Practices: Occultation, cover crops, compost, field borders, reduced tillage, companion planting, crop rotation

Mary Jean Russell runs Pickalittle Farm, a diversified vegetable operation in Bakersfield, CA. She provides organically-grown vegetables and herbs to local restaurants and to CSA members. She started growing food in 2000, on the 3 acres of land surrounding her house. 

She started implementing conservation practices in 2004 to save money and labor. The goal is to promote a healthy soil that produces nutritious food while minimizing costs and labor. To that end, she's developing a closed-loop system to reduce expensive external inputs. She's even found that weeds encourage beneficial insect populations. She calls her cocktail of cover crops, compost, and animal manure a bone broth for the soil, since it adds nutrients and organic matter to keep the soil healthy. 

Last year, she expanded her operations to a 14 acre parcel on the edge of town. She currently farms on about 4 acres of the new property.

Black plastic tarps provide weed control

Practices

The first climate smart practice Mary Jean implemented on her farm was spreading compost. She then stopped spraying herbicides and insecticides and reduced her tillage. Then she started planting cover crops. 

Mary Jean puts down tarps to reduce her weed population without resorting to herbicides or intensive tillage. This process is called occultation.

Black plastic covers the ground for a couple weeks and kills the growing weeds. She then takes the tarps off and irrigates the plot to encourage more weed growth. Once the new weeds have sprouted, she covers the area with the tarp again to kill off the nascent weeds.  

This process worked well in the plots where she's already gone through the entire process and planted crops. The row of summer squash she planted enjoyed an almost weed-free plot – without any hand weeding, flaming, or tillage! 

Zucchinis enjoy a weed-free bed

Effects

Yield effects

She started seeing increased yields at her first farm after about 1 year of compost applications and no sprays. The insects and soil started to balance out and she saw an increase in food quality. 

Pest effects

Mary Jean has seen an increase in earthworms and other beneficial insects. The first year of not spraying insecticides at both her original farm and her new property saw huge swings in pest populations – a boom and bust cycle of pests like earwigs and flea beetles. 

Erosion effects

She has found that dust devils that come onto the farm quickly die out because the weeds in the non-farmed areas, the cover crops, and the crops keep the soil covered. All these plants reduce the amount of dust that is available for the wind to pick up, so dust devils have to slow down and even stop when they get to her property. 

Water consumption effects

She is working on reducing her water consumption and hopes that all the work that she is doing to increase the soil's organic matter will increase the soil's water holding capacity. Once her tomatoes start to fruit, she turns off the irrigation. This keeps the tomatoes from splitting and intensifies the flavors. She also has started planting cover crops like radish and sorghum to improve the soil's infiltration rates. 

Effects on overall profitability

She does not buy sprays and does not have to apply for a pesticide applicator license. This saves her both money and time, since she doesn't have to deal with the paperwork or the continuing education credits she would need if she were farming conventionally. Plus she doesn't have to buy the specialized equipment for spraying insecticides or herbicides. Instead, she spends about $2,000 per half acre plot every 18 months to reduce her weed pressure by doing occultation and cover crops. This cost is less than what she would spend if she were farming conventionally. 

Flowering plants attract a variety of insects

Rows of flowers and herbs bring much-needed biodiversity to the farm

Planting basil near the vegetable crops promotes pollinator and beneficial insects

Recommendations

Mary Jean explained that there is a steep learning curve when implementing these practices. You have to understand the specific conditions of your field. Even the couple miles between the first garden and the new farm made a huge different in terms of pest and weed issues. At her new farm, Mary Jean learned the hard way not to put down any plastic tarps between November and April because the strong winter winds would destroy them. 

She would recommend these practices to other growers, with some caveats. Plastic, after all, can pollute the soil and water and eventually ends up in the landfill. But for her, it's better than spraying synthetic chemicals and she hopes that another year or two of occultation work will knock down the weed pressure to the point that she won't have to use so much plastic in the future. She recommends that growers keep the occultation to a small scale. 

For cover crops, she is still on the steep part of the learning curve, since there is so much to figure out: timing, termination, and species selection. She would recommend starting out with a dry-farmed winter cover crop. 

