CHAPTER 7
 OVERALL CONCLUSIONS


 Introduction



 The industrial development of Africa requires concurrent advances

in the productive capacity of the farmer to meet an ever-increasing

demand for agricultural products. Success in the transformation from

subsistence to market-driven surplus farming will depend on development

and utilization of farming practices that are based on the efficient use

of available resources. The preponderance of soils with low nutrient-

holding capacities under high-rainfall climates presents a formidable

challenge to the scientific community to characterize the behavior of

these soils and to aid in the development of resource-efficient

management practices.

 Strict adherence to soil-fertility evaluation criteria developed

in temperate-climate schools-of-thought may overlook the potential of

"agriculturally poor or marginal land". The soil studied in this

dissertation is a case in point. The presence of stones in high P-

fixing soils actually reduces the quantity of P-adsorption sites per

soil volume and land area. The size of farming systems in Africa is

frequently limited by labor shortages during sort periods of peak

demand (e.g., during immediate planting at the onset of rains).

Development of fertilization schemes for these types of soils based on

preplant application of non-leachable nutrients but repeated application