Effect of Seaweed Extracts on Crop Growth and Soil: A Review

Seaweed is the common name for countless species of marine plants and algae that grow in the ocean. The seaweed cultivated by bamboo raft, tube mesh and stone method and harvested generally by acid, alkali and water extraction. However, the mostly commercially available in market, which is extracted by processing of bio refinery method. These seaweeds consist of 80-90% moisture. The dry seaweed extracts contains 50% carbohydrates, protein 10-47% with high proportions of essential amino acids, 1-3% lipids and 7-38% minerals. The essential nutrients contain in seaweeds are nitrogen, potassium, phosphorous, calcium, magnesium, sulphur, iron, sodium, zinc, and copper. Seaweed extracts are available in market viz, Sagarika, Kelp, Sea Secret, Sivarika, Solumax, Biovita etc. The soil application of liquid seaweed extracts through drip @ 0.5-1 L-1 water and foliar @ 2-5 ml L‑1 of water at various critical growth stages of different crops. The application granules of seaweed were recommended @10-20 kg acre-1 during sowing or standing crops. The application of seaweed extracts either through drip or direct application to soil at lower concentrations were positively impact on germination, shoot growth, root growth, nutrient use efficiency, soil properties, soil microbes, biotic stress, abiotic stress and crop yields.