Regenerative agriculture

Regenerative agriculture is a term for farming practices that capture carbon from the air and put it into the soil. Through photosynthesis, plants capture carbon dioxide from the air, which is used to build their tissues, releasing the remaining carbon deep into the ground. Carbon enriched soils have been shown to have greater resilience to floods and droughts. Regenerative agriculture practices include minimizing tillage (such as soil disturbance from plowing), keeping the land covered with plants at all times, and rotating a diversity of crops and livestock across the fields. By avoiding tilling and minimizing soil erosion, regenerative agriculture practices are thought to have the potential to store a significant portion of carbon in the soil and improve the nutrition of food. A core concept in regenerative agriculture is a circular economy, which includes steps that reduce or recover losses of nutrients and greenhouse gases.

Regenerative agriculture focuses on building soil health through ecosystem-centered techniques, such as composting or adding animals to complex crop rotation practices. This is often considered to be in contrast to the industrial agriculture model, which is responsible for stripping the soil of nutrients and often creating destructive feedback loops that require more inputs over time, such as synthetic fertilizers or pesticides. In regenerative agriculture, farmers use different techniques to maintain healthy soil structures, create a rich nutrient environment for crops, and restrict or completely remove the use of synthetic fertilizers or pesticides.

The benefits of regenerative agriculture are generally understood to include no need for synthetic fertilizer. This is based in part on the use of plant-based compost and animal manure, green manure, and cover cropping to amend the soil, while also employing crop rotation—all to contribute to healthier soil. Healthier soil can also increase water retention, with at least a one percent increase in soil organic matter, helping soil hold 20,000 gallons more water per acre. This can help plants grow in biologically diverse soil with plenty of nourishment and thriving microbes, which helps the plants be less susceptible to plant pests and better able to defend themselves, thereby removing or reducing the need for pesticides. And the techniques in regenerative agriculture can help soil sequester carbon, which can help with climate change and help produce healthy plants.

The following techniques are used in regenerative agriculture:

• Complex crop rotating
• Composting
• Green manure, cover cropping, and mulching
• No-till or low-till techniques to reduce soil compacting
• Limited to zero pesticide use and sustainable pest management techniques, such as using buffer zones and courting beneficial insects
• Adding animals on pasture and animal manure to farm systems and crop rotation

The Rodale Institute, a non-profit that supports organic farming, claimed that regenerative techniques “could sequester more than 100% of current annual CO₂ emissions with a switch to widely available and inexpensive management practices.” While the practices are supported by evidence, there have been objections that claims may be exaggerated beyond the scientific evidence. Tim LaSalle, cofounder of the Regenerative Agriculture Initiative, has stated his belief that it will solve the climate crisis, hunger crisis, water crisis, and topsoil crisis.

Use of the term “regenerative” in agriculture appears to be initiated by Bob Rodale, who popularized organic farming with lifestyle and gardening magazines. Rodale noticed people were latching onto the word “sustainable,” and in a 1989 interview said he thought that rather than aspiring to a sustained environment, the average person aspired to live in an environment that is getting better. The term “regenerative agriculture” has pushed forward due to awareness of climate change and also the rise of environmentally conscious farmers who dissociate themselves from “organic”.

ROC certification label

A “Regenerative Organic” certification has been introduced by the Regenerative Organic Alliance, including organizations and brands such as the Rodale Institute, Patagonia, and soapmaker Dr. Bronner, in an effort to inform consumers about food products. Some of the non-organic farmers that are practitioners of regenerative agriculture come out of the no-till movement, which advocates for the eschewal of plowing. Other practitioners of regenerative agriculture are followers of the grazing practices established by Allan Savory. There is a spectrum of users of regenerative agriculture methods from farmers that avoid tilling and embrace ag-tech to farmers who dislike ag-tech and tolerate some tillage.

New Zealand uses a pastoral agriculture system that may be considered regenerative compared to tilled fields. By farming animals on pasture, transportation of feed to animals is avoided and nutrients excreted by the animals as manure and urine go back into the land. However, animals such as cows, sheep, and goats emit greenhouse gas methane due to their stomachs and their diet. Nitrous oxide is a long-lived greenhouse gas that is released into the air when cows urinate. The nitrogen concentrated in urine could be reduced by reducing the protein content of the pasture.

Indigo launched The Terraton Initiative in June, 2019, a program that will pay farmers $15 per ton of carbon sequestered in order to give them incentive to transition towards regenerative practices.

