Posted on Wednesday, September 26th, 2012
There are so many directions to take when discussing the state of soils not only our backyard gardens, but also on a much larger scale. Many people don’t realize the far-reaching soil and water resource problems that cross international borders in ways hard to imagine. An example of this would be the soil dust blown to the Asia, Europe and the US over the Atlantic Ocean from Africa. This soil dust contains pesticides and chemicals like arsenic, plant pathogens, and even insects.
How does this relate to gardening and landscaping? To bring this down in scale, I want to discuss the importance of healthy soil and the critical role that it plays in maintaining overall plant health and vitality. I’ll focus on what we as stewards of the garden can do in the way of converting our land areas into sustainable and self-sustaining gardens.
Let’s start with some basic facts about soil. On average, less than one inch of native topsoil exists in the United States. There is an estimated 25 billion tons of topsoil lost each year. It takes between 200 and several thousand years to renew one inch of topsoil on Earth. These statistics are sobering reminders that as stewards of the land we need to be mindful of the conservation of this precious, slowly renewing resource that we have. We must be intentional with enriching the soil on our own properties and with ways we can become actively involved in maintaining what we’ve got.
A present day example of mismanagement of soil and resources is the land area known today as “The Little Grand Canyon” or Providence Canyon State Park in Lumpkin, Georgia. These huge gullies and canyons of sculpted soil do not result from rivers or streams, but from excessive water runoff from agricultural lands. Huge expanses of native forest had been cleared so the land could be farmed and early nineteenth-century farmers took no measures to protect the soil from runoff. In the first 50 years, 3-5’ wide and deep gullies had eroded and since then, the staggering results of this massive erosion developed a canyon in the southwest part of our state. Today, some of these small ditches have reached depths of 150 feet and are up to ½ mile long and 300 feet wide!
The GA Soil and Water Conservation Commission was formed to protect the soil and water resources of Georgia. Contractors in every industry are required to obtain certification in Erosion and Sediment Control in order to manage any soil disturbing projects in Georgia. Other organizations, such as the Upper Chattahoochee River Keepers, have worked to bring attention to and action against the serious damaging effects of things such as sedimentation, non-point source pollution and the overall well-being of the riparian habitat along the buffer zones of the river. With the urbanization of the metro and North metro Atlanta suburbs over past decades and with too few control measures in place governing contractors in the past, there is much damage to this environment that needs to be repaired and cleaned up.
Now you’re wondering, what is the goal and how do we begin working toward it. Sustainable Agriculture by definition is to meet the needs of the present without compromising the ability of future generations to meet their own needs. Additionally, this generally refers to practices that are viable over long periods of time, both environmentally and economically. In this, the garden tender strives to achieve soil that can produce crops reliably without nutrient depletion and with minimal amendments. Largely, this calls for a philosophical shift in the garden tenders away from control to cooperation and evolves the role from being a master over the garden to being a steward of the garden.
To be this kind of garden steward is not difficult, especially if embraced at the outset. This role can be most demanding during the planning phases as with deciding where to put the garden, which varieties to plant, when and where to plant them, how to feed the soil, where to put the compost pile if you choose to have one, what kind of mulch to use and, quite importantly, how perfect you want the produce or ornamentals to appear. These decisions help resist the urge to use quick fix chemicals later.
Recognize that in improving your soil is more about feeding the soil, not the plants. To improve soil tilth, understand the following and use them as guidelines.
- Loose tilling reduces compaction.
- Added organic matter decays and enriches soil with valuable nutrients.
- Never work wet or overly dry soil
- Avoid unnecessary traffic over the soil
- Turn under “green manure” and clippings
- Tilth relates to the texture, structure, permeability and consistence of the soil.
- Tilth can be improved by improving the structure and avoiding compaction.
I’ll help to clarify some terms that are often associated with gardening, but may not be fully understood.
