If you will excuse me I would like to return to the discussion and mostly reiterate my previous concerns regarding code of conduct regarding fertilizer use. This goes back to keeping careful track of the financial limits of most developing country that limits the amount of effective regulation and supervision that is possible without providing civil officer a major opportunity to extract gratuities for service assumed run, but not done. The result of this is an almost total reliance on the private sector to handle the distribution of fertilizers, with an emphasis on the village based family enterprises that are in direct contact with the smallholder farmers. They are also friends and neighbors and their best prospects for remaining in business is highly dependent on return business, which make them very quality conscience of the service they are providing.
Also, there is a need to be careful on any soil testing expected. Typically soil test cost approximately the same as a bag of fertilizer, and thus if the text in like to result in less than a bag of difference in fertilizer application, it will not be cost effective. Since most of the fertilizer in N based the difference of a whole bag of fertilizer on a one hectare or less field is unlikely. Can any host country actually get soil test results in the timely manner available in the USA (24-48 hours).
Also, be careful on your emphasis on organic fertilizer. While fully support the idea, it must be cost effective both financially and operationally. The latter being mostly associated with the labor needed to move around large volumes of low concentrated nutrients. In the context of developing country smallholder farmers that are already energy limited, the extra energy must come from the increased yield resulting from the organic nutrient application even if this is some 6 months later. I would guess that the farmer will need to gain 100 g of grain for each hour of additional labor handling the organic material. (100 g grain = 300 kcal, the energy exerted by an hour of diligent effort). Is this possible? In addition, there are limits on the amount of organic material available on farm for nutrient recovery. I think when dealing with crop residues the ratio of accumulated area to distributed area is about 3 to 1. Given all this I suspect the best means of nutrient recovery and recycling is to leave it up to the mobile composter (goats) they will take material normally burned and fairly quickly convert it to a material easily in cooperated, while actually gaining some energy from the process. Isn’t feeding rumens animals the same process as composting? Microbial de-carboning and concentration of the material. Again, please check the webpage:
http://smallholderagriculture.agsci.colostate.edu/organic-source-of-nut…
Д-р. Dick Tinsley