Assessment of Macro and Micro Mineral Compositions at Different Depths of Forest Nursery Soils in Federal University of Agriculture Abeokuta, Nigeria

Forest soil is characteristically fundamental in the establishment of healthy seedlings for eventual planting out on the field. It is composed of mineral particles, organic matter, water, air, and numerous microorganisms. Two forest nursery soils at different depths were investigated at the Federal University of Agriculture Abeokuta (FUNAAB) for their mineral compositions. With the aid of a soil auger, twenty soil samples were randomly collected from different points in two sites at different depths (0-15 cm and 15-30 cm, air dried and taken to the laboratory for further analysis. Site 1 and site 2 (frequently cultivated portion for agroforestry bare-root seedlings and intermittently used portion). The obtained data were subjected to descriptive statistics. The composition of mineral elements varied with sites and depths. The level of Potassium was higher at depths 0 – 15 cm and 15 – 30 cm in site 2 than other macro-minerals (Sodium, Calcium and Magnesium) when compared between sites. The order of concentration includes K>Mg>Na>Ca. Micro-minerals were significantly higher at soil depth 0 – 15 cm in site 2 than site 1 (Fe>Zn>Mn>Cu). At soil depth 15 – 30 cm, levels of copper, zinc and manganese were significantly higher (p < 0.05) in site 1 with the following trend Cu>Fe>Zn>Mn. The study showed that forest nursery soils varied in their mineral composition along with depth in the studied sites. Site 2 had better physicochemical properties and higher level of some essential minerals needed for good performance of seedling growth at nursery stage.