Effect of Biofertilizers and Soil Amendments on the Growth of Aleurites molucanna, Eucalyptus camaldulensis and Terminalia catappa in Acidic Soil

Abstract

Aleurites molucanna, Eucalpytus camaldulensis and Terminalia catappa are plant species that produce oil/biofuel, thus, they could serve as alternative sources to the limited supply of commercial fuel when planted en masse. The effect of mycorrhizal inoculation and addition of soil amendments to these plants when grown in acidic conditions were determined. Seeds used were grown in seven treatments: a control set-up (uninoculated) and six different treatments. The treatments included different biofertilizers and soil amendments namely Mykovam, Compost and Biological Indigenous Microbes (BIM) used singly and in combination with chemical fertilizer. Height, fresh and dry weight of shoot and root, leaf area, and nitrogen (N) and phosphorus (P) content and uptake were measured/determined in a two- month duration nursery experiment. Mycorrhizal infection was also determined. Results showed that the mycorrhizal association observed in the plants in the control was due to unsterilized soil used. Association was dependent on the host plant and the treatments in the soil. Evident enhancement in the growth of Eucalyptus and Terminalia when treated with biofertilizers and soil amendments compared to the control was observed, however, there was no evident enhancement in the growth of Aleurites. There were also increased uptake in nitrogen and phosphorus in plants treated with biofertilizers and soil amendments. These enhancements were attributed to the increased nutrient uptake brought upon by the microorganisms and the nutrient reservoir property of the compost. However, the effect of the biofertilizers and soil amendment treatments on the growth of the plants was comparable with each other, hence, implying that growth of the plants in acidic infertile sites can be improved through the inoculation of effective biofertilizers Mykovam and BIM and the application of soil amendments such as chemical fertilizers and composts.