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Achieving sustainability in the use of green manures

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  • Gary
    Achieving sustainability in the use of green manures By Roland Bunch ************** Teaching farmers that green manure and cover crops have valuable uses
    Message 1 of 3 , Nov 2, 2002
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      Achieving sustainability in the use of green manures

      By Roland Bunch

      **************
      Teaching farmers that green manure and cover crops have valuable uses
      besides maintaining soil fertility can help sustain the widespread
      use and adoption of green manuring practices.
      **************

      Today, well over 125,000 farmers are using green manure and cover
      crops in Santa Catarina, Brazil. Green manure and cover crops are
      equally popular in neighbouring Parana and Rio Grande do Sul. In
      Central America and Mexico, an estimated 200,000 farmers are using 20
      traditional systems involving some 14 different species of green
      manure and cover crops and organisations from Central Mexico to
      Nicaragua are promoting their use in at least 25 additional systems.
      Across the ocean in West Africa more than 50,000 farmers have adopted
      Mucuna spp. or Dolichos lablab as green manures in the last eight
      years.

      The present widespread use and rapid adoption of green manure and
      cover crops has taken many people by surprise. To some extent this is
      because little attention has been given to the extent to which green
      manures and cover crops have always been used in traditional systems.
      Gene Wilken, for example, in his otherwise excellent book, Good
      farmers: traditional agricultural resource management in Mexico and
      Central America stated that "cover cropping is not widespread in
      traditional Middle America," (Wilken 1987). Many scientists believed
      the technology inappropriate for village farmers. As late as 1989,
      Anthony Young in the classic Agroforestry for soil conservation
      dismissed green manuring as "a form of non-productive improved fallow
      which has rarely found favour with farmers" (Young 1989).

      Sustainability

      For more than a decade it has been accepted that green manures and
      cover crops would only be accepted by small farmers if they could be
      grown on land that had no opportunity cost, could be intercropped
      with other produce, grown under tree crops or on fallow land and be
      cultivated in periods of expected drought or extreme cold. They would
      also be favoured if they involved no extra labour and out of pocket
      cash expense (Bunch 1995).

      Whilst these assumptions have proved correct, recent experience has
      shown that the sustainability of green manure and cover crops is more
      likely to guaranteed when they provide farmers with some other
      benefit besides fertile soil. This condition is consistent with the
      observation that village farmers generally prefer multiple use
      technologies.

      Experiences worldwide

      Experience from many parts of the world confirms the value
      farmers'
      attribute to green manures and cover crops that have multiple uses.
      In most known, traditional systems legumes are appreciated not only
      because they maintain soil fertility, but because the seeds or pods
      can also be eaten. Examples include the Vigna spp. which is
      intercropped in Southern Honduras, El Salvador and South-east Mexico
      and the high-altitude scarlet runner bean (Phaseolus coccineus),
      which is widely used from upstate New York (Seneca bean) to Mexico
      (ayocote) and from Guatemala (piloy) to Honduras (chinapopo) and
      Northern Chile.

      The velvet bean (Mucuna spp) is easily the most popular of all the
      green manures/cover crops used today and was initially used and
      spread by farmers along the southern border of the Himalayas in
      Nagaland partly because it was such a valued source of food (Young
      1989). In Central Honduras, where World Neighbours and COSECHA have
      taught farmers to intercrop velvet bean with maize, there has been a
      disappointing failure (35%+) to continue this technology except in
      those villages where it is consumed as a major component of coffee,
      hot chocolate, bread and tortillas. In fact, their value of green
      manures and cover crops as human food seems to be the strongest
      factor motivating in their sustained adoption.

      Perhaps the second most common use of green manures and cover crops
      is in weed control. In South-east Asia, a perennial species of the
      velvet bean is use to improve fallow and to control weeds. More
      modern practices include using jack bean (Canavalia ensiformis,
      tropical kudzu (Pueraria phaseoloides) and perennial peanuts (Arachis
      pintoi) under a variety of plantation crops, including coffee,
      citrus, and African oil palm. The velvet bean is also used to control
      imperata grass (Imperata spp.) and this practice is spreading rapidly
      throughout Benin, Togo, and Columbia. Velvet bean and jack bean are
      used to control paja blanca (Saccharum spp.) in Panama and to combat
      nutgrass in several other countries.

