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[compost_tea] Re: in-furrow soil insect prevention?



Thanks, Elaine.  I will study this more using the sites you 
recommended.  I got this idea from a consultant in Canada, but he 
wouldn't give me the rates, something about it being propriatary
information. Jerry
 
--- In compost_tea@yahoogroups.com, soilfoodweb@a... wrote:
> Why would wet sugar make a hostile environment for any insect? 
> 
> Consider what we know about sugar, kelp and lignite added to soil.  
Is this a sufficient set of conditions to have teh desired result?  
> 
> No.  These additions will not work under certain conditions.  When 
will addition of these things be sufficient to have the desired 
effect?  You need to understand something more than just adding 
sugar, kelp and lignite.  
> 
> Do you have to add all three?  And how much? You need to understand 
WHY they MAY have an effect.  What are the conditions that allow for 
success, what conditions mean no benefit should be expected?
> 
> Simple sugars are bacterial foods.  As bacteria grow using the 
excess simple carbon that was added, they suck up all the other 
nutrients, like N, P, S, etc.  You get an area where anything else 
needing these nutrients is SOL.  Bacteria win in competition with 
anything else when they have enough simple sugar.  Of course, you 
have to have decent bacteria, so an inoculum is a good idea (as in 
good aerobic compost), especially in chemically treated soils.  
> 
> Add enough sugar, you'll kill your plants simply because there are 
no nutrients left for them to grow.  What is the right amount of 
sugar?  Kelp is added to provide nutrients, but what's the right 
balance?  
> 
> The nutrients in kelp supply which set of organisms with 
nutrients?  The bacteria and fungi.   Plants can't access the 
nutrients in kelp material.  How do you get the nutrients in kelp 
into a plant available form?  You have to have the protozoa, 
nematodes and microarthropods present to allow that to happen.  
What's the right balance of bacteria and fungi, and protozoa, 
nematodes and arths?  
> 
> Where can you find out this information?  Soil Foodweb.  The Soil 
Ecology Society.  Applied Soil Ecology.  Biology and Fertility of 
Soils.  Univ of Georgia's Soil Ecology program.  
> 
> But think about this - if you add enough sugar, the soil in these 
areas will go anaerobic as the bacteria grow and use up the oxygen.  
> 
> If you have wire worm, cut worm or other obnoxious pests, you might 
be able to drive them away, since these pests need some oxygen.  But 
then the soil is anaerobic.  Bad news for seed germination and root 
growth.
> 
> Will the soil stay anaerobic?  Depends on the health of your soil.  
If you have good soil strucutre, then life will be ok, as the oxygen 
returns, the normal set of organisms will revive and life goes on 
only a little hammered.  
> 
> But what if you don't have good soil structure?  Then your seed is 
in trouble.  You might even say, "See, the cut worms and grubs are 
hurting the seeds" when in fact the pests have been driven away from 
the seed by the anaerobic conditions and aren't responsible for this 
damage.  
> 
> What if the soil is anaerobic only in the zone you added the 
sugars?  Then the pests just go a little ways and hang out until the 
root arrives.  And the root may be weakened from the anaerobic 
conditions.  
> 
> These pests also like reduced oxygen conditions (how reduced? 
Probably in the range of 5 to 6 ppm, but I don't know of any hard 
data on this - does anyone?).  Why do the pests like the reduced 
oxygen conditions?
> 
> The bacteria that grow in aerobic conditions make the environment 
unpleasant for these pests.  If you are careful to add only enough 
sugar to help the beneficial bacteria, soil structure will be 
improved as these bacteria make glues, form microaggregates, and help 
oxygen diffuse more rapidly into the soil.  The critters that eat the 
pests move back into the soil.
> Get some fungal and bacterial species that prey on the pests to 
grow - but they require aerobic conditions, or at least not-reduced-
to less than 6 ppm oxygen.
> 
> What does the kelp do?  Micronutrients, some plant growth factors 
(which the bacteria and fungi consume quite rapidly, probably long 
before the factors make it to the root.  If the soil is healthy, the 
bacteria and fungi that these things grow are probably the real 
answer to why kelp growth factors work well).  Kelp also contains all 
the foods normally in plant cytoplasm, and so good growth foods for 
bacteria and fungi.  Probably more bacteria than fungi, but some 
really great fungi.  So, the nutrients are made plant-available 
because the biology is functioning.  
> 
> Lignite is a source of very complex foods for the fungi.  Only 
after fungal enzymes start chewing on the lignite will any bacterial 
food be released.  Which fungi and bacteria grow on these materials?  
There's a whole area of research that needs to be addressed, and 
people are addressing it.  SFI is part of that work.  
> 
> So, again, is too much of these foods are added in, the soil can be 
driven anaerobic as the organisms start to grow faster than oxygen 
can diffuse into the soil.  If the soil has good structure, then this 
problem is less likely to occur.
> 
> I had to laugh when I read something the other day that said that 
molasses or sugar causes root-feeding nematodes to explode.  Really?  
And what's the mechanism there?  Root-feeding nematodes have no 
mechanism to take-up sugars from the soil solution.  They eat plant 
cellular liquid.  Sap-suckers, if you will.  They like reduced oxygen 
conditions.  They have thick cuticles that prevent bacteria from 
having much affect on them.  Could root-feeders get drunk on the 
alcohol produced when lots of sugar is added and the bacteria and 
fungi (yeasts) grow?  Maybe that's the mechanism.  But some data on 
that would be useful, because then you would need to know that sugar 
addition only works on root-feeders when the soil is badly 
compacted.  
> 
> Please, make sure you understand that I'm trying to point out lack 
of knowledge here - do not go around saying that Elaine said alcohol 
kills root-feeders.  We don't know that.  
> 
> I'm saying we need to know the mechanism by which SOMETIMES 
molasses addition reduces pests.  It does not work in all cases, and 
until we understand WHY it works sometimes, we will never be able to 
predict when additions will work and when they will not. 
> 
> It isn't appropriate to claim that sugar kills pests, because there 
are many conditions where it doesn't work.  When does it work?  We 
need to understand these things first, or these statements lead 
people to believe that organic ag, or sustainable ag, does not work.  
> 
> So, to understand when this group of soil amendments have an effect 
on soil pests, you need to understand the life in your soil. 
> 
> Elaine Ingham
> President, Soil Foodweb Inc.
> SFI Corvallis, OR
> SFI Port Jefferson, NY
> SFI Lismore, NSW, Australia
> SFI Hilversum, The Netherlands
> SFI Cambridge, New Zealand
> www.soilfoodweb.com


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