Sustainable soil management is often considered a part of regenerative agriculture, except where regenerative agriculture can include the types of crops and rotation of crops, and the use of pasturing and animal waste. Sustainable soil management has a greater focus on the soil itself and includes techniques that some do not consider a part of regenerative farming, such as micro-dosing fertilizer or pesticides. However, the goals of sustainable soil management are the same as that those of regenerative agriculture, which are to build healthy soil; reduce soil erosion; and reduce the need for fertilizers, pesticides, and herbicides. This includes a variety of practices:

• Planting cover crops, especially in the fall to prevent erosion and add nutrients and organic matter to the soil
• Using mulch around plants when possible to prevent erosion, suppress weeds, hold moisture, and add nutrients and organic matter to the soil
• Rotating crops to disrupt disease and pest life cycles and reduce excess nutrients
• Reducing soil compaction which helps fungal and insect life in soil thrive, and whenever possible reduce tilling and using equipment that results in soil compaction
• Providing habitats for beneficial insects like cover crops, mulch, wildflower patches, and insect hotels

Example of a diversified crop rotation in sustainable soil management.

The rationale for sustainable soil management often comes from the perspective of soil as a non-renewable resource and the necessary goods and services soil provides that can be vital to human and non-human ecosystems. Soils are fundamental for producing crops, feed, fiber, and fuel, and they filter and clean tens of thousands of cubic kilometers of water each year. The balance between supporting and provisioning services for plant production and the regulation service for the soil to provide water quality and availability and for atmospheric carbon dioxide composition and sequestration are often a part of the consideration of sustainable soil management.

Sustainable soil management comes down to the development of healthy soil, which can be determined by soil high in organic matter content, a balanced structure, and high nutrient availability, which provides a basis for good plant production. It can also decrease the amount of inputs a grower needs to use, since many of the nutritional requirements of the crops will be supplied through the soil. This increased nutrient availability also increases stronger roots and creates crops more resistant to environmental stressors.

Soil erosion, either by wind or by water, has been identified as a significant threat to global soils and the ecosystem services soil provides. Soil erosion causes the loss of surface soil layers, which are often the most nutrient rich layers of the soil, and can result in partial or complete loss of soil horizons. Soil erosion can also result in off-site impacts, such as damage to private and public infrastructure, reduced water quality, and sedimentation. Soil erosion has been accelerated by the reduction of plant or residue coverage, tillage, and other field operations. And a reduced soil stability has also led to soil creep and landslides. Using techniques such as low or no-tillage and using plant or residue coverage can maintain soil and reduce overall erosion as well.

Soil organic matter (SOM) plays a role in maintaining soil functions and preventing soil degradation. The millions of microbes making their homes in the soil are a part of the nutrient cycling of breaking crop residue into organic matter in the soil and making those nutrients available for plants. This can help growers reduce their use of additives of fertilizers.

Appropriate land use, or the use of soil following sustainable soil management techniques, can improve the soil quality and can help sequester carbon dioxide in the soil, and the loss of SOM can cause an increase in atmospheric carbon dioxide levels. Besides carbon dioxide, soil organic matter also applies to nutrient dynamics in the soil, which follows along the soil-water-nutrient-plant root continuum. Plant nutrients also need to be based on the crop needs, local soil characteristics and conditions, and local weather patterns. Plant nutrition can be enhanced through nutrient recycling or additions, including mineral fertilizers, organic fertilizers, and other soil amendments. It can be crucial in this process to select an appropriate plant management system and approach, and to assess the land for a given land use. For example, trying to grow crops not native to a region can introduce stresses to the soil and lead to the use or over-use of fertilizers and pesticides.

Whereas, the appropriate use of land and a sufficient and balance nutrient supply for plant needs are well-established and the benefits can include production of food, feed, fiber, timber, and fuel at levels close to the optimum potential in the specific geographical context; a reduced need for pest control measures, external application of organic and inorganic amendments, and mineral fertilizers; less pollution resulting from inappropriate use of agro-chemicals; and enhanced soil carbon sequestration through biomass production and restitution to the soil.

Salinization is another problem in soil, which is caused by the accumulation of water-soluble salts of sodium, magnesium, and calcium in the soil. It is a consequence of high evaporation and transportation rates, inland sea water intrusion, and human-induced processes. Salinization reduces crop yield, and above certain thresholds, eliminates crop production.

