Who

The SSJV MPEP Committee is working with a team that includes experts from University of California, Davis, University of California Cooperative Extension Specialists and Farm advisors, and the MPEP Technical Team that includes a translation specialist and scientific illustrator.

What

The project goal is to develop and implement Integrated Water & Nitrogen Management Trainings to review interconnected topics related to irrigation efficiency and nutrient management, including decision-support tool tutorials. The project team will deliver 9 in-person Integrated Water & Nitrogen Management Trainings in English and Spanish, and on-demand GWP Resources in English, Spanish, Hmong, and Punjabi.

Why

Despite substantial efforts to identify nutrient load reduction goals throughout the Central Valley of California and protective management practices to achieve those goals, efforts are still needed regarding outreach and education to growers and their advisors to ensure groundwater protection into the future.

When

The project will be implemented from Nov 2023-Nov 2026. Training curriculum will be developed in the first year. Trainings will be delivered in Fresno, Tulare, and Bakersfield in the project’s second and third years through 6 live events and 2 viewings of pre-recorded, translated trainings.

How

We will deliver a 3-part curriculum that leverages the wealth of educational resources already developed by partners from the University of California and the California Department of Food and Agriculture.

The curriculum includes:

• Irrigation efficiency and nutrient management content tailored to local environmental conditions and with crop-specific information for tree nuts, citrus, small grains, and row crops,
• Decision-support tool tutorials that describe how to use CropManage in the SSJV, and
• Context setting to describe the Irrigated Lands Regulatory Program, GWP Formulas, Values, and Targets, and the connection between management and groundwater quality at the landscape scale.

Anticipated Outputs

• Integrated Water & Nitrogen Management Trainings will benefit over 9,000 producers with over 1.85 million acres in the SSJV by offering them access to educational materials that can help them to realize nitrate leaching reductions where needed and meet or maintain groundwater quality targets.
• Curricula, recordings, and educational materials will be accessible by growers and their advisors in the Central Valley and beyond.

Who

The SSJV MPEP Committee is working with local technical assistance providers and selected growers in four SSJV townships.

What

The project goal is to provide free technical assistance from certified professionals to a group of growers in four focus townships. The goal is to refine Irrigation and Nitrogen Management Plans (INMPs) to enhance crop production efficiency and township-specific environmental sustainability metrics. The project will assess grower practice adoption of protective management practices and deliver 3 years of INMP Development Workshops and technical assistance to growers.

Why

Meeting groundwater quality protection goals will require increased protective management practice adoption throughout the SSJV, particularly in townships with impaired groundwater. However, more effort is required to develop site-specific plans to improve nitrogen efficiency on farms in these townships. The outreach and planning efforts developed in this project can be applied to all 93 townships with impaired groundwater in the SSJV.

When

This project will be implemented from 2024 – 2027 with support from an $1M grant to the SSJV MPEP from the NRCS Conservation and Innovation Grant program.

How

We will develop a comprehensive assessment, outreach, and workshop delivery strategy for four focus townships that can be applied to 93 other groundwater-impaired townships in the SSJV. This includes:

• Analyzing grower protective management practice co-adoption trends correlated with productivity and nitrogen efficiency
• Identifying participant growers and technical assistance providers and preparing for INMP Development Workshops in the first year. Workshops will be delivered in Tulare, Kern, and Fresno counties.
• Growers and technical assistance providers co-developing site-specific INMPs in years 2 and 3.
• Assessing economic, environmental, and social outcomes in year 3.

Anticipated Outputs

• Analysis of protective management practice co-adoption trends to generate recommendations for profitable and nitrogen-efficient crop production in the SSJV.
• 40 site-specific INMPs will be developed for 40 growers in four focus townships.
• Township-specific outreach and education materials will be developed for 3 INMP Development Workshops in each of the four townships
• Economic, environmental, and social outcome assessment of project implementation.

Who

The SSJV MPEP Committee is collaborating with researchers at the University of California, Davis and University of California Cooperative Extension Specialists and Farm advisors.

What

The project goal is to build citrus-specific modules for UC’s CropManage online decision support platform (for oranges, mandarins, and lemons). Insights from field studies and modeling efforts will inform the module production. This will provide accurate, reliable recommendations for nitrogen and water application to citrus orchards throughout the SSJV.

