Demystifying Regenerative Agriculture

Introduction

Ten years ago, the phrase "Regenerative Agriculture" would have captured the curiosity of very few farmers. Today it has caught the attention of many.  A century ago, farming practices emphasising single species cropping, nitrogen application, heavy tilling, use of pesticides and herbicides, etc. emerged to lead the conventional farming revolution.  Increased greenhouse gas emissions, soil erosion, water pollution, and a threat to human health are some of the headlines depicting conventional agriculture.

Regenerative Agriculture aims to solve all of these issues by working with the environment. Like a contract, Regenerative Agriculture mainly involves forming a symbiotic relationship with the soil where both parties gain something. There are various methods to achieve this; however, the following are the most popular:

Diversifying – This is not a new concept. In the 18th century, it was proven that mixed plants were more productive than monocultures. Along with higher yields, other benefits include; ecosystems thrive, the soil is nurtured, animal health improves, and pests are kept at bay. Mixed seeds can be sowed to invoke efficient nutrient uptake, and it is an opportunity for farmers to be creative. Diversifying will be prevalent throughout this literature.

Low to no input systems – In this case, farmers will rely on diverse plants, nitrogen-fixing bacteria, and fungi to maintain homeostatic nitrogen and carbon balance. Some 90 percent of nutrients are locked up in the soil, can bioprocesses help unlock them? If so, this could revolutionise how we treat plants, soils, and fertiliser.  A low input system also entails refraining from tilling, artificial nitrogen, pesticides, and herbicides. In summary, attaining a healthy ecosystem is the goal of Regenerative Agriculture.  

Characteristics of a Healthy Ecosystem

Efficiency

A healthy ecosystem has efficient energy and water flow. Green plants capture the sun's energy, which is then used by many organisms. Bacteria and fungi decompose organic residues and are then fed upon by other organisms, which are themselves fed upon by others higher up the food web.

Natural ecosystems capture and use rainfall and cycle nutrients. This prevents the ecosystem from running down because of excessive loss of nutrients. The quality of the groundwater and surface waters is also maintained. Rainfall tends to enter the porous soil, rather than run off, providing water to plants as well as replenish groundwater, slowly releasing water to streams and rivers. Rain leaching of minerals is a major environmental issue that a healthy ecosystem mitigates with its livened root diversity.

Diversity

As briefly aforementioned, diversity provides nutrients to plants, checks on disease outbreaks, etc. High biological diversity above ground enables high microbiological diversity in the soil. There are millions of microorganisms living with each other and competing for resources. Some self-defense mechanisms such as antibiotic production from the multitude of soil organisms usually keep soil-borne plant diseases from severely damaging plant species in a natural ecosystem.

A consequence of efficiency and diversity in natural terrestrial ecosystems is that they become self-sufficient, requiring only inputs of sunlight and rainfall (Clark, 2007). Due to the great variety of organisms, outbreaks of diseases or insects that severely damage plants or animals are uncommon.  Moreover, plants have several defense mechanisms that help protect them from attack.

Resiliency

Ecological resilience is the ability of an ecosystem to maintain its regular patterns of nutrient cycling and biomass production after being subjected to damage caused by an ecological disturbance. Strong ecosystems are more resistant to distress and can bounce back more quickly.  The loss of an ecosystem’s ability to recover from a disturbance whether due to natural events such as hurricanes or volcanic eruptions or due to human influences such as pollution and soil mismanagement endangers the benefits (e.g., food, clean water, and aesthetics) that humans derive from that ecosystem (Darwin, 1859).

Themes from Regenerative Agriculture

Management of Topsoil

Healthy soil organic matter management is significant for creating a habitat below the ground that is suited to optimal root development and health. Reducing the losses of soil organic matter as the result of excess tillage or erosion is essential to manage the topsoil better. This provides an active organic matter (that fuels the complex soil web of life) to help in the formation of soil aggregates, plant growth, stimulating chemicals, as well as reducing plant pest pressures (Magdoff & Harold, 2009).

The decline in organic matter following the industrial, extractive experiment in agriculture drives the dramatic loss of topsoil. Currently, more than two-thirds of our organic matter has been lost. Organic matter is the soil glue that prevents wind and flooding from tearing dust from the fragile upper layers of our food-producing soils.

