Conservation Agriculture Research Updates - May 2024

Soil health has become a foundation for sustainable goals associated with mitigation of climate change and reversing soil degradation and loss of biodiversity. There is also an array of indicators of soil health but what are the key indicators important for soil health outcomes and ecosystem functioning? This paper proposes and integrated approach to assess soil health.They list important key indicators because of their position in the soil food web and linkages to key soil processes. They recommend that future soil health assessments directly measure soil organisms in conjunction with indicators that reflect key ecosystem functions. 

This article advocates for sustainable soil management to prevent soil degradation and maintain food security and ecosystem services and indicates that regenerative agriculture (RA) is gaining momentum in the UK. But they suggest two knowledge gaps that need further research - 1) what do farmers consider are sustainable management and and how these  relate to regenerative agriculture; 2)how are sustainable management promoted in agricultural knowledge and innovation services (AKIS). They used a national scale survey to address these two information gaps. They found high levels of awareness (>60%) and uptake (>30%) of most sustainable soil management practices among mixed and arable farmers. Importantly, 92% of respondents considered themselves to be practicing sustainable soil management. Overall, they conclude that there are multiple understandings of sustainable soil management among UK farmers and land managers and that they do not correspond to regenerative agriculture principles in a straightforward way. By the way, this paper says that  RA principles are based on reduced soil disturbance, soil cover and crop diversity. Those are the same 3 pillars of CA!

This is an interesting article that compares regenerative agriculture with CA in a Mediterranean climate that is characterized by poor quality soils, high climate variability, and resulting heavy agrochemical reliance. CA has helped with these issues and enhanced crop productivity and helped mitigate financial risk, but other issues including herbicide resistance, input costs rising, and increasing climate variability require attention. The aim of this review was to evaluate a set of agroecological practices that constitute a Regenerative Agriculture (RA) concept, for their potential to address these challenges from a soil quality, crop productivity and whole-farm economics perspective. Organic soil amendments from agro-wastes and multi-species cover crops subjected to adaptive multi-paddock (AMP) grazing as a phase within the crop rotation to reduce weed pressure, enhance soil multi-functionality, and resilience against environmental stresses were two interventions discussed. However, they recommend the need for more long-term and context specific research in the future to validate these technologies.

This paper reviews the international literature through a sustainability framework. It identifies precision CA, digital agriculture (DA) and resilient agriculture (RA) practices as being of value in meeting future challenges. They further note that although adopting CA, DA, and RA would improve the sustainability of present agriculture, adoption of these systems is slow. They recommend  more in-depth social science research to better understand how to get better uptake and barriers that impede farmer adoption.

This paper starts by saying Green Revolution (GR) agriculture is faltering and needs to be replaced to meet the needs of the Sustainable Development Goals (SDGs). It describes the role of CA in accomplishing this goal. They explain that CA can raise productivity, reduce inputs, regenerate degraded land, reduce erosion, and improve the flow of ecosystem services and so contribute to several SDGs. It highlights that CA is spreading globally at an annual rate of about 10 mHa per year. In 2015-16 it was estimated to cover 180 Mha with 48% in the Global South. It further discusses what is needed for CA to contribute to SDGs to contribute to lasting  quality of human life and nature.

This paper explains what "Regenerative Agriculture" is from an agronomist point of view. Why is it gaining such prominence? Which problems does it solve, and how? It has been promoted strongly by civil society and NGOs as well as by many of the major multi-national food companies. Many practices promoted as regenerative, including crop residue retention, cover cropping and reduced tillage are central to the canon of ‘good agricultural practices’, while others are contested and at best niche practices (e.g. permaculture, holistic grazing). The paper suggests RA represents a re-framing of what have been considered to be two contrasting approaches to agricultural futures, namely agroecology and sustainable intensification, under the same banner. More importantly, it draws attention away from more fundamental challenges.

This 2020 paper discusses Regenerative Agriculture (RA). They looked at 28 studies to identify activities that fit the definition of RA. Convergence was found to be related to environmental enhancement, and stress socioeconomic issues that impact food security, but the latter were general and lacked ways to implement. The paper suggests that the definition of RA and approach to farming should use soil conservation as an entry point to regenerate and improve various ecosystem services.

This paper reviewed 92 empirical studies that investigated the effects of 17 regenerative farming practices across 11 broad categories of crops on SOC stock or content in Southeast Asia. They found that use of organic amendments like biochar, compost, and manure, as well as cover cropping, crop rotation, and conservation tillage to increase SOC. However, addition of compost and manure reported increases in greenhouse gas emissions like methane (CH4) and nitrous oxide (N2O), demonstrating that increases in SOC may be offset by increases in greenhouse gas emissions. Only a few studies measured both the changes in SOC stocks and greenhouse gas emissions and none of the studies completed full greenhouse gas inventories. 

This paper was included because it includes information on regenerative agriculture (RA) and permaculture (P). They promote these two practices because present farming practices have adverse impacts on natural resources, ecosystem services and sustainability of food production, especially in developing countries. The paper examines the affects of RA, P, and Smart technology (ST) on sustainable production, decision support systems, and Global food security. They state "Collectively, regenerative agriculture and permaculture are semi-closed holistic systems approach designed to reduce or eliminate dependence on external inputs" that restore and maintain natural systems. What I didn't find in the abstract was information of what management systems achieve RA or P and what impact they have on yield or farmer security.

This paper by a renowned soil scientist looks at regenerative agriculture (for 5-10 years) compared to conventional Synthetic fertilizer, and herbicide). They used paired farms with these two practices across the USA and found soil health and crop nutrient density differences. Farms that used CA produced crops with higher SOM, soil health scores, and levels of nutrient density in the crops. Their data support the conclusion that regenerative agriculture (using CA) enhance the nutritional profiles of plant and animal foods.