At the risk of alienating some of my readers I make the
following statement, “I do not use any chemical pesticides, fungicides, or
herbicides on my garden, but I do use some chemical fertilizers.” I use chemical fertilizers as part of what I
like to think of as a balanced approach to soil amendment. Some people will only use organic methods of
soil amendment, while other people think that organic growing is a waste of
money and is more of a philosophical statement than an actual gardening
method. Let me explain my reasoning for
a balanced approach to soil amendment and then you can decide if you think it
makes sense or not. Here are my reasons
for using both natural and chemical soil amendments in my garden.
Reason 1: You can’t raise food without putting nutrients
back in the soil.
Everything that grows in your garden represents nutrients
that have been taken out of the soil. If
you save every non-edible part of the plants that grow in your garden and all of
the peels, cobs, rinds, etc from the food that you harvest; and compost all of
that and return it to the soil; you will still be removing the nutrients that
are contained in the food that you eat.
You can rotate your crops so that you plant legumes that add nitrogen
back into the soil, but this alone will not be enough to make up for the
nutrients that you remove. You can bring
in outside organic materials and compost them, as I do; but consider this. My
garden is about 3000 square feet. To
cover my garden with a three inch layer of compost would require about 750
cubic feet of compost. This would be a
10 foot by 10 foot pile that is 7 ½ feet tall.
And since organic material shrinks down by as much as 75% as it
decomposes, this means that I would have to start off with as much as 3000
cubic feet of compostable material. Who
has the time to do this? So the
alternative is that you have to bring in some kind of concentrated soil
amendment to add to your garden, which brings us to fertilizer.
Reason 2: Organic fertilizers are not all that organic
So I think I’ve made a reasonable case for having to add
some kind of amendments to the soil, but the question is, “What kinds of
amendments?” Many people who follow the
totally organic method of gardening use natural sources of nitrogen,
phosphorus, and potassium. Some people
use animal manure for a balanced fertilizer. Blood meal is often used as a good source of
nitrogen; bone meal and rock phosphate are used as sources of phosphorus; and
hardwood ashes or granite dust can help provide potassium. Let me address these one at a time and tell
you my feelings on each of them.
Manure
I use manure on my garden, but only the manure that I rake
up out of my goat pen. I am about to get
back into raising chickens, and I will also use their manure in my compost
pile. I don’t buy manure. The bagged manure that you buy at garden
centers and big box stores is usually packaged and sold from feedlot
operations. The cattle that produce this
manure have been injected with steroids and antibiotics. They have been treated with worm medicine and
sprayed for ticks and flies. They have
also been fed large amounts of salt to increase their weight by water
retention. All of this stuff finds its
way into the animal’s manure. Doesn’t
sound all that healthy or organic to me.
If you are going to use manure I would suggest that you use manure from
unvaccinated, grass fed animals only.
Ditto to everything above as it applies to factory raised chickens also.
If you have a neighbor that ranges cattle you can get some
good manure from them but be sure that you compost it in a good hot compost bed
to kill the grass seeds. I made the
mistake of gathering up a truck load of manure from one of my neighbor’s
pastures and throwing it straight onto my garden without composting it. I am still fighting Bermuda grass ten years
later.
Blood Meal and Bone Meal
Both blood meal and bone meal are by-products of the
slaughter house. The animals that are
slaughtered are typically raised in industrial animal operations. This means steroids, growth hormones,
antibiotics, etc. All of these unnatural
products make their way into the blood and bones of the animals before they are
slaughtered. Again, this doesn’t sound
healthy or organic to me.
Rock Phosphate
I have no problem with rock phosphate. Rock phosphate is a mined product that
contains about 20% phosphorous whereas the phosphorous in chemical fertilizer
is also a mined product that has been chemically treated to extract a more
concentrated phosphorous from it.
Granite Dust
I have no problem with granite dust as a source of
potassium. Well, I do have one
problem. If you don’t have access to
some kind of free granite dust, it can get pretty pricey. A bag of granite dust costs about
$25.00. If applied at the recommended
rate, and depending of the condition of your soil, this will treat about 500
sq, ft of garden. For me, that would be
about $150 to amend my entire garden.
That’s not horribly expensive, but it is a little steep. One advantage of granite dust is that it
releases the potassium slowly, so you don’t have to make an application every
year.
Hardwood Ashes
Hardwood ash can contain up to 10% potassium, and hardwood
ash raises the pH of soil; so it is a good fit for my garden which has very
acid soil. I cut hardwoods off my farm
to burn in my wood stove, and every time I clean out the stove it is a simple
matter to take the ash out and sprinkle it on the garden. Wood ash should be applied at a rate of one
to two pounds per 100 sq. ft. depending on your soil. If your soil is already alkaline you may want
to stay away from wood ash or be sure to balance out the alkalinity with a lot
of compost.
