With the potential to enhance soil health, increase biodiversity and foster resilient crop production systems, regenerative agriculture has captured the attention of farmers, policymakers, and consumers worldwide.
Small-grain cropping systems in Mediterranean-climate regions are often compromised by a legacy of tillage practices, inherently impoverished soils, and a mismatch of crop water requirements during critical growth stages and rainfall distribution. In some Mediterranean rainfall regions like South Africa and Australia, conservation agriculture (minimum soil disturbance, permanent soil cover, and rotational cropping) has contributed significantly to preserving and restoring these soils and the ecosystem processes. However, more erratic and extreme weather events associated with climate change and heavy dependence on potentially harmful and increasingly costly agrochemicals still threaten these systems’ sustainability. Regenerative agriculture practices were evaluated for their potential to address the challenges.
Researchers from Stellenbosch University, Department of Agronomy, and the Western Cape Department of Agriculture in South Africa, have described a set of agroecological practices comprising a Regenerative Agriculture concept adapted for existing small-grain conservation agriculture systems under dryland Mediterranean conditions. Recent literature discusses expectations for these individual measures that produce specific ecosystem services from a soil quality, crop productivity, and economic perspective.
Although lacking a clear-cut scientific definition, key characteristics distinguishing ‘regenerative’ systems from conservation agriculture are an integrated approach to managing pests and diseases, minimising agrochemicals, and an emphasis on fostering environmental and economic resilience.
Various innovative practices and technologies aligned with the ‘regenerative’ concept may be employed to achieve this. Organic soil amendments, like biochar and compost, derived from agricultural wastes, show promise for supplying large quantities of organic matter that may improve soil structure and associated water-retentive and erosion-preventive properties of the soil. These amendments may also contribute to soil fertility as they build up a nutrient ‘bank’ in the soil with slow release of nutrients and minimising leaching losses. The efficacy of microbial and non-microbial, so-called bio-effectors or biostimulants, is under much scrutiny for their role in field conditions. Recent research indicates that the non-microbial bio-effectors and specific combination options show the most promise, particularly in the Mediterranean context, where environmental stresses (heat, moisture, soil salinity, and nutrients) are commonplace. Bio-effectors still need more site-specific research in the given context.
Although the grazed pasture phases utilised in many conservation agriculture systems have provided soil quality, weed suppression and economic benefits, innovations from other farming systems demonstrate further potential realisable benefits. As an alternative to the continuously grazed single-species pasture phases, which are standard practice, the option of growing multi-species cover crops subject to high-intensity rotational grazing may provide superior benefits, including, although not limited to, improved fodder flow, weed control and soil health, as well as reduced erosion and leaching.
More context-specific research is needed for the value of the ‘regenerative’ approach to be accurately assessed for these systems evaluated accurately, holistically considering all the associated benefits and trade-offs of the specific technologies. Nevertheless, the explored technologies constituting a ‘regenerative’ concept show promise in Mediterranean-climate regions.