Understanding the importance of organic matter is crucial to success with organic gardening. Organic matter is a term that encompasses a wide variety of living or dead plant and animal material, ranging from kitchen wastes and shredded leaves to well-rotted manure and compost. Here's what adding organic matter to your soil can do:
- Supply nutrients for plants by providing surfaces where nutrients can be held in reserve in the soil
- Facilitate better drainage by loosening soil structure
- Store water in the soil
- Help increase air drainage
- Increase the activity and numbers of soil microorganisms
- Encourage earthworms
You can increase your soil's organic content by mulching with organic materials such as compost or shredded leaves, or by digging or tilling them into the top several inches of the soil. Then, to maintain a healthy, humus-rich soil, make adding organic matter part of your yearly garden activities.
Organic matter does not remain unchanged once you add it to soil because soil microorganisms act to break it down to simpler compounds. That's a good thing, because these compounds are then food for your plants. You can renew soil organic matter by side-dressing crops with compost, mulching during the growing season, and mulching or planting a cover crop during winter.
As a general rule, strive to maintain 5 to 6 percent organic matter in your soil. Don't overdo it! Adding too much fresh organic matter, such as plant stalks, sawdust, and other plant residues and uncomposted manure, can overstimulate soil microorganisms, which then consume so much nitrogen and other plant nutrients that soil fertility temporarily declines.
Keep in mind that in hot, humid climates, organic matter breaks down more quickly than in cool or dry climates. If you want to slow the loss of soil organic matter, cultivate the soil as little as possible, and when you do work the soil, do it gently, by hand, rather than using a rotary tiller.
Find Out More
You can learn more about the importance of organic matter and about materials you can use to increase soil organic matter content by reading: