[Terrapreta] biochar and sugarcane growth (reply to AD Karve) (cont'd, part 3)

[Ron Larson]

AD  (cc Tom and Terra preta list members)

    I think we are getting near the end of this valuable dialog.  Thanks for the education.  I think we have agreed on these points:

1.  Sugar cane is an important potential opportunity for terra preta testing -  because it is a highly productive crop, grown around the world, and there are zero or low costs for gathering the bagasse and trash material to pyrolyze.
2.  There have been essentially no tests on the value of adding charcoal to the cane soils.  No proofs of either benefits or costs are available.
3.  There will be some opposition to adding the charcoal - based on a perceived high cost or better opportunities for the charcoal.

Just a few more notes below in your message today, which said:

  Tom has already answered most of the questions related to bagasse and trash burning. About 40 years ago, when I shifted my attention from botany to agriculture, I had this idea of using ash from a sugar factory boiler as a source of potassium in agriculture. But I was told at that time that under the high temperature of the boiler furnace, the potassium and silica in the bagasse fused and became insoluble in water. In those days, I was still naïve enough to believe in the textbook wisdom that water-insoluble inorganic compounds were useless as agricultural nutrients. Now I know better. A crop of sugarcane in India removes about 500 kg of silica per ha from the soil. I am quite sure that this silica comes from the water-insoluble components of the soil. I am also quite sure that soil micro-organisms have a role to play in solubilizing insoluble inorganic substances in the soil. 

      [RWL:  I think soil scientists are in agreement with your present view.  Presumably there should be agreement that adding charcoal back to the soil that contains these nutrients cannot possibly be harmful - even if in an altered chemical form (which is not clear).   But the char seems to have at least three additional big advantages behind the documentd productivity improvements - 1)  promotion of fungal growth, 2) (because of large internal surface area) an improved growth environment for bacteria (and fungus) and 3) improved tilth.
  As to my way of sugarcane planting, all I have been recommending is to produce seedlings from single-node cuttings of sugarcane in a plastic bag, and to transplant two months old seedlings at a spacing of 1m X1m. I served in 1974 as a member of a Sugarcane Study Committee, that was commissioned by the State Government to study why the yield of sugarcane in the state was falling. One of the reasons identified by this committee was that the cane fields did not have adequate number of canes. The recommendation at that time was to increase the seed rate of sugarcane, but this recommendation did not produce the desired results. Studies conducted by me in the 1980s established that lateral organs (branches or flowers) developed on a stem, only if that part of the stem is exposed to sunlight. It was also later established by me that this reaction was regulated by phytochrome. That is why densely planted corn has a large number of sterile stalks. when I discovered that tillering of sugarcane was promoted by reducing the mutual shading in the crop, I started expeimenting with low seed rates, but this practice resulted in a very gappy field, because the seed cane did not germinate uniformly. Therefore, I tried out the method of seedling transplanting, and it worked. The transplanted seedlings survive in the field to the extent of 98%. At 1mX1m spacing, there are 10,000 seedlings per ha. At this spacing, each seedling produces at least ten tillers, giving 100,000+ canes per ha, at the time of harvest. If each cane weighs 2 kg, you have your 200 tonnes per ha. This is of course the fresh weight. On an average, sugarcane contains about 14% solids that are water soluble, and another 14% fibre. Thus the total dry weight of 200 tonnes of stripped sugarcane i.e. without the leaves and tops, would be about 56 tonnes. 

      [RWL:  Thanks again for the new information.  The only remaining question I have is whether applying charcoal to the field would change any of these optimizing approaches.  We read (and I finally saw this in Australia in two places) that growth rates for many plant species are much increased after application of char.  Perhaps ratooning would make for more net farmer income with applied char.  Your farmers are not applying the commercial fertilizers that perhaps justifies the 6-8 years spacing between starting a new set of seedlings that seems to be the norm in much of the sugar world.  I have an unjustified prejudice in favor of the ratoon system - taking advantage of the existing root system - and so have hopes that a terra preta approach would have that also make sense in Maharashtra.

      I don't have good data, but I think that the 56 tonnes (as great as this is)can be improved with terra preta practices - and hope some small TP experiments can be started - especially under your own procedures and knowledge.]

  Farmers are too lazy to make their own seedlings. Therefore they purchase seedlings from nurseries. Since the transport of live seedlings is costly, a large number of nurseries have sprung up, supplying seedlings to about 100 ha each. The transplanting technology was standardised by me under a project funded by the Ministry of Science and Technology of the Government of India. Our efforts of popularizing the nursery business based on sugarcane seedlings was initially supported by a small grant from GTZ. The transplanting method also allowed a farmer to grow a short duration crop prior to sugarcane. Our advertisement states, " while your soybean, mungbean or sunflower is growing in your field, your sugarcane is growing in our nursery".

      [RWL:   1.  Congratulations to GTZ (the German equivalent of USAID).  They have done many great things and would be ideal to support TP experimental work.

      2.  Transplanting of seedlings would seem to be an excellent way to apply (and stretch a limited supply of) charcoal.  If the size of the transplanting (decomposable) container with the seedling had to be greatly increased to get a lot more charcoal in  the soil, would that be a major impediment?  Or can you see an easier way to get charcoal in the right place as the seedlings are transplanted?

      3.  Having seen at your ARTI test/training facility in Phaltan (sp?) a test site probably related to a typical "seedling nursery" - I believe this list would benefit from your describing a little more on what you have learned about the importance of wind barriers in the "greenhouse" approach you have developed.  And anything else about successfully doing more with seedlings.