Example of contaminated soil in a forest.

Besides salinization, another major issue is the prevention of soil contamination with other possibly toxic or dangerous elements in the soil. Contaminants can enter soils from a variety of sources, including agricultural inputs, land application, atmospheric deposition, flood and irrigation water, accidental spills, inappropriate urban waste, and wastewater management. And while soil is capable of filtering and removing contaminants, a contaminant can exceed the possible rate of removal of a soil, which can lead to contamination that can cause plant toxicities, productivity declines, contamination of water and off-site areas, and increased human and animal health risks.

The prevention of soil contamination includes taking measures to prevent the soil from acidifying. Acidification can, and often is, a result of human activity, and is primarily associated with the removal of base cations and the loss of soils buffering capacity or increases in nitrogen and sulfur inputs. Soils with low pH-buffering capacity or high aluminum content are most prevalent when the soil has a low content of weatherable minerals.

Soil sealing refers to the reduction of arable land to human settlement and infrastructure, which can reduce a region's capability of growing food and increasing food production. Urban sprawl can be an especially difficult problem for the loss of arable land and often removes some or all of the soil functions form the ecosystem. Soil compaction, on the other hand, is related to the degradation of the soil structure due to imposed stresses by machinery and livestock trampling. Soil compaction reduces soil aeration by destroying soil aggregates, and collapsing macropore density, and reduces the ability for soil to drain and infiltrate water and generates higher runoff rates. Compaction also limits root growth and seed germination by high mechanical impedance.

Example of compacted soil complication crop growth.

In soil management or regenerative agriculture, tilling should be retained for the improvement of problem areas, including where the soil is compacted or where drainage issues are heavily impacted. Tilling can increase the number of weeds in a field by bringing them to a surface, where they can germinate and grow, which can reduce overall field space and nutrients. The machinery used for tilling can also cause soil compaction in sub-layers or horizons, despite being capable of recovering soil compaction.

Sustainable soil management requires rapid water infiltration, optimal soil water storage, and efficient drainage when the soil is saturated. Waterlogging and water scarcity are problematic conditions for crop growth. Waterlogging, which relates to the oversaturation of soil, creates rooting problems and can reduce overall yields. It can also cause contaminants such as arsenic and methylmercury to become mobile in the soil. While water scarcity can cause crop failure through crop dehydration.

Example of cover crops and crop waste being used as soil cover.

Soil coverage, or cover crops, has become an increasingly popular method of maintaining soil health in sustainable soil management. Not only do cover crops offer another opportunity for farmers to improve their soil, their use can also increase the availability of nutrients in the soil and reduce the possible erosion of the soil. Whereas, when fields are left uncovered after harvest, they become susceptible to erosion from wind and rain, which reduces the possible healthy foundation for spring growth.

The type and amount of nutrients used by different crops vary depending on what is being grown and what the target crop is. However, different crops can also increase the availability of different nutrients, which can be used to replenish the soil for the crops that follow. And crop rotation, especially a complex multi-crop rotation, can include crop coverage and plays a part in preventing soil erosion through the root growth. The root growth can help develop the soil structure at different depths throughout the seasons and maintain its stability against heavier rains and winds.

In a joint report developed by the RSC, the University of Sheffield, the Natural Environment Research Council (NERC) and the Environmental Sustainability Knowledge Transfer Network (ESKTN), called "Securing soils for sustainable agriculture - a science led strategy," the organizations highlight areas of concern and related actions with possible technological solutions that could be taken to develop advances in soil science.

The report focuses on soil research and innovation in the United Kingdom, with each agricultural zone arguably dealing with different soil conditions and different soil concerns. It highlights four areas with possible interdisciplinary research that could be developed to generate technologies for increased crop production and reduced resource consumption. This includes the possible technologies:

• Biosignalling and sensors for precision monitoring and control of crop conditions
• Closed-loop systems for recovering plant nutrients, such as phosphorous from waste
• Integrated computational models of plant-soil-water to design crop technologies
• Innovation in plant nutrient and water use efficiency to reduce resource demands

With that, there are existing approaches to soil management that are seen as relative innovations, either because they rely on newer technology or because they represent a shift in the understanding and approach to agriculture. These include things like micro-dosing fertilizer, using wastewater for irrigation, reintegrating livestock into a field, and preventing nitrogen leaching.

