Soil magic
Soil
magic
Nerd
Alarm: this for all the garden lovers (who wish they hadn’t drop out of biology
in 11thgrade)
„Of
course you have terrible soil problems in your country. What do you expect when
you call it dirt” is my new favorite quote.
However,
my number one take-away from all my agricultural reading and Congo gardening project
is: It’s all in the soil.
Take
away number two: Forget about composting elsewhere, pile it all on the bed –
and call it mulching (Most
of the following sophisticated-sounding data comes from ‘GAIA’S Garden by Toby
Hemenway).
Okay,
so I was trying to understand what is going on in the soil, and how I can help
my plants to become big and strong ... and bear delicious veggies for me. Here
is what I learned.
So...
let’s start in the beginning. Soil is pretty much everything – it’s like our
supermarkets, kitchens, roads and hospitals – it provides the plants everything
it needs. Its magical and miraculous, but likes to be taken care of as well,
because in fact it is full of life. And like all living beings, they want to be
loved : )
I
didn’t really think I would need biology in my later life this much, so when
they talked about all the organisms, I tend to tune-out. But I do understand
numbers… so here one concerning the life in one teaspoon of soil: one billion bacteria, one million fungi
and ten thousand of amoebae. I always had a hard time picturing anything
smaller than a cat, but clearly there is a lot going on in this seemingly
lifeless spoon full of soil (btw there is also clay, sand, water, air and humus
on the spoon!).
Soil
is also the home for worms, millipedes and mites (among others) who eat stuff
you put on top of the garden bed, let’s say dried leafs. So they eat this
‘organic matter’ and of course have to use the bathroom – their poop being
super food for plants, easy to take in via roots, also because those little
worms loosen the soil when building their underground mansions. Millipedes,
bugs, beetles, snail, spiders, ants, ... all help as well.
All
to help and grow delicious food for us! Pretty magical stuff, Mother nature.
For
the ones that realize that there is a bit more to this…
So
some parts of these leafs can’t be ‘eaten’ by the plant just yet. So other
organisms, such as fungi, break down the pieces further. I guess it’s like mom
cutting the Steak into pieces for the little ones, after dad cooked it already
(or in the worm example: pooped it out). Maybe not the best metaphor, but it is
just to illustrate that the life in soil is like a big family, working
together, breaking down and preparing food for the plants.
The
x-mas dinner being HUMUS. Humus is the end of a process (that is poorly
understood) in which microbes and other ‘forces’ convert the ‘hard-core’ leaf
compounds – maybe like your favorite aunt that prepares the most delicious
dessert, even the most pickiest eater cannot resist. I am thinking warm apple
crumble with ice cream – only out of hard-core leaf compounds. The dirty dishes
are the humus – only that they are biodegradable eventually and it has more to
offer than attracting cockroaches when it sits around. Humus can be described
as ‘the end of the road’ for organic matter, but it is also very good at
holding moisture and at the same time fluffy enough to let roots and soil
organisms easily dig tunnels in search for food (which airs out the soil
further). On top of it humus is really awesome at bonding with other nutrients.
And
this part is for all the people that also regret dropping-out of chemistry
class…
So
humus involves a lot of oxygen atoms, which are negatively charged. And as
opposites attract, it catches some other important food for the soil and
animals in it, which are: potassium, calcium, magnesium, ammonium, copper,
zinc, manganese…. So it is kind of like the dirty dishes attracting
cockroaches, and other animals after all. Assuming you like cockroach stew :
)
Because
the nutrients on the humus molecule are actually washed into the soil, creating
like a really healthy soup, which can be drunken by the plants, until they are
full (to avoid depleting the humus)
So
just to complete the list: microbes also excrete/poop-out food for plant, and
together with fungi they even secrete antibiotics that protect the plants from
disease. Again, my conclusion: pretty magical stuff, mother nature – and: it’s
all in the soil.
If I
you are still with me after all this detail, you must like it to some degree,
so no stopping us now… to dive into this whole Nitrogen - Carbon thing, people
throw at me, every time I encounter a fellow gardener.
So,
here it goes… our leaf, like most living things in fact, is primarily made out
of carbon. When the little animals eat the leaf some of the carbon is digested
and ‘reused’ so to say, by them (to form a membrane or an eye ball :) the rest
is released as gas (carbon dioxide aka CO2 – our breath contains CO2 for the
same reason btw). There are other elements in the leaf, such as nitrogen,
calcium, phosphorus – usually also digested and staying earth bound. With the
CO2 escaping into thin air, obviously its ratio to the other elements is decreasing,
right? Specifically interesting for garden enthusiast is the ratio toward
Nitrogen, and they love to mention of C:N or Carbon to Nitrogen ratio.
Carbon
is a bid of an Houdini, only that a piece of him goes to everybody in the
audience (as you can see, I am continuing my row of bad metaphors) So by the
time the microbes (who are kind of last in line at the buffet) are finished
with the leaf, most of the carbon is gone. All that is left is
inorganic/non-carbon matter such as phosphate, nitrate, sulfate, and stuff they
like to put in bags and sell them to us as fertilizer (only that plants can
absorb just 10% of the applied fertilizer and rarely more than 50% of those
mixtures, leaving the ‘rest’ to be flushes in streams, lakes and ocean). So we
could get it for free – no shipping and handling and already mixed in with the
soil – if we let nature run the show.
Keeping
the carbon coming seems like an important part of feeding those little one, as
organisms need about twenty parts carbon for every one part of nitrogen
(similar to my chocolate intake compared to all other foods). The other three
letters that are used in gardening are: NPK – nitrogen we already know, that
there is phosphors and potassium (why they didn’t call it NPP? only god knows).
Anyhow,
how to we get all this letters to our soil:
Add Organic Matter! Apparently you can
do this via compost, mulching or cover crops. Since I am on the lazy side, I am all for mulching. It is like
composting right on the garden bed, only that you also kill weeds, protect the
soil from harsh sun and heat, or rain, keep the moisture in and provides food
at the same time!
Clearly
Good stuff. Apparently there are some sophisticated methods on how you can sheet
mulch multiply layers.
Without
sheets I just use this stuff: dried leaves, dried leaves crumbled up, wood
chips (cut ourselves), hay, hay with rabbit poop, and chicken poop. It’s like
tucking you kid in at night – a cold night I guess, trying to cover everything
with a heavy blanket.
Other material you can use: newspapers, lime,
rock phosphate, bone meal, straw, yard waste, seaweed, sawdust, pine needles,
grain hulls… and much more.
The
kitchen waste was a bit of a disappointment. Apparently its better to build a
worm mansion separately, were the little fellars can take of all Your (kitchen)
garbage....
Enough
science for today. Take away: Nature is magical, soil your sole concern when
gardening : )
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