Biointensive no-till farming in California: farmer-driven research and education on soil health, water efficiency and economic resiliency

Progress report for SW20-919

Project Type: Research and Education
Funds awarded in 2020: $251,036.00
Projected End Date: 12/31/2023
Host Institution Award ID: G112-21-W7899
Grant Recipients: University of California Berkeley; University of California Davis; Community Alliance with Family Farmers; Multinational Exchange for Sustainable Agriculture
Region: Western
State: California
Principal Investigator:
Dr. Timothy Bowles
University of California Berkeley
Co-Investigators:
Amanda Hodson
University of California, Davis
Sara Tiffany
Community Alliance with Family Farmers
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Project Information

Summary:

Small-scale farmers create innovative strategies for dealing with environmental and societal challenges, yet limited access to land and capital impacts their response capacity. One emerging, farmer-led innovation is a "no-till" management system that requires little capital investment and aims to enhance ecosystem health through a soil conservation ethos that reduces tillage, increases cropping density, and maximizes biodiversity. Farmers utilizing this method have reported promising outcomes for soil health, water conservation, farm profitability, and adaptive capacity to climate change. Yet agroecological research has not caught up, and limited documentation of these benefits exists despite increasing adoption across the state (Biointensive No-Till Symposium Report, February 2019). Furthermore, information on this no-till system has primarily spread through non-traditional channels such as social media and farmer-led courses. Producers have expressed a desire for an accessible and robust learning network, as well as for support from scientists in monitoring farmer experimentation. To address these needs, this project has been collaboratively designed with small-scale, limited-resource farmers in California to sustain economically and ecologically sustainable farms through research, education, and extension on biointensive no-till systems.

Specifically, a coalition of researchers, non-profits, and partner farms will explore how management practices on existing biointensive no-till systems affect soil health (carbon, microbial activity, and biodiversity), water conservation (soil water retention), farm economic resilience (including labor costs, land security, distribution networks), and potential response to climate change scenarios (crop nutrient density, drought response, seed biodiversity). This research builds on existing farmer partnerships that have included co-created colloquia, field days, and preliminary on-farm and field station research. These initial findings will inform replicated experiments at partner farms and trials at producers’ existing no-till sites. Further, producers will guide the continuation of no-till experiments begun in 2017 at the Berkeley’s Oxford Tract Field Station and 2012 at the UC Gill Tract Community Farm. This extensive experimentation will help a growing network of farmers better understand how their management practices are impacting their soil, farm, and community.

We will also establish a ‘community science’ training program through a partnership with the Bay Area Farmer-to-Farmer Training Program (BAFFTP) to increase producer participation in research and education, ensure the scientific rigor of farmers’ observations, and share science-based extension. Education-based partnerships are already well established in many of our cooperating producers and partners. BAFFTP will expand on these existing relationships, tying together producers in our network with regional training programs in soil science, agroecological management, and basic research techniques. The program will couple online coursework with on-farm field days and workshops. Ultimately, this set of nested programs aims to produce a thriving network of knowledge exchange between growers and their communities who span a range of traditional categories in agriculture (rural and urban, for-profit and nonprofit, volunteer and paid labor) but are united in their struggle against structural land and capital limitations.

Project Objectives:
  1. Assess how producer-selected biointensive no-till practices on replicated field station and on-farm experiments impact functional dimensions of soil health identified by farmers as highest priority: A) Carbon stabilization and nutrient cycling; B) Microbial activity; C) Soil biodiversity, food web complexity and pest suppressive potential; D) Soil hydrologic properties and water retention. Years 2-3. (Bowles, Hodson, Rainey, Tiffany, Baurer)
  2. Assess how biointensive no-till management could help farmers adapt to impacts of climate change in California by: A) Comparing productivity of high-value dry-farmed tomatoes in a replicated experiment in soils with contrasting 5-yr histories of no-till vs. till management; and B) Evaluating water retention, infiltration, and availability for soils under no-till management across a replicated experiment and farmers' fields. Year 2. (Bowles, Rainey, Tiffany, Baurer)
  3. Conduct an indicator-based analysis of economic resiliency through surveys and interviews across a rural-urban gradient investigating establishment cost and time, changes to inputs and labor, land tenure, impacts on total crop production, and distribution networks. Year 2. (Tiffany, Rainey) 
  4. Implement a community science network through partnerships with the Bay Area Farmer-to-Farmer Training Program to establish site-specific, farmer-led internships, agroecological education, and increased knowledge exchange between farmers, community members, and students of agroecology and soil science. Year 2-3. (Atwood, Porter, Tiffany, Kaiser, Kern, Whamond, Rainey, Bowles)
  5. Host a series of field days, workshops, and trainings through the community science network to hone on-farm and producer-driven evaluation of soil health – including nutrient availability, pests and disease, water availability, and food web complexity – and offer technical assistance and resources to students and farmers evaluating the success of their practices. Years 1–3. (Rainey, Bowles, Atwood, Porter, Tiffany)
  6. Through workshops, events, written materials, and online learning platforms, share project findings and facilitate practical knowledge exchange on biointensive no-till adoption, implementation, and continued management. Years 2–3. (Rainey, Tiffany, Baurer)

Modification of project timeline

Our project started in Fall 2020, when the COVID-19 pandemic was still in its early stages. At that time, and through summer 2021, access to our labs at UC Berkeley were severely limited to "essential research" only, which did not include starting new projects. Additionally, our farmer partners were not keen on much on-farm work and in-person meetings during early 2021 when vaccines were only becoming available. Thus, we decided to postpone most  portions of the project by one year. This did give us an opportunity to use WSARE resources for synthesizing more of our past research on biointensive no-till (see Research) and for conducting education and outreach activities not anticipated by the project (see Education). We anticipate needing to request a no-cost extension for our project. This project will be complete by December 2023, with all research and extension activities finalized.

