While it may seem that there is no difference between soil and dirt, those who want to promote the growing of food or vibrant garden beds know that soil is something special. In fact, healthy soil is “a vital living ecosystem that sustains plants, animals and humans.”
A healthy soil is a complex mix of dead organic matter and living organisms. Nature continually creates healthy soil, as is easily seen on forest floors. Too often, however, modern garden and agriculture practices do the opposite. Synthetic pesticides and other harsh methods strip soil of its most important elements.
Soil is an essential player in life on our planet. At a time when Earth continues to heat up, we need not only to put less carbon into the atmosphere but also to take out and sequester what is already there. Soil is a major resource for carbon sequestration, and the healthier the soil, the more it can help our planet. Among its other beneficial characteristics, a healthy soil
- promotes water retention
- helps support a balance between beneficial microorganisms and potential pests, diseases and weeds, reducing or eliminating the need for pesticides
- may mitigate the effect of some heavy metals.
Understand your soil before you start
So how do you know if your soil is healthy? Having a thriving garden may indicate healthy soil, but that’s not always the case. Synthetic chemicals can artificially boost plant growth, masking hidden deficiencies. Contaminants such as lead may not affect plant health, so you can’t tell whether it’s present just by looking. The best way to help determine your soil’s health is to test it.
What to look for
There are two main things to measure when testing your soil: nutrients and contaminants. Knowing how much you have of some key markers of soil health (pH, organic matter, etc.), will help you decide whether you need to amend the soil and with what. Figuring out whether there are heavy metals such as lead or arsenic in your soil will help you decide whether you can grow vegetable crops or should stick to ornamental plants. Some soils on sites with lead-painted houses, near roadways, or with a history of certain pesticides (such as lead arsenate) may have “hot spots” with very high levels of contamination. It is always better to test. Do not assume the soil is clean no matter where you live.
A testing facility should be able to help you decide which tests you will need and give guidance interpreting the results. Since soils vary greatly--even within one backyard--you will probably want to take a range of samples in order to get a better understanding of what might be in your soil.
Once you have a baseline understanding of your soil, you may only want to test for certain aspects in order to make sure your amendments are working, for example...
Keeping your soil happy
Most soils in our communities could use a little help to become healthier and more productive. After decades of overusing synthetic chemicals, suburban soils are especially lacking. Best practices such as mulching, cover crops, adding amendments, chemical-free weed control, and winter protection will help you maintain healthy soil year-round, while still enjoying a bountiful harvest or blooming season. Start with small changes, until you get comfortable. Then incorporate as many practices as you want, depending on your garden space and its needs.
Presuming there are no contamination issues, soil preparation will vary depending on what you want to plant. For example, native plants may require less intervention and vegetable gardens will need specialized nutrients.
Compost
Using compost instead of artificial fertilizers is one way to help your soil as well as your pocketbook. Look for local compost sources, or start making compost yourself. If your soil tests indicate a specific nutrient deficiency, you may want to use a specialized amendment.
Mulch
Mulching, such as with wood chips or straw, is a great way to keep your soil protected. Mulch slowly decomposes over time, providing an extra source of nutrients to plants and microfauna while shielding the soil from harsh elements. It also adds color and texture to your landscape, a desirable feature in garden design.
Soil erosion
Besides needing nourishment, your garden also needs protection, especially from erosion by wind and water. The ubiquitous leaf blower degrades your soil; while mulch and cover crops help guard it from the elements. If you don’t want to use wood chips, leaves or straw, you may also consider filling the space with other plants suitable for this area. Cover crops offer excellent winter protection and soil nourishment. Native ground covers could be an optimal solution to protect bare soil in the long run, and will also help with weed control.
A home garden is not an island but affects the environment around it, both on adjacent property and even further if the property is near a water resource. Wise water use and appropriate soil amendments can help.