Soil Health

Main ways to improve soil health

• No till agriculture
• Introducing a cover crop
• Using herbivores and selective grazing
• Adding biochar to the soil
• Avoiding herbicides and pesticides which kill helpful mycelium and bacteria

In one 1.8 hectare farm in India they are able to produce enough food for 15 people https://www.youtube.com/watch?v=P6BL_64HJ88&list=PLEIUu-htPZpgUk-RQM8ofwAMS...

Imagine a wonderful world, a planet on which there was no threat of climate breakdown, no loss of freshwater, no antibiotic resistance, no obesity crisis, no terrorism, no war. Surely, then, we would be out of major danger? Sorry. Even if everything else were miraculously fixed, we’re finished if we don’t address an issue considered so marginal and irrelevant that you can go for months without seeing it in a newspaper.

It’s literally and – it seems – metaphorically, beneath us. To judge by its absence from the media, most journalists consider it unworthy of consideration. But all human life depends on it. We knew this long ago, but somehow it has been forgotten. As a Sanskrit text written in about 1500BC noted: “Upon this handful of soil our survival depends. Husband it and it will grow our food, our fuel and our shelter and surround us with beauty. Abuse it and the soil will collapse and die, taking humanity with it.”

The issue hasn’t changed, but we have. Landowners around the world are now engaged in an orgy of soil destruction so intense that, according to the UN’s Food and Agriculture Organisation, the world on average has just 60 more years of growing crops. Even in Britain, which is spared the tropical downpours that so quickly strip exposed soil from the land, Farmers Weekly reports, we have “only 100 harvests left”. George Monbiot - Guardian Article

Zai, is a farming technique to dig shallow pits in the soil during the preseason to catch rain and collect compost. Traditionally used in western Sahel to restore degraded drylands and increase fertility. One farmer (Yacouba Sawadogo) filled them with manure and compost to provide plant nutrients. The manure attracted termites, whose tunnels helped further break up the soil. They helped improve the yields of trees, sorghum and millet.

Is there a link to to GHG emissions? "Land misuse accounts for 30% of the carbon entering the atmosphere... No other natural process steadily removes such vast amounts of carbon dioxide from the atmosphere as photosynthesis, and no human scheme to remove it can do so on such a vast scale with any guarantee of safety or without great expense... with good soil practices we could reverse global warming."

"Worldwide, if the organic matter- which is about 58 percent carbon- in all the land that we currently farm and graze were increased 1.6 percent to a foot in depth, atmospheric C02 levels would be at pre-industrial levels... that carbon might as well go into the soil where it can do some good."

According to Christine Jones, soils hold more carbon than the atmospheres and all the worlds plant life combined- and can hold it longer, in a more stable form than, say, trees. The carbon pools of most of the world's agricultural soils have been depleted between 50 and 70 percent.

Cover Crops: they help replenish the soil when so much of agriculture is about taking away from the soil. They protect the soil from the sun by offering shade, and depending on the plant the farmer chooses they can add nutrients like calcium or nitrogen back in the soil. Jay Fuhrer explains, “when you apply cover crop combinations to your cropping system, you can accelerate biological time. You can improve the soil health, feed a balanced diet to soil microorganisms, store carbon, improve water filtration- all this faster… [whereas] if you have low crop diversity, you will run into problems and require inputs.” One farmer found that using cover crops dropped his herbicide cost in half and also led to less use of the tractor and significant fuel savings because it was harder for weeds to move into the land when the cover crop was already there.

The added biodiversity makes the land more resilient to drought, the more extensive microorganic tunneling helps the soil receive water from flooding, and for ranchers cover crops provide a significant source of feed for cattle thereby significantly reducing their operational costs. Crop rotation can be specifically planned to address fertility goals for a farm, adding biodiversity and preventing pests, weeds, and disease through building soil fertility.

Why is this so important? If soils are degraded they lack the capacity to store carbon. The remaining carbon is oxidized and contributes to climate change. Absent plant cover and moisture, the bare ground absorbs heat... when this happens on a large enough scale you change the macroclimate of an entire continent. The added heat makes any moisture that is present more prone to evaporate, and lack of moisture makes the soil more inhospitable to micro-organisms, which deprives plants of nutrients and means fewer types of plants are able to grow in such a region which limits the number of birds and insects that might pollinate or spread seeds. Then sparse vegetation means little protection from winds or heavy rains which leads to more soil blowing away and more carbon oxidizing.

Bruges, James. The Biochar Debate: Charcoal's Potential to Reverse Climate Change and Build Soil Fertility. White River Junction, Vt.: Chelsea Green Pub., 2010. Print.
Cernansky, Rachel. "Agriculture: State-of-the-art-soil." Nature. Nature Publishing Group, 14 Jan. 2015. Web. 8 Apr. 2015. .
"International Year of Soils 2015 - IYS 2015." GSP: IYS 2015. Web. 8 Apr. 2015. .
Monbiot, George. "We're Treating the Soil like Dirt. It's a Fatal Mistake, as Our Lives Depend on It." The Guardian, 25 Mar. 2015. Web. 8 Apr. 2015. .

Ohlson, Kristin. The Soil Will save Us: How Scientists, Farmers, and Foodies Are Healing the Soil to save the Planet. Rodale. Print.
Schwartz, Judith D. Cows save the Planet and Other Improbable Ways of Restoring Soil to Heal the Earth. White River Junction, Vt.: Chelsea Green Pub., 2013. Print.
Zhang, Jining, and Fan Lu. "Multiscale Visualization of the Structural and Characteristic Changes of Sewage Sludge Biochar Oriented towards Potential Agronomic and Environmental Implication." Nature.com. Nature Publishing Group, 24 Mar. 2015. Web. 8 Apr. 2015. .