» Manure or Minerals – A Comparison

Manure or Minerals – A Comparison

Some have expressed concern about using chemicals to feed their plants, wanting to stay away from “synthetic” materials. Others don’t know how much to use.  Let’s review some basics!

Suppose you have a garden 20′ X 30′ and you want to have a good yield of healthy tomatoes. A common practice is to work 2-3″ of composted horse or cow manure into the soil in the plot before planting.  Is that a reasonable supposition? That’s 20′ X 30′ X 1/6′, – 100 cubic feet, or about 3 1/2 cubic yards of manure.  A yard of clay soil weighs about 3,000#, may we assume composted manure weighs a third as much? that would mean we have applied about 3,500# of manure to our garden.

If the manure is 1% nitrogen (a general assumption – plus roughly comparable amounts of P and K and smaller amounts of several other salts, often including table salt from the animals’ salt licks), then we have applied 35# of actual “chemical” nitrogen to the garden – all at once – at the beginning of the growing season. And total chemical salts you’ve applied amount to between 150# & 175# (let’s say 150# or 2,400 ounces)!

When you think you don’t use chemicals, you’re only fooling yourself. Everything in this world is a chemical! And your plants can’t use that nitrogen – or anything else until it has decomposed from the organic state and become a water-soluble mineral.

Now, please remember also, there’s something called the nitrogen cycle. Nitrogen is volatile, and doesn’t stick around long – especially in warm weather, so how long do you suppose you have the benefit of those 35#’s of nitrogen applied all at once at the beginning of the growing season?

A Mittleider gardener uses a 13-8-13 mix (that’s percentages of each N, P, and K nutrient). Is that scary – using such a highly concentrated material?  Let’s compare the actual amount of nitrogen we’re applying to that 20′ X 30′ garden.  First off, we only apply fertilizers to the root zone of the plants, not the entire garden.

Each week – 4 times for lettuce, 5 times for bush beans, 6 times for corn, and 12+ times for indeterminate tomatoes – we apply 8 OUNCES of nitrogen, 8 OUNCES potash, and 5 OUNCES phosphate, along with much smaller amounts of the other 10 elements, for a total of about 25 ounces. That’s for the entire 20′ X 30′ garden!  So I am actually applying only 1/96th (2400/25) as much mineral nutrients to my garden at any one time as the organic gardener – but doing it several times over the growing season. Which is better?

So, how much nitrogen do I use in total? It obviously depends on the crop, but let’s compare.  If I planted the entire garden in one crop here is the total nitrogen I’d use:

Lettuce – 2# – less than 1/17th the amount applied using manure.

Bush beans – 2 1/2# – less than 1/14th the amount applied using manure.

Corn – 3# – 1/12th the amount applied using manure.

Tomatoes – 7# – 1/5th as much as is applied using manure.

And I give my plants very small amounts on a regular basis, and apply it 4″ from the plant stems (far enough so as not to burn them) and water it in so that it’s immediately available. Doesn’t that make sense?

So, what is the cost? Between $25 and $40 for the growing season. How much work is it to apply it all those times? Less than one hour over the growing season. What is the result, or yield? At least double that achieved using manure, and most often 5 to 10 times. And I’ll match size, looks, taste, and any other measure you’d care to make. after all. “THE PLANT CAN’T TELL THE DIFFERENCE BETWEEN NITROGEN FROM A LEAF AND THAT FROM A FERTILIZER BAG” (J. I. Rodale – Organic Gardening magazine).

Please also consider another factor in this equation. How many people have access to 3,500# of manure to use on their garden – (and remember I’m describing a very small garden!)? In rural areas it may be relatively
plentiful for the few who care enough to use it. But just suppose everyone had to depend on it!! There is not enough manure available to satisfy even 5% of the people if everyone had to grow a garden and live off it’s bounty.

Is a loving and all-knowing God going to arrange things so that 95%+ of the people can’t get “the only true” fertilizer?? I don’t think so! He has made concentrated deposits of all the necessary mineral (rock) plant nutrients (which are also humans’ essential nutrients!!), and man has learned how to grind them up and mix them in the ratios they’re needed, and how to accurately apply them to the soil to grow healthy plants.

So, let’s do it!! :o)  You can get the essential Micro-Nutrients and instructions on how to make the perfect natural mineral fertilizer, at