ABSTRACT
The chapter is aimed at verifying the environmental crisis hypothesis using published agronomic and range science experiments across East Africa. Two ecological theories are tested: equilibrium (i.e. environmental crisis) and disequilibrium (the alternative, testing environmental variability). In rationalizing experimental protocols, responses of proxy environmental indicators (sediment production, crop yields, stream discharge, range production and livestock production performances, reseeding and bush clearing) to intensifications of land use are used. Interpretations of the responses of the proxy indicators to land-use intensifications underscored which of the ecological models was appropriate. In agronomic experiments rates of soil erosion were influenced by vegetation cover and intensity of rainfall storms that influenced river discharges. Soil moisture influenced variable crop production. In agronomic experiments commercial fertilizers and cattle manure showed temporary improvements in soil fertility, the lower soil fertility was attributable to other factors, as opposed to intensifications of land use. In grazing experiments, rainfall variability, and not grazing, was decisive in rangeland productivity and restoration. Grazing experiments, without exception, demonstrated superiority of the indigenous methods over the officially preferred systems. Environmental restoration was possible only when rainfall was plentiful showing that none of the experiments supported the environmental crisis but the disequilibrium model, suggesting that climatic drivers had overarching roles to play on environmental changes.