      A third practice, which is now more widespread but which is still
      under-appreciated, is the use of green manures and cover crops to
      stabilise swidden agriculture. Since decreased fertility and weed
      infestation are the two most important reasons why farmers abandon
      their fields today, and since green manures and cover crops can, to
      some extent, often solve both these problems they have proved to be
      an effective way of stabilising shifting cultivation in many
      countries.

      One dramatic example can be drawn from the work of the Centro Maya in
      Guatemala's northern Peten region. In this humid forest area, farmers
      could only grow maize for one or two years and then the ground had to
      be left to regenerate. Now hundreds of farmers are growing velvet
      bean intercropped with maize on the same fields year after year.
      Those who initially adopted this system have been growing maize on
      the same land for eleven consecutive years and productivity has
      improved over time. Another interesting example is that of Central
      Ghana, where village farmers are inventing their own ways of
      stabilising their agriculture, including one system in which 30,000
      leucaena trees (Leucaena spp.) are intercropped with maize and burned
      very lightly each year. This practice has allowed maize to be planted
      on the same land for 20 years in succession.

      A fourth potential benefit that will probably acquire more
      insignificance as experience increases, is the use of green manures
      as animal feed. Most green manures and cover crop species, with the
      major exception of Melilotus albus cannot be grazed well, but many
      can be used for cutting and carrying even after months of drought,
      the most notable examples of this type being Lathyrus nigrivalvis and
      lablab bean (Dolichos lablab). Seeds also provide fodder, one good
      example being the seeds of the velvet bean which in Campeche, Mexico
      are cooked for half-hour, mixed with an equivalent amount of maize
      and then ground into pig feed. The University of Yucatan calculated
      that this velvet bean feed cost less than commercial feeds per unit
      of weight gained.

      Green manure and cover crops can be used in other ways as well. Two
      years after Alter-Vida stopped working in El Naranjito, Paraguay,
      farmers abandoned using velvet beans as a green manure, but continued
      to used to use them when they wanted to prepare their land for
      tobacco. In Southern Brazil, hundreds of thousands of farmers
      regularly use some 25 different species of green manure and cover
      crops for soil improvement partly because this allows them to
      increase the amount of organic matter in their soil to the point
      where tilling is no longer necessary. The financial as well as
      ecological advantages of zero-till systems are tremendously
      attractive.

      Conclusions

      A number of conclusions can be drawn from the examples given above.
      First, the variety of sustainable green manure and crop cover systems
      already established in traditional as well as more recently
      introduced agricultural system is remarkably diverse. Green manures
      and cover crops have been adopted on a wide scale despite the
      seemingly prohibitive conditions mentioned earlier in this article.
      The fact that virtually every system we have refered to has some
      elements of these conditions confirms their predictive value. Thus,
      programmes to introduce new green manure and cover crop systems
      should teach farmers not only how these species can be used to
      improve their soil but that they have other uses as well.

      Tremendous potential still exists for the development of new green
      manure and cover crop systems. Scores of potential systems for using
      green manure and cover crops still need to be investigated, most
      notably the major possibilities of using them for animal feed; the
      potential latent in new as yet untried species, including trees and
      non-legumes, and the value to be derived from using combinations of
      green manures and cover crops rather than individual species.
      Experience leads us to believe that, with the possible exception of
      very intensive farming systems such as irrigated vegetable and rice,
      green manure and cover crops systems can probably be introduced into
      many, if not most of the world's, small-scale farming systems.

