Green Global
Foundation   Journal
...an emerging window for scientific research and publication across the globe

SOIL FERTILITY EVALUATION OF COFFEE (Coffea canephora) PLANTATIONS OF DIFFERENT AGES IN IBADAN, NIGERIA (Pages : 17 - 21)

A study was carried out to investigate the nutrient status of coffee plantations of different ages, viz. 6 years, 19 years, 37 years and 42 years. Each coffee plantation was divided into four blocks. Soil samples were collected at soil depths of 0-15cm, 15-30cm and 30-45cm from five different points within each block. The soil samples collected were processed and analyzed for some of their physical and chemical properties. Plant samples taken from the coffee plants were also processed and analyzed for some of their chemical properties. Results indicated that the nitrogen content of the coffee plantation ranged between 0.9-2.4g/kg for 0-15cm soil depth, 0.7-1.3g/kg for 15-30cm soil depth and 0.6- 1.2g/kg for 30-45cm soil depth. This was above the soil critical level of 0.9g/kg required for coffee. This is reflected in the high nitrogen level of the coffee leaf 1.56-2.0%, which is higher than the foliar critical level of 1.10% required for coffee. Soil phosphorous was also adequate across the coffee plantations irrespective of age, with phosphorous content ranging between 18.45-22.65mg/kg soil. This was well above the soil critical level of 6mg/kg soil required for coffee. Similar high phosphorous content of 1.1%-1.37% was observed on the coffee leaf. The potassium content of the soils across the coffee plantations ranged between 0.07-0.30cmol/kg. This was inadequate for coffee production. There is need to return potassium mined from the soil through guided fertilizer application to supply deficient K and enhance coffee production. Download