[Terrapreta] biochar and alkaline soils

[Michael Bailes]

Sugarcane needs an acid soil; 8 is way too high for optimal growth.

> "the optimum pH for sugar cane is about 6.5 Yates 1978"
>
http://www.alfredhartemink.nl/PDF/1998%20-%20Sugar%20cane%20PNG.pdf

High soil pH can cause deficiencies.

> "Plants such as maize and sorghum and sugarcane shows reduced
> photosynthetic carbon metabolism due to zinc deficiency."
> The solubility of zinc is highly dependent upon soil pH. Presence of
> calcium carbonate decreases the availability of zinc due to higher soil pH.
>
http://www.spraygro.com.au/documents/Zincnutrition.pdf

Lack of SOM could also be a problem
http://72.14.253.104/search?q=cache:h0t2xhfiMAwJ:www.daff.gov.au/corporate_docs/publications/word/sugar_assessment/art.doc+optimum+soil+pH+for+sugarcane&hl=en&ct=clnk&cd=8&gl=au&client=firefox-a

There are some newly discovered nitrogen fixing bacteria for sugarcane. See:
http://www.springerlink.com/content/g1672n6225871028/

Burning cane residues gives you very,very little charcoal.
Ploughing it into the soil as SOM may be a better option?

adkarve <adkarve at pn2.vsnl.net.in> wrote:

> but after reading that biochar might not work in alkaline soils,


No one has actually said or  proved that yet. We are still kicking the ball
around the paddock.Without much research to help
.It would be nice if all charcoal researchers gave a detailed chemical run
down (including pH) of exactly what they are using when they say "Charcoal"
,
 Different chars may have different pHs.
We are still unsure of the role of resins and bio oils on pH
 Char's effects on soil may also change quite quickly over time (months),
then settle down for the long 10,000 year haul..
 It is always possible that charcoal normalises pH !
It seems to do 100 other impossible things before lunch; so why not that?.

m

On 18/05/07, adkarve <adkarve at pn2.vsnl.net.in> wrote:
>
>  I live in India, in Masharashtra state, that produces 40% of the total
> sugar in India. We have had sugar factories since the early 1930s. All the
> sugarcane is manually harvested. Typically, a hectare of sugarcane produces
> about 10 tonnes of dry leaves, so that after the harvest is over, the field
> is covered with a layer of dry leaves that is often 30 cm thick. Farmers
> just burn the leaves to clear the field. The charred leaves and ash are then
> ploughed into the soil. Farmers do not grow consecutive crops of sugarcane
> but always rotate it with other crops. About 50 years ago, there were many
> farmers who harvested more than 200 tonnes of sugarcane per ha and the
> average of the state in the 1960s was 100 tonnes per ha. But then yield
> started declining. The average has now come down to about 80 tonnes per ha
> and one hardly meets a farmer who harvests more than 150 tonnes per ha. The
> soil in the sugarcane area is vertisol, having a pH ranging from 8.2 to
> 8.7. I am not saying that incorporation of char and ash caused decline in
> sugarcane yield. There might be entirely other reasons for it, but after
> reading that biochar might not work in alkaline soils, one is tempted to
> come to this conclusion.
>
> Yours
>
> A.D.Karve
> <http://tech.groups.yahoo.com/group/biochar/>
>
>


--
-------------- next part --------------
An HTML attachment was scrubbed...
URL: /pipermail/terrapreta_bioenergylists.org/attachments/20070518/9a804ba2/attachment.html