Reason 3: Chemical fertilizers are cheap, convenient, and
easy to use; but they won’t solve all of your problems.
Let’s face it, to obtain the same amounts of nitrogen,
phosphorus, and potassium found in one bag of chemical fertilizer from natural,
organic sources would cost a minor fortune.
For example, I looked at a bag of cow manure at one of the big-box
stores. It was rated at .5-.5-.5. In other words it would take 26 bags of cow
manure to equal the amount N-P-K in one bag of 13-13-13. And here’s the thing, plants absorb nitrogen
on a molecular level. They don’t know if
the molecules are coming from manure, blood meal, or chemical fertilizer.
Blood meal is rated at 12-0-0, but a 50 lb. bag of blood
meal costs around $50.00. Bone meal is
rated at 3-15-0; but a 50 lb. bag of bone meal costs nearly $60. Granite dust is rated at about 0-0-5, and a
50 lb. bag costs from $20 to $25. If you
add it all up, it would cost about $160 to purchase natural, organic
fertilizers that would contain approximately the same amount of N-P-K that is
contained in one $20 bag of 13-13-13 chemical fertilizer. Now do you see why the grocery store price of
organic produce is so high?
Of course chemical fertilizers are not the be all and end
all of good gardening. One of the big
arguments against chemical fertilizers is that they only supply the three
macro-nutrients (N-P-K) necessary for plant growth, while plants actually
require an additional 12 or 14 elements known as micro-nutrients if they are
going to have healthy growth and production.
I agree with this argument 100%, and I would go on to add that these are
only the micro-nutrients that we know about at this time. The scientific study of plant growth is still
in its infancy, and I would be willing to bet that, over time, we will find
many other things that are necessary for healthy plant growth. So, the bottom line is that you have to do
something beyond basic chemical fertilizers to address the need for
micro-nutrients.
It is also argued that chemical fertilizers don’t add any
bulk to the soil. This is also 100%
true. If you have heavy clay soil,
adding chemical fertilizers won’t change that.
If you have loose sandy soil that loses moisture too quickly, chemical
fertilizers won’t change that either.
You have to do something else to add bulk to your soil and address
proper water retention.
There is much debate over whether chemical fertilizers
kill/repel earthworms and soil micro-organisms.
It has been my personal experience, using the methods that I use, that I
have an abundance of earthworms in my garden.
I think that if you use nothing but chemical fertilizers, and if they
are applied at a high rate; then this might have an adverse effect on
earthworms and micro-organisms, but I don’t know this for a fact. I wonder if the lack of earthworms and
micro-organisms in some chemically fertilized soils might be more related to a
lack of organic mater in the soil.
Again, I don’t know; but I would sure like to see some good scientific
data on the subject.
The final argument against using chemical fertilizer,
especially from a preparedness perspective, is that it is not sustainable. This is also true. If everything collapses, you will no longer
be able to run down to the feed store and buy a bag of 13-13-13 or anything
else. But the good news is that chemical
fertilizers can be stored indefinitely if they are kept away from
moisture. I raise around a hundred ears
of corn using a total of about 6 lbs. of chemical fertilizer. I use more fertilizer on corn than on any
crop I raise. If I continue raising this
amount of corn, two 40 lb. bags of fertilizer would last me for over 13
years. By the way, a 40 lb. bag of
fertilizer fits almost perfectly into a 5 gallon plastic bucket with a
water-tight lid. After the fertilizer
runs out I, and everyone else, will go all organic, but by then I will,
hopefully have plenty of time to compost, gather manure, etc. I guess if I need potassium I can always bust
up my wife’s granite counter tops, but then survival would probably take on a
whole new dimension.
A Brief Summary of How I Amend My Soil
In summary: My soil
has a lot of clay in it and it is very acid.
I bring in sand to help keep the soil loose, and I turn in home-made
compost and uncontaminated manure. I use
a pre-plant application of dolomatic limestone, Epsom salts, and borax. I turn
in a light broadcast of 13-13-13 fertilizer before planting unless the bed is
to be planted in legumes. I rotate my
plantings and try to plant all beds in nitrogen fixing legumes every other
year. I mulch every year, allow the
mulch to decompose, and turn it in. I
use targeted side dressings of chemical fertilizers to boost the N-P-K content
of the soil. I use 10-20-10 for my root
crops like onions, turnips, and sweet potatoes, and I also use 10-20-10 for my
cucumbers. I use one application of
13-13-13 around peppers, squash, tomatoes, etc just before they bloom. I side dress my corn with 33-0-0 when it is
knee high and again when it tassels. I
find that this program works great for me, and I get wonderful yields.
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