- Agronomic: corn, soybeans
- Crop Production: cover crops, crop rotation
- Farm Business Management: agricultural finance, budgets/cost and returns
Decreased water quality due primarily to nitrate loadings from agricultural drainage has plagued the US Midwest for the past several decades. There are a variety of on-farm nitrate reduction technologies that can be employed to reduce this problem, but implementation may be limited by education of the available options. The outcomes of this work were (1) to provide producers increased understanding of nitrate reduction technologies and (2) to provide researchers increased knowledge of levels of acceptance of various nitrate reduction approaches so as to better focus educational approaches. The foundation of this work was a comparison of economic cost efficiencies and ecosystem services provided by seven nitrate reduction methods (wetlands, controlled drainage, cover crops, crop rotation, fertilizer rate reduction, fertilizer timing modification, and denitrification bioreactors). These comparisons were used to develop and inform an educational program with an associated survey evaluation and a supplementary farmer discussion group. The educational program providing financial cost/benefit and ecosystem service information of the seven approaches was given at five Iowa Learning Farm Field Days during summer 2011. Following the events, the producers in attendance had the opportunity to answer mailed survey questions about their background, their understanding of the technologies and their interest in implementing one or a combination. The survey was also mailed to participants of four field events where the education program was not presented in order to obtain control data providing a baseline on producer acceptance of these technologies. To further study the perceived adoption potential of these practices in the context of ecosystem service provisioning, a small discussion group was held with farmers.
Each N reduction strategy provides landowners an additional distinct option for drainage water quality improvement and different strategies or combinations of such will be applicable in different locations. While the N management practices were very cost effective and had high interest and compatibility, they offered few additional ecosystem services. Conversely, the practices that had high ecosystem service provisioning generally had lower compatibility (wetlands) or interest (crop rotation). A notable exception was cover crops which, although more expensive per unit nitrate treated, had high compatibility, interest and ecosystem services.
Nitrate from agricultural sources, primarily tile drainage in the Midwest, has been identified as a major source of nitrate loadings in the Mississippi River. These loadings are a key cause of water quality impairment in the Gulf of Mexico with this resulting hypoxic zone larger than average in 2011. The time is right for increased implementation of nitrate reduction strategies for agricultural sources in the Midwest to lead to increased sustainability of such agricultural systems.
Numerous nitrate reduction methods are currently under investigation to examine effectiveness in varying agricultural systems. These strategies include wetlands, controlled drainage, cover crops, crop rotation, and nutrient management. Denitrification bioreactors are the newest addition to this slate of nitrate reduction technologies. From the producer perspective, each of these nitrate reduction strategies has associated advantages/ disadvantages. While each approach can be valuable, the effectiveness will be site specific and the acceptability of each individual approach will differ between producers based on varying ecosystem services and economic benefits of the approach. A comparison of the economic value of and the ecosystems services offered by each of these methods would be valuable to producers and landowners interested in nitrate reduction.
The foundation of this work was a comparison of economic cost efficiencies and ecosystem services provided by seven nitrate reduction methods (wetlands, controlled drainage, cover crops, crop rotation, fertilizer rate reduction, fertilizer timing modification, and denitrification bioreactors). These comparisons were used to develop an educational program with an associated survey to gage the social acceptance of these seven nitrate reduction methods. To further study the perceived adoption potential of these practices in the context of ecosystem service provisioning, a small discussion group was held with farmers.
Project objectives:div style="margin-left:1em;">
The goal of this work was to provide producers increased understanding of nitrate reduction technologies and to provide researchers enhanced knowledge of producer acceptance of various nitrate reduction approaches so as to better focus research and education. As of submission of this Final Report, all major Performance Target tasks, barring submission/acceptance of results for peer-reviewed publication, had been performed. This project’s Performance Targets included:
• Perform an economic analysis to develop cost efficiencies for seven drainage water quality improvement technologies (wetlands, controlled drainage, cover crops, crop rotation, fertilizer rate reduction, fertilizer timing modification, and denitrification bioreactors)
• Create an educational program focused on this economic comparison
• Present this program at five field events with a post-event survey mailed to participants afterwards (plus survey mailed to a control group)
• Convene a discussion group with farmers to further explore the perception of ecosystem services associated with these seven drainage water quality practices
• Analyze survey and discussion group data
• Create a university extension factsheet focused on the newest of the technologies, denitrification bioreactors
• Incorporate results into the Project Director’s Ph.D. dissertation and into peer-reviewed journal publications
Consistent with the proposal and 2010 Annual Report, a short term outcome is increased knowledge of costs and benefits of various nitrate reduction strategies, including the new technology of denitrification bioreactors, for producers, land owners, and contractors. Additionally, on a more basic level, these programming efforts will also increase producer understanding that there is a nitrate water quality problem associated with agricultural drainage.
Intermediate outcomes include assessment of factors limiting implementation of nitrate reduction strategies allowing more focused research and education efforts pertaining to drainage water quality. It is thought this assessment will be informed by the producers’ survey results. Moreover, these survey results will bring about increased understanding of the effectiveness of the educational efforts. Other intermediate outputs include results being incorporated into the Project Director’s Ph.D. dissertation and into peer-reviewed journal publications.
A projected long term outcome (systemic change) is the potential for increased adoption of nitrate reduction methods by Midwestern farmers leading to decreased transport of nitrate to the Mississippi River and Gulf of Mexico. However, evaluation of actual adoption of these technologies was beyond the scope of the work here and is recommended for future work.