Timeline:

 

Task

Year 1

Year 2

Year 3

 

Q1

Q2

Q3

Q4

Q1

Q2

Q3

Q4

Q1

Q2

Q3

Q4

Objective 1: Assess how producer-selected biointensive no-till practices affect soil health

Select practices

X

                     

Implement trials

 

X

X

X

X

X

X

X

X

X

X

 

Collect soil samples

 

X

X

   

X

X

   

X

X

 

Lab analyses

   

X

X

   

X

X

   

X

X

Data analyses and writing

               

X

X

X

X

Objective 2: Drought stress tests

Implement trials

 

X

X

X

X

X

X

X

X

X

X

 

Collect soil samples

 

X

X

   

X

X

   

X

X

 

Lab analyses

   

X

X

   

X

X

   

X

X

Data analysis and writing

               

X

X

X

X

Objective 3: Economic resiliency analysis

Design surveys and interview questions

X

X

X

X

               

Implement surveys with producers in network

 

X

X

X

   

X

X

       

Analyze survey results 

       

X

X

   

X

X

X

X

Conduct semi-structured interviews

     

X

X

X

   

X

X

X

X

Objective 4: Establish ‘community science’ network

Advertise internship positions, select cohort (1,2 and 3), design curriculum

X

X

X

   

X

X

         

Bay Area Farmer to Farming Training executed for Bay Area cohort of trainees

   

X

X

   

X

X

    X X

Student work plans set 

     

X

     

X

       

Objective 5: Facilitate on-farm monitoring and sampling

Monitoring trainings and sampling by producers and students

   

X

X

   

X

X

X

X

X

X

Receive samples at UC, lab analyses

     

X

X

   

X

X

     

Data report-back and interpretation to producers

       

X

X

   

X

X

X

X

Objective 6: Build extension and outreach materials

Community workshops with biointensive no-till farmers

   

X

X

X

X

X

X

X

X

X

X

Creating extension materials

     

X

X

   

X

X

X

X

X

Build online learning platform and forum

               

X

X

X

X

 

Cooperators

Click linked name(s) to expand/collapse or show everyone's info
  • Elizabeth Kaiser - Producer
  • Aaron Kern - Producer
  • Coleman Rainey (Researcher)
  • Doria Robinson - Producer
  • Brooke Porter - Technical Advisor - Producer (Educator)
  • Sara Tiffany - Technical Advisor (Educator and Researcher)
  • Leah Atwood - Technical Advisor - Producer (Educator)
  • Michael Whammond - Producer

Research

Hypothesis:

This project is farmer-driven, meaning that it puts community organizations, farmers, and producers at the center of the investigation. From its inception this project has been guided and defined by a growing network of land stewards across California. Through a series of field days, farm visits, conference meetings, programmatic collaborations, and a symposium, growers have been able to shape and define the scope of the project. Most importantly, they have been asked to express their own questions about how minimal disturbance methods affects the soil, and how a soil-first approach to land stewardship can change the trajectory of ecological food production and food sovereignty. This participatory process has allowed us to develop a series of central research questions, determined by farmers and land stewards across the state. For growers seeking to minimize soil disturbance on their farms, what role does soil health have in their land stewardship praxis?  How do different soil conservation and agroecological principles play out across the diverse agricultural landscapes in California? What are the soil health outcomes under no-till farming systems, and how do those outcomes map onto farmer's perceptions?

We hypothesize that while farmers practicing no-till share a similar set of principles regarding soil health, they will be implement those principles in diverse ways depending on their context. Implementation of no-till principles will likely have diverse methods, intensities, frequencies, inputs, and tools. Given this diversity of practice, universal outcomes for no-till farmers will be less likely than relative changes within each landscape. Each of our partner organizations are innovators, often piloting multiple different management systems and soil conservation regimes within their farm. We believe that no-till management will demonstrate significant increases in soil carbon stocks and fractions, water retention, and soil food web complexity when compared to other management systems across partner farms. However we also hypothesize that no-till management's focus on high rates of compost amendment, minimal disturbance, high biodiversity, and intensive management will have a homogenizing effect on soil ecology. Preliminary results from both on-farm and replicated research station trials suggest that the additive, layered nature of no-till soils can create similar soil health outcomes even across diverse soil types, climates, and landscapes. We also anticipate that a common soil conservation ethos across these farms will "smooth out" or converge their divergent land use histories. The farmers and organizations participating in this project span urban and rural landscapes, with diverse land use histories from auto industry, to industrial farming, to oak savanna. We expect that agricultural production that focuses on soil conservation will interrupt these divergent histories, creating ecologically distinct soil profiles over time. 

Finally, it is important to again highlight the diverse coalition of farmers, community organizations, and land stewards participating in this project. The network of practitioners utilizing hand-scale, no-till techniques brings together diverse cultural backgrounds, racial identities, geographic locations, organizational structures, and economic models. What motivates these farmers, land stewards, and community organizations to put soil care at the center of their work? How does soil act as a medium for collective memory, action, and imagination?

