Assessment of Soil Biology and Plant Available Nitrogen for Soil Health and Water Quality

Final report for EW16-026

Project Type: Professional Development Program
Funds awarded in 2016: $49,690.00
Projected End Date: 09/30/2018
Grant Recipient: CAFES Center for Sustainability
Region: Western
State: California
Principal Investigator:
Hunter Francis
CAFES Center for Sustainability
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Project Information


Soils are at the forefront of many exciting discussions currently happening within agriculture. The concept of soil health is adding to our understanding of soil in agricultural systems and to traditional understandings of soil quality. This project provides education on soils, soil biota and organic matter to help illustrate techniques useful for assessing soil biology and its relation to soil health. New assessment methods were explored, which are increasing general understanding of these important aspects of soil health and how that understanding can be used better to manage soil organic matter, nitrogen, crops and water quality – often to the economic benefit of producers and to environmental benefit for us all. The project engaged a wide cross-section of stakeholders to develop both live and web-based training and resources, including hands-on field workshops for professionals on soil health, with a specific focus on new, practical methods to assess soil biological activity and nutrient mineralization.

Project Objectives:

Overall objectives of this project included:

1) Provide training to agricultural and other professionals on the assessment of soil biology and plant nutrients;

2) Equip professionals with data-driven solutions for pressing soil and water challenges;

3) Expand the “toolbox” of professionals by providing them with information and hands-on training;

4) Provide a comprehensive overview of how soil biology and organic matter, as well as to other physio-chemical parameters, relate to soil health;

5) Put a special focus on how carbon and nitrogen cycle in soils, and how soil organic matter content relates to the mineralization of plant available nitrogen;

6) Promote understanding of the role and value of organic nitrogen and its relation to inorganic nitrogen;

7) Provide basic training on how to create/manage nutrient budgets and promote methods for increasing soil organic matter and building beneficial soil biology;

8) Discuss the relevance of educational materials developed to other pertinent fields, such as biological amendments, composting and carbon sequestration; and,

9) Leverage alumni and industry supporters to disseminate project deliverables and results.


Soil biota and organic matter are being increasingly recognized as a fundamental component of soil health. While this fact has long been known to soil scientists and segments of the professional community in agriculture, recognition is becoming widespread for several reasons: 1) depletion of soil organic matter is resulting in erosion and loss of soil fertility, 2) the ability of soil organic matter to increase soil water holding capacity is gaining attention as the West struggles with prolonged drought, 3) the ability of biologically-rich soils to cycle and retain otherwise leachable nutrients is being linked to the maintenance of water quality, and 4) the capacity for soil biology to play a significant role in the sequestration of atmospheric carbon is attracting considerable attention as leaders look for ways to mitigate and adapt to climate change. Better understanding and validation of all of these important aspects of soil health is needed overall, and better understanding of the relationship between soil organic matter and mineralizable nitrogen is particularly needed in the assessment of a soil’s potentially positive contribution to plant nutrition and potentially negative effect on water quality (through leaching). The deliverables of this project were designed to increase practitioner understanding of these important considerations.


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  • Dr. Claire Balint
  • Dan Noble
  • Dr. Ashraf Tubeileh


Educational approach:

Our strategy in executing this project built upon established relationships and previous offerings (including former SARE projects) we had conducted in the realm of soil health and composting. We assembled a team of collaborators and assessed opportunities to deepen awareness of soil health through new educational offerings. What resulted was a series of lectures, on-farm filed days and informal meetings geared to production agriculturists and consultants, but available to the general public. Resources garnered and new relationships developed through these activities enabled us to create an on-line educational series compiling the new information for continuing education purposes for a wide audience.

