Nr. Hulugalle, LONG-TERM EFFECTS OF LAND CLEARING METHODS, TILLAGE SYSTEMS AND CROPPING SYSTEMS ON SURFACE SOIL PROPERTIES OF A TROPICAL ALFISOL IN SW NIGERIA, Soil use and management, 10(1), 1994, pp. 25-30
The long-term effects of land clearing methods (manual, shear blade, t
ree-pusher/root-rake combination, traditional), tillage systems (disc
ploughing, mechanized no-tillage, traditional) and cropping systems (a
nnual cropping, alley cropping, grazed pasture) on surface soil physic
al and chemical properties were evaluated on an Alfisol in south-weste
rn Nigeria ten years after land clearing. Long term soil physical degr
adation was greatest after mechanized land clearing or tillage systems
. The erosion resulting from soil compaction with mechanized land mana
gement systems resulted in exposure of subsoil. Cropping system had no
significant effect on soil physical properties. Alley cropping decrea
sed exchangeable calcium and pH, and increased total acidity mainly th
rough the greater demand for calcium by the hedgerow species. Grazed p
asture depleted exchangeable potassium because it was taken up by the
grass and exported from the site by the cattle following consumption o
f the grass.