It’s All About the Soil

It’s All About the Soil

  • By Ralph Morini
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  • February 2022-Vol.8, No.2
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  • 0 Comments

Regenerative farming is a movement aimed at changing farming practices to repair the environmental damage done by chemical-based agriculture over the past 100 plus years. Going beyond the stop the harm strategy of sustainability, it advocates rebuilding environmental health by focusing on building soil health naturally. Practitioners claim success in both crop production and environmental impact. It is based on a few basic principles and practices that are readily adaptable to home gardening.

Principles and Practices

At its core, regenerative growers work to improve soil health by:

  • Keeping the soil covered
  • Minimizing soil disturbance
  • Maximizing living roots in the soil
  • Building diversity, above and below ground.

The specific means to these ends are:

  • Minimize tillage. While tillage temporarily fluffs up soil and offers short term weed control, it breaks up soil aggregates and beneficial fungal communities, reducing soil life and ultimately leading to compaction and increased runoff. It also mixes oxygen into the soil, leading to higher CO2 emissions. While deep tilling may be beneficial to break up hard pan or mix organic matter into new beds, continued tilling does more harm than good.
  • Utilize cover crops, crop rotation, composts, and manures to restore soil microbes while providing the organic matter that the microbes cycle into essential plant nutrients.  This is counter to the use of synthetic fertilizers that disrupt the natural cycles, create a chemical dependency for needed nutrients and pest control, and ultimately weaken soils.
  • Build ecosystem diversity, below and above ground, by regular organic matter additions, keeping live plants in the soil full time, intensively planting mixed crops, including cover crops and pollinator plants in and around the growing areas.
  • Managed grazing, which can stimulate plant growth and increase soil fertility by increasing carbon-based nutrients in the soil, as well as through the manures that animals leave behind. For home gardeners without grazing animals, regularly adding organic matter is an appropriate substitute practice.

Let’s look at how home gardeners can implement regenerative practices.

Minimum Tillage

Not tilling can seem counterintuitive to those of us who grew up tilling. No-till benefits are proven however, so let’s figure out how to handle the weeds and compaction that can be problems if we don’t till.

First, the exception. For new beds or where ground is seriously compacted, it may make sense to do an initial till to break it up. Be sure to work in organic matter like finished compost or composted leaves to gain some soil building benefit.

Sheet mulched garden plot with organic materials over paper base and compacted clay soil.
Cultivate Charlottesville CATEC Garden. Photo R Morini

An alternative for new beds is to use sheet mulching. This typically means covering the bed area with newspaper or corrugated paperboard and building a thick layer of organic materials on top, letting it decompose for a few months before planting directly into the composted materials. The video Sheet Mulching: Lawn to Garden in 3 Steps from the Penn State Extension shows how to do it.

In future plantings, minimize soil disturbance. Surface weeds can be removed mechanically, with a hoe and rake. Or use solarization or occultation with plastic tarps, the hot sun and a few weeks time to kill surface weeds, seeds and pathogens.  After removing tarps, with minor surface prep, transplants can then be planted directly. For seed beds, shallow raking or use of a tilther (a light-weight tiller that only tills the top two inches or so of soil) can prepare a smooth, welcoming seed surface by loosening only the top couple of inches of soil. The article Reducing Tillage in Your Garden from the University of Minnesota Extension provides good guidance.

A broadfork at work, from the video, “The broadfork – Jean-Martin Fortier – The Market Gardener’s Toolkit,”

To reduce compaction, drive a broadfork or sturdy digging fork into the ground, inserting it as deeply as possible and rock it back and forth. The effect is to loosen the soil without destroying structure. Work your way across the garden area. Converting from row planting to wider beds accessed from from permanent paths, reduces unnecessary compaction as well as the size of the area needing to be worked.

Adding compost to the soil surface after weed removal and before broadforking is a good way to get organic matter into the top few inches, making it available for soil organisms to go deeper over time.

Plant Diverse Crops Intensively

 There are a lot of elements to this point:

  • Wide beds, rather than rows, allow close planting in two dimensions. Crop spacings should be such that at maturity, plants will just touch, so they don’t crowd, yet cover the soil. Find guidance on plant spacing in the publication Planning an Intensive Garden from the University of California Extension.
  • Companion planting, which means planting different plant families together, is a good way to add diversity and potentially to get some benefit from pest reduction by repelling or confusing pests. There is a lot of questionable information about good companions, but the article Trap Crops, Intercropping and Companion Planting from the University of Tennessee Extension has a good discussion of principles. The article Cool Season Planting for Companion, Interplanting and Square Foot Gardening from Washington State University provides a chart for cool season vegetable companions.
  • Crop rotation, i.e., not placing plants in the same family in the same garden location more than once every three years, helps disrupt pest and disease carryover.

Keep the Soil Covered

Keeping soil covered at all times is a key principle in regenerating soil health. Moderating temperature and moisture variation, minimizing carbon loss, and reducing runoff and erosion are all important benefits.