Education & Outreach Initiatives

Soil health and nutrient assessment on-farm education and web-based learning

Our goal was to provide informative but easily understandable educational trainings and web modules to as many people working in agriculture and allied industries as possible as a means of fostering adoption of healthier soil stewardship and assessment practices. Soil organic matter enhances a soil’s potential to provide multiple ecosystem services, including the provision and sequestering of nutrients. Production agriculture can degrade soil organic matter, especially through repeated tillage and application of synthetic chemicals. Thus, there is a need to both protect and replenish soil organic matter through sustainable soil management. The first step in this process and an important part of on-going monitoring involves the assessment and quantification of soil organic matter and biological processes. With training and resources developed through this grant, we helped to “train trainers” resulting in a more comprehensive soil health “toolbox” for adaptive management decisions, integrating chemical, physical and biological parameter interpretation methods for the betterment of agro-ecological systems.


The project had five principle components. Details on each are listed in ‘outcomes’ below.

  1. Inaugural Soil Health Presentation

A full-day seminar entitled “Healthy Foodwebs, Healthy Soils”, which was held on April 21, 2017 at the Inn at Morro Bay featuring leading soil microbiologist and soil foodweb pioneer Dr. Elaine Ingham.

  1. Three Follow-up Field Day Workshops

Three Soil Health Assessment Field Days were conducted at three separate farm locations in California (Central Coast, Central Valley and Sacramento Valley). Each featured presentations from farm owners, representatives from NRCS and soil testing laboratories.

  1. Six-part Screen-cast Webinar Series

An online educational modules of six parts, hosted on our website and accessible to all.

  1. Compilation of Resources on the Center’s Webpage

These resources for soil health and assessment are featured on the home pages of our six online training modules.

  1. Certificate of Completion

An option of receiving continuing ed credit will be made available for participants who officially enroll in our online educational module and take a test of comprehension.

Outcomes and impacts:
  1. Inaugural Soil Health Presentation

We were extremely fortunate to have secured leading soil microbiologist and soil foodweb pioneer Dr. Elaine Ingham as our featured speaker for the soil health presentation promised in the grant. The title of this full-day seminar was “Healthy Foodwebs, Healthy Soils”, which was held on April 21, 2017 at the Inn at Morro Bay. The event webpage can be viewed at: Western SARE Outreach Specialist, Stacy Clary, wrote an article about the event in Spring 2017 Western SARE Simply Sustainable newsletter (pg.4) The event sold out, with 200 people attending. The diverse group of attendees included students, faculty and staff from Cal Poly SLO, UC Santa Barbara, ALBA (Salinas), the Center for Urban Agriculture (Santa Barbara), and the Center for Regenerative Agriculture (Ojai); professionals from the Central Coast Regional Water Quality Control Board (RWQCB), Bonipak, Dole, Kings River Produce, New Era Farm Service, Monterey Pacific Inc., Plant Sciences Inc., Crop Production Services, and Inocucor Technologies; farmers, vineyard managers, garden managers, composters, landscaping professionals. Testimonial feedback indicated this was a highly successful event, which was followed by a wonderful industry reception overlooking Morro Bay that enabled participants to interact with Dr. Ingham personally.

  1. Three Follow-up Field Day Workshops

Three Soil Health Assessment Field Days envisioned in the grant were held in spring 2017 at three locations with prominent speakers. The May 5th field day took place at Cal Poly and featured speakers Dr. Alan Franzluebbers, USDA-ARS professor at North Carolina State University, and Ken Oster of USDA-NRCS Templeton. Many of the attendees from the April inaugural event also attended this field day. Prior to the event, Center staff collected representative soil samples from various farming operations throughout the Cal Poly campus. Dr. Franzluebbers’ lab kindly donated their services to run carbon mineralization, flush of CO2, and soil microbial biomass carbon analyses on the Cal Poly soil samples for demonstration and discussion during the field day. In addition, Dr. Franzluebbers presented an overview of soil biology and soil carbon to over 100 Cal Poly faculty, staff and students, and a more focused research seminar on soil activity indices for soil and crop science faculty during his visit.

The May 25th field day took place at Macon Seed Farm in Turlock and featured speakers Joe Mullinax, director of Denele Analytical Laboratory, and USDA-NRCS representatives Zahangir Kabir, Tony Rolfes, and Sid Davis. Mr. Mullinax and his lab kindly donated their services to provide soil analyses, including those for biological activity, collected for Macon Seed Farm. NRCS representatives demonstrated the importance of soil physical characteristics for erosion control and microbial habitat, and discussed management strategies for soil health. Attendees included farmers from Burroughs Family Farms and Frog Hollow Farm, composters from Comgro, Harvest Power, Zare Agrhos and the Association of Compost Producers, and representatives from the East Stanislaus Resource Conservation District (RCD) and the Central Valley RWQCB.