For Photosynthesis to take place sustainably, we must trade with our plants. The plant pumps one-third of the sugar produced from Photosynthesis back into the soil to feed the microbes, which in turn fix nitrogen, deliver minerals and protect against plant and soil pests. Removing crops from a field extracts carbon and minerals. This model is not sustainable. Over-tilling soils oxidises the humus, and often the vital minerals that determine the health of humus-building microbes are not replenished.

General strategies for organic matter management

Using adequate crop residues more effectively and finding new sources of residues to add to soils. New residues can include those you grow on the farm, such as cover crops, or those available from various local sources.

Using many different types of materials, crop residues, manures, composts, cover crops, leaves, etc. It is important to provide varied residue sources to help develop and maintain a diverse group of soil organisms. Crop residues (including cover crops), animal manures and composts, help to supply organic materials and cycle nutrients without a buildup of excessive levels of nutrients.

Implementing practices that decrease the loss of organic matter from soils because of accelerated decomposition or erosion. Changing grazing practices, such as shifting animals between paddocks regularly, give the crops a chance to recover, carry out Photosynthesis for growth, and limit the impact animals have on soil erosion. Planting trees and natural scrubs to acts as windbreaks is also an effective and long-term strategy.

Mycorrhizal fungi (AMF)

Most plant species form mycorrhizal associations. A mycorrhiza is a symbiotic association between a green plant and a fungus. The plant makes organic molecules such as sugars by Photosynthesis and supplies them to the fungus, and the fungus supplies to the plant water and mineral nutrients, such as phosphorus, taken from the soil. Mycorrhizas are located in the roots of vascular plants. Research has demonstrated that compost has a significant capacity to stimulate both existing and introduced mycorrhizal fungi.

Composting

Composting involves the conversion of organic matter into stable humus. It is an aerobic method of decomposing organic solid wastes. It can, therefore, be used to recycle organic material. Compost stimulates and regenerates the soil life responsible for building humus more efficiently and rapidly. It can be used to increase plant immunity to diseases and pests.

The inclusion of 6-10% of high-clay soil to the compost facilitates the creation of a clay-humus crumb where the humus created lasts in the soil longer. It remains stable in the soil for up to 35 years (compared to a bacterial-dominated compost, based on something like lawn clippings where this "active humus" is only stored in the soil for around 12 months) (Sait, 2015).

Protection of soil life

It is essential to protect soil life and its humus home base.  Reintroducing beneficial microbes and protecting their ecological niche are inextricably intertwined. Over 90% of our AMF has been lost due to the use of unbuffered salt fertilizers dehydrating and killing microbial beneficiaries, over tilling thus dicing AMF and oxidizing humus.

In terms of soil life, the most destructive component of conventional agriculture has been farm chemicals. Some of the herbicides are more destructive than fungicides in removing beneficial fungi.  All plant disease and pest infestation in crops is a direct result of mineral deficiency or imbalance. In his research (Huber, 2011) notes that Glyphosate-based herbicides are potent chelating agents that lock up minerals and disrupt the nutrient bioavailability of many trace elements prompting plant and animal disease and infertility.

Glyphosate was designed to inhibit the Shikimate Pathway, which is significant in the creation of essential nutrients, including crucial amino acids tyrosine and phenylalanine, which are then used to generate serotonin and tryptophan.  Issues arising from Glyphosate application are:

• Environmental/soil conditions inducing mineral deficiencies and, in turn, plant disease.
• Destroying soil mycorrhizal fungi and all the beneficial soil and gut microbes.
•  Killing beneficial microbes while enhancing the virulence of pathogens like Clostridium, Fusarium, and Verticillium.
• Human and animal health issues.

With regenerative agriculture capturing farmers’ attention, the importance of viewing the soil as a living medium and change is inevitable.

Cover crops

Planting cover crops as part of a diverse cropping system is an indispensable carbon-building tool. Like the Amazon forest, evidence suggests that the increased moisture retention associated with this regular injection of organic matter compensates for the moisture removed in the production of cover crops. Diverse cover crops are also drought protective, in that the great mass of roots involved exudes a gel-like paste that can absorb 10,000 times its own dry weight in water.

