Proposed nitrogen fertilizer policies could help protect farmers’ profits and the environment

The use of nitrogen fertilizer has significant implications for crop yields as well as environmental health, particularly in the Gulf of Mexico. Federal and state governments have avoided regulating nitrogen fertilizer use. However, voluntary and incentive-based programs have not been very successful. The oxygen-starved Gulf “deadzone” is still much larger than the hypoxia Task Force’s goals.

A University of Illinois study examines possible policy solutions to reduce greenhouse gas emissions. NitrogenFarmers can still protect their bottom lines while minimizing loss.

“We want to stimulate discussions about such policies, not give definitive answers on which policy is best.” Nicolas Martin, assistant professor at the Department of Crop Sciences at Illinois, and co-author of this study, says that instead, we show what is possible, given the information and limitations we have. “We are trying to come up with alternative scenarios or ways of improving current agriculture, taking into account profitability, food security, the environment, and other factors.”

Martin and his collaborators simulated more than 4,000 fields over a period of 30 years to assess economically optimal nitrogen rates.

The first policy would change price ratios by imposing a tax on nitrogen at an appropriate ratio to corn prices. The second policy would charge farmers for excess nitrogen leaching from Illinois fields above the baseline levels. The third would subtract nitrogen from the grain at harvest and apply fertilizer to it. It would also charge a fee. The final policy represented a voluntary nitrogen reduction plan similar to the ones in place in the U.S. Midwest.

In the study scenario, farmers would receive compensation for nitrogen fees or profit losses. This would guarantee a healthy bottom line. All policies led to the desired environmental outcome of less leaching.

The study set a target of 20% leaching, and found that this level could be achieved with only a 3.3% yield hit. This would have little impact on profits.

German Mandrini, a doctoral graduate from the Department of Crop Sciences who is the first author of this article, said that higher targets led to an exponential increase in the cost. “The 20% reduction target has a pollution control cost of $30-$37 per hectare, which amounts to $147 million annually when taken up to the Illinois state level. This is within the range of current government payments to existing conservation programs.

Research done in the past Groundwater contaminationHidden costs of $16.10 per kilogram nitrogen are due to colon cancer risk, unwanted odor, taste and increased eutrophication. This means that reducing nitrogen leaching to 20% will lead to a reduction of environmental externalities of $524million per year.

Mandrini says that 260% is a return on investment if policies are implemented that encourage smarter use of inputs.

The nitrogen leaching fee was the most successful of the four policies. Researchers noted a higher cost-efficiency, better hot spot control, and higher internalization of penalizing situations where pollution is greater.

“This is seen across multiple” Environmental studiesMandrini states that direct charging the pollutant we wish to control is the best method to reduce externalities.

Martin states, “The nitrogen leakage fee policy allows people to assess and measure how much nitrogen is being released from a field, and they are charged according that amount.” Implementing this policy can be difficult because it is hard to measure the nitrogen that has left a farm’s soil. However, technology advancements have made it possible to estimate the nitrogen leaving a farm with high accuracy by using modeling or measurement devices.

He says that hot spots can develop when large amounts of nitrogen are released from the soil or field under certain management. “By focusing more attention on these regions, it is possible to implement smarter policies and achieve reductions in those areas that matter the most.

The researchers point out that simulations can be based on assumptions that might not hold in real world scenarios. Therefore, the article should only serve as a starting point to discussion among farmers, commodity group leaders, policymakers, and all other stakeholders.

“These assumptions make it possible for us to use the most recent approaches in cropping system modelling to start working on questions we couldn’t answer any other way. Martin states that future work will attempt to validate and update our assumptions.

The article has been published in Frontiers in Plant Science.