CICEET Progress Report for the period 9/01/03 through 2/29/04

Project Title: Developing a Desktop DNDC Tool for Evaluating Best Management Practices for Reducing Nutrient Loading to Elkhorn Slough NERR.
Principal Investigator(s): Changsheng Li, William Salas

Accomplishments
Scheduled Tasks:
During the third six-month project period there were four main tasks. The tasks were:

1. modify ES-DNDC user environment,
2. prepare for 2nd workshop at Elkhorn Slough in May 2004,
3. collect more detailed information on physiology and phenology of crops in Elkhorn Slough watershed for improving model performance with the local specific crops, and
4. work with local stakeholders to document local management practices and promote the tool for improving local nitrogen management.

Progress on Tasks
Task 1: Modify User environment
We have made several modifications to the ES-DNDC system to enable users to:

• Query the GIS data and model results based on land ownership parcel data or individual fields. Field designations are based on California DWR field polygons and the ownership polygons are based on parcel data obtained through the Elkhorn Slough foundation. Both GIS databases have been built into the ES-DNDC system.
• Perform simulations based on water years in addition to calendar year simulations. Users can now look at annual and seasonal N loading based on crop calendars.
• Create standard map products for reports or handouts. Using capabilities of our GIS system, we have built a prototype product generation that will create a suite of standard maps and graphics. (see Figure 1 for an example)
• Run sensitivity or uncertainty analyses. We have built tools in ES-DNDC to perform sensitivity and uncertainty analyses with either (a) single- or double-parameter ranges using our Most Sensitive Factor (MSF) approach or (b) more traditional Monte Carlo analyses for multiple parameter analyses (see Figure 2 for example of Monte Carlo analysis results for sensitivity of nitrous oxide emissions across range of soil conditions found in a single soil polygon).

Task 2: Prepare for 2nd Workshop
We have scheduled the 2nd workshop for June 7th and 8th 2004 at the Elkhorn Slough NERR and Moss Landing Computer Labs. The agenda and speaker lists for this workshop have been finalized with Grey Hayes who is the Coastal Training Program coordinator at Elkhorn Slough. The agenda is provided in a separate document called Agenda.doc.

Task 3: Collect more data on crop physiology and crop management
We have been collecting more detailed information of physiological and phenology data for the local crops (e.g., strawberry, lettuce, artichoke, truck crops etc.) to improve the parameters embedded in the model library for modeling development and growth of these crops. In addition, additional crop management data were also collected to better simulate impacts of management on crop yield and environmental safety.

EDNDC uses a suite of parameters for simulating crop growth, including carbon and nitrogen allocation, water requirements, light use efficiencies, and optimum yield. In addition, for each crop we estimate the fraction of total biomass that is harvested, which in turn indicates the amount of crop residue. Values for these parameters have been collected from literature, discussions with University of California Continuing Education staff and their Cost and Return Studies, California Department of Food and Agriculture, California Air Resources Board and a national EPIC database. Table 1 provides a listing of the default parameters used in ES-DNDC. As an example, based on these parameters, corn produces almost 4235 kg C/ha (11,145 kg C/ha, total biomass, times 0.38, leaf+stem fraction of total biomass) of above-ground litter. Assumptions on the fraction of % of litter left on site have a tremendous impact on soil carbon sequestration, greenhouse gas emissions and overall N dynamics and thus can be a significant source of uncertainty. ES-DNDC users can adjust these baseline assumptions to either reflect actual management practices for a specific field or to assess the impact of various management alternatives (e.g. shifting from conventional tillage to no-till with 100% residue incorporation).

Task 4: Work with local stakeholders, project outreach and model dissemination
Project outreach including dissemination of this tool is a major focus of this project. In addition to the workshops we have and will hold for this project, we are working with local researchers, managers and policymakers to promote, train and educate them to use the ES-DNDC tool. Thus, we have begun to build outreach materials to promote and educate the public regarding this project. Over the past 6-months our technology transfer and outreach activities have been successful and generated significant interest in ES-DNDC.

