Conservation and regenerative agriculture ("CA/RA")
Conventional cultivation, a practice where land is tilled to a certain depth, left bare for a period of the year and a mono-crop grown, results in soil degradation, soil carbon loss and loss in productivity. In response, a range of interventions have emerged that limit soil disturbance and loss, create sources of soil organic content and introduce a variety of crops and other species that together improve soil health and production over time. This is termed CA/RA.
Conservation Agriculture requires, as a minimum, that farmers follow three key practices :
Minimum soil disturbance
(i.e. no till)
Crop rotation and species diversification
Soil cover with crops, cover crops and residue retention
In addition to this minimum set of criteria, where appropriate, farmers are encouraged to adopt further activities, termed Regenerative Agriculture, such as the integration of livestock, maximising annual growing periods and reducing chemical use.
The key principles complimenting good agricultural practices of conservation and regenerative agriculture systems:
Benefits of CA/RA for the farmer
Cost savings – reduced fuel and operating costs: Completely halting tillage and the turnover of soil, significantly reduce tractor usage and associated diesel consumption. Overhead costs of tractor and equipment maintenance are also significantly reduced. Field assessments in the Western Cape have indicated that a reduction in power consumption (including diesel usage, tractor hours, tractor size) of 50% can be reasonably expected.
Cost savings – reduced use of fertiliser and agrichemicals: CA/RA reduces the need to apply synthetic fertilisers and other agrichemicals over the medium to long term. Depending on the objectives and practices of the farmer, in a South African context, a reduction in synthetic fertiliser usage of 15% to more than 50% in the first 5 years is achievable.
Improved soil health and erosion control: Planting a diversity of crops and maintaining organic soil cover throughout the year lead to an increase in microbial activity, soil health and a significant reduction in the loss of topsoil through wind and water erosion.
Increased water holding capacity and adaptation to climate change: Increasing the organic content of soil leads to an increase in water holding capacity, which in addition to reducing immediate irrigation needs, can have a profound impact on the magnitude and resilience of production, especially in dryland systems. CA/RA is a crucial climate change adaptation response, especially in regions that are predicted to become significantly hotter and drier over time.
Increased crop yields and additional income from carbon: South African studies have shown that CA/RA leads to stable, and even increased, production and associated income over time. In addition, the sequestration of carbon in soils and a decrease in GHG emissions mean farms can be eligible for carbon revenues, which together with increased crop sales and a reduction in operating costs ensure greater profitability for farmers.