      Roland Bunch, COSECHA, Apartado 3586, Tegucigalpa, Honduras

      http://www.ambergriscaye.com/BzLibrary/trust473.html
    • Justin .
      Larry, I was taking a look at the website. I checked the Links pages, and was rather surprised. I was expecting to find many links - so many have been posted
      Message 2 of 3 , Nov 6, 2002
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        Larry, I was taking a look at the website. I checked the Links pages, and
        was rather surprised. I was expecting to find many links - so many have been
        posted on this group, so many wonderful links to wonderful things. But on
        the website I found only a shor list of things, only directly relating to
        Fukuoka. The were links for seedballs, links for seeds, and links for
        Fukuoka's books. That is all great, but don't you think that it could be a
        little broader? Personally, when I find a really good website, I am glad.
        Let's say I find a site which is really on my wavelength. Then I will
        apreciate links that are directly connected, but also links which that
        person (/persons) is also interested in. The chances are that I will also be
        interested in at least some of them. Like on Amazon, you find a book, and
        you click on "those who bought this also bought..." or those who bought this
        recommend.." I know some people feel that Fukuoka should not be mixed wth
        other things. Well, I disagree. At least in a way. I mean, even he mixes. He
        gets a lot from Buddhism, and also a lot from Daoism, for example. That is
        great. How about some Permaculture links. And links to Agroforestry. Perhaps
        to the various projects in Thailand, Sri Lanka and so on. How about to CAT
        (centre for alternative technology) which is also about living in a
        sustainable way. How about to the Schumacher college, founded on principles
        of holism, us being a part of nature, and bringing that into eduation. It is
        wonderfull that we can help open peoples' eyes to Fukuoka, and I feel that
        it can only help to also provide some links to other such good ideas. If you
        ask me, I almost feel that we are a part of the bottom-up drive system
        powering the paradigm shift that is all so important in these times, and
        networking and working together is so important for this.
        Well, that's an idea!
        Best wishes,
        Justin.

        _________________________________________________________________
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      • Larry Haftl
        At Wednesday, 06 November 2002, Justin wrote: Hi Justin, ... It s good to know that someone is... :) ... have been ... But on ... to ... could be a ... I ve
        Message 3 of 3 , Nov 6, 2002
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          At Wednesday, 06 November 2002, Justin wrote:

          Hi Justin,

          >Larry, I was taking a look at the website.

          It's good to know that someone is... :)

          > I checked the Links pages, and
          >was rather surprised. I was expecting to find many links - so many
          have been
          >posted on this group, so many wonderful links to wonderful things.
          But on
          >the website I found only a shor list of things, only directly relating
          to
          >Fukuoka. The were links for seedballs, links for seeds, and links for
          >Fukuoka's books. That is all great, but don't you think that it
          could be a
          >little broader?

          I've gone back through the entire archive and extracted all of those
          links. You are right that there are a lot of good ones there. I've
          also added a bunch of possible others gathered from my surfing/searching.
          I haven't added them to the website yet because I was waiting to
          see how the people here want to see the site develop. One option
          is to keep it as closely focused on Fukuoka as possible since there
          are no other sites that do this or provide comprehensive or extensive
          info about him and his methods. It's easy to find info about other
          methods of sustainable agriculture -- any Google search turns up
          thousands of links to such sites. It's not easy to find hardcore
          detailed info on Fukuoka and his method.

          The other possibility is what you suggest. Add a bunch of links to
          other sustainable ag sites (I also have a HUGE collection of those).
          I don't mind doing that, but I'm concerned that it might dilute
          what the Fukuoka site is all about. That's where I need input from
          other list participants.

          Even though I built and maintain the site I don't think of it as
          "mine". I don't feel I have the right or freedom to do just anything
          I want to with it. Changes and direction should come from concensus
          amongst participants of this list. Maybe your questions and suggestions
          will stir some dialog about this. I would definitely welcome that.



          >I know some people feel that Fukuoka should not be mixed wth
          >other things. Well, I disagree. At least in a way. I mean, even
          he mixes.

          The more I come to understand what he is saying and doing, the more
          I come to realize just how unique his message is. All of the other
          methods (I've spent more hours than I care to think about researching
          them) are human-centered and human-dominated. They all come at it
          with the attitude of dominating and overcoming natural processes
          even while they talk of working "with" nature. Holmgren, one of the
          co-creators of the Permaculture concept, alluded to this in that
          article Robert Monie told us about.

          Having said that, I also have to add that I agree about mixing other
          methods into the process if its needed. There are parts of Permaculture,
          agroforestry and biointensive gardening that I think can be used
          very effectively in certain circumstances.

          >He gets a lot from Buddhism, and also a lot from Daoism, for example.

          I know that he weaves a lot of Buddhist philosophy through his books,
          but in that interview with Plowboy he made the point that its all
          about farming, not religion. I get the feeling that all of the mystique
          surrounding him often obscures the fact that he was, first and foremost,
          a commercial farmer. Raising food for sale was his primary occupation
          and all the rest was wrapped around and focused on that.

          >Well, that's an idea!
          >Best wishes,
          > Justin.

          Excellent comments. It will be interesting to see what others have
          to say about all of this.

          Larry Haftl
          larry@...
          http://larryhaftl.com/fukuoka
          http://FukuokaNaturalFarming.org
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