This is slow-release organic fertilizer derived from ground-up shrimp shells is a by-product of shellfish processing. Besides providing slow release Nitrogen and Phosphorus, shrimp shells are very high in chitin. Studies show that chitin provides a source of carbon and nitrogen that stimulates beneficial chitin-feeding microbes which multiply in the soil and consume the chitin in the shell meal until it is gone. At that stage they move on to consume any other high chitin sources that might be in the soil. Apply at 500-2000 lb/acre or 12-50 lb/1,000 sq ft.