Ask most any gardener whether they prefer organic or chemical fertilizer, and chances are you’ll spark a lively debate. However, if you could ask your plants the same question, you’d find out that at the most basic level, they really can’t tell the difference – nutrients are nutrients.
Yet there ARE significant differences between organic and chemical fertilizers in terms of nutrient availability and the long-term effects on soil, plants, and the environment. So how does a conscientious gardener decide?
To begin with, the terminology can be confusing, since labels and gardeners freely throw around words like organic, natural, inorganic, chemical, synthetic, artificial, and manufactured. The good news is that the choice can be reduced to either organic or chemical fertilizers.
The words “organic” or “natural” in this case simply means that the product is only minimally processed, and the nutrients remain bound up in their natural forms, rather than being extracted and refined. In the case of fertilizer, “organic” does NOT refer to the standards of processing associated with food.
Organic fertilizer is usually made from plant or animal waste or powdered minerals. Examples include manure and compost, as well as bone and cottonseed meal. They are usually sold as “soil conditioners” rather than as fertilizer, because the nutrient ratios are difficult to guarantee. Organic fertilizers may be processed in a factory, or, in the case of manure and compost, at a farm.
There is also a growing selection of more highly processed products now available, with labeled analysis of nutrients and contents. For example, Scotts Miracle-Gro Organic Choice Plant Food is a manufactured product composed entirely of chicken litter and ground up feathers, with an N-P-K ratio of 7-1-2. Garden Safe Organic Plant Food is made of poultry manure with a label very similar to chemical fertilizers.
Advantages of Organic Fertilizer:
- In addition to releasing nutrients, as organic fertilizers break down, they improve the structure of the soil and increase its ability to hold water and nutrients. Over time, organic fertilizers will make your soil–and plants–healthy and strong.
- Since they are the ultimate slow-release fertilizers, it’s very difficult to over fertilize (and harm) your plants.
- There’s little to no risk of toxic buildups of chemicals and salts that can be deadly to plants.
- Organic fertilizers are renewable, biodegradable, sustainable, and environmentally friendly.
- Although rather expensive in packages, you can make your own organic fertilizer by composting or find inexpensive sources—such as local dairy farms—that may sell composted manure.