Smart climate farming practices are gaining prominence on policymakers’ agenda to compensate for the impact modern farming has had on soil health and climate change. Unlike other issues within sustainability which require technological development, farmers can look to nature-based solutions within the agricultural sector. Promoting the adoption rate of such practices among farmers can have exponential benefits both for the climate and for land productivity, as they help improve the carbon reserves of soils, cut greenhouse gas emissions, while contributing to biodiversity restoration.
Cover crops cover carbon capture
It is the case of “cover crops”: the practice of keeping the land covered with plants during the winter instead of using fertilizers, by planting non-cash crops during the fall. These are crops that aren’t planted with the intention of selling their produce, but to reduce soil erosion, improve soil health, and to help with water retention. Different non-cash crops have different benefits: as they are early ground covers, farmers often choose brassicas (mustards and oilseed radish) to protect the land already from the autumn and improve deep rooting. Legumes (vetch and clovers), and cereals (winter wheat, rye and ryegrass) are best to diminish nitrogen in soil and raise fertility.
Planning in advance is key to the process, but it might be difficult to know how to fit them into crop rotation or what benefits each crop brings. Currently, only a small number of farmers are using this method: “Cover crops have a low adoption rate among U.S. farmers, less than 5%,” said William Hohenstein, director at the Office of Energy and Environmental Policy of the U.S. Department of Agriculture, during a webinar hosted by Columbia University on May 4.
When evaluating average fields in average weather conditions, researchers agree that it can take time to see results. A study from the Sustainable Agriculture Research and Education Department of the University of Maryland calculated that it can take up to three years for cover crops to pay off if no incentive payments are obtained. However incentives and crop schemes do currently exist in the U.S., and President Joe Biden seems willing to support these measures. In his address to Congress on April 28, Biden mentioned the national “agriculture innovation mission” and the importance of cover crops in fighting climate change. According to Hohenstein, cover crops remain one of the many practices in the Agriculture Innovation Mission’s package: “We are looking at policies and measures where we can incentivise farming practises that are ‘climate smart.’ These are practises that reduce GHG emissions, sequester carbon, generate renewable energy and make the agriculture system more resilient to climate change, while still improving productivity,”
The soil is a carbon reserve and plays an important role in its cycle because it is naturally exchanged between the earth’s ecological system and the atmosphere. These crops are also “carbon crops” as they help enhance carbon retention within land, the second deposit of carbon to the world, after the oceans .
As this practice has the ability to increase soil carbon concentration, and the adoption rate might increase in the next few years, its potential has captured investor’s and policy makers’ attention, as it can create further opportunity for carbon offsetting. Last April, the European Commission released a report assessing existing projects developed in the EU zone in the past two years and drawing conclusions to plan, set up and implement carbon farming in the EU.
The extent to which this practice can capture carbon more effectively is still being investigated, as models for accounting soil carbon benefits are still far from giving a reliable measure: ”No doubt there are some uncertainties in measuring soil carbon, there are a lot of variabilities, but we know that carbons accumulate over time and it will be easier to measure when we can collect sample on a larger scale,” said Hohenstein.
Don’t mow the lawn
A new report launched today (12 May) by the British Ecological Society details how nature based solutions can provide a valuable contribution to climate change mitigation and should complement other climate and conservation actions.
Besides its impact on soil erosion and health, modern farming practices and an increase in land use for agriculture have also affected the habitat and habits of pollinators. Bees are key to biodiversity, as they pollinate over 80% of the Earth’s flowering plants, including almost all fruit and vegetables, but large farms’ monocultures are deserts for these creatures as plantations of corn, wheat or soy do not blossom with flowers. Urban areas have a role to play in preventing the loss of pollinators as here they can find plenty of nectar and pollen due to the higher diversity of flowering plants in city parks, gardens and balconies.
Last year, the U.K. experienced the driest May since 1896. According to Plantlife, Europe’s largest conservation charity dedicated to wildflowers and other flora, that spring took its toll on flowering, with 56% fewer dandelion flowers and 40% fewer daisies growing on lawns. “56% less dandelions could have a serious impact on early emerging bumblebees for example – and these changes will be felt across other grassland habitats,” said Dr. Trevor Dines, botanical specialist at Plantlife.
The charity relaunched the No Mow May initiative which aims to raise awareness among gardeners that mowing the garden less often—ideally every four weeks—can attract up to ten times more bees.
The charity’s calculations show that less mowing can have a dramatic effect on peoples’ CO2 footprint, both because it means a lower energy consumption, but also because, as it happens with cover crops, grass swards with more species store more carbon in the soil.
A consortium of Belgian NGOs and other stakeholders is replicating the initiative at a national level. At least 10% of Flanders, the northern regions of Belgium, consists of gardens. Over 3,500 Belgians—and their gardens— signed up to the initiative in the first 10 days since it launched
Municipalities can also adopt smart biodiversity practices by avoiding cutting road verges: “About seven out of ten councils in the U.K. now are making efforts to encourage wildflowers on verges,” said Dr Kate Petty, road verge campaign manager at Plantlife.
The report from the British Ecological Society analyses as well the potential of urban trees in cities as carbon capture storages. Urban trees also provide a localised cooling effect, estimated to save $31 million in annual energy consumption across inner London.