She also advises growers to test their soil often and to create concrete, measurable short-term and long-term benchmarks and goals. She recommends reaching out to your local resources, including the extension office.  

Practices: No-till, animal integration, alley cropping, poly cropping, composting, and cover cropping

Nathanael Siemens is an organic grower juggling a variety of crops, fields, and systems across California. He has a 150 acre farm in Modoc County and another 10 acres in Kern County. He is also working at the Rodale Institute's new farm research center in Ventura County. 

He grew up on a farm in Kern County but left for college and only returned to farming 15 years ago. When he first got back into farming, he was doing management for other growers and didn't have the capacity to change up existing practices. Later on, he was hesitant to make big changes since the conventional system was already functioning. 

This all changed during the recent drought, when it became clear to Nathanael that conventional farming was no longer viable. He started thinking outside the box by doing dry farming and implementing practices that build up organic matter. He also started planting multiple crops at once so that they don't all fail at the same time. 

Nathanael puts up fencing for the sheep. Photo from https://fibershed.org/2019/09/04/california-cotton-fields-nathanael-siemens-on-a-10-acre-model-toward-regeneration/

Practices

In Modoc, Nathanael dry farms grain crops. Dry farming is common in that area, but he also does no-till on this farm, which is less popular. He's also begun planting trees in the grain fields as part of an alley cropping system. He brings sheep onto the fields to graze after harvest. 

In Buttonwillow, on the western side of Kern County,Nathanael grows grains, along with cotton and corn. He tried poly cropping, where he planted a wide variety of grains all together in one field. He reported that this was a fun practice, but he ended up only being able to sell about 5% of the product since the market for organic mixed grains hasn't materialized yet. He used the rest of the harvest for animal feed. He planted this mix of grains to reduce the likelihood of total crop failure. He tried doing reduced till in his cotton field here last year, but it didn't work out very well because of intense weed pressure. For this reason, he's scaling this experiment down to just 2 acres this year. The rest of the field is in corn. He hasn't transitioned to a no-till system for his corn yet, since this practice is more popular and thus less exciting to try out. 

He implements a wide variety of conservation practices, but didn't start them all at the same time. The first practice he implemented was cover crops, 5 years ago. Then he started transitioning to no-till 4 years ago. He started planting poly crops 3 years ago, incorporated sheep into his systems 2 years ago, and started spreading compost one year ago.  

Integrating sheep into his cropping system. Photo from https://fibershed.org/2019/09/04/california-cotton-fields-nathanael-siemens-on-a-10-acre-model-toward-regeneration/

Effects

Yield

Nathanael has seen an instant yield increase after implementing poly cropping. It has been harder to see the immediate effects on yield of compost and cover cropping. 

He sells most of his grain at farmers' markets. This niche market supports farmers who have an interesting or compelling narrative. Farmers' market customers will pay a higher price for dry farmed crops. 

Pests

Poly cropping/intercropping cotton has encouraged more biodiversity. In Buttonwillow, in Kern County, he has noticed a huge difference between his field and his neighbors' fields. There are more beneficial insects and birds in his field. Last year, his cotton suffered no insect damage. 

Erosion

These practices, especially cover cropping and no till, have led to a noticeable decrease in wind erosion.  This helps to improve the local air quality. 

Water

In Modoc, Nathanael has seen a positive impact of these practices on his dry farmed grains. Wherever there is more mulch on the surface because of his no-till and poly cropping practices, he has noticed that there is more water in the soil. The crops therefore stay green longer. 

Weeds

As already mentioned, the reduced till regimen for cotton didn't work out last year because the cotton was overwhelmed by weeds. 

However, Nathanael has seen in his grain fields in Modoc that no till has reduced weed problems after the first year. The first year of no till there was difficult, but once the mulch layer gets established, it keeps weed seeds from germinating, especially the annual weeds that normally take over disturbed soils. 

