Wednesday, January 20, 2016

Soil 301: Addicted

Conventional agricultural soils and crops are addicted to chemical fertilizer.

Corn is especially addicted to...

Nitrogen. The modern corn hybrids need copious amounts of nitrogen. Most farms do not have the livestock to provide high amounts of manure based fertilizer (if they did they would be introducing too many salts) so they use supplemental liquid and anhydrous ammonia. For corn, this fertilizer is like mainlining heroin, you load up the clay, organic matter and interstitial moisture in the soil with nitrogen. The plants have no where to turn but this readily available and extremely high level of nitrogen. Corn, sorghum and Sugar Cane love nitrogen and responds with massive tons and bushels of output.

I've tried growing sweet corn without supplemental nitrogen and it just doesn't work (in our case we use very expensive organic fertilizer that costs $25 per 50 pound bag). About two bags per 300 foot row.

The non-organic farmer can make the economics work because he can apply fertilizer that is made from relatively cheap oil.

Another area where our soils are addicted is in the use of super phosphate fertilizer. This suppresses (read kills) the biology in the soil and is often over applied causing phosphate to be in the spring run off, polluting our rivers, lakes and causing massive algae blooms in the gulf.

Our crops are unbalanced when phosphate is overused and the insects seek to remove unbalance crops, which drives high levels of pesticide use.

It can take several years to rebuild the biology in the soil after super phosphate use is stopped. Eventually the biology will repopulate the soil and convert nutrients the way they should. Most soils have enough phosphate for normal garden plants.

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