Abstract ID: 3.8916 | Reviewing | Talk/Oral | TBA | TBA

Acacia mearnsii (Black Wattle), native to Australia, has become an invasive species in regions like Africa, including Malawi, causing ecological disruptions. Its aggressive growth threatens native biodiversity by outcompeting indigenous plant species and disrupting agricultural practices. Various control methods have been implemented, but their impact on soil’s physiochemical properties remains understudied. This study examines the impact of Acacia mearnsii control methods (uprooting and Impala chemical application) on soil properties in Nyika National Park over four years. Two experimental plots (29 m x 23 m) were established, and treatments were replicated at least five times in 5 m x 5 m quadrants. Soil samples were collected at a depth of 0.15 m before and after treatments and analyzed for pH, soil organic carbon (SOC), total nitrogen (N), exchangeable calcium (Ca²⁺) and magnesium (Mg²⁺), available phosphorus (P), exchangeable sodium percentage (ESP), and electrical conductivity (EC). Data analysis was conducted using One Way Analysis of Variance (ANOVA) via Minitab 18.0 to assess the effects of the treatments on soil properties. The findings showed significant differences (P < 0.05) between treatments in exchangeable magnesium and calcium levels, total nitrogen content, and electrical conductivity. Notably, Impala treatment increased SOC by 30.4% and exchangeable calcium by 81.7%, while uprooting increased SOC by 8.1% and calcium by 60.3%. Impala chemical treatment significantly enhances soil organic carbon (SOC) and exchangeable calcium levels more effectively than uprooting, indicating that chemical applications can provide a quicker restoration of vital soil nutrients. Conversely, uprooting demonstrated a substantial increase in available phosphorus, increasing it by 73.1%, suggesting its potential benefits for long-term nutrient availability, though Impala treatment resulted in a more pronounced increase of 90.5%. On the other side, uprooting decreased both exchangeable sodium levels and electrical conductivity, but Impala treatment led to significant increases in these parameters. Both treatments led to a reduction in total nitrogen levels, decreasing from an initial 2.52% to a final value of 0.61% for uprooting, and from 2.51% to 0.62% for Impala treatment. Therefore, both methods modify soil properties, offering insights for ecological restoration, with chemical interventions yielding quicker results and uprooting supporting sustained nutrient enhancement.