By John B. (JCAJ)
Agriculture is essential to society. In 2020, it was reported that around 4.8 billion hectares were used for agricultural purposes globally, which is 37% of the world’s total land area.1 But agriculture is also a massive contributor to global greenhouse gas emissions, being responsible for 24%.2 Some of these emissions are inevitable, such as the methane produced during the digestive process of cows. However, a large part of these emissions is a result of the inadequacies of conventional farming practices. These practices focus on alleviating the financial burdens farmers have by maximising yield, and thus revenue, in the short-term.
However, these practices often have disastrous long-term consequences for ecosystems and the farmers themselves. One such example is intensive tillage. Tilling is a process to loosen and aerate soil, essentially mechanically disturbing it, to prepare it for planitng. It disrupts the soil’s structure, leading to the loss of soil organic matter (SOM) – which contains organisms and decomposing matter and acts as a carbon sink – thus resulting in carbon emissions.
In an attempt to fix this, over the past few decades, there has been a call from the scientific community to change the way that the agriculture industry operates globally, and to encourage practices which are more sustainable environmentally and socially. One way this has been done is through the encouragement of regenerative agriculture (RA). RA focuses on championing ecological processes and leveraging them to reduce the environmental and ecological impact of farming, and, reportedly, to increase the yield of farms and potentially profits. It is not a single practice or method, but rather an agricultural philosophy.
One focus of regenerative agriculture is to maintain, and even improve, the health of soil. Soil health is defined by Intergovernmental Technical Panel on Soils (ITPS) as ‘the ability of the soil to sustain the productivity, diversity, and environmental services of terrestrial ecosystems.’3 As such, soil health is essential to the long-term success of agriculture without the need to introduce synthetic compounds such as fertilizers to supplement the plants with nutrients healthy soil would naturally provide them with. One principle of RA is to minimize soil disturbance. Minimizing soil disturbance keeps the soil structure intact, resulting in less carbon escaping and more water retention as well as maintaining microbial communities all of which are either beneficial or do not impact crops.
Another essential RA principle is encouraging species diversity, contrary to the conventional monocropping practice. Different species of plants have different types of roots, and so by planting different species near to each other, these different root types intermingle and break up the soil, aerating it and improving water filtration. Furthermore, the different roots mean that there is a greater access to nutrients, and thus nutrient cycling increases. This ultimately reduces dependence on synthetic fertilizers and supports the sustainability of farms.
Similarly, cover crops increase the organic matter in the soil as they grow and decompose. Perhaps more importantly, cover crops provide shelter for the soil below: this protects it from wind erosion and drying out by the sun whilst providing a insulating layer for the soil. Cover crops can also be used as a natural fertilizer. Some plant species, particularly legumes such as clover, have nitrogen-fixing bacteria nodules in their roots. These convert ammonia in the soil into useful nitrogen compounds which can be used by the plants for growth.
While the apparent benefits of regenerative agriculture seem endless, the actual benefits rely heavily on policymakers and individual farmers switching from conventional and unsustainable practices to RA practices, which often is no small task given the associated uncertainty of switching methods for farmers and the short-term yield loses (often 5-20%) – which is often too high for farmers who are struggling to get by as it is.
References:
1FAO. 2020. World Food and Agriculture – Statistical Yearbook 2020. Rome. https://doi.org/10.4060/cb1329en [Accessed 1 October 2024].
2Food and Agriculture Organization Report on Climate Change and Agriculture (2023)
3 ITPS. 2020. Towards a Definition of Soil Health. https://openknowledge.fao.org/server/api/core/bitstreams/ffb5feaf-8388-4e2f-b319-2260a9a6f5a2/content [Accessed 1 October 2024].
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