A topic that has been gaining momentum over the last decade is soil health, because it is the key to producing both healthy plants and protecting water quality.
The definition of soil health, provided by the Natural Resources Conservation Service and U.S. Department of Agriculture, is “the continued capacity of soil to function as a vital living ecosystem that sustains plants, animals and humans.”
The following practices will improve your landscape’s soil health, providing you with healthier plants, and in the case of edible plants, more nutritious food. Read the suggestions below to see if you would like to begin using any or all these practices so your yard can be part of the solution for the Indian River Lagoon or the St. Johns River.
Add organic matter. Top dress the lawn with half an inch of organic matter every six months to increase the organic matter in the soil. Our soil is typically very low in organic matter, so a great way to improve the soil is to add some. Organic matter increases both the nutrient- and water-holding capacity of the soil, which is why a healthy soil protects water quality.
After adding the organic matter, don’t stop there, because the next step is to inoculate the soil with life in the form of beneficial soil microbes such as mycorrhizal fungi and bacteria. Soil microbes have been called the “stomach” and “engine” of the soil, and without their presence, any added organic matter will eventually disappear.
When microbes are present, they create organic matter and carry-on nutrient cycling, providing plants with various nutrients in small amounts, on a continual basis. Mycorrhizal fungi not only supply phosphorus and other nutrients to plants, but they also move water from one area to another.
There are many products available to inoculate the soil, including organic fertilizers and liquid products. For a St. Augustine lawn, pick a product that contains Glomus species of arbuscular mycorrhizae. Research at the University of Florida has found that Glomus species of mycorrhizae form a symbiotic relationship with St. Augustinegrass.
With the help of the mycorrhizae, your grass and other perennial plants will receive more phosphorus, other nutrients and water than their roots could obtain on their own. Trees are mycorrhizal dependent, so if you love your trees, inoculate their roots.
For the soil to be a living ecosystem, it must have a healthy and diverse microbial population.
Trace elements. It’s also important to provide plants with a wide range of nutrients and the ones often missing are trace elements. Volcanic rock powder is an easy way to re-mineralize the soil to produce healthy plants that will become nutritious food for the animals that eat them.
If you are growing vegetables, fruit crops and/or herbs, be sure to re-mineralize the soil.
This is one of the main reasons to grow your own food, because you can make sure that the soil is re-mineralized.
Of course, when thinking of lawns and landscapes, weeds are a common element. Though weeds are viewed as a problem, they are just a sign of an unhealthy soil. The use of herbicides won’t improve the soil and will therefore never be a cure.
Weeds grow in locations that have specific nutrient imbalances and other physical properties that create anaerobic conditions. Their long roots can grow deep into the soil to bring the nutrients up to the soil surface and create pathways for water and air to penetrate deeper into the soil.
If you choose to fight the weeds and not address soil health, the battle will never end. Weeds do best in disturbed soils and their presence is the first step in repairing the soil.
Organic fertilizers will also help improve soil health because they are a source of organic matter, a food source for the soil microbes, and many of them also contain soil microbes.
Organic fertilizers also typically have much lower amounts of quick-release nitrogen than synthetic fertilizers. After applying any fertilizer that contains quick-release nitrogen, make sure to immediately water it in lightly (with approximately a quarter inch of water) to dissolve the quick-release nitrogen and carry it down to the root system of the plants where it will be absorbed.
If quick-release nitrogen is watered in with large amounts of water, it can be carried past the root zone, down to the ground water and carried to the nearest water body.
If you haven’t tested your soil within the past two years, have it tested before applying any type of fertilizer.
Increase diversity. My last suggestion in to increase the diversity of plants growing in your yard. Living roots provide food for the soil microbes in the form of carbohydrates.
Make a note on your calendar for every November, if the temperatures have cooled down, to over-seed your lawn with scarified annual ryegrass seed. Annual ryegrass creates a gorgeous spring green, soft grass that bends in the breeze.
During the short days of winter, St. Augustinegrass stops actively growing and turns yellowish. Annual rye grass will green up your lawn and, in the spring, when the rye grass dies it will add organic matter to the soil.
In ornamental plant beds and under trees plant some annuals, perennials and/or ground covers will support a larger variety of microbes living in the soil.
If you begin using all these suggestions, your soil health will improve rapidly. Even just adopting a few will benefit your plants. Email me at [email protected] if you would like more information on how to add life to the soil.
Sally Scalera is an urban horticulture agent and master gardener coordinator for the University of Florida’s Institute of Food and Agriculture Sciences.
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