This past weekend we had the folks from Mountain Gate Organics over at the Charlottesville store talking worms, soil, and biology. In anticipation of the day, we had made a couple hundred gallons of compost tea and were giving it away to any interested gardeners. Even more exciting was a little display we had set up with a microscope connected to a computer screen. Underneath the microscope two drops of the tea (made from worm castings and molasses introduced into water and supplied with air) were wedged between two pieces of glass.
Over the next couple of hours we witnessed protozoa, hyphae strands, amoebas, and carbon chains as they constantly moved, ate, grew, and changed before our eyes. And it was a stark reminder of what happens below the surface (so to say). Those two drops were full of life – and that life, those microbial populations of bacteria and fungi are critical to the entire ecosystem that is your garden!
You see, plants need that biology in the soil. They rely on it to break down vital nutrients and convert them into forms that plants can use. They can also make those nutrients immobile, essentially holding them in the soil (preventing leaching) until a plant is ready or able to use it. On the other side of this relationship, the biology in your soil relies on plants for food. They attach themselves to root systems and depend on the carbohydrates created by plants for food.
When your soil biology fails to thrive, that little ecosystem can collapse, and it makes successful growing more difficult. So what can be done? Here are a few things that kill or harm your soil’s biology and the alternatives that you can employ to make your soil (and garden) healthier and more productive:
Synthetic, Petrochemical Fertilizers
They are produced using large quantities of petroleum or fossil fuels and they contain ingredients like ammonium nitrate. You probably see these a lot, but don’t realize it. They are usually easy to identify by formulas like 10-10-10 or 20-20-20. The N-P-K ratios on a fertilizer denote the concentrations of the macronutrients – nitrogen, phosphorus, and potassium. The problem here is two fold. First, a plant can’t use all of that nitrogen at once; it will absorb some, but the rest leeches into and through the soil and eventually into waterways causing a chain of environmental issues. Second, it is essentially too much for your soil biology and can effectively kill it, thus making your soil more depleted of available nutrients and ways to absorb them and making you more dependent on – you guessed it! – fertilizer.
So, when you do need to supplement with a fertilizer, look for a mineral, plant, or animal based option. Most organic fertilizers are made up of things like bone meal, alfalfa meal, and aragonite. Healthy soils, full of beneficial microbes, don’t need massive amounts of fertilizer, so if you do your job right you will be less dependent on fertilize, which also saves $$$.
Overworking the Soil
Tilling the garden sometimes seems like a thing people just do, because that’s what you are supposed to do. But that level of disruption can actually harm the life in your soil. It can also create a compact layer below your topsoil called a hardpan, which makes drainage more difficult. Look at no till methods for working your garden. But, also realize that a healthy soil, with a balanced support system of bacteria and fungi, will actually be easier to work overtime.
More of an issue in large-scale farming, but something to be aware of. Essentially, it is planting the same crop from year to year to year. Solution – rotate your crops! Plant different things in different areas from year to year. This topic has a lot of attention already, so go out there and find a plan that works best for you. The best cheat code though is a circular system, which is easy to remember Legumes (peas, beans) –> Roots (carrots, beets) –> Fruit (tomatoes, squash) —> Leaf (lettuce, cabbage) and back to the beginning.
Don’t let the garden sit empty! After the fall harvest if you don’t plant on a winter garden, put in a cover crop. Remember plants rely on biology, but the biology relies on plants. We talked about this in a previous blog post about cover crops, but don’t starve the biology in your soil by letting your garden sit empty all winter. A cover crop not only feeds and supports your soil biology it also can assist in scavenging nutrients from the soil and preventing erosion and compaction.
Lastly, think about giving your garden’s biology a jumpstart. Worm castings are a great way to do that, using them in place of certain fertilizers. Not only do they provide low levels of macronutrients, they are full of beneficial microbes. Better yet, use those worm castings to make a compost tea. Very simply this is a way to take the microbial populations in the castings, feed them with sugars and let them rapidly multiply before watering them into your soil. Use a mycorrhizal inoculant when transplanting your plant starts, this will help with nutrient uptake and absorption.