Fashioning Amendments and Seeding Techniques to Rebuild Essential Genera of Endophytes and other soil Nutrient mobilizers (FAST REGEN)

View the project final report

Commodities

• Agronomic: corn, peas (field, cowpeas), wheat
• Additional Plants: Camelina

Practices

• Crop Production: cover crops, seed saving
• Soil Management: soil microbiology, soil quality/health
• Sustainable Communities: local and regional food systems

Geopolitical conflict, supply chain problems, high fuel and fertilizer prices, or legislative reactions to climate concerns could cause Western farmers to suddenly need to work without synthetic fertilizers and herbicides. Farmers could respond to this existential risk with a regenerative agriculture approach, planting dense, diverse cover crops to suppress weeds and rebuild soil microbial activity and soil organic matter (SOM). However, rapid transitions are challenging and socially dangerous, as recent Sri Lankan experience demonstrates.

Residual herbicides and a dearth of appropriate symbiotic microbes may impair cover crops. Adding compost to improve microbial activity and SOM is expensive and logistically difficult at scale. Farmers consequently transition infrequently and gradually from conventional to regenerative soil management.

A robust microbial community can “learn” from repeated exposures to efficiently metabolize herbicides. Emerging cover crop roots should carry and nourish a symbiotic microbial community throughout the topsoil. Theoretically then, planting diverse cover crops with supportive microbes might clear herbicide residues, smother weeds, add SOM, and create a microbial community that can support a subsequent cash crop. An ideal combination would allow farmers to make a fast regenerative agriculture transition, over a single winter.

FINAL REPORT (updated January, 2026): 

Brief results:

1. Anti-herbicide compost was not required for 2,4D, glufosinate, and glyphosate. Cover crop seeds planted into plots treated several weeks earlier with these herbicides grew into viable plants, with or without anti-herbicidal support. In contrast, atrazine sprayed on soil had prolonged negative effects on a variety of seed pellets. 
2. We estimate the half life of atrazine in the anti-herbicide compost at 24 days: although relatively fast, this rate of degradation was not fast enough to clear toxic doses of atrazine from seed pellets in the time we allowed. A precise calculation of half life and comparison of atrazine degradation in control versus anti-herbicide compost is pending. Anti-herbicidal compost was not a sufficient treatment for a plot treated with a full dose of atrazine several weeks earlier. Seeds germinated, then young plants died, with or without the anti herbicidal treatment.  An additional field trial in very poor soil crossed 100% to 1.5% of standard atrazine doses (simulating 0 to 6 half lives passing since the last atrazine spray) with diverse seed pellets made with anti herbicidal compost, anti herbicidal compost leachate, or water. Radish, pea, wheat, and camelina/clover seed pellets generally failed to establish. 
3. The clays available to manufacture seed pellets present difficulties for large scale implementation of the FAST REGEN concept. Clay pH can be too alkaline, seed pellets can be too fragile, and pea seeds in particular are likely to swell and break a pellet while it is drying. Some clays make pellets that are too fragile (e.g. Surround WP). Some significantly impair seedlings (e.g. Volclay, a sodium bentonite product). Cat litter would be great if it were a powder. Frustrated with available bulk options, we primarily used an expensive seed ball clay purchased on Amazon. 
4. Pea and camelina plants did not do well in the field. Both were sparse enough to actually try counting survivors in 24 plots of 400 square feet, which is a bad sign. Wheat was much more abundant, but unlike the robust wheat plants that grow in rich soil, the wheat plants in the field were relatively skinny. The poor cover crop cover had multiple unfavorable consequences. First, there were not enough legumes to fix enough nitrogen to feed the subsequent corn. Second, the cover crop biomass was meager. Third, the shading of weeds was incomplete. Fourth, with diverse grasses in the field, there was not a time where all of the grasses were at an appropriate stage to terminate by crimping. 
5. We attempted to pamper seed crops in parallel small plot trials on herbicide-free soil, and had similar results. Although we experienced drought, which delayed germination and probably increased predation of seed pellets, more favorable conditions still did not really a rich cover crop. 
6. In retrospect, we could have included a dwarf clover as a legume, and freeze-susceptible radishes as a brassica. The radishes would add organic matter to the field even though most would die over winter. Clover might have added more nitrogen than the peas. However, as mentioned in point 2, a small trial including clover and radishes was also unimpressive. 
7. Pig manure plus glyphosate did better than the seed pellet trials, but ears of corn were smaller and poorer quality than the urea-fertilized crop. Elemental analysis of corn kernels fertilized with pig manure was unremarkable, and in particular did not show a significant decrease in nickel levels. 
8. We incidentally created an auspicious corn stand on two plots that had been managed regeneratively for 3 years. Weeds were crimped about 2 weeks before planting and covered with 1/2 inch of compost immediately before drilling. Two months later, local farmers estimated that these plots were 6 weeks ahead of other corn planted at the same time, and were larger and greener than conventionally managed fields. 

We did not succeed in creating seed pellets that established cover crops in poor soil. Seed pellet components, atrazine persistence in soil and anti-herbicide compost, and baseline soil degradation were all potential contributors to poor results. A SLOW REGEN program entailing 3 years of on site composting followed by weed crimping and planting corn into freshly spread compost was far more successful than the FAST REGEN strategy or more conventional NPK fertilization. 