Diverse winter cover crop growing through winter-killed buckwheat. Photo: R Morini

Cover crops are the recommended option during times when a regular crop isn’t growing. While they can be used any time a crop is not planted, or even alongside row crops, winter is a prime time. Planting is typically done in late summer/early fall to give the cover crop time to establish. Winter-kill crops, like buckwheat, grow until hard frost, then die. In spring their residue can be used as mulch; alternatively, it can be collected and composted to be added back later. Winter hardy cover crops will go dormant but survive winter and resume growth in spring, to be cut just prior to going to seed. Cutting them flush to the ground with a flail mower or string trimmer, allows the vegetation to be used as a mulch, composted, or tilled in as a green manure, as long as planting can be delayed for a few weeks to allow for decomposition. If cutting is done after flowering but before seed formation, root energy is largely exhausted and root and stem will die. Residue can be left as mulch and transplants inserted into it, or stalk remnants can be removed as described above.

The benefits of cover crops are many. In addition to protecting the soil, the plants and roots provide organic matter, and carbon residues are deposited in the soil from photosynthesis. Diverse plantings provide diverse benefits. Legumes, like clovers, peas, and beans fix nitrogen in the soil. Forage radishes penetrate the soil, reducing compaction, plus their roots add organic matter after cutting. Various grasses and grains add organic root mass and carbon-based photosynthetic compounds while helping crowd out weeds. Cover crops require some work, but bring many benefits and are considered essential by regenerative farmers.

Mulches are the second best way to protect soils between crops. They help stabilize soil moisture and moderate temperature variation while reducing erosion and runoff and providing valuable organic matter. Compost, mulched leaves, straw, aged wood chips, and sawdust are all good mulches.

Some regenerative farmers advocate leaving chopped up crop residue on the soil as a mulch or “armor” to protect the soil between crops. As home gardeners, we typically don’t have the equipment to do the chopping efficiently, and in my view at least, the risk of leaving pest or disease remnants in place argues for removing crop residues and replacing them with clean mulch.

Minimum Chemical Use

Regenerative farming isn’t necessarily organic. But utilizing natural practices and creating diverse ecologies is fundamental to the movement. This means working to minimize use of synthetic fertilizers and pesticides.

Integrated Pest Management (IPM) is an ecologically based process for treating pests as sustainably as possible. It specifies:

  • Regular observation
  • Early recognition of pest and disease issues
  • Accurate identification of the problem
  • Investigating alternative ways to treat the problem
  • Accepting low level damage, taking action when problems progress to unacceptable levels
  • Treating with the least toxic means first:
    • Preventive cultural practices
    • Mechanical methods
    • Bio-control methods like building beneficial insect populations
    • Chemicals, preferably organic, as a last resort.

The article Integrated Pest Management in the May 2020 Garden Shed explains it.

No doubt, adhering to IPM principles takes more time than simply reaching for a pesticide. But, given the damage that excessive chemical use has caused, to both environmental and human health, there is a compelling argument for this practical approach.

Pollinator plantings around the garden perimeter improve pollination and pest control. Photo: R Morini

Pollinator plantings add beauty and diversity to a landscape while helping build a beneficial insect population that supports reduced chemical use. They can include trees, shrubs, and perennials. Native plants are preferred since they provide food and habitat for more native insects than do non-native plants. They can be inter-mixed with food crops, established as borders, or worked into the landscape wherever appropriate. Diversity is key, and the goal is to have blooms from early spring through late fall to maximize benefits to pollinators and the garden. The Garden Shed article Plant a Pollinator Paradise provides helpful guidance. The Virginia Native Plant Society and Xerces Society offer resources to support building native habitats.

It’s Important

It’s hard to deny the environmental damage we have done over the last hundred-plus years. At the same time, it may be hard to see how we as individual home gardeners can have a measurable impact on improving things. Beyond our home gardens, the fact is that widespread change in public commitment and consumer demand is likely essential to drive a change in commercial agricultural practices. But applying regenerative agricultural practices gives us a way to help. And besides, it can improve both our garden production and our health. Why not give it a try?

Sources:

“Intensive Gardening: More from less (space),” University of Missouri Extension: https://ipm.missouri.edu/MEG/2018/4/intensive_gardening/  

“Using the Sun to Kill Weeds and Prepare Garden Plots,” University of Minnesota Extension, https://extension.umn.edu/planting-and-growing-guides/solarization-occultation

“Trap Crops, Intercropping and Companion Planting,” University of Tennessee Extension, https://extension.tennessee.edu/publications/documents/w235-f.pdf

Xerces society: https://xerces.org/publications

Virginia Native Plant Society: https://vnps.org/#

Lead photo: “Healthy Soil Maximizes Moisture, Boosts Profits for Oregon Farmer” by NRCS Oregon is licensed under CC BY-ND 2.0

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