Agricultural research has had limited impact in sub-Saharan Africa. Attempts to transfer modern biological and mechanical technologies have been unsuccessful. This paper argues that scientists' failure to conceptualize the mixed cropping systems of low-resource African agriculture in a manner that treats conservation of resources as an output similar to annual crop output has impeded research progress. Insights permitting such a reformulation of the classical production function have been recorded over the years by many perceptive field observers, but these have not been systematized so as to inform the research effort on the physical science side. This paper contributes some methodological proposals
