Healthy soil can sustain plant growth, prevent environmental damage, mitigate stormwater runoff, and help recharge and clean groundwater.
Soil type is probably not something that people consider when they move to a new property, so it reminds me of the statement “you get what you get and you don’t throw a fit”. However, it is no secret that soils are not all created equally in their ability to grow plants. To make matters worse, the soil is constantly being manipulated to accommodate our needs. When infrastructure like roads and buildings are constructed soil is moved and in many instances, there may not be any native soil profiles still intact on the property. Often a small layer of topsoil is put back onto the landscape after construction and regrading of the land, but there is no guarantee that it was the topsoil found there before construction began. Once the excavation is completed there is no going back. This article from Penn State Extension, Can Disturbed Soils Grow Healthy Landscape? is a great read. If you suspect that the soil you are planting vegetables into has been hauled in from another location, it is wise to get the soil tested for lead content. Some labs also test for heavy metals like arsenic (As), cadmium (Cd), and chromium (Cr), which can be found in soils on old industrial sites.
Soil is the gift that can keep giving, but there are some management practices that can help improve all soils. The physical, chemical and biological processes of soil are all interconnected. If you want to learn more about your own soil, I recommend the Kansas State publication that walks you through the steps to Estimate Soil Texture by Feel. Knowing the soil texture in your garden is one piece of the soil puzzle.
Soil organic matter increases water holding capacity, improves water infiltration, serves as a source of micro and macronutrients, and provides large particles for micro and macroorganisms to break down. Soils that are high in clay or sand can benefit from the addition of organic matter, which comes from anything that was once alive. Macro and microorganisms help to break down organic matter and release nutrients into the soil. There are many forms of organic matter that include compost, plant material, livestock waste, humus or leaf litter.
Cover crops are another way to improve your soil because they capture excess nutrients that are left over from the growing season and prevent the nutrients from becoming environmental pollutants. Cover crops also prevent soil erosion from wind and rain during the late fall, winter, and early spring seasons when weather is not appropriate for most vegetable or agricultural crops. Once cover crops are terminated they can be plowed into the soil and add organic matter. This is called green manure. I’ve found that in my own garden, cover crops can also help prevent weeds from growing. Some cover crops like forage radishes die and create natural pathways through the soil for water to flow.
Other management practices to help your soil include regular soil testing to monitor any changes and keep the soil pH in the correct range for your desired plants. Limit soil compaction by keeping vehicles, equipment, and even people from walking through gardens, especially when the soil is wet. At the very least, I think the best practice for improving and keeping your soil healthy is to leave it alone as much as possible, keep it covered with plants that are not invasive, and let the natural processes of the Earth work together to benefit the soil.
This year, the University of Maryland Extension Master Gardener Grow It Eat It Program celebrates the resource that supports all life on earth – soil! Look for soil education programs offered by your local Master Gardener program, and visit the Home & Garden Information Center website for more information about soil health.