Soil Micronutrients and Aluminum in Agricultural Fields as Affected by Plant Species at Masako Forest Reserve, Kisangani, Democratic Republic of Congo

Plant species can significantly influence soil nutrients. We assessed how soil micronutrients (B, Fe, Cu, Zn, Mn) and Aluminum were affected by plant species in agricultural fields at Masako Forest Reserve. Soil samples were collected in June 2022 and 2023 at three depths: 0–10 cm, 10-20 and 20-30 cm in fields grown to Costus lucanusianus, Manihot esculenta, Zea mays, Triumfetta cordifolia, and Xanthosoma sagittifolium. A completely randomized design was used with 3 soil depths (SD) x 5 plant species (PS) replicated 4 times. Soil samples were air-dried, sieved 2 mm and sent to Brookside Laboratories (OH, USA) for analyses. Results showed that in 2022, Fe, Mn, Cu and Zn were significantly affected by soil depth (p< 0.05). Mn, Cu and Zn concentrations were higher in 0-10 cm while Fe dominated in 10-30 cm depth. Only Cu (p=0.0001) was affected by plant species. The soil under Xanthosoma sagittifolium (0.19 mg/kg) and Triumfetta cordifolia (0.47 mg/kg) had significantly the lowest level of Cu. In 2023, however, only Zn was significantly affected by SD (p=0.0004) with its highest level (1.22 mg/kg) in 0-10 cm. PS significantly affected Fe, Mn, Cu, Zn and aluminum (p< 0.05). The soil under Manihot esculenta had the highest concentration of Fe (171.42 mg/kg) while Zn (1.03 mg/kg) was significantly higher in the soil under Zea mays. The 0-10 cm layer significantly held more micronutrients. Plant species such as Manihot esculenta had a noticeable effect on soil micronutrients.