The AMMONIUM SULFATE High NITRO/Hydro 21-0-0 Professional Fertilizer by Martin Brand is a fast-release organic fertilizer made with nitrogen as its main ingredient. Packaged in a convenient zip bag, this fertilizer is suitable for all-purpose application in home and garden settings. Ideal for those looking for a reliable and effective way to nourish their plants and soil with essential nutrients, this product offers a high nitro formula to promote healthy growth and development.