A comparative study on zero tillage with bulldozing as land preparations on oil palm growth, and nutrient status after 5 years of planting

Abstract

A comparative study on zero tillage and bulldozing, as land preparations for oil palm seedling transplanted into the field was conducted at Ayip Eku Oil Palm Estate between 1993 and 1997. The experimental site was a five-year fallow land in which Panicum maximum (Guinea grass) and Centresoma pubescence were dominant fallow species. Sprouted oil palm nuts were obtained from the Nigerian Institute for Oil Palm Research (NIFOR) and established in a single stage nursery and used for the experiment. Number of leaves per palm, palm height and leaf area (LA) determined after 12 months of field planting, were significantly higher in the zero tillage plots than the bulldozed plots. Zero tillage exerted a more significant (P<0.05) effect on growth parameters through increased plant height, leaf number per palm, and Leaf Area and nutrient status of the soil than bulldozing. On the average, the number of leaf blades per palm and palm height increases were 25.0% and 34.7% respectively, higher in the zero tillage plots compared with bulldozed soil. Seasonal trend showed that zero tillage had the highest N content of 32.29g/kg within the 0–20cm depth compared with the bulldozed plots. Cropping for 5 years under both tillage systems resulted in a decrease in soil pH by approximately one unit in the surface horizon. Zero tillage system maintained a significantly (P< 0.05) higher level of exchangeable Ca and Mg in the surface depth, 0-20cm layer that by implication has the highest organic matter content. Equally, both tillage systems had more than adequate amount of available P and exchangeable K up to 80cm depth. These findings are discussed in light of tillage systems and soil nutrient status in oil palm management.

Keywords: zero tillage, bulldozing, crop growth and nutrient status after 5 years

Global Journal of Agricultural Sciences Vol. 4(2) 2005: 149-154