by Taylor Vandiver | Jan 22, 2015
You’re digging up a ridiculously stubborn patch of Florida betony when an earthworm crawls across your path. As you break apart the soil in your hands a world of active organisms is being sifted through your fingers. Fertile soil is teeming with beneficial microbes. It is estimated that there can be billions of microbes in a single gram of soil.
Bacteria, fungi, and protozoa are major players in soil microbial processes. They perform a variety of functions beneficial to soil and the plants growing in that soil. Other soil organisms of importance are nematodes, arthropods, and earthworms.
Soil Food Web. Photo courtesy USDA-NRCS.
Rather than being an inert material, soil houses a dynamic living ecosystem. Most soil organisms are too small to be seen, however they are still performing a great service to gardeners in many ways. These organisms are vitally important to improving the health of our soils. They also play a key role in making nutrients available to plants.
Soil organisms are naturally active during certain times of the year. Most are active during late spring and early summer when the soil is warm and moist. If the soil dries out during the summer months, soil organism activity will decline. During fall months, if there is rain or snow that moistens the soil while it is still warm, soil organisms may resume partial activity. As the soil cools in the fall, many organisms go dormant. It is important for gardeners to note that soil organisms help breakdown certain fertilizers and during the cool, dry months these fertilizers, if applied, will be less available for plants to take up.
Soil profile. Photo courtesy UF/IFAS.
Soil organisms are generally placed within three categories: organisms that are beneficial to plants, organisms that play a neutral role in plant growth, and organisms that are harmful to plants. Creating a favorable environment for beneficial soil organisms can improve plant growth and reduce garden maintenance. Encouraging their efforts is key to building a healthy fertile soil. Here are some ways you can encourage beneficial organisms in your soil:
- Add organic matter to the soil. Soil organisms require a food source from soil amendments (compost, crop residues) and/or mulch.
- Water effectively. Soil organisms are happiest in an environment that is damp, but not soggy. (Avoid over-irrigation because waterlogged soils will be harmful to beneficial soil organisms)
- Avoid unnecessary tilling, as it can destroy the mycorrhizae and soil structure. Instead of tilling, mulch for weed control.
- Avoid pesticide applications that aren’t necessary. Some fungicides, insecticides and herbicides are harmful to various types of soil organisms.
by Les Harrison | Jan 22, 2015
Fallen leaves add much to the landscape. They feed the plants and many insect, retain water, and help stabilize the soil
For the homeowner who feels the need to rake leaves and pine needles, the task can be something of a minor nuisance. The showers of earth-toned leftovers appear suddenly and at inconvenient times, and their removal is never added to a chore list without dispute.
Disarray aside, these organic remnants provide far more benefits than problems. Their suburban untidiness becomes an insulating blanket which nurtures plants, animals, and insects with time released nutrients for use by the efficient and fortunate in the wild and those of us in civilization.
First and foremost, leaf litter is critical to the water holding capacity of the woodlands. The dried leaves, needles and twigs absorb and shade rainwater from the evaporative effects of the sun and wind.
When heavy rains inundate the soil causing flooding and runoff, it is the leaves that act as part of the natural delaying system to minimize the negative impact on streams, creeks and rivers. The delayed or halted runoff provides time for water to be absorbed by the soil and be filtered by the natural screening capacity of this organic material.
The moisture works in conjunction with native bacteria and fungus to convert the leaf litter into nutrients usable by plants and trees. While not as concentrated as commercial fertilizers, many of the same plant nutrients are present in the decaying leaf litter.
The decomposition is aided by a variety of insects and worms which nest in, eat and overwinter under the debris. The animal activity breaks up and stirs the elements along with inoculating microbes in the matter which speeds nutrient availability to plants and trees during ideal years.
Luckily, the region’s leaf drop is spread over months with the plants and trees responding to the solar cycle and weather. Autumn, winter and spring each bring defoliation of specific trees and plants.
During dry years the bug and bacteria activity slows in accumulated leaf litter, but the naturally occurring fire cycle continues the nutrient recycling under the tree canopies. The easy to burn material aides in controlling insects and plants that can aggressively overpopulate an area if unchecked.
Controlled burns also prevent destructive wildfires which are harmful to all north Florida residents. While these uncontrolled fires do deposit nutrients, they have many negative effects which far outweigh this single benefit.
January’s weather is part of a continuing natural succession which the native plants and trees incorporate to continue the wild beauty so common in the region. The current cold and rain will combine with the leaf drop to produce much growth in the next few months.
by Mary Salinas | Dec 16, 2014
This is the time of year when leaves are turning shades of yellow and red and falling from the trees. And this spurs homeowners to get out there with their rakes and rid them from their lawns. This is a good practice as too many leaves will shade out the grass and decrease the quality of the lawn come next spring. So, go ahead and rake them up. However, think about using as many as you can as mulch in other parts of your yard.
Leaves as mulch. Photo credit: Mary Derrick UF/IFAS Extension.
Leaves can be placed as mulch in landscape beds “as is” or chopped up with your mower or shredder into finer pieces and then spread around perennials, shrubs and trees. When chopped up or shredded, they tend to stay in place much better and don’t blow around when it gets windy. As the leaves break down over time, their nutrients are released and become available; that’s free fertilizer for your landscape plants. Leaves as mulch do have a natural look in the landscape, so if you prefer a more formal or polished look, you can spread a thin one-inch layer of a commercial mulch over the leaves.
Organic mulches (those made from plants) offer many benefits. They add organic matter and improve soil fertility as they decompose, thus reducing the need for added fertilizers. Mulch helps to maintain soil moisture so less frequent irrigation may be needed. Soil-borne disease can also be prevented as the soil does not splash up on the bottom leaves of plants during periods of rain. One of the favored reasons to use mulch is to prevent weeds in your landscape beds. And, of course, mulch is much prettier to look at than bare ground!
So how deep should you apply mulch? University of Florida experts advise a 3 to 4 inch layer of mulch around shrubs and trees. However, keep mulch from setting against the stems and trunks as that can cause moisture and pests to adversely affect them. Place just a thin one-inch layer of mulch over the rootballs of your plants.
Using leaves as mulch recycles a natural resource and saves you money, enriches your soil, fertilizes your plants and keeps them out of the local landfill.
For more information:
Landscape Mulches: What Are The Choices in Florida?
Mulch Recommendations
