support practical climate policy solutions. Current GHG emission offset credits generated by agricultural nitrogen (N) management activities are based on reducing the annual N fertilizer application rate for a given crop without reducing yield. We performed a "road test" of agricultural N management protocols to evaluate differences among protocol components and quantify nitrous oxide (N 2 O) emission reductions under sample projects relevant to N management in dryland, wheat-based cropping systems of the inland Pacific Northwest (iPNW). We evaluated five agricultural N management offset protocols applicable to North America: two methodologies of American Carbon Registry (ACR1 and ACR2), Verified Carbon Standard (VCS), Climate Action Reserve (CAR), and Alberta Offset Credit System (Alberta). We found that only two protocols, ACR2 and VCS, were suitable for this study, in which four sample projects were developed representing feasible N fertilizer rate reduction activities. The ACR2 and VCS protocols had identical baseline and project emission quantification methodologies resulting in identical emission reduction values. Reducing N fertilizer application rate by switching to variable rate N (sample projects 1-3) or split N application (sample project 4) management resulted in a N 2 O emission reduction ranging from 0.07 to 0.16, and 0.26 Mg CO 2 e ha −1 , respectively.
Mitigation and Adaptation Strategies for Global Change, 2018
Biofuels vary greatly in their carbon intensity, depending on the specifics of how they are produced. Policy frameworks are needed to ensure that biofuels actually achieve intended reductions in greenhouse gas emissions. Current approaches do not account for important variables during cultivation that influence emissions. Estimating emissions based on biogeochemical models would allow accounting of farm-specific conditions, which in turn provides an incentive for producers to adopt low emissions practices. However, there are substantial uncertainties in the application of biogeochemical models. This paper proposes a policy framework that manages this uncertainty while retaining the ability of the models to account for (and hence incentivize) low emissions practices. The proposed framework is demonstrated on nitrous oxide (N 2 O) emissions from the cultivation of winter barley. The framework aggregates uncertainties over time, which (1) avoids penalizing producers for uncertainty in weather, (2) allows for a high degree of confidence in the emissions reductions achieved, and (3) attenuates the uncertainty penalties borne by producers within a timescale of several years. Results indicate that with effective management, N 2 O emissions from feedstock cultivation may be < 5% of the carbon intensity of gasoline, whereas the existing policy approach estimates emissions > 20% of the carbon intensity of gasoline. If these emissions reductions are monetized, the framework can provide up to $0.002 per liter credits (0.8 cents per gallon) to fuel producers, which could incentivize emissions mitigation practices by biofuel Mitig Adapt Strateg Glob Change
Management Strategies to Mitigate N2O Emissions in Agriculture
Life, 2022
The concentration of greenhouse gases (GHGs) in the atmosphere has been increasing since the beginning of the industrial revolution. Nitrous oxide (N2O) is one of the mightiest GHGs, and agriculture is one of the main sources of N2O emissions. In this paper, we reviewed the mechanisms triggering N2O emissions and the role of agricultural practices in their mitigation. The amount of N2O produced from the soil through the combined processes of nitrification and denitrification is profoundly influenced by temperature, moisture, carbon, nitrogen and oxygen contents. These factors can be manipulated to a significant extent through field management practices, influencing N2O emission. The relationships between N2O occurrence and factors regulating it are an important premise for devising mitigation strategies. Here, we evaluated various options in the literature and found that N2O emissions can be effectively reduced by intervening on time and through the method of N supply (30–40%, with ...