Soil Nourishment: Using Seaweed for Soil Fertilization and Soil Removing Heavy Metals from Soil

The increasing demand of food requires use of fertilizers, but it has led to many Disasters, which will lead to the degradation of agricultural land, especially the soil. So, this research was done to support using bio extracts from seaweed. The study includes the extraction of nutrients from seaweed by microwave-assisted extraction (MAE), to extract the nutritional benefits, essential minerals and active compounds of seaweed. The soil was fertilized with the extracts of each seaweed alone and with mixture. Seaweed extracted solution increased organic matter and nutrients content and induced proteins, polysaccharides, cytokinesis and growth hormones to the soil. The extracted solution of 30 ml amount contained NPK at the concentration 82.8 ppm, 13.28 mEq, 13.8ppm. In addition, the slow release of seaweed enhances soil efficiency and plant health and minimizes environmental pollution which continuously prevents soil erosion and salinity unlike chemical fertilizer. Seaweed mixture shows efficient heavy metal biosorption capacity due to the existence of active functional groups on their cell wall surfaces. This decreased the content of heavy metals (Pb, Cd, Hg, Cr) to tolerable limits which accumulate in the plant and affect the health of human and animals who feed on. The solution was prepared by microwave-assisted extraction (MAE) with conditions of 900 W, liquid/solid ratio 15ml/5g of dry mass, extraction time (30 min) at three different temperatures 25, 40, 60°C. Results show that the content of micro and macro-elements increase by temperature. Germination tests on mint plants show higher height, longer roots, and more nutrients. Results show that algal extracts obtained by MAE have the highest potential applied in agriculture as bio stimulants.