Greenway Biotech Crustacean Meal 4-0-0 is dried, ground crustacean shell. It supplies 4% nitrogen, held in shell protein and chitin, which soil microbes release gradually: Washington State University counts 40 to 60% of it as available to plants in the first season. The shell minerals are mostly calcium carbonate, the compound in limestone, so the meal can raise soil pH over time.
Apply it by weight to a nitrogen target. Washington State University’s vegetable garden rate works out to about 10 lb of this product per 100 sq ft for the season, worked in before planting. Apple and stone fruit trees take 2.5 lb per inch of trunk diameter, up to 25 lb per tree (University of Arizona). Use it on acidic soil; for neutral or alkaline soil, blueberries, and other acid-loving plants, choose another nitrogen source.
It does not dissolve, so it is not for hydroponics or sprays, and people with a shellfish allergy should not handle it. Packed in Madera, California, in 2 to 40 lb bags.
