The Effect of Bacterial Inoculation and Organic Amendments for the Establishment of Some Multipurpose Trees on Degraded Land

Abstract

Rehabilitating poor soil can be achieved in part by planting trees. In the field, bio-augmentation and organic amendments (OAs) promote plant establishment and growth. Hence, this study was initiated to assess the role of organic amendments and bacterial inoculations (BI) on tree establishment on degraded soil under field conditions. Six plots measuring 41 m x 4 m were established on which the soil was amended with organic matter and bacterial inoculation (BI) of the transplanted plants quarterly, which were followed by monthly bacterial counts and measurements of plant growth parameters and the survival rate of the plants for one year. Plots receiving OAs showed the highest counts of bacteria (21.66), actinomycetes (2.29), and fungi (0.82) x 105 colony-forming unit g− 1 soil. Also, there were significant (p ≤ 0.05) increases in stem height (1, 0.42, and 0.39 m/plant), girths (12.0, 2.28, and 11.33 cm/plant), and branch numbers (5, 4, and 4.3/plant) on transplanted apple, acacia, and prunus respectively, compared to the control. The highest survival rate was observed on an apple tree (Malus domestica) (80%) and acacia (Acacia abyssinica) (66%). The result concluded that using OAs and BIs enhanced the growth and establishment of trees for the successful rehabilitation of degraded land.