Why

As citrus growers grapple with significant water quality and quantity issues, the need for precise fertilization and irrigation practices is more critical than ever. Currently, citrus growers in the SSJV lack access to a specialized, free decision-support tool that could guide them in making informed decisions about irrigation, fertilizer, and water application. The crops’ physiological characteristics are unique amongst commodities grown in the valley, adding a layer of complexity to developing such a tool.

When

This project will be implemented from 2025 – 2027 with support from a $225k CDFA Fertilizer Research and Education Program grant.

How

We will develop accurate, reliable recommendations for SSJV citrus irrigation and nitrogen management. This includes:

• Improving the understanding of nitrogen and water use dynamics in micro-irrigated SSJV citrus orchards through field measurements, monitoring, and data-driven modeling.
• Developing CropManage citrus modules with knowledge gained from field studies and modeling.
• Ground-truthing CropManage recommendations for nitrogen and water applications at heavily monitored citrus study orchards.

Anticipated Outputs

• Scientifically-informed and verified CropManage citrus modules freely available to SSJV citrus growers

Who

The SSJV MPEP Committee is collaborating with Dr. Daniel Geisseler, Assistant Professor, Nutrient Management CE Specialist, University of California, Davis.

What

The project goal is to continue to develop nitrogen removal and sequestration coefficients for 33 SSJV crops and to update publicly-available N removal materials and tools.

Why

This serves to support SSJV MPEP growers by providing accurate coefficients to convert yield information into amounts of N removed from fields in harvested crop materials. Growers need such information to inform nutrient management planning, so that N application rates can be scaled to meet crop requirements while minimizing excess N at risk of leaching below the root zone.

When

This project will be implemented from 2021 to 2025 with support from a $225k CDFA Fertilizer Research and Education Program grant.

How

We will update N removal coefficients for 33 SSJV crops and N sequestration rates for 8 perennial crops. This includes:

• Analyzing data collected through targeted, new sampling and analysis in collaboration with partner scientists and grower/packer/shippers.
• Refining Yield-to-N Removed conversion factors for use by growers and grower advisors during nutrient management planning, and by coalitions for large-scale performance assessment
• Promoting and enabling expanded knowledge and appropriate use of N-removal coefficients and N-sequestration rates by growers, grower advisors, and coalitions. This includes:
  • updating results in an update of Geisseler (2016),
  • updating existing online and off-line tools for estimating N removed in crops and incorporating them into regional assessments of N balance in irrigated crop lands,
  • and updating N accumulation rates in crop models used in the ILRP.

Anticipated Outputs

• N removal and sequestration coefficients for 33 SSJV crops and N sequestration rates for 8 perennial crops.
• Updated publicly-available N removal decision support tools for SSJV MPEP growers.

Who

Dr. Isaya Kisekka and Dr. Thomas Harter at the University of California, Davis are collaborating with the SSJV MPEP Committee and Dr. Michael Cahn from University of California Cooperative Extension on this project.

What

The project goal is to leverage existing data to validate and strengthen existing, innovative modeling (CV-SWAT) and management (CM) tools that are used by growers and their regulators to make nitrogen and water management decisions.

Why

The Central Valley (CV) Irrigated Lands Regulatory Program (ILRP) regulates discharge of nitrate and other soluble constituents from irrigated cropland. To comply with this program, growers utilize precision irrigation and fertigation practices informed by decision support tools like CropManage (CM). ILRP coalitions assess efficacy of these practices on 5.2 million acres managed by 23,500 irrigators using versions of the Soil Water Assessment Tool (SWAT) and the Nonpoint Source Assessment Tool (NPSAT) that were adapted specifically for the CV. CV-SWAT has been calibrated and requires validation to increase confidence in results from the model simulations. This work has been requested by the Central Valley Regional Water Quality Control Board and growers, and plans have been made to use data from 3 study sites (almonds, oranges, and tomato) where nitrate concentrations are being monitored, but the work has not been funded. There is a need to validate the CV-SWAT model simulations to ensure solute losses are not under- or over-estimated, to demonstrate the performance benefits of using decision support tools (like CM) and expand their applications, and to study how these changes are reflected in CV-SWAT.

When

This project will be implemented from 2024 to 2026 with support from a $225k CDFA Fertilizer Research and Education Program grant.