Micro-dosing fertilizer has been suggested as a possible innovation in soil health. Defined as the application of small, affordable quantities of fertilizers with the seed at planting time or as top dressing at three to four weeks after emergence, the process is intended to be precise and stand in contrast with field-wide fertilization often associated with industrial agricultural techniques.

Micro-dosing fertilizer.

Fertilizers are also often expensive, especially in developing areas, such as sub-Saharan Africa. Micro-dosing in these cases can reduce fertilizer costs while increasing overall field and soil health. Programs to test the viability of micro-dosing fertilizer undertaken in Mali, Burkina Faso, and Niger, with over 25,000 small-holder farmers participating, found that sorghum and millet yields responded well to the technique and boosted yields by 44 to 120 percent, while also increasing incomes for those farmers by as much as 130 percent for some families.

Example of a farm using wastewater irrigation.

The proper disposal of sewage and wastewater has become more challenging as urban areas have grown, and the United Nations Food and Agriculture Organization notes that wastewater contains most of the essential elements of fertilizer in the proper amounts. Treating and applying wastewater, effectively, could contribute both to healthier urban areas, and provide a vital and organic fertilizer for rural areas. This could provide an easy way for farmers, especially those near cities, to fertilize their crops. However, it also presents some risks, as wastewater often contains biological and chemical substances harmful to human health. Further innovations into sanitation could provide a better infrastructure for waste and create a more efficient wastewater for use in energy and fertilizer.

Livestock integrated into a field as part of its crop rotation.

Animals are important for their egg and meat production, but they can also be integrated into a larger agricultural system. This is as animal manure, or animal feces, especially when the animals are on a diet of grasses and similar crops, can be an effective and inexpensive method of boosting the health of organic topsoil.

Nitrogen is an essential nutrient to soil health and for productive crops. Chemical fertilizers and nitrogen-fixing plants, such as legumes, can help provide nitrogen to soils. However, nitrogen, same as water, follows cycles that include leaching from the ground as a gas. Poor land management, erosion, over-fertilization, and chemical runoff all contributes to nitrogen depletion. This leaves land in a different state of dehydration and degradation and reduces the possible productivity of plants.

To combat nitrogen loss, soil scientists have experimented with chemical inhibitors to keep those nutrients in the ground for longer. These have been shown to actively stimulate the nitrogen cycle, keep nitrogen in the soil for longer, and could increase crop yields. Tests into chemical nitrogen inhibitors in Brazil found an increase in sugarcane production. However, these inhibitors do not present an absolute solutions for nitrogen depletion, but these could be used in small doses in combination with natural nitrogen-fixers and better land management to rebuild healthy soil.

Soil moisture monitoring systems include sensors and software systems that provide information for different soil conditions, including sensors for agricultural systems, systems for sandstorm warnings, and systems for environmental protection or detecting environmental hazards. Monitoring the moisture helps farmers understand when crops are getting the right amount of water and when is the right time to water crops. This can lead to higher yields, better product quality, improved plant vigor, reduction in plant disease, more effective use of water, and reduced irrigation costs.

Example of soil moisture monitors.

These sensors come in different versions and for different use cases. For example, there are portable instruments, also known as instant read devices, which are best suited for growers accustomed to walking their fields regularly. There are similar devices, known as "bury in place" instruments, which also require farmers to walk the field, but do not require them to carry the instrument. The "bury in place" instruments tend to offer automated data logging, some of which are capable of communicating to a central computer and others that still require walking to log the data.

Also known as soil conditioners, soil amendments often are differentiated into three classes of amendments. The first is the most well known, fertilizers, which can be organic or synthetic and works to provide nutrients, especially nitrogen, phosphorus, and potassium, and also known as macro nutrients. The second is soil inoculants which work to add biology to the soil to improve the soil food web; this usually includes an emphasis on bacteria and fungi, but can include beneficial nematodes and related biological entities that can play vital role in the carbon cycle or nitrogen cycle.