The June 22nd field day took place at Full Belly Farm in Guinda (Yolo County) and featured speakers Judith Redmond and Paul Muller, owners of Full Belly Farm, Joe Mullinax and USDA-NRCS representatives. Ms. Redmond and Mr. Muller led the group on a tour through their farm to discuss the connection between their management strategies and their soil health objectives, and how these have impacted the quality and efficiency of their operation. Mr. Mullinax and his staff provided representative soil analyses for Full Belly Farm and discussed the ramifications of those results for present and future management. Zahangir Kabir, Tony Rolfes, Sid Davis and other USDA-NRCS representatives attended this event as well, along with participants from CDFA (CA Dept. of Food and Ag), RCDs, UC Davis, CAFF, and Bay Area farmers. The impending launch of the upcoming CDFA Healthy Soils Program (HSP) and its requirements were discussed at the workshop. Since that time, the Center has now received over $200,000 funding from the HSP to study the effects of implementing no-till and compost amendments on two area vineyards.

All three workshops were attended by prominent agricultural and conservation professionals from throughout the state. Presentation materials and information about the field days is available at:

  1. Six-part Screen-cast Webinar Series

The six-part educational series we have completed is now online and can be accessed through our website at: Chapters included are:

  • Foundations of Soil Health
  • Soil Biology
  • Soil Organic Matter
  • Nutrient Cycles
  • Nutrient Management
  • Assessing Soil Nutrients and Biology
  1. Compilation of Resources on the Center’s Webpage

A multitude of resources have been developed in recent years for education on soil health and nutrient management, including by USDA. We have included links to many of the best of these resources on our Soil Health Dimensions website, categorized by topic within the six chapters of the series.

  1. Certificate of Completion

Beginning in 2019, viewers of the online series will have the option of obtaining professional development continuing education units by enrolling for the course through Cal Poly Extended Education. Upon successful completion of an online exam, Cal Poly will award the course participant with a certificate of completion and 1 CEU credit. We plan to apply for certified crop advisor (CCA) credits with the American Society of Agronomy, which we expect with make additional credits available for participants. Enrollment for credit is entirely optional, however; the series may be watched by anyone free of charge at any time.

Educational & Outreach Activities

4 Curricula, factsheets or educational tools
3 On-farm demonstrations
1 Online trainings
1 Published press articles, newsletters
3 Tours
4 Webinars / talks / presentations
3 Workshop field days
1 Other educational activities

Participation Summary:

2 Extension
12 Researchers
21 Nonprofit
18 Agency
85 Ag service providers (other or unspecified)
45 Farmers/ranchers
180 Others

Learning Outcomes

360 Participants gained or increased knowledge, skills and/or attitudes about sustainable agriculture topics, practices, strategies, approaches
35 Ag professionals intend to use knowledge, attitudes, skills and/or awareness learned

Project Outcomes

5 Grants received that built upon this project
8 New working collaborations
Project outcomes:

All of our envisioned deliverables were successful completed and attended. Overall this project led to a greater understanding among participants of how soil biology relates to soil health, and importantly, of new methods for assessing soil nutrients and biological activity. This understanding will help producers will do a better job managing soil nutrients (especially nitrogen), thereby protecting the environment and potentially saving money. It has helped increase appreciation for organic amendments and soil building practices. It will also help consultants and other service providers to make better recommendations in the field. Knowledge supplied will help the agricultural community overcome barriers to adoption of sustainable soil management practices. Feedback on our workshops and lectures was very positive and numerous new relationships and partnerships we formed as a result of the excellent networking opportunities they provided.

4 Agricultural service provider participants who used knowledge and skills learned through this project (or incorporated project materials) in their educational activities, services, information products and/or tools for farmers
45 Farmers reached through participant's programs
Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.