Posts Tagged ‘green manure’

Dec04

Supporting Climate-Friendly Food Production

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By Laura Reynolds

This summer, record temperatures and limited rainfall parched vast areas of U.S. cropland, and with Earth’s surface air temperature projected to rise 0.69 degrees Celsius by 2030, global food production will be even more unpredictable. Although agriculture is a major driver of human-caused climate change, contributing an estimated 25 to 30 percent of global greenhouse gas emissions, when done sustainably it can be an important key to mitigating climate change.

Agroforestry is one practice that can reduce greenhouse gas emissions while adapting to the effects of climate change. (Photo credit: Christensen Fund)

Because of its reliance on healthy soil, adequate water, and a delicate balance of gases such as carbon dioxide and methane in the atmosphere, farming is the human endeavor most vulnerable to the effects of climate change. But agriculture’s strong interrelationships with both climatic and environmental variables also make it a significant player in reducing climate-altering emissions as well as helping the world adapt to the realities of a warming planet.

The good news is that agriculture can hold an important key to mitigating climate change. Practices such as using animal manure rather than artificial fertilizer, planting trees on farms to reduce soil erosion and sequester carbon, and growing food in cities all hold huge potential for reducing agriculture’s environmental footprint.

The United Nations Food and Agriculture Organization estimates that the global agricultural sector could potentially reduce and remove 80 to 88 percent of the carbon dioxide that it currently emits. By adopting more-sustainable approaches, small-scale agriculture in developing countries has the potential to contribute 70 percent of agriculture’s global mitigation of climate change. And many of these innovations have the potential to be replicated, adapted, and scaled up for application on larger farms, helping to improve water availability, increase diversity, and improve soil quality, as well as mitigate climate change. (more…)

Posted by Laura Reynolds in Agriculture, Biodiversity, carbon, Carbon Sequestration, Climate Change, Conservation, Drought, Environment, Erosion, Farmers, Indigenous, Indigenous Vegetables, Irrigation, Land, Livestock, organic, Permaculture, Research, Soil, Sustainable, Trees, Urban Farming, Water

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Nov22

Five Innovations that are Boosting Soil Fertility

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By Joseph Zaleski

Crops need air, sun, water, and soil to thrive. When it comes to soil, however, quality usually trumps quantity. Rich and fertile land boasts a healthy mixture of phosphorous, potassium, and nitrogen, along with water, air, and soil micro-organisms that break down organic matter.

But what happens when these elemental building blocks are disrupted? The Green Revolution of the mid-20th century implemented a variety of practices, including the widespread use of pesticides and fertilizers. Yet, improperly applying the Green Revolution’s principles can sometimes do more harm than good. Overfertilizing and destructive land use practices, including deforestation, can deplete vital nutrients in soil, and no amount of inorganic fertilizer can replace fundamental topsoil. In addition, higher annual temperatures, more extreme weather events and persistent droughts, and increasing population are also exhausting the land. These conditions are creating a cycle of soil degeneration which is stunting agricultural yields and presenting farmers with a new crop of concerns.

Today, Nourishing the Planet provides five methods that farmers and scientists are using to combat rising soil infertility.

Soil is an ecosystem unto itself. It’s what we don’t see underground that makes or breaks a harvest. (Photo credit: Bernard Pollack)

1. Cover Cropping / Green Manure: In our State of the World 2011 report, agroecologist and author Roland Bunch defines cover crops / green manure as “any plant, whether a tree, bush, or vine, that is used by a farmer to…improve soil fertility or control weeds.” In practice, cover crops are planted alongside or interspersed with other crops to cut soil-eroding wind, prevent overexposure to the sun, and stimulate a healthy soil system. Just as farmers will turn to manure to bolster the soil, they can also clip and spread cover crops’ leaves as organic green manure.

Cover Cropping / Green Manure in Action: According to Roland Bunch, there are more than a million farmers now actively using cover crops / green manure worldwide. In Africa alone, there are over 120 plant species that are being used or could be used for this purpose. One promising example is the cowpea (also known as the black-eyed pea). This legume is both a nitrogen-fixer, which means that it takes nitrogen from the air and replenishes it in the soil, and deeply rooted, which makes it resistant to drought. Furthermore, the cowpea itself is a nutritious staple food for both people and animals.

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Posted by Nourishing the Planet in Agriculture, Fertilizer, Livestock, Permaculture, Soil, Waste, Water

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Jun07

What Works: Healing the Soil with Agriculture

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By Mara Schechter

This post is part of a series where Nourishing the Planet asks its readers: What works? Every week we’ll ask the question and every week you can join the conversation!

Africa’s declining soil fertility has already caused yields to drop by 15 to 25 percent in six African countries, including Malawi, Zambia, Kenya, Uganda, Mali and Niger, according to Dr. Roland Bunch, Director of Sustainable Agriculture and Rural Livelihoods at World Neighbors, in his chapter of State of the World 2011.

Agroforestry and inter-cropping are two practices that are helping to heal the soil. (Photo credit: Bernard Pollack)

Dr. Bunch suggests using green manure/cover crops, or living trees, bushes and vines, to improve soil health and avoid a potential famine. In Mali, the Dogon people have developed a multi-layered system, where they plant leguminous trees, such as acacias, and trim them annually to provide shade and fertilize their fields. Many Dogon farmers now have yields that are three times higher than the average yield of other Sahel areas with similar rainfall.

In other parts of the Sahel, farmers are reviving traditional management practices. Farmer-Managed Natural Regeneration (FMNR) is a process that involves pruning the stems of indigenous trees to cultivate and regrow trees. This revegetation is helping restore the area’s land: the trees release nitrogen into the soil and protect the soil from erosion.

To increase the use of FMNR, the Web Alliance for the Re-Greening in Africa (W4RA) has created web-based information exchanges between farmers, and the organization, SahelEco, has started Trees Outside the Forest and the Re-Greening the Sahel Initiative to effect policy changes that support FMNR.

Integrating trees with crops is part of an approach known as agroforestry. The World Agroforestry Centre is helping farmers use a combination of agroforestry and conservation farming methods, known as Evergreen Agriculture. Evergreen agriculture can help not only improve soil moisture and nutrients, but also reduce agricultural inputs–leguminous trees, for example, add nitrogen to soils naturally–and enhance food security. In Malawi, intercropping acacia trees with maize increased yields by up to 280 percent.

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Posted by Nourishing the Planet in Africa, Agriculture, agroforestry, Environment, Erosion, Farmers, Soil

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