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  • From: <pbunch@cox.net>
  • To: Healthy soil and sustainable growing <livingontheland@lists.ibiblio.org>
  • Subject: Re: [Livingontheland] phosphate fertilizer too?
  • Date: Sun, 6 Jun 2010 3:32:49 -0700

Thanks Ken. I now am in contact with Roland. He seems to be very helpful. I
also suspect that he may be a relative as we have family from the same part
of the country and Bunches are scare everywhere except there :-)


---- Ken Hargesheimer <minifarms2@yahoo.com> wrote:
> I posted this; not Roland. 
>  
> Roland's address is  <rolandbunchw@yahoo.com>.  I have a lot of his
> materials.  He is the most knowledgable man on the earth when it comes to
> low input, sustainable farming.  He is famous among subsistence farmers but
> not high society agriculturist.
>  
> Ken Hargesheimer
>
>
> --- On Sat, 6/5/10, Ken Hargesheimer <minifarms2@yahoo.com> wrote:
>
>
> From: Ken Hargesheimer <minifarms2@yahoo.com>
> Subject: Re: [Livingontheland] phosphate fertilizer too?
> To: "Healthy soil and sustainable growing"
> <livingontheland@lists.ibiblio.org>
> Date: Saturday, June 5, 2010, 3:01 PM
>
>
>
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>
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> I visited three farms on one of my trips to Honduras.
>
>
>
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>
> Date:
>
>
> 11/25/2002 9:12:29 AM Central Standard Time
>
>
> From:
>
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> Reply-to:
>
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>  
> Frankly, I would disagree strenuously with the general conclusion. Of
> course, in a sand, you're going to have a problem. But I have seen farmers
> build up soils to very high levels of productivity in thousands of cases,
> without using chemical fertilizers. 
>  
> OK, first of all, in the simple logical sense, you can't argue something is
> impossible just because you haven't seen it yourself.  That's how we got to
> the idea that you can't build up and maintain high levels of organic matter
> in tropical soils (now disproven) and grasses can't access N from legumes
> (it's now been shown that this very thing DOES happen, through micorrhyzae)
> and a whole raft of other mistakes having to do with soil dynamics. The
> problem with this reasoning is that we may have tried to WRONG way to do
> it, or even many wrong ways. (Such as growing clean-ploughed row crops for
> 40 years in India. Sure, if you try to do it THAT way, it's impossible!)
>  
> So how do farmers build up their soils? Well, of course, the first problem
> with this question is, what do we mean by "build up"? If our definition of
> to "build up" is based on the nutrient quantity theory, then by definition,
> we will need NPK. But NPK can, of course, be obtained in purchased chicken
> manure, purchased urban wastes, from a composting latrine, from incoming
> irrigation water, incoming water-borne soil, etc. Or even birds and bats.
> (And the quantities in the last case are more than a lot of people would
> ever dream.) So much for the argument that inorganic NPK is needed. Not
> even theoretically, using the nutrient quantity theory, is it necessary,
> unless you want to do it on a huge scale. I frankly don't see how anyone
> can say what I have just said is impossible--chicken manure (which
> thousands of farmers use here in Honduras every year) has all three
> nutrients, and in decent enough quantities to get very good yields. So the
> proposition that
> inorganic NPK is necessary to build soils is false. Period. In the
> theoretical sense.
>  
> But the above argument really only has value for theoreticians who don't
> care much about the real world. If we are going to be practical, we need to
> go a lot further than this. We need to ask: "Can poorer farmers increase
> substantially their productivity on initially very poor soils without
> spending any more than their increased yields would pay for, and can they
> do it with resources that would be available for the vast majority of poor
> farmers around the world? Now we're asking a question that has widespread
> developing nation applicability.  And, incidentally, this is precisely the
> question World Neighbors/Central America, COSECHA, and CIDICCO have been
> working on for the last 20 years (all of which I have been involved with).
>  
> My answer? YES. Resoundingly. In most cases. You don't believe me? Come
> visit us. I'll have my personnel take you to see any number of farmers you
> want, as long as the number's less than 5,000.
>  
> How?  Well, I can't go into it all that deeply here. (We do have papers on
> a lot of these subjects that are available.  For instance, I could get into
> issues like the nutrient access vs nutrient quantity theories, but I won't. 
> Let's just say that we use all sorts of tropical legumes, some trees, some
> viny or bushy or crawly. These are capable of fixing commonly from 75 to
> 150 kg N/ha/crop. They make the soil softer, more able to hold water, and
> increase the CEC (none of which chemical fertilizers can do). They decrease
> erosion, cover the soil much of the year, and eventually allow farmers to
> switch to zero tillage, which also improves soil fertility in at least half
> a dozen additional ways (none of which chemical fertilizer can do). They
> also buffer pH (while most chemical fertilizer used acidifies the soil,
> making most tropical soils worse.) And they defend plants significantly
> against a whole array of insects and diseases, from white grubs and
> striga to termites and the corn borer worm (which is, of course, endemic
> here in Honduras, but no longer a worry for our farmers). Chemical
> fertilizer's impact on these problems is arguable, but nowhere near as good
> as that of organic matter. 
>  
> But I said the interventions had to be economic. Well, the way we use green
> manure/cover crops is not the traditional way (plant monocropped, cut at
> flowering and bury). This system is neither economically attractive nor
> best for the soil, in most cases.  We use gm/cc's in such a way that the
> soil they are in has no opportunity cost (known to the farmers involved),
> that they are not generally buried, nor are they cut before maturity. We
> also use multi-purpose legumes: ones that can be eaten, preferably, or ones
> that can serve as fodder, major controllers of noxious weeds, or as income
> producers.
>  
> As a result, productivity of basic grains has gone from, say, 0.5 t/ha/year
> to 4.5 t/ha/year. Yes, with no chemical fertilizer use.
>  
> But now I can hear the eternal cry of, "What about the phosphorus?" Well,
> it isn't necessary for about the first 15 years, at least. (In northern
> Honduras farmers have been getting good yields for 40+ years with no
> phosphorus applications and there is STILL no response to phosphorus
> applications.  Why? Now this time, you got me. I can't explain that one,
> either.)
>  
> But allow me to admit that phosphorus IS necessary sooner or later, and
> that farmers shouldn't just mine it down to nothing. Fine. What do we do?
> We use some animal manure. Or we recommend superphosphate (farmers don't
> always use it, ergo the 5,000 farmers out there I can show you.) (Although
> I am NOT an organic farming advocate, I do believe strongly that many
> scientists have failed to understand its potential without ever becoming
> well-informed about it.) 
>  
> So, what about phosphorus? A die-hard organic person would have two
> possibilities. Phosphorus-accumulating plants would be one, but then we're
> back to robbing Peter to pay Paul--something not everyone can do.  Or
> mining our own soils.  So then we have rock phosphate.  But it doesn't work
> very well--the response of crops is way too small.  Once again, we're back
> with the "If I haven't seen it, it doesn't work" phenomenon.  In fact, if
> rock phosphate is applied to the MULCH instead of the soil, the response is
> dramatic--MUCH more than if chemical fertilizer is applied directly to acid
> soils.
>  
> In fact, after years of working with both, I feel the evidence says that if
> you were restricted to one or the other, organics will improve soil a lot
> faster and MUCH cheaper than will inorganics.   So at this point I rest my
> case. And invite comments.
>  
> Roland Bunch
>








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