We hypothesize that soil can act as a medium of translation. Many growers are turning to small-scale, low cultivation techniques because they believe that soil care is central to a better future. The soil forms a horizon; it holds a future that we can both look to, and stand upon. Each grower engages on diverse landscapes and cultural contexts, and yet they are all embedded in connected struggle against ecological ruination and social injustice. They are linked into networks of mutual aid, knowledge sharing, and collective governance. They seek to create biodiverse and productive landscapes that can nourish, heal, and serve as inspiration for social change. We hypothesize that these systems of land care are knowledge and labor intensive, utilized to overcome the confluence of economic, cultural, climatic, and technological challenges farmer's face. We hope to amplify and uplift collective theory of soil stewardship through a series of transect walks, interviews, and mixed media pieces that showcase farmer perceptions and praxis regarding soil. We anticipate that sharing these stories will deepen and enrich our understanding of how human-scale soil regeneration might be a seed for food systems transformation.

Materials and methods:

Definition of biointensive no-till 

The community of practice involved with our project described a common set of principles underlying biointensive no-till that includes but also goes beyond just reducing soil disturbance: recycling on-farm resources, maintaining soil coverage with composts and mulches, minimizing or eliminating tillage, and maximizing on-farm biodiversity. This community of practice converged specifically around a form of no-till agriculture that sought to minimize disturbance by utilizing hand labor over mechanization. Practitioners employed the soil health principles mentioned above primarily through hand labor. It is important to note that a wide range of systems are referred to as "no-till," some of which are highly mechanized, industrial, and rely heavily on chemical fertilizers and herbicides. No-till, in this network, refers to an organic and human-scale system of minimal soil disturbance, hand cultivation, maintaining root residues, and surface mulch application.

Preliminary on-farm research

As noted above, most of the on-farm research was delayed by one year due to the COVID-19 pandemic. Project partners at the Community Alliance with Family Farmers (CAFF) had been able to collect some soil samples from two participating farms, which has helped inform the broader on-farm research effort that is now ongoing. Soil samples were collected to 60cm depth across multiple till and no-till plot, the latter with various ages of management. Soil analyses focused on soil organic carbon.

In addition, our team members at UCB were able to conduct a preliminary analysis at a lighthouse community farm in our network, the Gill Tract Community Farm. In collaboration with the community, our team helped to evaluate soil organic matter stocks, texture, nematode community analysis, ACE protein index, and more from areas of different tillage and disturbance regimes. These findings were of immediate consequence to the community as they negotiated with university and city administration about the future of their land tenure. By engaging the community in soil health sampling and analysis that was of political consequence, we were able to engage dozens of community members in soil sampling techniques, metrics, and data sharing.

Synthesis of prior research station results

WSARE's support of our ongoing replicated field experiments allowed us to analyze and compile the findings from our field station experiment on biointensive no-till. During the summer of 2019 (prior to the start of this grant), our research team had simulated a possible drought scenario in which irrigation to our fields was terminated mid-growing season. This meant irrigating all crops at 100% evapotranspiration (ET) for the initial three weeks to ensure plant establishment, then cutting irrigation to 50% ET irrigation for two weeks, and finally eliminating irrigation entirely for the remainder of the season. For California farmers, this could be the outcome of power outages that terminate well pumps, catastrophic fires that force families to leave their property, or future water shortages due to drained aqueducts.

With support from this grant, we were able to synthesize results from that prior work during the period in 2021 when new on-farm research was delayed due to COVID-19.

The Soil Horizons Project: On-farm soil health analyses and farmer praxis

One critical arm of our research is now underway doing no-farm soil health analyses for 16 small (<3 acre) farms across California (Obj. 1). Our methodology centers farmer knowledge by conducting a series of farm "transect walks" and in-depth interviews to determine soil sampling frequency, location, and methods. These interviews followed the same script for every farmer. First, we asked them to explain their soil health ethos, and how soil health motivates their work as a farmer and land steward. We then asked the farmer to define soil health in their own words. Ultimately, we used this definition to explore the entire landscape of their farm together, determining locations on the landscape that represented the full range and diversity of soil health outcomes on the farm. From those transect walks and interviews we create soil sampling plans with corresponding maps that look like this:

sampling plan

In this way, each experimental unit within the study represents a unique region of soil health properties as defined by the farmer. Each experimental unit is paired with key management practices and systems used by the farmer, including "no-till", "cover cropping", "occultation", "hedgerow", and more. In order to bring ecological and natural science data into conversation with practitioner knowledge, we also asked farmers to rate each experimental unit along a series of Likert scales. This asked the farmer to rate each experimental unit's productivity, resilience to stress, cultivation intensity, tillage intensity, and likelihood of soil contamination. In doing so, we will be able to compare soil health outcomes with farmer perceptions.

Composite soil cores down to 100 cm depth are currently being collected from each experimental unit, and will be completed in May 2022. From there, we will be conducting the following analyses:

  • Total carbon, nitrogen
  • Particulate organic matter (POM), mineral-associated organic matter (MAOM) 
    • These methods may help determine the long-term stability of soil carbon
  • Plant nutrients (extractable P, K, Ca, Mg, Fe, Mn, Zn, Cu, B, S, Al)
  • Soil chemical and physical properties (pH, cation exchange capacity, base saturation, texture) 
  • Contaminants (heavy metals, PCBs, petrochemicals, pesticides, herbicides) 
  • Soil food webs (nematodes, collembolans, mites)
  • Soil water retention and infiltration

Praxis is the joining of theory and practice. In order to effect meaningful food systems change, agroecological research must look to the complex intersection of practitioner's methods and the ideas they have about those methods. Thus, in order to better understand farmer praxis and motivations, we have recorded and transcribed all interviews and transect walks with participating farmers. We will also be collecting photographs and videos from our engagement on their farms, including transect walks, soil sampling, future field days, and educational programs. These transcriptions and other media will be used to better understand the motivations and perceptions of growers practicing small-scale, no-till management.