Cover crops in the cotton field. Photo by Paige Green. https://www.csuchico.edu/regenerativeagriculture/demos/fat-uncle-farms.shtml

Profitability

Once Nathanael started bringing in sheep to graze his fields, he gained an extra income stream. This practice brings in additional revenue but only requires minimal additional inputs. 

Overall, he said that these practices have helped the farm's bottom line. It's hard to determine the exact dollar amount because it has been a total lifestyle change. Instead of spending hours on a tractor, he's now spending that time talking to customers and managing animals. 

Difficulties

Nathanael explained that there has been a steep learning curve in implementing these practices and that he is still on the steep part of that curve, especially for animal management. As he's found with his poly cropped grains, marketing his products has been a challenge. However, the farm has managed to find good opportunities to sell their niche products to people willing to pay for them. 

Recommendations

He would recommend these practices to other growers. He would advise reaching out to consultants and other resources to learn from experts. Also, he learned that it is easier and more efficient to contract out instead of doing everything himself. This has been especially true with the sheep grazing, since he had not dealt with sheep before. He also pointed out that many regenerative practices aren't new, they're just not generally paired together like he's been doing. 

He would advise trying a practice out on a few acres and seeing the results for yourself.

Steven Lee, PhD, has worked as the farm manager for Quaker Oaks Farm in Visalia, CA for the past 5 years. This 22-acre nonprofit educational center includes 8 acres of native wetlands, 2 acres of organic mixed vegetable crops, and 1 acre of organic stone fruit and Asian pears. 

Steven has been working in agriculture for about 20 years, both in the lab and in the field. In 2017, he applied for the first round of Healthy Soils funding to implement a wide variety of conservation practices. The farm already did reduced tillage, but they used HSP funds to offset the costs of buying compost, planting cover crops, spreading mulch, and installing hedgerows. 

He started these practices to improve the health of the soil and benefit the local ecosystem. 

Practices

For the orchard, Steven has followed the following schedule: 

In the spring, he mows down the cover crops and then applies compost. He spreads wood chips on top of the compost. The mulch has not yet caused a nitrogen deficiency in the fruit trees because it stays on top of the soil and is not thoroughly mixed in. In the fall, he disks the mulch in lightly and seeds the cover crops right before a rain. The cover crop mix he planted last year included triticale, vetch, bell beans, and field peas. However, he prefers planting oats over triticale. 

In the vegetable cropping area, he follows a different procedure:

He drives up to Williams, CA in the fall to procure organic straw to maintain the farm's organic certification. He then spreads the straw mulch in the area between the vegetable beds. He found that rice straw was too clumpy to spread easily and thus prefers more traditional oat or wheat straw.  He then seeds the cover crops into the mulch. The mulch improves cover crop seed germination, as it provides both moisture and protection from hungry birds. After disking in the cover crops in the spring, he plants his vegetable crops. 

One of the hedgerows on the farm, next to the vegetables. Photo by Shulamit Shroder.

Effects

Soil

In just the past 3 years of doing these practices, the soil organic matter has increased from 1% to 2%. However, the soil pH has also gone up from 7 to 7.5. At some point, the increase in organic matter should help buffer and stabilize the soil. 

Yield

The total yield has decreased because of the difficulty of incorporating cover crops into the vegetable system schedule. Cover crops and mulch require more work and effort to implement, and Steven and his team of volunteers couldn't get everything done in time. However, for him, the long-term ecological benefits are more important than a season or two of reduced yields.  

Pests

The cover crops and hedgerows have led to increased insect diversity. There are more beneficial insects like ladybugs, green lacewings, assassin bugs, praying mantis, along with more pollinators like bees and hoverflies than there were a couple years ago. 

However, there are also more ground squirrels, rabbits, and gophers. There are birds of prey and snakes, but not enough – the cover crops offer cover and protection for these pests. 

Erosion

The mulch between the vegetable beds has reduced dust emissions, which makes working in the vegetable beds easier. 

Water consumption

In both the trees and the vegetable crops, the mulch and compost keeps the soil moist. Steven has only watered the young fruit trees 3 times this year using furrow irrigation and has not seen any ill effects on tree health. 