• We have continued to work with agricultural engineers at the Santa Clara Valley Water District to use the model to evaluate irrigation and fertilizer schemes to reduce agricultural nutrient loading. Recently, they have been funded for a $900,000 project by California State Water Resources Control Board to implement a “Regional Integrated Program for Irrigation and Fertilization Management Assistance” in 5 counties in California. They will be working directly with local growers to assist in evaluating the impacts of management practices on the efficiency of water and fertilizer use to minimize non-point source pollutions. The project will be using the ES-DNDC model to train local managers to evaluate impacts of irrigation and fertilizer management practices on nitrogen loading.
• By request from the Kearney Foundation of Soil Science and the California Department of Food and Agriculture we presented our DNDC modeling and decision support tool at their “Interface between Science and Policy” workshop held in Davis, CA in September 2003.
• Building collaboration with local scientists in using the ES-DNDC tool to examine impacts of agricultural management on the fate of nitrogen and carbon dynamics in agro-ecosystems of Coastal California. Activities include collaboration with Dr. Ken Johnson at MBARI to link our upland estimates of nitrate leaching with his Land/Ocean Biogeochemical Observatory in Elkhorn Slough and Monterey Bay; with Dr. Marc Los Huertos at UC Santa Cruz on county scale analysis of management practices impact on carbon sequestration and nitrous oxide emissions; and a proposal with Dr. Joji Muramoto at UC Santa Cruz on using ES-DNDC as a nutrient management tool for organic agricultural systems in the Central Coast region of California.

Difficulties Encountered
We have not experienced any significant difficulties during this project period.

Anticipated Success in Meeting Project Objectives in Scheduled Project Period
We continue to anticipate meeting all our modeling objectives, as well as developing a strong outreach component of interested users from regional and state level stakeholders.

Preliminary Results
The goal of this project is to create a tool for the local regulators, farmers, or researchers. As our major product, ES-DNDC is available now. It can be downloaded from http://www.dndc.sr.unh.edu.

Tasks and activities for next reporting period

Tasks for the next reporting period
We have four main tasks for the next project period (3/1/04 to 8/31/04):

1. hold second workshop at Elkhorn Slough NERR in June 2004 for distribution of the final product and training of local stakeholders,
2. perform validation of ES-DNDC using existing field data from literature and colleagues at UC Santa Cruz,
3. create and distribute final ES-DNDC tool, and
4. write final report.

Work plan to accomplish tasks
Task 1:
Our second workshop will focus on introducing and distributing the final version of ES-DNDC to interested users, training of the proper use of the tool, and continuing efforts to maintain and build relationships with area stakeholders for potential future collaborations. The workshop is planned for June 7th and 8th 2004. The agenda for this workshop has been finalized with Grey Hayes who is the Coastal Training Program coordinator at Elkhorn Slough.

Task 2:
Over the past 6 months we have been collecting published data on nitrate leaching, nitrate concentrations in local rivers and creeks and nitrous oxide emissions for validating our model estimates. We will use these data to validate and/or corroborate ES-DNDC estimates of N leaching and N₂O emissions.

Task 3:
Based on feedback and participants input from our second workshop we will consider making final changes to our decision support system. However, we do not anticipate making major changes to ES-DNDC. We do anticipate adding a feature to our product generation system to include our best estimates of uncertainties given the input data and results of our validation analyses. The final version of ES-DNDC will be distributed to all workshop participants and copies will be made available to ES-NERR and the Elkhorn Slough Foundation for their use and distribution. We also plan to distribute the tool via the web. We also plan to work with ES-NERR to create a project brochure for distribution at the ES-NERR visitor center.

Task 4:
A final project report will be submitted to the CICEET program office by September 15, 2004.

Concerns or difficulties
We have no major concerns. Based on our discussion with local researchers there is not a large amount of nitrate leaching data available within the Elkhorn Slough watershed. In addition, the systematic in water measurements through the LOBO system did not begin until Fall 2003. Therefore, availability of field data for a comprehensive validation over the next 6 month time period is a concern. However, we anticipate that more field data will be available in the near future through new activities in the region (e.g. Santa Clara Valley Water District irrigation and fertilizer project).

Expenditures
Our project expenditures are in line with expected costs.