What motivates these farmers, land stewards, and community organizations to put soil care at the center of their work? To answer this question, we plan to compile stories of farmer praxis into a series of short mixed media articles, meant to highlight each farm in the network and how soil informs, shapes, and motivates their work. When soil health datasets are complete farmer perceptions with soil health findings, creating stories of ecological and social networks. By placing farmers in conversation, with soil as the translating medium, we hypothesize a weave together how diverse cultures, geographies, racial identities, economic models, and visions converge in the care of soil. We are interested in using soil as a storytelling medium to reflect on collective memory, action, and imagination.

Comparing tomato dry farming between tillage systems

For Objective 2, the experiment was conducted at the University of California, Berkeley Oxford Tract Research Station, a 0.5 ha urban field site in Berkeley, California, USA (37.876187, -22.267345), during the 2022 growing season. The soil is a clay-rich Terra complex, with an average annual rainfall of 64 cm. In Fall 2017, a long-term field experiment was initiated to assess the multiyear effects of tillage and other agroecological management techniques on soil health (Rainey et al. in progress), as described in prior progress reports. The experiment was arranged in a split plot randomized block design with tillage system as the main plot, and winter cover as the subplot (the latter is not part of the current experiment so the focus will only be on the main plot). Given the small size of this urban research field, main plots were necessarily limited in size, at 30x1 m (i.e. one bed wide). Thus, we focus on changes apparent at this small scale, including soil biological and chemical properties, rather than changes that may only be seen with much larger experimental plots such as differential access to subsurface water and aboveground arthropod communities.

For this experiment, we used the main tillage plots (four replicate blocks) and added subplots for the genotype, with two or three levels (Early Girl, Momotaro, and Zapotec; OR 76R and rmc, see below), replicated four times within each main plot (Supp. Fig. 1). Thus, there were four experimental units for each tillage and genotype combination. 

Over the course of the growing season, measurements included tomato fruit yield and quality, soil water and nutrients, and plant physiological status.

 

Research results and discussion:

Analyzing and compiling preliminary results from partner farms

One of the research findings from preliminary work with two partner farms was that soil carbon levels were significantly greater in each farm’s no-till plots than their control plots at both the soil surface (0-15 cm) and subsequent soil depth (15-30 cm) (Figure 1). Furthermore, total carbon levels were not just greater in the no-till plots, but specifically the older no-till plots included in the research project. In other words, the longer the no-till practice had been established, the greater the soil’s carbon concentrations were. The positive sloping lines drawn through the green dots in the graphic to the left are visual representations of these findings.

Figure 1

Our on-farm trials and field experiments revealed rapid shifts in soil health indices and ecological functioning under no-till management. Some of the most striking features of these results have been in soil structure and hydrology, fungal community structure, and soil carbon cycling. 

Soil structure and hydraulic properties changed by farming system, with tillage negatively affecting gravimetric water content at all depths (ANOVA, F=16.5, p=0.00015), and cover cropping increasing water content by as much as 30%, especially at deeper soil depths (at 50 cm; ANOVA, F=5.6, p=0.021) (Fig. 2). Soil structure, here expressed as pore size distribution derived from a soil water retention curve, changed significantly with farming system in the second but not the first year (Fig. 2).

This could be explained by a shift in pore architecture, a unique and powerful finding that could drive many of the ecological shifts demonstrated in this paper. Figure 2 illustrates the shift in pore size distribution between 2018 (top) and 2019 (bottom). In the first year of implementing no-till management, while there were some minor changes in the total amount of water held in the soil profile, the distribution of pore classes did not change significantly. In 2019, just two years after the implementation of no-till management, the data is quite different. Minimizing disturbance and introducing winter cover crops shifted the soil matrix towards a relatively larger population of smaller pores, more effective at retaining plant-available moisture during severe conditions. Meanwhile, conservation tillage combined with continuous crop production began to shift pores in the opposite direction, opening up larger pores that freely drain or evapotranspire more easily. This physical shift in soil structure was realized in a relatively short time frame, with significant implications for water conservation, reduced irrigation, and more. Pore size mean, median, and mode were all demonstrably larger in tilled systems, illustrating the physical creation of soil cavities by the tractor during tillage. 

This figure illustrates soil hydrologic and structural changes under no-till.[Figure 2. Soil hydrological properties, demonstrating a) soil moisture content at four depths (5 cm, 15 cm, 30 cm, and 50 cm), showing higher quantities of water stored under no-till management and b) pore size distributions evaluated in 2018 and 2019, showing a rapid shift in pore architecture between the first and second year of the study. The bottom-right quadrant illustrates a shift towards small pores in low disturbance, cover cropped systems and demonstrates a physical mechanism for observed changes in soil properties.]

