“Introducing (though to many he needs no introduction) Agmates member Allan Yeomans.
I have tremendous respect for Allan and personally regard him as of the great contemporary “thinkers” in world Agriculture. I approached Allan last week to see if he would share some of his wisdom, knowledge and insights with our online community.
Like all of us here at Agmates Allan has a burning passion for the betterment of the rural industry. Although this piece is twice as long as what I’d normally publish, it is an absolute cracker -
Your Agmate -Steve”
Allan [pictured below] writes.
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To fix global warming: is improving soil better than planting trees? We have to decide.
Back in the late 1980s I proposed the concept that we could combat global warming by sequestering atmospheric carbon dioxide from the air and converting it into soil organic matter.
Thankfully the idea has spread and is beginning to be considered seriously by those knowledgeable in soil science and atmospherics. But sadly not fast enough.
The Keyline System of soil land management was designed and developed by my father P.A. Yeomans on our family farms at North Richmond N.S.W. in the late forties and early 1950s.
Keyline management includes techniques for the rapid enhancement of soil fertility. Keyline is now taught in agricultural colleges and universities around the world. I’m a moderately competent meteorologist as my sport is flying and racing gliders. I’ve also lectured on meteorology.
Putting the two disciplines together presented an unusual concept. Soil enhancement, on a world scale could beat global warming; and all the climate change horrors would stop.
Regrettably the concept receiving exclusive government support and copious media attention is not soil; it’s the planting of trees.
So let’s compare, let’s first look at soil.
In my writings and lectures and in my book “PRIORITY ONE Together We Can Beat Global Warming” I argue we can restore the atmosphere to normal by increasing the organic matter in the world’s soils directly under man’s control by 1.6 percentage points (That’s a one percentage point rise in actual carbon).
The terms humus and organic matter are somewhat interchangeable. Both are the stuff that makes rich soil black. Organic farmers often exceed that 1.6 figure tenfold. It’s not hard to do.
So in essence we switch to an agricultural system that generally approaches that used by organic farmers. Keyline is itself such a system. We either stop using or drastically minimise the use of agricultural chemicals such as pesticides, fungicides, most herbicides and particularly ammonia based fertilisers. Those chemicals kill soil friendly earthworms as well as the friendly bacteria and fungicides that convert dead plant material into rich humus.
We re-adopt the old practice of crop rotation that sustained agriculture and food production for centuries.
And we also stop the practice of “turning the soil”. Turning a clod of soil upside down plays havoc with the specialised life cycle of our friendly soil bacteria, earthworms and fungi.
A hectare of soil 30 cm, a foot or 3 hands-width deep weighs about 4000 tonnes. A 1.6 percentage point increase in soil organic matter content is thus about 64 tonnes per hectare or near 40 tonnes of carbon. And to create that increase in soil fertility extracts 145 tonnes of carbon dioxide from the air.
An organic farmer, in the first few years will often sequester 150 tonnes of carbon dioxide from the air while massively enriching his soil and simultaneously producing huge quantities of healthy, tasty and nutritious crops. Production costs and yields for large scale organic farming are surprisingly similar to conventional based agriculture.
About three quarters of a hectare of agricultural land, grazing land, cropland, golf courses or whatever is every human’s individual foot print on our Earth. Remember that number.
Now let’s look at trees.
A reasonably productive forest, from planting the seedling to the maturity of the forest produces about 20 cubic metres of wood per hectare per year, which equates to about nine tonnes of carbon.
Generally forests can be considered to reach maturity in about 20 years. At which time the forest releases carbon dioxide as fast as it is sequestering it and the forest thus becomes completely and utterly, global warming neutral and note that global warming protocols (e.g. Kyoto) mandate no harvesting nor clearing for 100 years,
Let’s say we planted enough trees to sequest the carbon dioxide we produce.
Every human in a modern western society would need about three quarters of a hectare of new forest to sequest the carbon dioxide produced from the burning of the coal, gas or oil to cover that person’s footprint of power requirements, and another three quarters of a hectare to cater for the car she or he might drive.
Within 20 years we would need another three quarter hectare of new plantings for each human and each car. If we all had a reasonable lifestyle and standard of living then, most unfortunately, within 20 years there would be no agricultural land, no grazing lands, no golf courses and absolutely no place anywhere on Earth to grow any food whatever. Those lands would be all forests. And yet more forests would need to be planted.
That’s the arithmetic of the trees.
Additionally if you’ve ever grown trees from seedlings you’d know the trouble, care, the watering and nurturing it takes.
Tree seedlings have a high attrition rate so would need to plant between 400 and 4000 seedlings per hectare. So depending on the tree type and variety you would need to plant anywhere from 300 to 3000 seedlings in your three quarter hectare plot every twenty years.
So why have trees become flavour of the month to beat global warming? Sherlock Holmes told Watson “Look for those who will benefit”. And I don’t think the planet will.
The agrochemical people believe more chemicals produce more food per hectare, and food demand is constant. So take some agricultural land out of production and the rest needs more chemicals.
Then “wasting” the land left on growing biofuel becomes antisocial. That’s good for the oil people.
Have concerned citizens preoccupied with trees and they’re successfully blindsided. That’s good.
So I say to you, “first get understanding”.
I’m Allan Yeomans
END
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