RELATIONSHIP OF LANDSCAPE POSITIONS WITH SOIL PROPERTIES ON MAIZE YIELD IN ULTISOL

Abstract

Relationship of landscape position and soil properties to maize (Zea mays L.) yield was studied incoastal plain soils of Akwa Ibom state. The study aimed at assessing the physico-chemical soil attributesdown the geomorphic surface as well as assessing the yield of maize in the respective landscapepositions. A total of 3600 plant population (hybrid maize) were planted on 0.072ha in a Randomizedcomplete block design. The traditional land preparation technique was employed with slashing of regrowth vegetation with cutlass. The trashes was left on the sites and allowed to dry for three weeks. Preburn soil samples were taken before burning the trashes at the end of three weeks after slashing. Thesamples collected were analyzed in the laboratory for physico-chemical properties using standardmethods. Collected data were statistically analyzed and means of statistically significant parameters wereseparated using LSD (0.05). The results showed that sand particle of burnt and un-burnt soils weresignificantly different at 0-15cm of Upper slope (US) but not significantly different in other landscapepositions (p<0.05). Soil pH in burnt soil was significantly different from the un-burnt soil (both atsurface and sub surface) in the three landscape positions. Mean maize yields (with husk) was 0.09 and0.11kg/ha ‘before’ and ‘after’ burning plots of US ; 0.12 and 0.16kg/ha in ‘before’ and ‘after’ burningplot of the middle Slope (MS) while the Bottom valley (BV) had 0.14 and 0.16kg/ha in ‘before’ and‘after’ burning plots. Altogether, both husked and de-husked yields were higher in burnt plots than unburnt plots. Along the slope, husked yield followed the order: BV (0.15kg/ha) > MS (0.14kg/ha) > UP(0.10kg/ha)) while de-husked yield also followed similar pattern but different magnitude.