Read the label. What is true of synthetic fertilizers and pesticides is true of organic and microbial alternatives, too. Never think that either is completely safe in all situations. Labeling regulations are strict and consistent, so comparing labels is much better than just comparing names and claims.
- Is the product labeled as “organic” or only “organic based?” Does it have the USDA Organic or OMRI label? Both of those guarantee adherence to standard organic guidelines while others may not. While lawn and landscape practices are not regulated under the USDA National Organic Program, that is the Gold Standard to your customers -- make sure you are not mis-leading them!
- Does the material have any nutrient value – N-P-K? If it does you need to know both so you can figure its contribution into your overall fertility program and because many jurisdictions are adopting phosphorus bans. Organic products may often claim both growth promoting and disease inhibiting characteristics.
- Look for any micronutrient claims, too. Many natural products, being made from byproducts of food or agricultural processing, include a wide range of micro-nutrients, and in the case of marine byproducts such as kelp or fish waste, significant levels of growth hormones as well.
- What is the source of the nutrients? Organic products should use only natural, not synthetic ingredients. Chilean nitrate, calcium phosphate and potassium sulfate, for example, are organic. Ammonium nitrate, urea, super-phosphate and potassium nitrate are not.
- Are there possible contaminants in the material? Some biosolids, like municipal sludge based composts are high in heavy metals, which can build up in the soil over multiple applications. Many states now require tests for heavy metal levels. Look for that information on the label.
- If the material is microbial based, read the list of species. Compost “teas” and biological pest controls achieve their results by inoculating the soil with good “bugs” that consume or out-competing their harmful cousins and then colonize plant roots, so the list of bugs in the bag or bottle matters.
- Make sure the microbial mix is appropriate for your use. Turfgrass and woody plants need different mixes of “bugs.” Lawns want an inoculant that has more bacteria than fungi; the reverse is true for woodies. To know which is which, see the side bar on understanding the new organic labels.
- Be sure to understand application procedures. As a rule, most of the bacteria and fungi in compost teas are soil microbes and that means that sunlight is deadly to them. Make sure your application procedures protect them until they can do their work. If you can’t follow the label recommendations – not really that hard -- then think twice before integrating that product into your service.
- Check out stated hazards and problems. Just because a material is organic does not mean it does not have hazards and problems; they are just different. Some organic materials are actually more acutely toxic than their synthetic alternates, and many compost derived products have more phosphorus than is allowed in restrictive jurisdictions. Again: READ THE LABEL.
- Compare cost per square foot (or acre) over time. If the material requires multiple applications to maintain its effectiveness, the full seasonal cost should be calculated before making a value decision.