Friday, January 18, 2013

How Organic Matter Level in Soil Relates to Drought



Nearly two-thirds of the U.S. has been covered by the 2012 (and now dragging into 2013) drought.  At the National Drought Mitigation Center, climatologists are concerned that this drought could stretch even further into the spring. With the continuing lack of rainfall, concerns about crop viability have grown more pressing.

But, another pressing concern may be lingering that could have just as big an impact on growth as sheer volume of precipitation - soil quality. Healthy, unbroken soils may be composed of as much as 15 percent organic matter. Unfortunately, due to long application of intensive tilling practices, many soils have plummeted down to 1 percent organic matter, or even less! With levels this low, the soils become very vulnerable to compaction and by extension, loss of porosity.

What does this have to do with the drought? Well, when organic matter levels fall so low, soil loses its ability to hold water. The complete lack of porosity makes the soil more analogous to pavement than a sponge. So whenever rain finally does arrive, it simply runs off, leaving the crops high and dry. Oftentimes, it takes the topsoil with it, causing tremendous amounts of erosion.

Long-term Solutions to Increase Soil Microbe Levels

The obvious, long-term answer to this problem is to treat the soil more gently. Reduce intensity of tillage. If you want to go to the extreme, consider going no-till entirely. Use a larger variety of crops to reduce the risk of catastrophic failure of a single crop. This will make the entire operation more sustainable. And plant soil-friendly cover crops - especially of the leguminous variety.

An Immediate Answer to Low Microbe Levels

But in the interim, you might look at taking steps to increase your soil’s organic matter levels immediately. An injection of microbial content could be a vital part of this short-term solution. Increasing organic matter levels from just 1 to 3 percent has been shown to double soil’s ability to hold water.  So, use of natural microbial products like EM-1 can help condition soil into a more high-quality base for crop growth. This comes as a result of the products’ ability to reopen the soil, giving it greater structure and porosity. This can be a valuable weapon in a farmer’s arsenal in the midst of a drought.

More Information

For more inspiration on how to improve soil for long-term viability, check out what Gabe Brown has been doing to encourage soil microbes up in North Dakota.

Read more about how the drought is impacting farmers and others throughout the United States at the National Drought Mitigation Center.

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