In 1992 I started my career as a newly fledged post-doc working on the Integrated Farming Systems project and so have been intrigued to see the rising interest in Regenerative Agriculture. But what is it and is it any different to Integrated Farming that has been promoted by organisations such as LEAF (Linking Environment and Farming) since it’s establishment 1991?
There have also been other similar approaches advocated since then such as biodynamic, sustainable intensification, sustainable agriculture, and agroecological while the conservation agriculture movement has been advocating reducing tillage and improving soil health since the 1980s.
Regenerative Agriculture originated in the USA and arose from the need to restore degraded soils for agriculture and increase soil carbon storage to help mitigate climate change. There are many definitions1, but perhaps the one that defines the approach most simply is this2 “a system of principles and practices that generates agricultural products, sequesters carbon, and enhances biodiversity at the farm scale”. It is based around four core principles, although may also include use of cover cropping and minimisation of pesticides and synthetic fertilizers (Table 1).
Other land management practices are also classified as being regenerative such as sustainable agriculture, conservation agriculture, no-till polyculture, silvopasture, holistic agriculture, agroforestry, permaculture and rewilding while there is also regenerative organic farming2.
Improving soil health is the core objective of regenerative agriculture as this leads to many other benefits. These include increased soil carbon storage, greater soil resilience to flooding and drought through higher organic matter levels and improved soil structure, improved nutrient recycling and improved soil biota that improves plant health and supports biodiversity up the food chain. A healthy crop also increases its resistance to pathogens.
So is all of this new or rebranding of other environmentally friendly farming practices. Integrated farming is the closest approach and was developed as an alternative approach to intensive agriculture, the impact of which was starting to cause concern. Integrated farming aimed to help reduce the impact on the environment and biodiversity whilst also maintaining profitability. It was defined by El Titi3 as ‘‘an holistic pattern of land use, which integrates natural regulation processes into farming activities to achieve a maximum replacement of off-farm inputs and to sustain farm income.’’ It is based around a similar range of the core components to regenerative agriculture, although integrated farming did not always include the integration of livestock as a core component.
So it appears that the two approaches are quite similar, but with a stronger focus on soil health with regenerative agriculture. Both approaches are flexible as the system that is devised needs to be adapted to local conditions, cropping, desired environmental outcomes, etc.
Evidence about their effectiveness to achieve environment improvements and increase profits are relatively scarce at farm scales or larger. Integrated farming and similar approaches were investigated in a series of long-term studies during the late 1980s and 1990s, but I’m not aware of much research since that time in Europe. The outcomes of this research on biodiversity and the environment were summarised from across Europe1 for 11 projects4. Across these studies a range of environmental, agronomic and economic metrics were investigated. In terms of inputs, overall IFM reduced nitrogen use by 18%, herbicide use by 43%, fungicides by 50% and insecticides/molluscicides by 55% compared with conventional management. IFM generally resulted in slightly lower crop yields, but the overall effect on net margins was usually slightly positive due to reduction in pesticide and chemical fertiliser costs. This was achieved through a reduction in the need for inputs as a consequence of the systems approach, but also a move away from manufacturer’s label doses supported by research by distributor agronomy companies. The integrated farming consistently increased the number of existing plants, non-target arthropods and earthworms and in one study also the diversity of plants and earthworms. The main negative effect was an increase in weeds, but other pests did not cause problems. It was not possible in these studies to directly attribute benefits to particular practices though reducing tillage is known to benefit earthworms and invertebrates5, whilst reducing herbicides and insecticides also benefits invertebrates. Crop type was also an important driver for biodiversity, especially switching to spring sown crops because they had more weeds but sometimes less invertebrates, whilst root crops such as potatoes were damaging to earthworms, as might be expected. The impact on birds and small mammals was rarely investigated although cover crops were shown to benefit birds.
Most of these Integrated farming research projects were arable only approaches and it was quite apparent that a much more sustainable system could be achieved by integrated livestock production or at least including some diverse leys that could help restore soil fertility and organic matter, providing a longer break to reduce weed and diseases. Regenerative agriculture includes this as a core principle which is a step further. Reducing the intensity of soil tillage was also at the core of integrated farming which today is much easier because of the greater knowledge and availability of dedicated minimum tillage machinery.
The evidence that Regenerative Agriculture delivers agronomic, economic and environmental benefits is difficult to ascertain because it has been defined in so many ways. The review by Burgess et al2 looked at approaches that are defined as regenerative while one from the USA6 sought out farms conducting the key regenerative practices (cover crops, not using insecticides, minimum tillage and integration with livestock).
In the USA on regenerative farms, maize crop insect pest populations were ten times lower and twice as profitable compared to insecticide treated farms, despite a 29% yield reduction. This was achieved though reductions in fertiliser, seed and irrigation costs, along with greater revenue from having meat production, selling directly to consumers and pricing extra livestock feed with cover crops. The profitability of the maize field also increased with the particulate organic matter level and decreased with increasing soil bulk density (soils with high soil organic matter have low bulk density).
So is Regenerative Agriculture the new silver bullet? Perhaps not new but I’m in favour of any approach that creates a more sustainable and environmentally friendly practices. It’s another name for what is good agricultural practice and in particular improving soil health through increasing the level of soil organic matter.
The link between higher profitability and higher organic matter is crucial to encourage adoption and there is also a compelling argument for reversing climate change. It has been estimated that adoption of regenerative agriculture across the worlds managed lands (crops, pasture and forests) could reduce atmospheric carbon by 50 parts per million to 350 in five years 7 Regenerative agriculture therefore has a key role to play in reaching Net Zero in the UK by 2050.
John Holland, January 2020
Source: Game & Wildlife Conservation Trust