ASSESSMENT OF MICROALGAL APPLICATIONS ON SOIL PROPERTIES AT INCUBATION CONDITIONS

ABSTRACT. Alternative soil improvement techniques have become important due to the adverse effects of intensive agricultural practices and various pollutants on soil properties. This study aims to evaluate the impact of Spirulina platensis and Chlorella vulgaris microalgae on specific soil qualities in a controlled environment. The microalgae used in the study were introduced into the soil at 1.5, 3, and 6 g kg⁻¹. The incubation time was designed to be the normal duration of 180 days. Soil samples were collected on Days 7, 15, 30, 60, 90, 120, and 180. The findings demonstrated that both microalgae species significantly decreased soil pH compared with the control (from 8.40 to 8.08; p < 0.01). Furthermore, soil electrical conductivity (EC) was markedly elevated relative to the control group, correlating with the escalating microalgae dosages and incubation duration (ranging from 268.06 µS cm-¹ to 290.30 µS cm-¹). Soil organic matter (OM) and available phosphorus (AP) concentrations were markedly elevated in both microalgae species when treatment quantities escalated (from 2.64% to 2.94% for OM and from 5.88 to 7.24 mg kg-¹ for AP). These results indicate that microalgae application represents a promising, low-cost, and environmentally friendly approach for improving the fertility of alkaline soils. Keywords: Microalgae, soil fertility, incubation, sustainable agriculture