A Sustainable Solution for Agriculture Practises and Biodiversity: Cover Crops
Climate-smart agriculture practices are developed to compensate for the negative impacts of modern industrial agriculture on soil health and climate change, taking into account climatic conditions and standing out on the current agenda of policymakers. Unlike other issues that require high-technological development within the scope of sustainability, farmers can be directed towards nature-based solutions in the agricultural sector: Promoting the adoption of natural and climate-friendly practices among farmers can help improve soils’ carbon reserves, cut greenhouse gas emissions and contribute to the restoration of biodiversity, with significant benefits for both climate and soil fertility. At this point, ‘’cover crops’’ hold strong potential.
What are ‘’cover crops’’?
‘’Cover crops’’, which we encounter as the practice of keeping the soil covered with plants during the months of winter, instead of using fertilisers by planting plants (which will not cause a loss of income to the farmer) in the autumn, are considered among the most important practices in terms of natural methods of agriculture. Cover crops are planted not for sale but to reduce soil erosion, improve soil health, and help the soil retain water. Moreover, cover crops help smother weeds and control pests and diseases in farming lands.
Each cover crop has different benefits. Farmers choose ‘’wild mustard (Sinapis arvensis)’’ and ‘’oilseed radish (Raphanus sativus)’’ seeds as cover crops due to the rapid growth of vegetation on the soil to protect their lands from the effects of adverse weather conditions and to improve the rooting of the crops they will plant. Legumes and grains [winter wheat (Triticum aestivum), rye, and ryegrass] are best at reducing soil nitrogen and increasing fertility. Cover crops mostly include mustard, alfalfa, rye, clovers, buckwheat, cowpeas, radish, vetch, Sudan grass, and Austrian winter peas.
For the successful process of using cover crops, advance planning is pivotal to yield efficiency; however, it can be challenging to determine crop rotation since it is included with a specific plan, and it should have been known what benefits each product will provide. Because of these difficulties, only a small number of farmers use this method today.
Soil, a carbon reserve, play a vital role in carbon exchange between the earth’s ecological system and the atmosphere within a natural cycle. These crops, used as cover crops, are also ‘’carbon products’’ since they help increase carbon sequestration on land, the world’s second carbon depository after the oceans.
The utilisation of cover crops attracts the attention of investors and policymakers with the potential to create much more opportunities for carbon offsetting, as it has the ability to increase the carbon concentration in the soil, and its prevalence is likely to increase in the next few years. In April 2021, the European Commission published a report evaluating existing projects in this area developed in the last two years in areas included in the European Union region and drawing conclusions for planning, establishing and implementing ‘’carbon farming’’ in the countries of the European Union.
The report emphasises that the extent to which cover crops can capture carbon more effectively is still under examination, and there are some uncertainties in measuring carbon in soils. Still, due to carbon accumulation over time, measurement can be made more easily when samples are collected on a larger scale.
A new report published by ‘’The British Ecological Society’’ in 2021 explains how nature-based solutions, such as the utilisation of cover crops, can contribute to reducing the negative impacts of climate change and why they can be collectively integrated with different climates and nature conservation actions. The report also explains how it should be implemented and analyses the potential of trees left inside cities as carbon capture stores.
The Importance of ‘’Carbon Farming’’
1.550 billion tons of carbon stored in the soil is soil organic carbon and 950 billion tons of inorganic carbon. The amount of carbon stored in the soil is approximately 3.3 times that found in the atmosphere (760 - 800 billion tons).
Due to the adverse effects of climate change and global warming, the organic carbon in the soil is seriously decreasing. However, if necessary precautions are taken, greenhouse gas emissions from the soil can be reduced.
Capturing carbon in the soil can be a bridge to the future regarding stopping the catastrophic consequences of climate change. Therefore, it needs to be taken back billions of tons of carbon from the air and returned to the soil. Concerning this, there is a need for a ‘’soil revolution (to improve and make it healthy)’’.
It is required to change and renew the route in agriculture. Farmland is the key to achieving a climate-neutral economy and net-zero greenhouse gas emissions. Because the soil can capture CO2 in the atmosphere and reduce the CO2 concentration; so, the soil can turn into a carbon sink. In addition to agricultural improvement practices, carbon farms increase the amount of carbon dioxide (CO2) stored in the soil and reduce its presence in the atmosphere. If the soil is managed by its nature, it becomes an important greenhouse gas sink area or organic carbon storage area, biodiversity increases, and carbon footprint decreases.
Frequent and deep tillage should be stopped because frequent and deep tillage causes carbon to escape from the soil. Conservation tillage is an important measure to increase soil conservation and sequester atmospheric carbon in relation to climate change mitigation.
The more the soil is vegetated, the grass is used as animal feed, and the compost is produced from animal manure, the more organic carbon is naturally stored in the soil. As a result, the soil becomes a significant carbon sink and becomes rich in organic carbon.
With ‘’carbon farming’’, the greenhouse gas carbon in the atmosphere is absorbed by the soils and the soil is enriched in terms of carbon. Through the biological process in properly managed and operated soils, crops absorb (bind) carbon dioxide from the atmosphere and release carbon into the soil through roots, root secretions, seeds and plant residues at different soil profile depths. In this respect, the place where carbon is the best and most practical is the soil.
Regarding cover crops and carbon farming, it is very significant that we analyse, measure and map because it is achievable to make enhanced soils resistant to climate change and improve agricultural product quality through carbon farming.
Farmers hold the potential to become climate farmers. This potential is very effective in reducing the negative effects of climate change. It should also be noted that soil cultivation as carbon sinks creates new business economic opportunities for farmers, foresters and other land managers. These practices are also critical in terms of the circular and local economy.
To summarise, it can be said that all the reports and studies that have been prepared reveal that nature-based solutions can be offered in all habitats. Furthermore, it should be remarked that investments in such natural practices have the potential to be a highly effective mechanism for achieving carbon capture not only within the agricultural sector but also for greater biodiversity and productivity.
You can read Deniz’s article on agroecology, another sustainable agriculture practice, here.