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Soil: An overlooked resource in the fight against global warming and hunger

Well-nourished soil can reduce carbon emissions and increase crop yields

April 22, 2020

On this 50th anniversary of Earth Day, we think of our fight against climate change, and one image that readily comes to mind is planting more trees. Trees are indeed effective at helping to convert carbon dioxide into oxygen, but surprisingly it’s not only a lack of trees that contributes to an unhealthy atmosphere. Here’s the reality: deforestation releases carbon held in the soil into the atmosphere as carbon dioxide. In fact, because of this, deforestation alone is to blame for 11% of all global greenhouse emissions. Experts have found that there is two to three times more carbon in soil than the amount of carbon in the atmosphere and all plant life combined.

Soil is an often-overlooked and largely misunderstood natural resource. Pedro Sanchez, of Columbia University’s Earth Institute says:

“We know more about soils of Mars than about soils of Africa”​

Soil can help prevent floods and supply us with drinking water, and now environmentalists are looking to use it as a way to help impede the growth of global carbon emissions.

Climate change in impoverished countries exacerbates soil degradation leading to a loss of crop production and income. Not only is land degradation bad for the climate and for agriculture, but it also costs us trillions of dollars per year.

The United Nations determined that we have the potential to store up to 3 billion tons of carbon annually by restoring the soils of degraded ecosystems. A small annual increase in global soil carbon stocks would be enough to offset CO2 emissions from fossil fuel burning. To do so would involve the process of carbon sequestration, where carbon dioxide is removed from the atmosphere and converted into soil organic carbon.

Soil that is enriched by carbon dioxide gives life to trees and vegetation, and provides arable land. In addition to helping slow global warming, carbon in soil also:

  • helps protect areas from environmental impacts, like floods or droughts
  • encourages plants to absorb more carbon, which helps restore farmlands, meadows and forests
  • provides more fertile land: agricultural yields in Honduras have almost doubled thanks to sustainable soil management

The United Nation’s Food and Agriculture Organization (FAO)’s RECSOIL initiative, campaigns for the recarbonization of global soils and recognizes that farmers are the key agents of change. The initiative provides support for sustainable soil management practices to increase soil organic carbon stocks, promises to enhance farmer income through increasing soil productivity and contributes to improved food security and nutrition.

These practices are not only necessary in developing countries; developed countries are major culprits of poor land management, from improper fertilizer use, over-tillage and over-pasteurizing. Poor land management is the main cause of emissions from agriculture, so sustainable techniques for managing land, water and soil are necessary worldwide.

What are sustainable land management practices that help enhance soil carbon levels?

  • mulching
  • zero tillage
  • green manuring and proper fertilizer usage
  • water harvesting
  • covering bare fields with perennials or cover crops after an annual harvest
  • rotational grazing: allowing old pastures to regrow and spread manure left by grazing animals

“Nowhere else in the biosphere do we have greater potential to effect substantive, positive change than in our soils.”

- United Nations

This is obviously good for the environment and for farmers, but how does it affect YOU individually?

Soil degradation impacts any industry that uses plant or animal products in their supply chains, including pharmaceuticals and fashion, and are affected when crops fail. This in turn affects the consumer by rising commodity prices. So not only does soil affect the price of your food, but it also affects things like the price of your clothes, whose fibers were grown from soil, or the price of your prescription: it is estimated that 25% of prescription drugs are derived from plants.

Moving towards a more sustainable future

Experts argue that businesses need to have a higher stake in soil by lobbying for better soil practices and policies and by assessing how much their operations depend on soil. The FAO hopes this will lead to a growth of corporate social responsibility (CSR) practices by the aviation sector, which is one of the major contributors to the rise of greenhouse gases in our atmosphere.

Rene Castro Salazar of the FAO says at least 20 nations are combating land degradation through efforts to replant lost forests, and dozens of countries have designed programs to reverse the loss of farmland. The 4 per 1000 plan put forth by the United Nations charges stakeholders, such as governments, farming organizations and private businesses, among others, to commit to sustainable soil management practices to demonstrate that agricultural soil can play a pivotal role in ensuring food security and sustainable development. The name of the plan explains the amount of carbon - 4 parts per 1000 - necessary in the top 30-40 centimeters of soil to significantly reduce the amount of atmospheric CO2.

How does this figure into The Harvest Fund’s model?

As a social enterprise, The Harvest Fund’s goal is to help bring women farmers out of extreme poverty by enabling them to increase their annual income by 5X within 3 years, thereby generating greater economic opportunity. We believe that all food producers should have access to good soil, water, and seeds, yet, so many women farmers in low-income countries don’t. Our systems change model focuses on educating and empowering women farmers by providing them the right agricultural innovations as well as nutrients for productive soils and high-quality inputs (seed, fertiliser, and crop protection products).

In addition to these provisions - which the women partially pay into - we advocate climate-smart agriculture practices from day one beginning with an intensive crop management “bootcamp.” These practices focus on keeping carbon in the soil by, for example, minimizing tillage, intercropping maize with nitrogen-fixing legumes, and using post-harvest crop residue as field coverings.

Most importantly, as each cohort completes Year 1 in our program, we test their soils with an AgroCares scanner to identify key missing nutrients. We then create custom fertiliser mixes to re-introduce these nutrients into the earth. Alternatively, if sufficient manure and crop mixes are available, we instruct and encourage farmers on application of these resources to improve soil health.

When these provisions are used together, women’s incomes increase, their families have enough to eat, their children go to school, and their communities prosper. Follow us on Facebook to see how we help our women farmers realize that their soil is a key resource in the fight against hunger, malnutrition, and extreme poverty in Zambia, Africa, and beyond.

Additionally, on this Earth Day 2020, we encourage you to think about how you can reduce your carbon footprint in your daily life and invite you to tweet this article to show others that soil is more than just dirt.

Author Bio:

Sarah is devoted to educating others on environmental issues, and believes in the importance of writing about sustainable farming practices that provide solutions to a healthier environment. Her early experiences in the wilderness have led to a life-long passion for our planet, and she is pursuing a career dedicated to protecting wild places in the United States. Most recently, Sarah has been working at a science station in Antarctica and as a wilderness guide in Alaska.