 
 
 
 
 
 
 
 
 

Fungal species richness within the soil was clearly influenced by management; both observed (F=4.9, P=0.03) and Chao1 (F=3.5, P=0.0740) richness indices were estimated as higher in continuous crop production systems, as illustrated in Figure 6. Fungal diversity was also found to be higher in the soils of high-disturbance systems, as estimated by the Shannon index. Shannon’s index accounts for species evenness, or the degree of spread in population count across the total list of species within a particular population. Keeping all else the same, higher degrees of species evenness within the soil fungal populations led to a higher Shannon index, likely driven by the homogenization of the soil profile by tillage. This demonstrates a complex interaction between disturbance, cropping system, and soil fungal species richness and diversity, with continuous plant cover emerging a key driver of fungal species richness regardless of differences in disturbance. And despite management driving fungal community structure in the soil, fungal communities within crop root systems demonstrated less pronounced response to management, with inconclusive patterns in indices of species richness and diversity. This suggests a selection bias on the part of plant roots, especially during periods of severe stress such as a drought. 

AMF community composition and colonization.

[Figure 3. Relative abundances of a) arbuscular mycorrhizal fungi (AMF) at the species level, and b) plant pathogens in the soil fungal community at the genus level, both divided by soil management system. Changes in the AMF communities between no-till and tilled systems are stark, with a shift from Claroideoglomus to higher relative abundance of Rhizophagus and Funneliformus species. There is also a significant difference across cropping systems even within no-till plots, demonstrating the influence of crop cover and crop residue recycling methods on mycorrhizal partners. These changes in the AMF ASVs found through molecular methods corroborates the low colonization counts under the no-till, cover cropped treatment. Meanwhile, soil management also had a measurable influence on fungal plant pathogens living in the soil, specifically an enrichment in the genus Cylindrocarpon, a large family of pathogens that cause root rot. Higher rates of fungal root damage were observed during the implementation of the project; these data confirm observations at the study site of plant pathogen pressure with conversion to no-till.

The relative abundance of AMF, plant pathogenic, and soil saprotrophic ASVs were all influenced by soil management system, with distinct assemblages of these fungal trophic groups across each treatment. Changes in the AMF communities between no-till and tilled systems shifted from Claroideoglomus to higher relative abundance of Rhizophagus and Funneliformus species. There is also a significant difference across cropping systems even within no-till plots, demonstrating the influence of crop cover and crop residue recycling methods on mycorrhizal partners. These changes in the AMF ASVs found through molecular methods corroborates the low colonization counts under the no-till, cover cropped treatment. Meanwhile, soil management also had a measurable influence on fungal plant pathogens living in the soil, specifically an enrichment in the genus Cylindrocarpon, a large family of pathogens that cause root rot. Higher rates of fungal root damage were observed during the implementation of the project; these data confirm observations at the study site of plant pathogen pressure with conversion to no-till.

This data is contextualized by arbuscular mycorrhizal fungi (AMF) colonization, which was most influenced by cropping system (F=7.6, P=0.01767 ), with colonization rates in the continuous, no-till farming system double that of the other systems (Figure 3). This, coupled with the changing AMF communities between farming systems, strongly suggests an ecological shift in the fungal symbionts recruited by the crops while under stress.

Soil organic carbon (SOC) increased by 207% (at 5 cm) and 47% (at 15 cm) after two years of implementing the hand-scale no-till system, with tillage systems (ANOVA, F=18.5, p<0.0001) driving changes in soil carbon stocks (Fig. 4). Carbon stock increases were more modest at depth, but were still increased by hand-scale no-till systems, including increases from 6.5 Mg C/ha with tillage to over 8 Mg/ha under no-till at 30-50 cm. Size-based fractionation of the soil revealed higher carbon stocks in all size fractions (2 mm-250 um, 250 um-53 um, 53-20 um, <20 um) when soils were managed for minimal disturbance. Higher mass percent of carbon in mineral associated fine fractions (<20 um), along with lower rates of carbon cycling enzymes in those same fractions, is possible evidence for improved soil C storage by mineral association under no-till management. While compost application can account for relative changes in soil carbon quantities by management system, it does not necessarily explain a shift in the division of soil carbon across particle size within those systems. This phenomenon, coupled with changing potential enzyme activity within classes of soil pores and changing pore architecture (reported below), suggests a shift in carbon cycling that results from minimizing soil disturbance.

Ammonium and nitrate were twice as high under no-till systems with continuous production, emphasizing the control that continuous crop cover and compost application have on plant-available N supplies. POXC, a form of labile carbon that readily reacts with oxidizing agents in the soil, also had the highest concentration in no-till systems, with an average 55% increase in permanganate oxidizable carbon from baseline in no-till plots. Meanwhile, tilled systems were depleted in labile carbon stocks from baseline by an average of 145%.

Soil carbon

[Figure 4. Total organic carbon (TOC), mineral-associated organic matter (MAOM), and particulate organic matter (POM). Total organic carbon was 2-3 times higher under more intensive farming systems. Of significant interest are the modest increases at 50 cm depth, from about 3.25% to almost 4.5% under no-till. MAOM is a measure of fine particulate organic matter (<53 um) that is likely to be bound to mineral surfaces, decreasing the likelihood of its degradation by microorganisms. POM includes larger pieces of organic matter (>53 um) and include plant residue, partially decomposed material, and more chemically recalcitrant particles.] 

Comparing tomato dry farming between tillage systems

Tillage did not significantly affect marketable tomato yields or quality, nor significantly affect plant physiology including plant water use efficiency (intrinsic [WUEi] and long-term [δ13C]), gas exchange, stem water potential (Ψstem) and leaf relative water content (RWC). Early Girl produced significantly greater number of fruits and fewer non-marketable fruits (<6%) than Momotaro and Zapotec. AM fungi root colonization was very low for both 76R and rmc but differed significantly depending on genotype and tillage treatment. 76R produced slightly greater marketable fruit, but physiological responses did not differ significantly between genotypes.