He has reduced his irrigation frequency on his vegetable crops from every other day to once a week. He estimates that he is now using about half the water he was applying before, but still has plenty of produce. 

Overall profitability

Steven doesn't need to buy expensive organic blood meal anymore because the cover crops and compost provide enough nutrition. The long-term stabilization of soil productivity through the implementation of these practices should lead to resilience. 

One of the difficulties he's had is that the timing for the Healthy Soils Program doesn't always match up with what makes the most sense for vegetable production. He had to skip a whole cycle to plant cover crops, which ended up costing the farm money. 

Recommendations

He would recommend implementing these practices if they fit into your system. If you're interested in trying one of these practices, his advice is to keep it simple. 

He is cautious about recommending straw mulch in vegetable crops, because he found it to be time-consuming and not cost effective. The biggest benefit for the straw mulch was that it improved cover crop germination. Spreading wood chips on the orchard floor was easier and so he would recommend that more than he would recommend the straw mulch. 

His highest praise was for the hedgerows. He pointed out that you can plant herbs like rosemary, oregano, or sage, which would allow you to both sell a product and promote biodiversity. 

Improvements

Looking back over the past 3 years, he would improve his implementation of these practices by simplifying and not overcommitting himself. He had better results when he seeded the cover crops between the vegetable beds instead of on the beds themselves. 

He would also like to try further reducing tillage and using a roller crimper. This would turn the terminated cover crops into mulch. That way, he wouldn't need to import mulch from another farm.

He's also interested in doing multiple plantings of cover crops, now that the farm has finished its Healthy Soils project and thus will have more flexibility with its scheduling. For example, planting buckwheat, which grows so fast that it can evade drought and attracts beneficial insects. 

In Spring 2019, one of the owners from Alves Dairy reached out about applying for an Alternative Manure Management Program (AMMP) grant through CDFA. Only one other project like this in the area exists, so tackling this sort of large-scale manure management project was exciting! 

The CDFA AMMP Program provides financial assistance for the implementation of manure management practices in California, which will result in reduced greenhouse gas emissions. This grant program is open to all livestock operations, although dairies are the most common applicants. A total of 58 projects have been funded since the grant program started in 2017, resulting in 716,800 metric tons of carbon dioxide equivalents reduced in 5 years. These projects can fall under four general categories, pasture-based management, solid separation, alternative manure treatment and storage, and conversion from flush to scrape. 

The Alves Family started their Dairy in the 1920's and have sustained their operation in the county ever since. The four brothers, Greg, Rich, Gary and Mike, and the next generation, Chris and Scott, share responsibilities for the operation, where they have game birds, corn, alfalfa, orchards and their dairy, with each partner taking on a role to make the whole farm run smoothly. The family is very involved in the community and support local projects and organizations as well.

The Alves originally came to UCCE with this idea because they wanted to improve manure management practices on the dairy and reduce their overall methane emissions. Greg, one of the brothers and owners, spent a large part of his time cleaning manure from the lagoons, taking time away from other important projects on the dairy. With this in mind, we constructed a plan to hopefully make his life, and others on the dairy, a lot easier and achieve significant environmental benefits. 

Alves' AMMP Project. Image by Dana Brady.

The Alves applied under the solid separation category to install a manure separator, a concrete slab and walls, and a new pump that would replace an old diesel pump. The separator filtered out the manure solids, resulting in nutrient rich solid manure to be spread onto fields and reduce the amount of time the solids spend in anaerobic lagoons, creating methane gases. This project will also reduce a substantial amount of greenhouse gases due to not needing to use the excavator to move manure around, or as many truck loads to export the material. 

Alves' AMMP Project. Image by Dana Brady.

On January 1, 2020, the project started and the Alves hit the ground running. All of the partners contributed their own time and energy to this project to make it such a success. Over the past six months, the Alves completely finished their project a year ahead of schedule, and have just recently completed their final verification with CDFA. The verification was done remotely this year and consisted of a Zoom call with Greg to answer some questions, talk about his experience and show off his finished project. 

Greg has already seen the both environmental and personal benefits from the separator project and hopes to continue making the dairy more sustainable in the future.