     4.  I had not previously known or remembered your amazingly long involvement with sugar cane - but have been much impressed with your comments elsewhere (not on this list I think) about the economic potentials of bamboo.  Since bamboo charcoal is much prized for other reasons, could you comment on the appropriateness of doing TP tests on bamboo - similar to what I hope you can initiate with sugar cane.  I presume you recommend transplants of seedlings with bamboo also?  Any reasons not to emphasize TP testing with bamboo?

    5.  I will add in a separate message what I learned in Australia about hydroponics - which also involved "transplants".

  Sugarcane is a photoperiodically sensitive crop. Any crop, planted up to May, would flower in November/December. The crop planted from June onwards, would flower in the next November. Thus farmers prefer to keep the ratoon of a crop that is harvested in the beginning of the harvesting season, i.e. November to January, because the ratoon crop gets about 10 to 12 months to grow. A ratoon kept later than this date does not get enough time to grow. It flowers in November along with other cane fields, and yields less.

      RWL:  This explains a lot about why successive harvestings in other countries (Cuba being my primary source of data) takes place on a 13 month cycle.  

      Could you add a few words about the similar solar cycle impact with bamboo production.   I haven't figured this out yet - but believe that there is a possible role for combined cane and bamboo in keeping the sugar mills operative year-round - for CHP benefits to the local economy.  Not sure that TP is needed for that, but it might be.

  AD - again thanks so much for answering so much and so well about the sugar industry - which I still believe holds a lot of promise for TP.    Ron]

  Yours

  A.D.Karve 

    ----- Original Message ----- 
    From: Ron Larson 
    To: adkarve ; terrapreta at bioenergylists.org 
    Sent: Sunday, May 20, 2007 5:35 AM
    Subject: Re: [Terrapreta] biochar and sugarcane growth (reply to AD Karve)


    AD (cc terrapreta list):

        A few more comments and questions below:
      ----- Original Message ----- 
      From: adkarve 
      To: terrapreta at bioenergylists.org 
      Sent: Friday, May 18, 2007 10:56 PM
      Subject: Re: [Terrapreta] biochar and sugarcane growth (reply to AD Karve)


      Dear Ron,

      It was a tongue in cheek suggestion, correlating the practice of burning sugarcane leaves with dropping yield of sugarcane. I know what is wrong with our sugarcane and I have already started teaching farmers a new practice of sugarcane cultivation. Those who follow my recommendations are getting 200 tonnes per ha. And please note that my suggestions do not include increasing the fertilizer dose. 

          RWL:   Sorry I missed the "cheek".  

          I presume 200 is NOT bone dry tonnes.  Can you estimate the lower "dry" number?  I presume that your recommendations include the periodic application of sugar/leaf mixtures for the bacteria?  Anthing else?

          Secondly, I am quite convinced that adding charcoal to the soil would work even in soils having high pH. After all, charcoal is chemically a neutral substance. Its porous nature offers the soil micro-organisms a safe haven to survive under adverse conditions. I also feel that the pieces of charcoal, loaded with micro-organisms, act like matrix bound enzymes. So, I would be surprised if charcoal were found to be not beneficial to alkaline soils.

      In my state, farmers generally produce only one crop of sugarcane of about 18 months. Only the farmers, whose cane is harvested right at the beginning of the campaign season keep a rattoon crop.The rattoon crop of late harvested sugarcane gives a low yield. 

          RWL:  I am surprised at the single crop practice in India (or Maharashtra?).  There must be considerable advantages to using the ratoon (sprouting from cut base) method - as 3, 4 or more ratoon crops seems to be widely practiced around the world (and avoids soil disturbance, etc).  Do you feel the single 18 month cycle is the right way to grow cane in India?  If the soil was more productive, might the ratoon approach be preferred?  Might the terra pretta approach provide that improved soil?

          If a farmer who ratooned "late", grew his crop so as to be "early" in the n+1st season (maybe 18-20 months?), might that prove economic?  In Australia, some at least have a 24 month cycle.

      Bagasse is traditionally used by the sugar industry as boiler fuel. In fact, sugar factories consider themselves lucky, because sugarcane brings its own fuel with it. The sugar industry in India is totally independent of external supply of energy. Some factories, that produce extra electricity to supply it to the utilities, need additional fuel, and they have turned their attention to the dry leaves of sugarcane, called sugarcane trash. But, at least in India, the bagasse as well as trash are directly burned as boiler fuel to generate steam, which in turn drives the turbines for generating electricity. Pyrolysis of the fuels and using only the pyrolysis gas as fuel is a new idea. I am a council member of the Deccan Sugar Technologists' Association. I shall air this idea in our next meeting. However, adding the char to the soil might not be acceptable to the colleagues, because they would like to briquette the char and sell it as fuel, to make more profit. 

          [RWL:  Good to hear you are active in this sugar association!

          I think the economics today will relate strongly on whether the bagasse is in excess - which has been my assumption.  

          Re your last sentence, I hope your associates will begin (best under your direction through ARTI!) some simple experiments first on the value of placing the pyrolyzed bagasse back into the cane fields.  They may be correct, but perhaps a CDM or JI project would change those economics, if the impact on the bacteria and fungus is as large as we hear from some investigators.   The projected profit must be based on more than the first year comparison - as briquetting can provide no continuing benefits.  Any cost data you can provide will help this list to better understand the magnitude of needed international funding for the negative carbon aspects of the terra petra practice.

         Before closing - let me modify a request in my last message which should have read:  {"Anything you can do to ascertain how much char remains in these burning operations in India would be a big help."  (NOT Australia, which I guess was on my jet-lagged brain.) 

          AD - thanks again for all your good work.   Ron



      Yours

      A.D.Karve



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