Microbiological characterization of soil treated with organic compounds from water hyacinth Eichhornia crassipes (Mart.) Solms

Abstract

Agricultural organic composts are soil correctives resulting from the microbiological transformation of fresh organic matter (OM), increasing its stable fraction and the stock of nutrients made available through the mineralization of the compost, which is expected to increase microbial biodiversity and soil functionality. Water hyacinth (Eichhornia crassipes) is an invasive aquatic plant that degrades water resources and reduces the biodiversity of aquatic ecosystems. Its control provides nutrient-rich biomass, which, when returned to the soil after aerobic composting, will offset the social cost of control operations. The BioComp_2.0 project aims to add value to agricultural and forestry by-products, with the residue from water hyacinth control being the main constituent of each of the six formulations. The microbiological characteristics of the soil enriched with the organic compounds produced were evaluated. The performance of the six composts in increasing aerobic, nitrogen-fixing, fungal and denitrifying strains was compared with the control soil (without fertilizer) and soils containing a commercial organic fertilizer and or a compost. There was an absence of pathogens and significant increases in aerobic and denitrifying strains. The levels of microorganisms in the soil treated with the composts produced were like those in the soil treated with commercial compost and organic fertilizer.