The third is soil conditioners, which work to enhance soil properties and are as often called soil enhancers. These products work to alter the soil structure and may affect properties of the soil including cation exchange capacity, soil pH, water holding capacity, and soil compaction. Soil conditioners can be organic, inorganic, or a combination of synthetic and natural matter. Some of the following ingredients in these can be included:

• Animal manure
• Compost
• Cover crop residue
• Sewage sludge
• Sawdust
• Ground pine bark
• Peat moss

Some inorganic soil conditioner ingredients include the following:

• Pulverized limestone
• Slate
• Gypsum
• Glauconite
• Polysaccharides
• Polyacrylamides

Although not precisely an innovation in soil, it is an innovative use of soil, with recent studies showing the several carbon-beneficial agricultural practices in increasing soil carbon sequestration. Part of this has been shown to be the use of compost, which has increased carbon stored in both grassland and cropland soils, and has increased primary productivity and water-holding capacity. Similarly, restoration on riparian areas on working lands has the capacity to sequester significant amounts of carbon. Related practices have also produced co-benefits, such as increased water retention and hydrological function, biodiversity, and soil resilience.

The Missouri Botanical Garden advises the following sustainability practices for gardening:

• Conservation of water and control of water runoff
• Reduction of fossil-fuel energy use
• Sustainable yard and garden waste disposal
• Selection of more sustainable plants
• Sustainable garden design
• Sustainable plant maintenance

For lawns, water should be conserved and water runoff controlled by watering plants only when they need it and using rain gauges to record weekly rainfall. Lawns should use a low-angle spray instead of oscillating sprinklers that cause more water loss due to evaporation. Watering devices should be positioned in a way that prevents water flowing to storm gutters, walkways, or on the street.

As in the case of lawns, gardens should utilize drip irrigation or soaker hoses instead of oscillating sprinklers to avoid water loss, and watering devices should be positioned away from the street. Other suggestions include the following:

• Garden beds should be mulched to retain soil moisture
• Rain barrels to collect rain water for watering plants can be utilized
• A rain garden can be planted or a swale developed in order to retain more water in the soil and prevent runoff
• The use of grey water use in the area where gardening takes place should be investigated
• Hard surfaces in the landscape should be removed to allow water to be absorbed by the soil; these surfaces can be replaced with porous materials
• Rainscaping features to manage stormwater should be incorporated
• The use of a hose to wash off the driveway, deck, or walkway should be avoided; brooms or electric blowers can be used as alternatives

In order to reduce the use of fossil-fuel energy, the Missouri Botanical Garden has a variety of recommends:

• Lawn size should be reduced by introducing beds of shrubs or drought tolerant perennial plants
• Lawn mowers should be serviced regularly to run efficiently and emit less pollutants
• It is preferable for lawn weeds to be removed by hand instead of chemical sprays
• Lawns should not be mown more frequently than required
• Gas-powered mowers should be replaced with an electric one or a push mower

The collection of lawn clippings is discouraged as it is not necessary and has the negative effect of depleting the soil of nutrients and organic matter. A mulching lawn mower is recommended so lawn clippings don’t have to be collected. If collected, lawn clippings can be used as compost. Disposing of plant-based garden waste at landfill sites is discouraged as they can be used as compost or recycled. This also applies to plastic, clay, and other types of pots. Gardeners should develop their own own compost piles in order to return plant material back to the soil in their yard. In addition, electric chipper shredders are recommended over gas-powered.

More drought tolerant grasses that require less mowing should be selected, and plants that require a lot of watering should be replaced with more drought tolerant plants, such as native plants. Generally, plants that perform well in a specific area and result in fewer problems should be selected. In addition, gardens can benefit from diversification among plants, which can serve as habitats for beneficial insects and mitigate damage from periodic diseases. Invasive plant species should be avoided.

Lawn size should be reduced insofar as it is feasible to do so. In gardens, trees can be used to help shade and cool the home in the summer to reduce energy costs. Deciduous trees can be selected for this purpose as they will let sunrays through during winter and warm the home. In addition, a windbreak (shelterbelt) can be planted to reduce the need for heating in winter, and new constructions can benefit from green roofs. Moreover, wood for decks, fences, and other garden structures should be sourced from a sustainable producer. The Forest Stewardship Council (FSC) certification for wood indicates sustainable production methods.

Soil tests should be used before fertilizer or lime is added to the lawn. Overfertilization can lead to excess plant growth, which can in turn increase the risk of plant disease. Attempting to grow grass in soil outside of its recommended pH range results in poor growth. In addition, fertilizer runoff can pollute streams and groundwater; therefore, proper care must be taken when applying fertilizers. Minor insect damage should be ignored as spraying the ground with pesticide can introduce harmful chemicals in the environment and can harm nearby plants. Low levels of weeds should also be tolerated.