Measuring Soil Nitrogen Available to Crops in East Africa

Abstract

It has been generally concluded that both the organic matter and the total nitrogen values of cultivated soils are related to crop yields in only a very general way [10]. These soil factors when determined as measures of the nitrogen release to growing crops do not generally provide the degree of differentiation necessary for soil test purposes. The literature does contain occasional references to researches which have illustrated the usefulness of these parameters for defining the soil nitrogen sup- ply to crops.