When we fertilize our gardens, we know it’s critically important to feed the soil, and not just the plants. We’re feeding important, nutrient-recycling soil microbes, and they need food. Real, natural and organic food, not chemicals. Chemical fertilizers can harm or kill soil microbes. But by applying natural and organic fertilizer ingredients, we nourish and nurture the organisms that will pay it forward, providing important nutrients to our growing plants. There is an entire network of organisms at work in your soil, millions of tiny organisms contributing to soil fertility. But at the foundation of healthy soil are two key players: bacteria & fungi. And they need energy to survive and thrive.
These two hard-working organisms are critically important for converting nitrogen in the soil into forms that plants can use. Grasses, vegetables and annuals prefer the nitrate form of nitrogen that is produced by bacteria, while perennials, trees & shrubs prefer the ammonia nitrogen that fungi provide. Bacteria and fungi are also a key food source for all the bigger organisms around them, who will consume, transport and deposit their nutrients for uptake by nearby plants.
So, what do you feed bacteria and fungi to keep them healthy and thriving? Bring on the carbs. Carbohydrate-loaded fertilizers, that is.
Most bacteria thrive on simple carbohydrates and sugars, which are easier for the bacteria to break down into energy. This is why they devour the fresh green material in your compost pile. Fertilizers that provide similarly simple carbohydrates will best satisfy bacteria’s energy needs. One of the best but often overlooked bacteria-feeding fertilizers is dried molasses. While it contributes no nitrogen, phosphorus or potassium, it does provide organic matter and a concentrated source of sugar to bacteria so they can power up their nitrogen conversion. That’s why an application of molasses helps a lawn green up more quickly than just a nitrogen fertilizer alone.
Fungi, on the other hand, draw energy from breaking down more complex carbohydrates like the lignin and cellulose found in carbon-rich brown matter. They thrive on fertilizers that contain chitin, such as insect frass, kelp meal and crab shell meal. The fungi use the chitin to strengthen their cell walls to enhance their survival in challenging conditions, and the rich micronutrients in those fertilizers get distributed through the soil as larger organisms feed on the fungi.
But nature usually does the microbe balancing for us, so unless your fungi and bacteria populations are completely out of balance, it’s usually best to choose fertilizers that feed them both. Alfalfa meal is one of the best ingredients for encouraging robust microbe populations because of its high carbohydrate content and trace mineral profile (added bonus: alfalfa meal also contains triacontanol, a natural root stimulant). Other plant-based nitrogen sources like soybean meal, distillers grains and wheat middlings are also great sources of carbohydrate-based microbe energy and nutrition. At Garden Maker™ Naturals, we’re proud to provide natural & organic fertilizers that nourish these important soil microbes, contributing to healthy soil and plants today, tomorrow and for years to come.