How

This project will newly apply CM and CV-SWAT to the 3 monitored sites to assess and enhance the benefit of CM and to validate CV-SWAT. The sites are distributed throughout the CV and represent unique crop systems: almonds (a deeper rooting permanent tree crop), oranges (a relatively shallower-rooted permanent tree crop), and processing tomatoes (a rotated annual crop). The project team will use field data from these pre-established, intensively monitored research sites to enhance existing modeling and management tools utilized by growers throughout the CV. Working with the MPEP, we will increase groundwater quality stakeholders’ confidence in the modeling tools used for ILRP compliance. Working with local (UCCE, NRCS, CCA & PCA) partners, we will leverage these applications of CM to spread understanding of and support for CM use by growers.

Anticipated Outputs

• Percolation and nitrate leaching monitoring results from existing projects will be used to validate and further improve CV-SWAT model performance for 3 high-acreage crops (almonds, orange, and tomatoes), and to validate the benefits of decisions informed by CM.
• Updated model performance metrics for CV-SWAT. Depictions of the effects of irrigation and nutrient management practices on rates of nitrate leaching will be shared with water quality stakeholders.
• Further comparison of CV-SWAT and HYDRUS for new combinations of crops and soil types.
• Expansion of CM application to 3 citrus crop types: orange, lemon, and mandarin.

Who

Seven coalitions, representing more than 9,000 growers farming approximately 1.85 million acres of irrigated land south of Fresno, formed the SSJV MPEP Committee to implement the MPEP. The MPEP Workplan was developed with extensive input from State and Central Valley Water Board staffs and with technical partners at United States Department of Agriculture Natural Resources Conservation Service, University of California, California Department of Food and Agriculture, and California State University.

What

This project worked to increase implementation of practices that protect groundwater from pollution by nitrate in fertilizers applied to irrigated lands in the SSJV and beyond.

Why

The MPEP was devised to complement other components of the Region 5 (Central Valley) Water Quality Control Board’s Irrigated Lands Regulatory Program general orders. This facet of the orders, along with the Groundwater Quality Management Plans, contains most of the actions to protect water quality, along with the most rigorous performance demonstrations. The MPEP moves beyond simple metrics that might indicate a problem to identifying solutions.

When

The project was implemented over a 3-year period (2016-2019) with $2 million that was awarded from the United States Department of Agriculture Natural Resources Conservation Service Conservation Innovative Grant program. This award was matched with member, partner, and collaborator contributions exceeding $2 million. In addition, the Committee funded other MPEP activities, either directly or (when available) with the assistance of outside funding.

How

• Identify protective practices for Central Valley agriculture
• Adapt the USDA’s Soil and Water Assessment Tool (SWAT) for Central Valley agriculture
• Increase adoption of protective practices through intensive producer/advisor outreach and an online decision support tool
• Assess adoption of protective practices by comparing a 2016 benchmark assessment with practices implemented throughout the project duration
• Quantify the reductions in nitrate leaching at the landscape-level using SWAT

Outputs

• A prototype Grower SWAT Results Viewer
• SWAT model refinement and calibration
• Targeted outreach and trainings
• Presentations delivered at annual FREP Conferences

Who

The SSJV MPEP Committee collaborated with Dr. Daniel Geisseler, Assistant Professor, Nutrient Management CE Specialist, University of California, Davis and numerous other industry and UC cooperators.

What

This was a project initiated by the SSJV MPEP Committee to provide growers and water quality coalitions with reliable data about nitrogen (N) removed from fields in harvested biomass, and N sequestered in perennial crop tissues (such as roots and wood).  

Why

To provide growers with information to guide their decisions regarding nutrient management practices and crop demand; and to increase the accuracy of regulatory metrics based on N removal that are calculated by the coalitions. 

When

The 2-part project was initiated in 2018 and received approximately $500,000 in funding from the California Department of Food and Agriculture Fertilizer Research Education and Program. The effort was supported with additional funds from the MPEP Committee and the concurrent Conservation Innovation Grant project.

How

• Assess N concentration of harvested material removed from fields (N mass removed [R]/Harvested material mass [Y]) for approximately 44 crops over several growing seasons. 
• Establish values for the annual amount of N sequestered in standing biomass for seven perennial crops. 
• Refine Y-to-R conversion factors, and add N-sequestration rate estimates, for use by growers and grower advisors during nutrient management planning and by coalitions for landscape-scale performance assessment. 
• Promote and enable expanded knowledge and appropriate use of N-removal coefficients and N-sequestration rates (as part of routine N-management planning and evaluation) by growers, grower advisors, and coalitions. This includes: 
  • Incorporate this information into updates to the N-concentrations Report. 
  • Develop an expanded discussion of the appropriate use and applicability of N-removal and N-sequestration estimates in formulating more precise N-fertilizer recommendations. 
  • Update existing online and off-line tools that facilitate estimation of N-fertilizer management in single fields, or in groups of fields, as well as regional assessment of N balance in irrigated croplands. 

