Abstract ID: 3.8881 | Accepted as Talk | Talk/Oral | TBA | TBA

Mountain soils are crucial for environmental sustainability and climate change mitigation. However, invasive species like bracken fern (Pteridium aquilinum) threaten these ecosystems. P. aquilinum, found globally except Antarctica, disrupts soil processes and biodiversity. In Malawi, particularly on Mulanje Mountain and Nyika plateau, it has become a dominant invasive species, significantly displacing grasslands and posing a substantial ecological threat. This study investigated the impact of physical and chemical control methods on soil chemistry in grasslands of Mulanje Mountain and Nyika National Park, Malawi, heavily invaded by the bracken fern Pteridium aquilinum. The research, conducted over four years, examined the effects of chemical treatments (Forester, Eco-Imazypyr, and lime application) and physical methods (mowing and slashing/cutting) on soil pH, soil organic carbon (SOC) stock, exchangeable calcium (Ca), magnesium (Mg), available phosphorus (P), total nitrogen (N), and the Carbon-to-Nitrogen (C:N) ratio. Four experimental plots (35m x 29m) were established at each site, with treatments randomly assigned and replicated. At least six soil samples were randomly collected from each of 5m x 5m quadrants at a depth of 0.15m before and after treatment application and analyzed using standard soil analysis procedures. Data were analyzed using ANOVA (Minitab 18.0). The results revealed significant differences (P<0.05) in total nitrogen levels, soil pH and organic carbon stock levels, with lime treatment resulting in the highest (14.46%) increase in pH from the initial 4.08 to 4.67 and Forester treatment yielding the most substantial (64.4%) increase in SOC from the initial 58.14Mg C/ha to 95.62Mg C/ha. The Forester treatment led to the most substantial (64.4%) increase in SOC, from 58.14 Mg C/ha to 95.62 Mg C/ha. No significant differences were observed in exchangeable calcium, magnesium, or C:N ratios. However, all treatments significantly enhanced available phosphorus in the soil, with physical methods, particularly mowing, showing notable effects. In conclusion, both physical and chemical control methods for P. aquilinum positively influenced soil chemistry. The increases in soil pH and organic carbon suggest improved soil health. These findings highlight the importance of implementing effective management strategies to preserve mountain soils and maintain ecological balance in the face of invasive species.