PROBLEMS WITH FREQUENT TILLING
The start of spring means it's time to start your garden. Most of us begin the planting season by tilling our garden. Tilling breaks up the soil, helps eliminate weeds, and aerates the soil. The aeration caused by tilling exposes the soil to the air, which in turn activates microbes in the soils which, along with the addition of organic matter, help to make the soil fertile.
How often you should till, however, is often a frequent question. Frequent tilling - more than three or four times a year - can damage the soil’s texture. The more soil is tilled, the further it breaks down, eventually turning into the equivalent of sand. Frequent tilling can also cause the soil to become glazed. Once this happens, you should use a pitch fork or spade to break up the layer of soil that is just beyond the reach of the tines or blade of your tiller.
You should also avoid tilling the soil in your garden while it is wet. Tilling wet soil destroys the texture of the soil, which should be comprised of different sizes of dirt and matter. Once wet tilled soil has dried, clods of dirt dry and can become as hard as rocks and recovery can be hard and time consuming.
Frequent tilling has also been shown to reduce the amount of small creatures living in the soil. Creatures, such as earthworms, help to turn and rejuvenate the soil. Reducing the effects these creatures have on the soil can have long-term ecological effects.
Finer soil caused by over-tilling becomes compacted and is not able to hold enough oxygen or water. Good soil should contain about 25% air, 25% water, and 50% soil particles and organic matter. Compacted soil can be helped by adding mulch to help the soil absorb water and promote the growth of beneficial organisms in the soil by increasing and maintaining a higher soil temperature. You can also prevent soil from becoming impacted by spreading gravel over the areas in your garden that are used as pathways for machinery. The gravel helps to distribute the weight of the machinery and lessens the potential for impaction. Tilling impacted soil is certainly not the answer and may even be nearly impossible depending upon the severity.
Certain areas of the garden, however, can benefit from frequent tilling. If you are trying to control a pesky plant problem, such as poison ivy or kudzu, frequent tilling can disrupt seedlings and starve existing weeds of nutrients.
You can develop a strategy to reconcile these two ways of tilling. Areas of your garden where planting occurs should really only be tilled twice a year - before and after harvest. Other areas, such as pathways, can be tilled more frequently. You can also combat the effects of over-tilling by being sure to add plenty of organic matter to your garden. Compost that has not been completely broken down can also help add texture back into overly-tilled soil.