Healthy soil and sustainable growing

["Tradingpost" <tradingpost@lobo.net>]

A couple exceptions if I may. Forested areas in tropical climates don't
build much soil organic matter. Southern U.S. pine forests for example are
notorious for thin soil, as is the Amazon in general. Northern U.S. and
European forests do have serious organic matter and stable humus. The U.S.
midwest grassland prairie - now the breadbasket - had very deep topsoil and
stable humus, tho it's been depleted by perhaps 50% since the coming of the
plow and water pumping windmill. They say the root system of grasses is the
best soil and humus builder. All according to the information I've seen. 

paul tradingpost@lobo.net

*********** REPLY SEPARATOR  ***********

On 10/7/2007 at 12:52 PM Dieter Brand wrote:

>Zack,
>   
>  You just turned conventional wisdom upside down.
>  The generally accepted view is that depletion (i.e.,
>  loss) of humus is greater in a hot climate than in 
>  a cold climate. According to one source, humus
>  is lost 50 times faster in the tropics than in the
>  North of Europe. I was born and raised on my
>  grandfathers farm in the North of Germany, and
>  now work and live on a piece of land in the South
>  of Portugal, I can assure you that this is more
>  than just theory.
>   
>  Loss of topsoil can have more than one reason. Mostly
>  it is agricultural practice, especially deep ploughing and
>  the use of chemical fertilizers without returning organic 
>  matter to the soil. Also, regions which were historically
>  covered by forest, like much of central and Northern
>  Europe, have more stable long duration humus than 
>  grassland, like the prairie in the US, the ploughing of
>  which resulted in the dust bowl.
>   
>  In the part of Portugal where I live it gets quite cold
>  during the night. Night temperatures below 10 C are
>  common. This is no problem for microbial activity, 
>  in fact, my compost temperature charts show much 
>  higher heap temperatures for the night than for the day. 
>  This clearly shows that microbial activity is higher at 
>  night than during the day even though ambient 
>  temperatures are lower. As long as the temperature 
>  doesn't drop below 0 C there is plenty of microbial activity.
>   
>  If you have a lot of torrential rain, then it is even more
>  important that you keep your soil covered.  The mulch
>  or cover crop will not wash away, the uncovered soil
>  will.
>   
>  Dieter Brand
>  Portugal