Wednesday, January 15, 2014

Chemical Agriculture 103 - Weeds and Herbicides

In our previous post we learned that chemical fertilizers create imbalances in agricultural plants that beg the insects to destroy them. Pesticides are not the savior from insects that we thought, because they kill the good with the bad.

The same thing happens with weeds,
chemical fertilizers create unbalances in the soil. For example the compaction and oxidation of the organic matter from anhydrous changes the soil Ph and oxygen content that trigger the germination of foxtail and other grassy weeds that are difficult to eradicate in a corn population (which is also a grass).

Weeds in the Field. Photo by Reed Petersen.
These are Foxtail weeds
Again very powerful chemicals are used to suppress weed germination and growth. Attrazine used on corn for years persists in the soil from season to season and would often kill the next years crop of soy beans if mixed too strong. Attrazine has also been implicated in genetic defects in frogs that have grown multiple tails and legs.

Broad leaf weeds are equally difficult in soy beans. So once again our farmer turns to a chemical solution, herbicides that are incredibly potent. We worry about cancers and other side effects from exposures.

Recently a second alternative has arrived on the scene, genetically modified crops have been invented by the creative types at Monsanto and Sygenta. We have added genes to GMO corn from bacteria that kill larva from the lepidoptra family (butterfiles and moths). From the farmers standpoint, that is good if you are a corn bore, root worm or ear worm. It is bad if you are a butterfly or any one of hundreds of beneficial insects.

We have also genetically modified certain varieties of corn and soybeans to be resistant to some very strong herbicides. But we are finding that many weeds are developing resistance to the herbicides and the pollen from these plants are contaminating unintended varieties.

See Chemical Agriculture 104 - Who Is the Customer

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