Now we need to select a product by comparing what would be provided to what the laboratory has recommended. Remember that we have done all of our calculations so far by just looking at the nitrogen content of the various products.

Example #

 

Formulation

Pounds to supply 3.0 pounds of nitrogen

Total nutrients recommended

Total nutrients this fertilizer would provide

Would this be a good product to use?

1

12-12-12

25

3-6-4

3-3-3

Not too bad; considerably less phosphorus than recommended

2

5-10-5

60

3-6-4

3-6-3

Very close to the recommended rates

3

4-10-10

75

3-6-4

3-7.5-7.5

Not too bad; just a bit more phosphorus, but almost twice the potassium needed

4

15-30-15

20

3-6-4

3-6-3

Very close to the recommended rates

5

24-6-6

12.5

3-6-4

3-.75-.75

Not very good; much less phosphorus and potassium than recommended


   In the final analysis, either product #2 (5-10-5) or product #4 (15-30-15) appear to be the best choices. Either one could be used to provide the nitrogen recommended, the phosphorus recommended, and almost all of the potassium recommended. But since they supply the same nutrients, which one should you buy? This is where pricing becomes the more important factor!

   Remember that it will take 60 pounds per thousand square feet of lawn to fertilize using the 5-10-5 product, but only 20 pounds per thousand square feet of lawn to use the 15-30-15 product. So even though the 15-30-15 product may be more expensive, unless it costs over three times as much, it would be the better choice! Of course, you also need to consider factors such as the application. Perhaps the 15-30-15 product is more expensive, but you will have fewer total pounds of fertilizer to  load into your car, then load into your spreader.

   If you have received results from CALMAR and need help in converting your recommendations to pounds of a product, please feel free to contact us and we will attempt to help you make informed decisions about what to apply to your lawn, garden, or landscaping bed. Your local lawn care professional or garden center may also be very helpful in choosing the correct products to use based on your recommendations from CALMAR.

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