This study provides field-based evidence that genotype has a greater impact on dry farmed tomato yield and plant attributes than site management. After five years of agroecological management and soil health improvements, tillage did not significantly influence dry farmed tomato marketable fruit yields. Genotype had a greater influence than tillage on tomato fruit quality and yields for the indeterminate tomatoes. While the grower standard, EG, had greater fruit yields than M and Z, fruit quality as represented by fruit Brix and moisture did not differ significantly between the three. Overall, Early Girl was a superior genotype, with future research needed to investigate the dry farming potential of other hybrid and heirloom genotypes. To optimise dry farming productivity as a meaningful option for food production in drier climates, strategies that increase and retain soil moisture should be combined with selection of drought tolerant, water efficient vegetable varieties.

Dry farmed fruit quality

[Figure 5. Mean fruit yield per plant for each harvest of the indeterminate tomato genotypes Early Girl (EG), Momotaro (M), and Zapotec (Z), grown with either biointensive no-till (NT) or tilled (T) soil regimes under field conditions. The first harvest occurred at 80 DAP on 29 July 2022. Shown are observed means ± se (n = 4). Means, error bars, and lines have been slightly dodged horizontally to avoid overlapping and for better visualization.]

 

 

 

 

 

 

 

 

Participation Summary
16 Producers participating in research

Research Outcomes

1 Grant received that built upon this project
15 New working collaborations

Education and Outreach

16 Consultations
2 Curricula, factsheets or educational tools
4 Journal articles
12 On-farm demonstrations
12 Online trainings
1 Tours
7 Webinars / talks / presentations
12 Workshop field days

Participation Summary:

630 Farmers participated
75 Ag professionals participated
Education and outreach methods and analyses:

Consultations

Transect walks, interviews, and soil health evaluations with:

  • Acta Non Verba (Oakland)
  • Agroecology Commons (El Sobrante)
  • Berkeley Student Farms (Berkeley)
  • Canticle Farm (Oakland)
  • Deep Medicine Circle (Pescadero)
  • Feral Heart Farm (Sunol)
  • Gill Tract Community Farm (Albany)
  • Hillview Farms (Lincoln)
  • Kern Family Farm (North Fork)
  • POOR Magazine (Oakland)
  • Red H Farm (Sebastopol)
  • Singing Frogs Farm (Sebastopol)
  • Sogorea Te’ Land Trust (Oakland)
  • Urban Tilth (Richmond)

Curricula, factsheets or educational tools

Syllabus, Spring 2021, "Agroecology in Action: Food Sovereignty and Land Liberation," Berkeley Student Farms Democratic at Cal (DeCal)

Syllabus, Spring 2022, "Agroecology in Action: Food Sovereignty and Land Liberation," Berkeley Student Farms Democratic at Cal (DeCal)

  • Both these syllabi included weekly practicals and workshops, including no-till management, soil health, bed preparation under no-till, crop planning for agrobiodiversity, and more.

Syllabus, Soil Fertility Module, Bay Area Farmer-to-Farmer Training (BAAFT), Agroecology Commons, Summer 2022

  • Development of this syllabus included contributions to the Soil Fertility Module and practical hands-on learning activities at Agroecology Common's demonstration farm.

CAFF Biointensive No-till Webpage

    • Includes project updates from CAFF’s no-till project, basic information about biointensive no-till systems and instructions for joining the Biointensive No-till google group.

On-farm demonstrations

Workshop, "Agrobiodiversity and plant propagation in a no-till garden," Center for Food, Faith, and Justice, February 2022.

  • We conducted a workshop on plant propagation in no-till farm and garden contexts in partnership with the Center for Food, Faith, and Justice. This was part of their Bay Area Farmer Training program in partnership with MESA, the Multicultural Exchange for Sustainable Agriculture. Evaluations were conducted on-site at the end of the workshop. Participants were asked to share reflections on what they learned about plant propagation, and all participants reported learning new methods for plant propagation.

Workshop, "Soil health in school gardens," Verde Elementary School, Urban Tilth

  • Members of our team collaborated with Urban Tilth to put on an educational workshop at Urban Tilth's Verde Elementary School site. We worked with 6-8 graders, leading soil science demonstrations to illustrate the importance of soil organic matter.

Bay Area Farmer-to-Farmer Training (BAFFT), Summer 2022, Summer 2023

  • Completed 8 on-farm demonstrations as part of training program, at Red H Farm, Scott Family Farm, Namu Farm, Urban Tilth, Feral Heart Farm, Cultural Roots Nursery, Agroecology Commons educational farm, and Raised Roots. Each of these on-farm demonstrations had different core learning objectives, from soil health and monitoring, to tractor use and implementation, to hand-scale cultivation, to nursery management. More in-depth assessment of this large part of our on-farm education is below.

Workshop, “Holistic Soil Management,” Healthy Hearts Institute, November 2023

  • In collaboration with the Contra Costa County Resource Conservation District and Agroecology Commons, in November 23 we hosted a practicum on soil health and soil testing. This was part of a series entitled “Roots to Fruits: Farm Resilience Workshop Series.” We have 65 participants from farms across the East Bay, with practical time spent augering soil samples and discussing sampling density, spacing, depth, etc. as well as tips for assessing soil health. 

