For nearly 20 years we have been working with green manure/cover crops and other ways of achieving higher productivity from tropical soils. Gradually, it has become more and more obvious to us that in situation after situation, the conventional explanation of what was happening in tropical soils and how best to get good levels of productivity from them, just did not correlate with what we were observing all around us. Finally, this last year, I got hold of and read Ana Primavesi’s earth-shaking book, The Ecological Management of Soils. There was the explanation of so many phenomena we hadn’t been able to understand previously.

Normally, I would just have recommended that book to everyone I knew, but it has only been published in Portuguese and Spanish. Thus, I have decided to write a paper entitled Nutrient Quantity or Nutrient Access? A New Understanding of How to Maintain Soil Fertility in the Tropics. It is available on the web as a pdf file, or you can write to me directly for the document in MSWord. This paper presents a few of Ana’s more basic ideas and their application to the developing world in general. It represents, I believe, a new paradigm, that can help us understand much more accurately what is happening when we use a more ecological approach to soil management.

I hope you find it worthwhile. I would certainly be grateful for any suggestions or corrections, or even additional evidence, that any of you would be willing to send this way. I’m sure there is a tremendous lot more to learn about all of this.

Sincerely,