Humic acid is a black or brown amorphous high-molecular organic compound that is hardly soluble in water, but has colloidal properties, can improve soil structure and increase soil fertility; it has chelating action, can increase the nutrient activity of phosphorus, potassium and trace elements and fertilizer Utilization rate; can also promote crop growth and improve crop resistance. In addition, humic acid has a sustained release effect on the elements such as nitrogen, phosphorus, and potassium combined therewith. bonito,australian bonito,smoked bonito,leaping bonito,black bonito Zhoushan Boda Aquatic Products Co.,Ltd , https://www.baida-aquatic.com