Project collaborators include UC Davis Department of Plant Sciences Project Scientist Sat Darshan Khalsa & Professor Patrick Brown. 

This project focuses on how California farmers make decisions about nutrient management and participate in policies regarding non-point source pollution from agriculture. We are surveying, interviewing and observing farmers and agricultural stakeholderes in the field to understand how real-time change is being made to improve nutrient management.

California adopted the Irrigated Lands Regulatory Program (ILRP) as the first nonpoint source pollution program of its kind in the U.S. to address non-point source water pollution concerns from agriculture. The ILRP focuses both on surface and groundwater protection from pesticides, sediment, salts, and nutrients- particularly nitrogen from nitrogen fertilizers, which pose one of the largest threats to contaminating groundwater drinking water resources in the state. We are investigating what drives farmer behavior to adopt various improved nitrogen management practices and participate in the ILRP.

The project studies how California farmers make decisions about nutrient management and participate in policies regarding non-point source pollution from agriculture. We are surveying, interviewing and observing farmers and agricultural stakeholderes in the field to understand how real-time change is being made to improve nutrient management.

Agriculture is a key component of California's landscape, growing 400+ commodity crops on more than 75,000 farms and ranches across 9 million acres of irrigated land (California Ag Statistics 2015). High productivity and food production from these systems must be balanced with the care for public and environmental health concerns that result from agricultural pollutants to water and air. In the early 2000's, the State Water Resources Control Board developed the Irrigated Lands Regulatory Program (ILRP) as the first nonpoint source pollution program of its kind in the U.S. to address non-point source water pollution concerns from agriculture. The ILRP focuses both on surface and groundwater protection from pesticides, sediment, salts, and nutrients- particularly nitrogen from nitrogen fertilizers, which pose the largest threat to contaminating drinking water resources. 

The ILRP requires the development of regional Management Practices Evaluation Plans (MPEPs) to evaluate and measure progress toward adoption of improved farm management practices that reduce the losses of nitrogen to surface and groundwaters.  Inherent in these MPEPs is the requirement to identify beneficial practices, to adapt these practices to specific site/crop/grower characteristics and to provide a strategy to measure progress toward achieving these goals.  Much progress has been achieved in identifying improved technical solutions has been achieved by research and extension personnel at the University of California, the CSU system, USDA-NRCS, commodity groups and industry funded programs. However, we do not currently have good strategies to determine rates of adoption of improved practices nor to identify the general or specific constraints to adapting specific practices for given site or grower contexts. Furthermore, we do not currently have an established baseline of practices against which to measure progress.

This project aims to (i) develop an understanding of the current status of grower adoption of improved  nutrient management practices, (ii) determine the key influences on grower decision-making, and (iii) identify the key incentives and barriers to enhanced adoption of improved management practices. The information developed will inform stakeholder groups including regional Water Quality Coalitions, UC Extension, private consultants, State Water Boards, commodity groups and others to inform policy-making and improve N management.

For project updates, see: 

https://blogs.cdfa.ca.gov/FREP/index.php/research-update-nitrogen-management-adoption-rates/

https://blogs.cdfa.ca.gov/FREP/index.php/research-update-understanding-grower-decisions/