Workshop, “Soil As Teacher: Preparing the Ground for Agroecology,” UCSC Center for Agroecology, August 2023

This event was a collaboration among the Agroecology Lab at UC Berkeley, the Center for Agroecology, CAFF and Agroecology Commons. We hosted a 5 hour participatory workshop which included a farmer panel and skillshare, questions and discussion with attendees, a networking lunch, a hands-on soil health activity and tour at the UC Santa Cruz Farm and finally a demonstration of aggregate stability. Throughout the day topics discussed included: the values at the core of soil health practices, connections between land stewardship and community, and lessons learned around implementation and adapting practices including no-till, on-farm composting, fermentation, perennializing and seed saving. The panel included both urban and rural farmers and others who participated in the no-till research conducted throughout the project: Kern Family Farm, Gill Tract Community Farm, Deep Medicine Circle, Berkeley Food Institute and Agroecology Commons. The hand-on soil health activity on the UC Santa Cruz farm engaged participants in assessing impact of different soil health practices on soil over time, looking at soil pits in four different fields. (85 attendees)

Online Trainings

"Soil Health Report-back for the Gill Tract Farm Coalition", Gill Tract Farm Coalition, December 2021

  • This event was held online in December 2021 for the diverse members of the Gill Tract Farm Coalition, and included 20 participants throughout the course of the training. Community members and farmers who participate in the Gill Tract Community Farm were asked to reflect on and analyze preliminary soil health findings conducted in the May 2021. Gill Tract has been implemented an intensive no-till system since 2012, modeled after other farmers in our network including Singing Frogs Farm. In a post-survey, participants shared enthusiastically about the opportunity to analyze soil health data as a community, and learn more about soil sampling and testing. When asked about particular topics they learned more about, responses included phrases like, "Urban soil is not as bad as I thought," "I learned what nematodes are!" and "That a ton of phosphorus can decrease uptake of other nutrients." 

Webinars, talks, and presentations

Webinar, The Agroecological City, "Ancestral healing through food and land stewardship," Berkeley Food Institute, March 2, 2021

Webinar, The Agroecological City, "Strengthening agroecological resilience in the city," Berkeley Food Institute, March 10, 2021

Presentation, EcoFarm, "Digging into the Research of Small-Scale No-Till Farming Systems," February 22, 2021

Webinar, EcoFarm, "Digging into the Research of Small-Scale No-Till Farming Systems," June 1, 2021  

  • Ongoing feedback was collected from these webinars and presentations through the creation of our "biointensive no-till" listserv, which now has over 200 members. 150 farmers and others work in food systems joined this online community after participating in our online webinars and presentations!

Online Panel discussion, CAFF Small Farm Conference, “Small Scale and No-Till”, Elizabeth Kaiser (Singing Frogs Farm), Michael Whammond (Hillview Farms), Alayna Reid (Deep Medicine Circle), Cole Rainey (UC Berkeley), Sara Tiffany (CAFF), February 28, 2022 (96 attendees)

Online Panel discussion, CAFF Small Farms Conference, “Unpacking Soil Disturbance: the Ecological & Management Implications of Till & No-till Systems”, Tim Bowles (PD) and Sara Tiffany (co-PD)Tim and Sara - panel with CAFF at Small Farms conferenceconferencev February 27, 2023 (199 attendees)

Online Panel discussion, CAFF Small Farm Conference, “Small Scale and No-Till”, Elizabeth Kaiser (Singing Frogs Farm), Michael Whammond (Hillview Farms), Alayna Reid (Deep Medicine Circle), Cole Rainey (UC Berkeley), Sara Tiffany (CAFF), February 28, 2022 (96 attendees)

Online Panel discussion, CAFF Small Farms Conference, “Unpacking Soil Disturbance: the Ecological & Management Implications of Till & No-till Systems”, Tim Bowles (PD) and Sara Tiffany (co-PD)Tim and Sara - panel with CAFF at Small Farms conferenceconferencev February 27, 2023 (199 attendees)

Day-long Presentation, EcoFarm, "Can Organic Farms Transition Soils into Low Disturbance Tillage Without Sacrificing Yield?", January 17, 2024

Education and outreach results:

Bay Area Farmer-t0-Farmer Training

Our subaward grantee, Agroecology Commons, successfully graduated 42 participants of the Bay Area Farmer-to-Farmer Training  (BAFFT) that took place between June-August of 2022. Agroecology Commons’ Bay Area Farmer to Farmer Training (BAFFT) weaves relationships of land stewards committed to food sovereignty. Our program facilitates on-farm agroecological training and mentorships between experienced and beginning farmers from BIPOC, gender-marginalized, poor, queer, and working-class backgrounds. BAFFT provides opportunities for localized food production by training farmers and supporting existing farmers within Northern California. The WesternSARE grant-supported modules focused on holistic soil stewardship and no & low-till farming. Topics included, but were not limited to: soil fertility, compost, microbes, benefits of cover cropping and different cover cropping techniques, no-till farming principles, linking soil health to human health, mycoremediation, soil testing, and contamination. Guest educators that contributed to these modules included; Aidee Guzmán, soil ecologist and agroecologist (bio) and Jibril Kyser, peasant farmer at Te Kwe A’naa Warep Farm (bio). You can view photos from this summer’s Bay Area Farmer-to-Farmer Training here. Throughout the entirety of the course, participants visited a network of farmers across Northern California every Saturday to partake in on-farm demonstrations and hands-on learning to develop different skills and techniques for holistic soil management. This network of farms included; Soul Flower Farm, Raised Roots, Feral Heart Farm, Scott Family Farm, The Goat Wild Collective, Red H Farm, Cultural Roots Nuersry, and Deep Medicine Circle.

