Composting of Tropical Toxic Weed Lantana camera L. Biomass and Its Suitability for Agronomic Applications

ABSTRACT

Lantana camara is an evergreen, which is the most notorious toxic weed of the terrestrial ecosystem. It is native to subtropical and tropical America, but a few taxa are indigenous to tropical Asia and Africa. An enormous quantity of green foliage is produced by this weed, which cannot be used as livestock feed due to its toxic properties. Management through utilization seems the only sustainable option for this problem. In this study, the composting of Lantana biomass was done and changes in chemical characteristics of waste biomass were measured. The composting caused decreases in pH, organic carbon, C:N ratio _totK and _totC by 2.0-, 1.25-, 1.66-, and 19-fold, respectively, but increases in electrical conductivity (EC), ash content, _totN, _totP, _totZn, and _totMg of 2.0-, 1.11-, 3.36-, 1.76-, 1.28-, and 1.70-fold, respectively. The C/N ratio (20.1) and soil respiration rate (47.12–66.20 mg CO₂-C/100 g) suggested the compost maturity at 52 days. The high bacterial (38.67 CFU × 10⁻⁷ g⁻¹), fungal (30.0 CFU × 10⁻³ g⁻¹), and actinomycetes (32.0 CFU × 10⁻⁵ g⁻¹) population in composted material suggested the suitability of compost for agronomic purposes. Phytotoxity measured through compost:water extract and compost pot trial suggested the germination index (GI) in the ranges of 52.3%–122.3% and 74.5%–166.9%, respectively. The high ranges of chlorophyll, protein, and carotenoids in seedling than control suggested the non-toxicity of ready materials. Results suggested that composting can be a potential technology to manage Lantana biomass for sustainable land fertility management programs.

ACKNOWLEDGMENTS

The authors are highly thankful to two anonymous reviewers for fruitful comments on an earlier version of the manuscript.