Outputs

• Nitrogen Concentrations in Harvested Plant Parts (Geisseler, 2021) 
• Final Report Phase 1 
• Interim Report for Phase 2 
• Presentations delivered at FREP Conference 2017, UCCE San Joaquin Valley Citrus Meeting 2017, Plant & Soils Conference 2018, and the FREP Conference 2018

Who

The SSJV MPEP Committee worked with Dr. Thomas Harter, Chair, Water Management and Policy; Groundwater Hydrology Specialist, Cooperative Extension, Department of Land, Air, and Water Resources, University of California; Dan Munk, Farm Advisor, Cooperative Extension Fresno County, Department of Agriculture and Natural Resources, University of California; Dr. Mae Culumber, Nut Crop Advisor, Cooperative Extension Fresno County, Department of Agriculture and Natural Resources, University of California; and Dr. David Cehrs, Site Owner/Operator, Grower, Geologist (retired), Sanger, California. 

What

This project was a demonstration project to allow growers to assess the applicability of rigorously controlled irrigation and fertigation, which have been shown to significantly reduce the rate of nitrate leaching to groundwater in high-frequency low-rate (HFLR) systems (e.g., drip or microspray). 

Why

There is a need to expand our knowledge base around the connection between nitrate in the root zone and groundwater and crop and soil management. 

When

The project was completed over a 2.5-year period (2018-2020) for $354,000 from a Conservation Innovation Grant from the USDA NRCS with additional funding from the MPEP Committee. Project collaborators also contributed to some costs and the grower participant was supported through the Environmental Quality Incentives Program (EQIP) that funds equipment purchases to shift irrigation and fertigation operations to boost production while diminishing leaching of N fertilizer.

How

• For shallow- and deep-rooted perennial crops, quantify the yield, crop quality, water use efficiency, and nitrogen use efficiency benefits of converting from a non-automated irrigation system (operated weekly) to widely available, replicable systems that provide more frequent and precisely timed irrigation and fertigation through automation and soil moisture monitoring feedback
• Evaluate the relationship between these management changes and reductions in the rate of nitrate leaching to groundwater
• Work with growers, commodities groups, and NRCS to develop an initiative that would facilitate cost-share funding of these types of system upgrades, encouraging and enabling their broader adoption. While not strictly a part of this study, this activity is essential to facilitate replication of the work at a scale that will have the desired impact

Outputs

Presentations delivered at FREP Conference 2017, the California Citrus Conference 2018, and the Plant & Soil Conference 2018.

Who

The SSJV MPEP Committee worked with researchers from University of California, Davis: Sat Darshan S. Khalsa and Patrick H. Brown were Project Leaders from the Department of Plant Sciences, and Mark N. Lubell and Jessica M. Rudnick were collaborators from the Department of Environmental Science and Policy. 

What

This project quantified the current use of improved nitrogen management practices and characterized drivers of grower behavior to inform future research, education, and outreach to citrus and raisin growers in the SSJV. 

Why

Citrus and raisin grapes are two commodities disproportionately represented in the SSJV and are a high priority for the SSJV MPEP. Their adoption of improved practices will, in some cases, be essential to meeting groundwater quality protection goals. However, more information is needed about their rate of practice adoption and the barriers preventing more extensive adoption. 

When

This project was conducted over a 1-year period (2020-2021) for $75,000 funded by the MPEP Committee’s Conservation Innovation Grant funded by the USDA NRCS. Collaborators provided in-kind contributions and used supplementary funding for complementary work in the northern areas.

How

• Develop a quantitative understanding of N management practices for citrus and raising grape growers in the region represented by the SSJV MPEP Committee 
• Distribute, collect, and aggregate survey data from grower members in the SSJV MPEP regions by way of focus groups
• Quantify current practice adoption and determine effects of growers’ decisions on adoption of N management practices
• Analyze responses to determine key grower motivations and barriers to adoption of N management practices. Validate survey responses by crosschecking with coalitions 
• Communicate findings directly to grower populations surveyed, as well as to academic and industry groups, to inform management and future outreach and education programs

Outputs

• Final Report 
• Poster presentation delivered at the FREP Conference 2021