Many types of plants can be used as cover crops. Legumes and grasses are the most extensively used, but there is increasing interest in brassicas (such as kale, rape, mustard, and forage radish) and buckwheat. Certain combinations of plants can trigger the release of phenolic compounds from these plant roots, which have been shown to stimulate rapid humus building. Having brassicas in the mix can also discourage pathogens like nematodes and some diseases with their biochemical root exudates.

Leguminous plants are effective cover crops wilding the ability to fix nitrogen from the atmosphere and add it to the soil. Legumes that produce a substantial amount of growth, such as hairy vetch and crimson clover, can supply over 100 pounds of nitrogen per acre. Legumes such as field peas, big flower vetch, and red clover usually supply only 30 to 80 pounds of available nitrogen. Legumes also provide other benefits, including helping control erosion, adding organic matter to soils, and attracting beneficial insects (Werner & Dindal, 1990).

In summary, cocktail cover crops promote microbial biodiversity as each species favors and feed specific groups of root microorganisms. The more diverse the plant species, the more varied the soil life, and the more soil thrives.

Conclusion

Feasibility

Regenerative agriculture is not a new concept. I guess a practise is nonexistent until it is defined.  The most important aspect of a farming business is value proposition, which in turn generates demand and revenue. With increasing demand for healthy and natural, foods farmers are ought to re-strategise to meet these consumer demands.

There are several external forces at work in the agriculture industry mainly the fertiliser and chemical industries; environmental and social which are under a political umbrella. Change on a large scale if any will be gradual if self-serving agendas are constantly lobbied.  Farmers need to take a risk on the healthy soils and healthy produce agenda and seek second opinions to provide a broader information scope.  One needs to recognise their impacts on the carbon and nitrogen cycle in the soil in order to make decisions that do not undermine the soils integrity. Transitioning to regenerative agriculture is a strategic play and sustainable rewards come later. It is also not a “one shoe fits all” regime, therefore making decisions based on research is critical.

No input enthusiasm

Some adopters of Regenerative Farming aim to operate a no input system where fertiliser is not used. For transitioning farmers, liberation from fertiliser is the end game. This is radically attractive considering the fertiliser costs incurred overtime. The theory of a self sufficient ecosystem supports not using fertiliser however research is far from proving the substantial advantages as opposed to conventional farming. While it is grand to aim for a strong natural ecosystem, it is significant to recognise the optimisation pressure we put on our farming systems derived from consumer demands.

The New Zealand sheep and beef industry has reduced its greenhouse gas emissions intensity to below 1990s levels while continuing to achieve strong productivity gains. It is a fact that there are many successful conventional farmers who use fertiliser, maintain healthy soils, deliver quality food and generate profit. The proper use of inputs, with the help of plants and microbes, optimises the soil toward an ideal pattern.

Like our bodies there are many illnesses caused by the lack of specific essential minerals. The soil and the microbiology it homes operate in similar fashion. Solve these problems by establishing what the problem is, then prescribing the right dose to treat the problem at the source. Similarly, if a patient had cancer, prescribing aspirin would not solve the illness sustainably. Indeed, regenerative farming aficionados understand this analogy precisely. 

Bibliography

Clark, A. (2007). Managing Cover Crops Profitably, 3rd ed . Maryland: Sustainable Agriculture Research and Education (SARE).

Darwin, C. (1859). On the Origin of Species. London: John Murray.

Huber, D. D. (2011, May Vol.41 No.5). GMOs, Glyphosate. ACRES USA , pp. 1-9.

Magdoff, F., & Harold, v. E. (2009). Building Soils for Better Crops, 3rd Edition. Maryland: Sustainable Agriculture Research & Education.

Werner, M., & Dindal, D. (1990). Effects of conversion to Organic Agricultural Practices on Soil Biota. American Journal of Alternative Agriculture 5(1) , 24-32.

 Diversifying Cropping Systems (2008). Sustainable Agriculture Research and Education (SARE). A 20-page bulletin on the soil and yield benefits of diversifying crops on farms and ranches.