Hydrolit: water retention fertilizer in dry soil from seaweed alginate, biochar, and zeolite

Climate change has an impact on the instability of rainfall patterns and soil degradation, especially on lateritic soils that have low water retention capacity and fertility. This affects plant infertility in lateritic soils. This research aims to improve water retention and fertility of lateritic soils through water storage media based on seaweed alginate (Gracilaria verrucosa), rice husk biochar, and zeolite as a sustainable agricultural solution. Alginate functions as a water binder, biochar increases soil porosity and provides organic carbon that supports soil microbial activity, while zeolite absorbs and releases water and nutrients gradually. The research methods included zeolite preparation and activation, seaweed processing, and rice husk pyrolysis. Water storage media were prepared by mixing laterite soil, biochar, seaweed, and zeolite in a certain ratio. Water absorption and storage capacity tests were conducted gravimetrically and analyzed by Duncan's test at the 95% confidence level. The results showed that the combination of seaweed alginate, biochar, and zeolite significantly increased the water retention capacity and fertility of the laterite soil. Thus, this innovation not only increases water availability in the soil but also improves laterite soil fertility, making it an adaptation strategy to the impacts of climate change while supporting sustainable agriculture in drylands.