permaculture

["Lawrence F. London, Jr." <venaurafarm@bellsouth.net>]

On 9/18/2011 2:03 AM, m_astera wrote:
> How much compost or manure would one need to add to raise the Soil
> Organic Matter SOM content of an acre of soil 6" deep by 1%?
>
> SOM percentage is calculated by weight, not volume. The convention
> used is that 1 acre of soil 6-7" deep weighs 2,000,000 (two million)
> pounds. Or a hectare of soil 15cm deep weighs 2,000,000 kg. One
> percent of that is 20,000 lbs/acre or 20,000 kg/ha
>
> Compost and manure can be assumed to be around 60% moisture and 40%
> dry organic matter. So
>
> 20,000 / 0.40 = 50,000
>
> To add 1% organic matter to the top 6" or 15cm of soil would require
>  about 50,000 lbs/acre or 50,000 kg/ha of organic matter at 60%
> moisture content.

Right on the money.

> Probably makes more sense to grow it in place.

Absolutely.

The National Weather Service predicts more drought this winter.
http://www.cpc.ncep.noaa.gov/products/expert_assessment/seasonal_drought.html

If climate change is the cause then biological farmers could help stave 
this off by sequestering carbon in soil by growing nitrogen fixing 
crops, high biomass cover crops, weeds and, of course, application of 
manures to fertilize the land increase yield. Soil tests and balanced 
mineral application would be very important also.

" If all landowners increased their soil organic matter by 1.6% then
carbon dioxide levels would fall back to normal and our climate would
stabilize, says farm expert Allan Yeomans in
http://www.youtube.com/user/AllanYeomans1#p/a/u/0/-o2N6vJDLpE
Free download of his book:
http://www.yeomansplow.com.au/priority-one-contents.htm
"...it could be done in a decade or two," says Yeomans.
http://groups.google.com/group/soil-age "