Organic – land use without the addition and use of synthetic and unnatural chemicals
Sustainable – add to organic, planning for least environmental impact and focuses on soil health
Self-Sustaining – an environment that supplies all of its own essential nutrients for balanced growth
To garden organically is simple but the results may take a few years. Begin with deciding to limit use of sprays and fertilizers or decide not to use them at all. An organic garden is an ecosystem, on large and small scales. Soil composition, air quality, water, birds, insects and weeds are influencing forces on the soil. Work with these forces, encourage balance to shift in your favor and do not dominate them with the goal of achieving perfection. Shift away from conventional soil amending practices toward organic methods. A good garden steward will work with the forces rather than try to control them by imposing an unnatural balance. Perfect ornamentals and produce can eventually backfire!
On farms where perfection is sought and imposed by use of fertilizers and other synthetic chemicals, commonly the grower’s land may not have pests, but also will not have earthworms in the soil, birds in the fields, or beneficial predatory insects. While this may seem benign, it is not. Non-sustainable practices used to obtain high yields of unblemished produce eventually promote the loss of three things:
- water penetration
- biologically available nutrients
These losses necessitate that the soil depend more and more on human-provided nutrients. Alternative and sustainable approaches will yield favorable results without harmful impact and environmental toxicity and no risk to human health or to future generations. Healthy soil provides a rich environment for beneficial soil microorganisms and earthworms which aid in feeding the ecosystem.
Ways you can enrich your soil are to invest in a first colony of earthworms, set up bird houses and bat houses and add compost and organic matter before your garden produces it for you. Other steps to take would be to install irrigation soaker hoses and to plant row-covers to protect your land and soil from runoff. This step may take several years to establish an ecosystem that operates in your favor.
a healthy ecosystem will have earthworms, insect-eating birds, beneficial predatory insects, soil with organic matter sufficient to drain well and retain water to prevent runoff, and soil nutrient levels that support healthy plant growth. In several years, these investments should reward you with a healthy garden that doesn’t require lots of imported materials or time-consuming pest controls.
Basic Guidelines to follow:
- Apply mulches to dress topsoil to prevent runoff and washing out.
- Till minimally
- Avoid heavy doses of chemical fertilizers. Chemical fertilizers can harm soil microorganisms and decrease earthworm activity. Excessive N fertilizer – no matter the source – harms the soil and USDA shows it can reduce vitamin C content in some vegetables. Use compost instead to provide slow-release food to the soil and plants.
- Water regularly, but not in excess, flooding or overwatering and drought or drying can all kill soil microorganisms and earthworms. Properly irrigate plants and landscape to maximize the water efficiency avoiding runoff and erosion
- Minimal tilling will cause less disruption to earthworms and other microorganisms through mechanical abrasion, drying out, and disruption of their environment.
- Shallow tilling – no more than 3” is best. Tilling up to 6” may be needed to expose the eggs and cocoons of some insects to hungry birds.
- Avoid uncomposted manure – as it contains seeds and possible disease pathogens. Spread compost over several seasons.
Going Green begins with a plan
Protecting soil in your own landscapes is where you can make a difference. Identify areas of your land where there is runoff or erosion occurring. Have your irrigation system assessed for efficiency and coverage – oftentimes old system parts need to be updated. Are your plantings WaterWise? Check into the Georgia Waterwise program for recommendations for your landscape. Is the soil mulched to maintain moisture? Start a composting pile. Commit to not using synthetic chemicals. These are some things that you can begin with to work toward being a better steward of your land and soil. I suggest consulting with a landscape professional that is skilled in the areas of Sustainable and/or Organic Gardening and Landscaping to help you identify any problematic areas in your landscape.
Usually people cannot take on the commitment of changing all of their habits at once. You may be a person who utilizes a chemical program for their turf, or perhaps, you are someone who sprays every now and then in the landscape for unwanted seasonal pests like aphids, whiteflies and japanese beetles. Maybe you have an irrigation system that is inefficient and, by design, irrigates landscape areas with mixed plantings even though the plants require different amounts of water. You might think it would be ideal to convert all of these ways to the most green, sustainable ways all at once. Sure, but in reality, these can be time-consuming and costly conversions that you are not able to revise at one time. I suggest beginning with one area and working your way through as your time and your budget allow.
Remember: whatever steps you begin taking will, day-by-day, get your landscape and gardens closer to being sustainable. The results of any efforts will positively impact your soil and the ecosystem that it supports.