Monday, February 8, 2016

Soil 307: Thirsty

Conventional agricultural soils are thirsty. In his book "Your Bodies Many Cries for Water". Dr. B. talks about the critical role that hydration plays in the health of the human body. The same thing applies to the soil. If there isn't enough organic matter in the soil to hold the rainfall our soils won't function properly.

Hydrating our soils is more about having adequate cover on the soil surface and organic matter to hold the moisture than having a certain amount of rainfall. Most cropping regions have enough rainfall, but they may not utilize it well. We should focus on building our soils with the need to retain moisture in mind.

Cover cropping, mentioned earlier in these posts, can be part of the answer. Conventional wisdom says adding another species into the mix may cause the soils water capacity to be diminished. But reality is, that different species have different requirements for water and blending multiple species in a poly culture (of the right species), can actually be synergistic in the use of both water, biology and nutrients.

This poly culture is how the great prairie soils functioned, by careful observation we can do something similar in our agricultural soils.

Building organic matter can help in the efficient utilization of available rainfall. Organic matter can hold upto eight times it's weight in rainfall and improve both the rate and quantity of absorption. The key is to maximize the capture of rainfall and minimize runoff. Zero runoff would be the goal . This is quite achievable when you get the organic matter up and biology funtioning well in the soil.

I have seen our organically farmed soil absorb a 2-3 inch rainfall with out any run off or soil erosion. That would be considered a gully washer on a conventional farm. If you can capture and hold all the rain that falls. Your soils will be more hydrated later in the season when the moisture is needed.

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