Posted: December 15, 2012
Over the years I’ve attended many soil health trainings. They all come back to one common theme. Increasing soil organic matter increases soil health. Let me define these terms so there is no confusion. Soil organic matter is part of the soil which comes from plant material and is now in various stages of decomposition. Soil health is the ability of a soil to support both plant and animal life. Healthy soil can withstand stress better than unhealthy soils. Plants in a healthy soil can better withstand a drought for example. Pests are less attracted to plants growing in healthy soils.
When organic matter like leaves, compost, manure, etc., is added to the soil, the decomposing organisms start to decompose it. These decomposers consist of earthworms, nematodes, fungi, bacterial, and other organisms that need organic matter to live on. As they feed on the organic matter, they excrete substances that help the soil stick together into aggregates. This helps the soil avoid erosion and increases the ability of plant roots to move through the soil. More rainwater can move into the soil instead of running off. When the microorganism’s short life is over, the nutrients in their bodies are made available to plants once again.
Once the decomposers have broken the organic matter down to its smallest component, we now have humus. Humus is great at holding moisture and essential plant nutrients. So soils benefit from both fresh organic matter and from organic matter applied long ago. The healthiest soils have a continuous supply of organic matter applied over a long period of time. The most productive tomato field I have ever seen was a field that was next to a dairy barn. The field received large amounts of cow manure every year for several generations. The tomato plants thrived.
Another benefit to the recycling of the nutrients in organic matter is that they are in perfect balance. Since the nutrients come from plant material, they have the exact nutrients in the exact ratio plants need.
For more information contact your local extension office. In Lackawanna County call 570-963-6842 or email LackawannaMG@psu.edu
John Esslinger, Extension Educator
Penn State Extension