In our evaluations, there were key areas in which farmers/program participants reported changes in knowledge, attitude, skills, and/or awareness were identified. 100% of graduates that filled out the final course evaluation noted that this program helped build their skills in agroecology and land stewardship. A 100% of survey participants noted that they also felt more equipped to pursue aspirations connected to agroecology and land stewardship. Lastly, 100% noted that they feel more connected to a network of like-minded farmers and land stewards.

Farmer Mobilization Program 

Agroecology Commons exceeded the project objectives when it came to the Farmer Mobilization paid apprenticeship program portion of this grant. The first cohort of apprentices included four participants partaking in a 200-hour apprenticeship across 3 farms including, Feral Heart Farm, Scott Family Farm, and Red H Farm. While our launch date started later than we had anticipated for the second cohort of apprentices we were able to exceed our outreach goals and now have thirteen apprentices being mentored by nine different farmers. The host mentor farms represent a diversity of production modules, including but not limited to, mid-scale rural farms, plant nurseries, livestock production, urban farms, etc. Host farm mentors include; Soul Flower Farm, Kula Nursery, Raised Roots, Feral Heart Farm, Scott Family Farm, The Goat Wild Collective, Red H Farm, Cultural Roots Nuersry, and Berkeley Basket CSA. The delay in launching the second cohort of apprentices (which ended up taking place in March 2023) was due to various factors including, extreme weather conditions in Northern California that caused multiple farm sites to flood, re-assessment of farmer’s needs to support spring plantings, and an extended program development period to allow for more direct and hands-on apprenticeship support. Through our enhanced program development, we were able to amplify our program offerings to include individualized learning plans for apprentices, increased 1:1 farm visits with host mentor farmers and apprentices, apprenticeship guidebooks for both mentors and apprentices and an independent learning stipend component for both farmers and the apprentices. We were also able to increase our payment for both apprentices and farmers as well as increase the apprenticeship length to 500 hours with the support of additional funding.  By pushing back the start date for the second group of apprentices, Agroecology Commons staff was able to receive professional development training by partaking in the NIFTI Farm Field School Training in October 2022. During this conference, peer-to-peer sharing informed beginning farmer trainers about how they run successful incubator and apprenticeship training programs. Partaking in this training greatly enhanced our program offerings for both apprentices and host farm sites. While the second cohort of apprentices is still underway we have collected the following quotes and data from the first cohort of farm apprentices. When asked to rate on a scale of 1-10 the value of their farm apprenticeship experience in relation to deepening their knowledge of agroecology, all evaluation participants reported 10. 100% of participants noted that, if it were available, they would have participated in a longer commitment as a paid apprentice. This data informed our decision to increase program offerings for the second cohort.

Soil As Teacher Event 

 

Summary and Takeaways

The Soil As Teach Event successfully brought together multiple institutions to host a participatory event centering farmers as well as engaging underserved students from University of California. The farmer panel set the tone of the event by inviting farmers to share experiences around soil health and land stewardship. Breaking into small groups allowed for attendees to share their own experiences and engage in knowledge exchange with fellow farmers and students about the benefits and challenges of implementing different soil health practices. Small group discussions lead into a networking lunch where attendees continue to build on conversations and make connections with fellow farmers. The second half of the day featured a hands-on soil health activity and tour on the UCSC farm and garden. Breaking in small groups, UCSC Farm staff lead farmers and students through several fields (each containing a soil pit) that had undergone different soil health management, including: 1) organic no-till vegetable production, rangeland, 2) cover crops, 3) garden scale double digging and intercropping and 4) tractor scale organic vegetable production with tillage. The last activity of the workshop included a soil aggregate stability (slake test) led by UCCE, showing the aggregate stability of soils under differing management systems (no-till, till, conventional, organic, etc).

Attendance for the event included 70 farmers and 15 students. Despite this turnout, only 33 attendees filled out the evaluation survey. While demographic information was not collected through the survey, faculty at UCSC shared that majority of the15 UC students invited to attend come from “historically underserved” communities.

Event evaluation surveys found that 70% of respondents indicated that they would either “definitely” or “likely” adopt soil health practices discussed during the workshop. Among survey respondents that answered they were “unlikely” or “uncertain” about adopting soil health practices, 75% indicated they needed more information, 50% claimed it would be difficult to integrate into their current management system and 25% claimed it would be too costly. When asked to choose 2-3 preferred sources of information about agricultural practices, 84% of responses preferred other farmers and land stewards and on-farm demonstrations; 33% preferred the internet while 27% preferred local technical assistance providers. When asked how this workshop and demonstration affected likelihood of adopting soil health practices or principles, 93% answered they are more likely to adopt.

Selected quotes from Soil As Teacher Evaluation Surveys:

“Nice to see concrete proof of soil health practices in slake test”

“Already using some practices, and excited to implement new ones!”

“I have been energized”

“Likely to apply new knowledge”

Education and Outreach Outcomes

150 Producers reported gaining knowledge, attitude, skills and/or awareness as a result of the project
Key areas taught:
  • No-till principles, practices, and challenges
  • Soil health metrics and on-farm evaluations
  • Land-based education and pedagogy
  • Soil sampling, soil health outcomes under no-till
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.