Are all organic fertilizers the same? No. 

Organic fertilizers feed soil biology and soil biology feeds the plant. Using an organic fertilizer slowly releases nutrients to the grass. These nutrients must be released at a rate the plant can absorb for healthy and steady growth. Water Insoluble Nitrogen (WIN), the nitrogen found in most all-natural organic fertilizers, lasts six to twelve weeks. When using an organic fertilizer, you will not encounter the rapid surge of shoot growth typically caused by chemical fertilizers. An all-natural approach results in mowing less, and having more uniform and sustainable growth than that of chemically treated lawns.

A healthy soil environment must provide microorganisms with food, water, and oxygen to survive. Without a balanced soil environment, beneficial microbes go dormant. Microorganisms prosper on carbon-based food sources that also provide other nutrients,  therefore organic fertilizers add organic matter and carbon to the soil. Carbon, a moist environment, and adequate pore space to hold oxygen, are all important for beneficial microorganisms. These beneficial microorganisms will regulate and attack the bad microorganisms in the soil. 

There are several categories into which organic fertilizers fall, each with associated pros and cons…

Organic Fertilizer Categories

1. 1. All-Natural Organic Fertilizers (like PJC Organic ProHealthy Turf Blends) get their nutrient content from plant and animal meals Plant and animal meals are high nitrogen sources.  Due to their high nutrient content, the cost-per-nutrient tends to be less than other organic alternatives.  They have been found to be excellent fungal and bacterial foods, which are critical in an all-natural program.  While the bulk associated with natural organic fertilizers is often seen as a disadvantage, the advantage is that organic matter and valuable nutrients are added to the soil.  
   2. Animal Manures are a common form of organic fertilizer. There is often a low cost per pound because the base is a waste product, although they are also lower in nutrient content (so the cost-per-nutrient tends to be high).  To reach a target nutrient value, a greater amount of product needs to be applied, thereby increasing labor costs as well.  Manures are high in phosphorus, which can increase seed germination in undesirable plants, leading to increased weed pressure. Poultry litter based fertilizers contain some level of copper and arsenic. Heavy metals can build up in the soil and cause health concerns for consumers and runoff; OMRI therefore restricts the use of these fertilizers in organic crop production.
   3. Amino Acids: The use of the term “amino acids” in the marketplace is relatively new and somewhat misleading, because all organic fertilizers derived from plant and animal meals contain amino acids.  Amino acids are the building blocks for protein which plant and animal meals contain. Vendors are attempting to use the term “amino acid fertilizer” to refer to a class of fertilizers that are soluble in water.  They are protein hydrolysates that are manufactured in one of three ways; either through enzymatic, acid, or alkaline hydrolysis of proteins. Protein hydrolysates are in effect making a water-soluble organic nitrogen source available to plants.  Because the nitrogen is water-soluble, there is the potential the nitrogen not taken up by the plant will leach. There are times when the use of such products may prove advantageous and times when they do not.
   4. Municipal Waste – Biosolids are the output from municipal sewage treatment plants and another form of fertilizer.  The greatest concern with these products is the potential inclusion of heavy metals from industrial waste, prescription medicines, along with potential chemical contamination from household cleaner, antibacterial agents, and other things poured down the drain.  Because of these concerns, OMRI prohibits the use of these fertilizers in organic crop production. 
   5. Chilean Nitrate (NaNO3) aka Natural Nitrate of Soda (NNS): NNS s a mined substance and is therefore classified as a natural product. It has an analysis of 16-0-0 and is considered soluble. NNS is available in cold soils and may be taken up directly by the plant without microbial activity – this may be a perceived advantage in Northeast soils. The National Organic Program (NOP) in Notice 2-1 and OMRI have changed the restriction on NNS in place since October 2012. Now, production practices must maintain or improve the natural resources of the operations. It must be used sparingly, since it is also a salt and when used excessively can have a negative effect on the health of the soil.
   6. Synthetic Organics or “Organic-Based”: A fertilizer can claim to be “organic” without being all-natural as long as it contains carbon.  Urea is an inexpensive fertilizer and is the most common form of a synthetic organic. It’s often coated in an effort to delay the release of nitrogen and reduce burn potential.  Urea, like other synthetic fertilizers, is a salt. The high salt index associated with urea has a negative impact on the soil biology by killing many microorganisms off. Salts also make it more difficult for seeds or plants to extract the water they need for normal growth.  

Phosphorus Restrictions

Grass does not require large amounts of phosphorus to grow and many states have restrictions on phosphorus in fertilizers. Phosphorus contributes to the buildup of excessive nutrients, algae bloom and WSN converts to nitrates in the water. On properties near water, select an organic fertilizer that does not contain phosphorus or water soluble nitrogen (WSN). The middle number on the fertilizer label refers to phosphorus, so select an all natural organic fertilizer with numbers like 6 – 0 – 6. The use of a no-phosphorus organic fertilizer helps further eliminate the runoff potential. 

Certain fertilizers lend themselves better to an All-Natural Organic Turf Care (OTC) approach and some work against an OTC approach.  When choosing an organic fertilizer read the label carefully. If any of the numbers for N-P-K are higher than “12” chances are it is not an all-natural organic fertilizer.   Packaging can be deceiving; just because it claims to be “organic” doesn’t mean it is free from synthetic chemicals.