Soil Degradation-Induced Decline in Productivity of Sub-Saharan African Soils: The Prospects of Looking Downwards the Lowlands with the Sawah Ecotechnology

Table 2

Erosion-productivity relationship for soils of Sub-Saharan Africa (natural erosion).

Soil loss (cm)	Yield reduction (%)	Soil order	Climate/location	Country	Source
Maize (Zea mays L.) as a test crop
0.0024	26.9	Alfisol	Semiarid Harare	Zimbabwe	[14]
0.0080	0.1513	Alfisol	Subhumid Ibadan	Nigeria	[21]
0.0080	0.1720	Alfisol	Subhumid Ibadan	Nigeria	[21]
Pearl millet (Pennisetum americanum L.) as a test crop
0.0928	51.6	Aridisol	Semiarid Niangoloko	Burkina Faso	[14]

All soil erosion rates were converted to equivalent depths of soil loss, assuming a bulk density of 1.25 mg m⁻³.