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Synthetic vs. Organic Fertilizers: Can Plants Tell the Difference?

Plants Can Indeed Tell The Difference


A 15-5-10 synthetic fertilizer is the classic 3-1-2 ratio high-nitrogen, synthetic fertilizer – the kind that the other guys recommend. These numbers mean that the bag contains 15 percent nitrogen, 5 percent phosphorus and 10 percent potassium. The remaining 70 percent of the material in the bag is filler. That can be hydrogen, oxygen and other compound parts but can also be just about anything – sawdust, sand, dirt or even toxic industrial waste.


Now you might ask, ‘Why do we need filler? They distribute the N-P-K throughout the filler or carrier so you don’t burn the heck out of your turf when you apply it. Does that tell you something?


When we use organic fertilizers we’re using very low amounts of buffered nutrients. Everything in the bag is useful to the plant. Our ‘filler’ is organic material with a variety of trace minerals. That translates to much better stimulation of biological activity in the soil.


There are all kinds of problems with synthetic, high-nitrogen fertilizers. The primary problem is that there’s too much nitrogen. It creates an unbalanced situation as far as nutrients in the soil and in plants.


High levels of nitrogen and low levels of trace minerals force fast growth that results in very weak watery cell growth in plants. People see the plants are growing and flowering so they think everything is fine. But the imbalance and the watery cells bring on insects and diseases. Nature's job is to take out sick plants and to encourage the survival of the fittest.


And, the form of nitrogen is wrong. It works too fast. Plus, it’s soluble. If it rains after you put it out, it washes away and leaches through the soil into the water stream.


The second problem is the phosphorous source. The phosphorous in synthetic fertilizer is usually triple super phosphate 0-46-0 made by treating rock phosphate with phosphoric acid. Years ago the phosphorous source was 0-20-0 or super phosphate. It was pretty darn good even though it was created by a synthetic process. Rock phosphate was made by treatment with with sulfuric acid. It was a more balanced phosphate and did not tie up trace minerals.


Well, somebody came up with the notion to use phosphoric acid to create more phosphorous for less money. So now all the synthetic fertilizer manufacturers use triple super phosphate. Big problem – the new material is so raw and so bare that when it’s put on the soil, it grabs and locks onto magnesium, manganese and all sorts of other trace minerals. It ties up these nutrients making them unavailable to plants.


The third problem is potassium. The source of potassium in most synthetic fertilizers is muriate of potash or potassium chloride. Potassium chloride is bad on specific types of crops – especially fruit crops. It’s also harsh on the soil. What we like as a potassium source is potassium sulfate. It’s made from the salt of The Great Salt Lake.


My definition of a fertilizer is anything that improves the soil and helps to stimulate plant growth. For example, dead leaves that fall off a tree are fertilizers. As they break down they turn into organic matter or humus and feed the soil microbes. Microbes such as the beneficial fungi on the roots protect and feed the root hairs of the plants. This feeding process releases the nutrients to feed plants. That’s how it works on the prairie and in the forest. We’re just speeding up the process.


All the basic soil amendments meet that definition, but they are intended for building the health of the soil more than for routine fertilizing. They are more gentle and work more slowly over time. The basic soil amendments are manure-based organic compost, cornmeal, lava sand, greensand, zeolite and dry molasses. 


Manure based organic compost – this is the basic building block of organics. It is the material we would find on an undisturbed forest floor. It acts as a gentle fertilizer encouraging microbial action.


Cornmeal – this natural fungicide is a mild fertilizer and disease fighter that should be used until your soil gets healthy.


Lava sand – you can use as much as you want as long as you want. Remember that the most productive soils in the world – Costa Rica, Hawaii, and parts of the West Coast and the Mediterranean – are places with a history of volcanic action and are almost solid lava.


Greensand – mined from ancient sea beds, greensand is a marine deposit that is loaded with iron – and other trace minerals. It can end up being a bit of a problem in soils with high levels of iron.


Dry molasses – this is not solid dried molasses. It’s organic material like rice hull bits that have been sprayed with molasses and dried. It is a powerful carbon source that really kicks up microbial activity.


There are many quality bagged organic fertilizers to choose from. Some people alternate among them on the perfectly logical supposition that each contains a slightly different combination of nutrients and by rotating over time you provide your soil a more balanced diet.


Some brands that are widely distributed are GreenSense, Lady Bug, Medina and Texas Tee. 


Similarly there are a lot of great choices in liquid fertilizers. I strongly recommend a regular foliar spray program. You can make your own Garrett Juice – the recipe is shown below.


Other good choices are Alpha Bio S.I., Bioform, Lady Bug, Maxicrop and Medina. 


You get indirect pest control from all liquid organic products because they stimulate biological activity. And that’s how we control pests the most effectively. We try not to kill, but rather stimulate the good guys. The good guys feed on the pathogens and balance results.


The recommended organic fertilization program is (it varies based upon where you live): 

First fertilization - as early as January on into April
Second fertilization – sometime in June or July
Third fertilization – between September and October


Garrett Juice (ready to spray):

1 cup manure based compost tea
1 ounce molasses
1 ounce natural apple cider vinegar
1 ounce liquid seaweed


For disease and insect control add:

¼ cup garlic tea or
¼ cup garlic/pepper tea
and 1 ounce of orange oil


For homemade fire ant killer add:
2 ounces of citrus oil per gallon of Garrett Juice


The ready-to-use solution should not have more than 2 ounces of orange oil per gallon.





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