The Master Gardener: Margaret Sams

What primarily can change the latter into the former? A long-term program of adding organic matter along with smart soil management practices can bring most soil types back to prime gardening shape. It requires time and patience, but after conditions improve, maintenance is not difficult. Just let the worms and microbes do their job!

Most of us understand that increasing the amount of organic matter in a soil will greatly improve its fertility. This is indeed true, but it also improves soil structure. Soil structure is the way that soil naturally cracks and breaks open when a small amount of pressure is applied with the fingers, like slowly breaking pieces off a candy bar. Good structure increases the amount of air in the soil, improves both the infiltration and drainage of water, and allows roots to more easily penetrate the soil and access nutrients. Soils without structure can be called “massive,” with no cracking or aggregate formation, like a brick of American or provolone cheese. As structure begins to form, the soil resembles aged cheddar cheese, with weak cracks defining separate cohesive units, called “peds.” Continued structure development will result in soil peds like feta or gorgonzola cheese – the ideal soil structure for gardening.

But simply adding organic matter, even if it is composted, is only part of the solution. To create structure, worms, fungi, microbes, plant roots and insects require time to work together to fully digest the organic material and bind it to soil particles. It is this biological activity that darkens the soil and makes it crumbly and spongy. Have you ever looked into a bait container and noticed how cohesive the soil peds are, with all those worms (and microbes) digesting organics and binding together the soil they are living in?

It takes time, possibly several years, to rehabilitate a dense, massive soil with low organic matter. Keep those worms, fungi and other microbes happy and busy by giving them a healthy supply of food (organic matter), watering the soil if it gets too dry and avoiding compaction. Repeatedly walking on the soil while it is damp will cause compaction, decreasing the porosity and air supply the worms and microbes require. Also, too much tilling and turning the soil will decrease structure, setting the clock back toward the formation of healthy soil. If your soil is low in organic matter and has little or no structure, a moderate amount of tilling is necessary to initially incorporate composted organic matter into the soil. As the number of worms and other critters gradually increase, they will begin to do the work for you. The soil will darken and become less dense, and simply churning the soil a bit with a broad fork may be sufficient before planting. Eventually, no tilling will be necessary! Just continue with additions of organic matter over the ground surface, and admire your healthy garden soil.

More information on creating and maintaining a healthy garden soil can be found at: https://extension.psu.edu/soil-quality. Soil tests are available at Washington County Penn State Extension Office at 100 W. Beau St., Suite 601, Washington.