This 2-year, 2-farm research project tested use of a mix of three cover crops – winter wheat, Austrian peas, and winter camelina – and three supporting biologic concepts to replace herbicide and chemical fertilizer in commercial field corn production.

Concept 1: Anti-herbicide compost

To remove herbicide residues that might impede cover crops, in year 1 we attempted to cultivate microbial metabolizers of atrazine, 2,4-D, glufosinate, and glyphosate in compost. We mixed deciduous leaves and spent coffee grounds in a 21 cubic foot ComposTumbler®, inoculated with herbicide treated soil and standard compost. Herbicide exposure began on June 15, 2023 at 6.25% of standard application rates for 10 cubic feet of 6-inch-deep topsoil after several weeks of composting, and doubled every 7-14 days for 6 weeks, reaching 200% on August 14, 2023. A ~2 cubic foot tumbler was maintained in parallel with similar feedstocks but without herbicide exposure. We conducted a variety of field studies and laboratory assays to assess the ability of the compost to degrade herbicides. We found that atrazine was by far the most relevant of the 4 herbicides, and concentrated efforts on mitigating its effects on cover crops.

Concept 2: Epigenetic adaptation

We planted commercially purchased winter wheat, Austrian pea, and winter camelina seeds in monocultures on regeneratively managed, herbicide-free plots in the fall of 2022 for both seeds and bacterial inoculants. The seeds collected from these plants in the summer of 2023 should have locally relevant genetic traits and epigenetic adaptations (GNE19-028). Wheat seeds were collected by combine from a commercial field. Peas and camellia were collected by hand from experimental plots. We did not specifically compare the biomass production of locally grown cover crop seeds to commercial seeds, but only used local seeds. 

Concept 3: Symbiotic composts

We composted plant tissues (e.g., panicles, chaff, non-viable seeds, root samples) and soil from the monocultures to obtain crop-specific endophytic bacteria and other beneficial microbes. We inoculated leaf-and-coffee compost in crop-specific 18 cubic foot Rubbermaid® compost bins. These composts were incorporated into seed pellets, and used directly as a soil amendment in 3 test plots. In parallel, we began growing cover crops over winter in compost. In retrospect, composting a cover crop in a fresh pile is likely to select for organisms that decompose the crop, while growing the cover crop in a nearly finished compost pile might create a rich ecosystem replete with endophytic bacteria and other microbial symbiotes relevant to growing the cover crop. We did not directly compare these two composting strategies, but have shifted to the second. Note that the seeds from a cover crop grown in compost are viable but not epigenetically adapted to growing on poor soils. This step is expected to generate locally tailored symbiotes but not tailored seeds. 

Biochar

We produced biochar from brush piles using Ring-of-Fire flame-capped kilns, and sifted it through hardware cloth and wire mesh to obtain different grades, including dust-like ultrafine and coarse (¼ to ¾ inch) grades. The pH of our biochar is consistently higher than 9, and can be 10-11, even after extensive rinsing, and requires neutralization if it is a prominent component of an agricultural project. Ultrafine biochar was incorporated into seed pellets (see below), while coarse biochar was treated with compost leachate and used as a soil amendment in 3 test plots. Typically, biochar should be loaded with nutrients and microbes before application to soil, to limit adsorption of nutrients already in the soil. 

Seed Pellets

In the fall of year 1 we manufactured separate seed pellets (a single seed with a protective and/or nourishing coating) with winter wheat and peas as nuclei. Camelina seeds are too small to use as nuclei of seed pellets and therefore were added as an outer layer to pea or wheat seed pellets, or to clay pellets, creating a seed bomb (a ball with a lot of seeds). We tumbled seeds in cement mixers without mixing paddles, with powdered clays, sifted generic compost, symbiotic and/or anti-herbicide compost tea, and biochar in various combinations.  We conducted a limited test adding radishes and clover as compliments to wispy camelina and peas with low uptake. We conducted a number of field trials and smaller performance tests on seed pellets and seed bombs to evaluate resilience and plant establishment.  

FAST REGEN

We began a block randomized experiment on 0.4 acre of a 2-acre field to compare 8 treatments’ effects on soil chemistry, herbicide residues, and microbial activity in 2023; planning to evaluate cover crop mass, field corn yield. and elemental composition in 2024. We also spread composted pig manure over about 0.2 acres, and managed the remainder of the 2-acre field with conventional fertilizer. Due to significant weather problems, we  performed some experiments using seed starting trays and pots, and planted multiple additional plots to evaluate the individual concepts at smaller scale. Four of the small scale plots were in line with a pair of "Slow Regeneration" plots that have been treated with large amounts of compost for years: these organically managed plots were crimped and planted along with the small FAST REGEN plots as a matter of convenience, and are included in comparisons.  

We terminated cover crops with a small roller crimper shortly prior to corn planting in year 2. Field corn planting and harvest then proceeded as usual.

FAST REGEN diagram 2022.12.01

Objectives

1. Confirm that exposing compost to herbicides accelerates its herbicide decomposition capacity before and after application to soil.
2. Compare growth rates of cover crops with and without endophyte enrichment and anti-herbicidal treatments, using locally adapted seeds
3. Describe trade-offs in complexity and expense versus effectiveness of 8 treatments for improving field corn yields and soil health measures, and compare with conventional management.
4. Share findings through field days, video and print publications, and local conferences.