There are many organic fertilizers currently on the market that claim to provide comparable quality and benefits of Nature Safe. In actuality, several different types of organic fertilizers exist based on the raw materials used in their formulations. To compare these types, you must look at the raw material, the processing method for this material, the protein value and the availability of this protein to the plant. Protein value in organic fertilizers translates into nitrogen value for a plant. The digestibility of the proteins will determine the product’s release characteristics.

Types of Organic Fertilizers


Formulated from feed grade quality meals derived from blood, bone, feather, fish, meat and grain by-products. In the case of Nature Safe produced by Griffin Industries, these highly digestible meals are homogenized and screened for granular size and uniformity. They consist of unique ingredients that include vitamins, minerals, chelated secondary elements, enzymes, sulfur amino acids, simple sugars, carbohydrates, starches, proteins and fats. Each meal is processed to make the protein as available as possible to supply the food energy to feed and stimulate the natural soil microbes, which aid in the breakdown of the product. In addition to characteristics including a neutral pH, low salt index, high organic matter, high WIN content, and low odor, constructed organic fertilizers have been shown to promote healthy plant growth which can reduce overall turf disease pressures. Nature Safe products contain no animal or human waste by-products or fillers.

*Nature Safe 12-2-0, 10-2-8, 8-3-5, 7-1-14 and 5-6-6 are all constructed fertilizers.


Formulated from animal manures and their bedding materials. The composting process utilizes the natural aerobic and anaerobic microbes and the free ammonia found in manure to breakdown the complex cellulose fibers found in the bedding. The finished product is sterilized by heat to destroy any harmful pathogens. This type of organic fertilizer is characterized by low analysis, high WIN product, and possibly a strong odor. It adds organic content to the soil and supplies slow release nitrogen to the turf. Due to the composition of the raw material and the varying composting methods, ingredient composition may vary, resulting in a higher probability of inconsistencies in the final product’s composition and performance.

Activated Sewage Sludge

Formulated from human and industrial waste by-products, this organic fertilizer is made using a series of screening and centrifugal processes to remove debris, oil, grease and grit. The final biomass produces a thick fibrous cake that is then kiln dried to kill all remaining microorganisms or pathogens. Activated sewage sludge is high in denatured proteins that are high WIN sources. These fertilizers have a very low salt index, are high in organic matter and may contain minor elements such as zinc, copper and iron. Because of the high heat used to sterilize the material, the protein becomes tightly bound, resulting in a high percentage of the nitrogen made unavailable to the plant.


Formulated by combining an organic fertilizer with a synthetic or chemical fertilizer. These products are either homogenized or blended to achieve a particular analysis. The final product offers a higher analysis than an all natural organic product alone. The key to success with fortified fertilizers is the ratio by which they are combined. Always read the label for the ratio between organic and synthetic fertilizer content and verify the source of organic nitrogen in the product.

*Nature Safe 20-1-5, 15-2-8, 13-0-11 and 12-2-6 are fortified fertilizers.

Editor’s Note: This information will be featured in the upcoming Food for Thought newsletter.