Rainbow worm farm experiments

What is a worm farm?

Rainbow worm farm experiments test just how much the wee actually does.

There's much rhetoric about the value of the organic liquid manure that drips from a worm farm; testing reveals that it's not in fact particularly high in nitrogen.

For that you need rotation with crops of legumes like broad beans and green peas; they have nodules of nitrogen fixation bacteria on their roots.

This page was last updated by Dr Bernard Preston on 13th June, 2019.

So I have set up a small experiment to evaluate the growth of a crop of corn. I have planted three rows, and we will irrigate the two on the left with diluted worm wee, twice a week. The one on the right will get an equivalent amount of water but no liquid manure.

This is not going to be a rigorous program. I will not be measuring the heights of the plants, though we may get to weigh the fruit if we are feeling strong. We will simply take successive photographs showing all three rows; let us see what happens.

More conventionally, the organic gardener would use compost, where possible laced with cow, horse or chicken manure. He would use crop rotation, or even simultaneous planting with a legume for the nitrogen fixation bacteria. They are perfectly satisfactory though do not produce the dramatic results of fertilizers.

I confess to using a little inorganic fertilizer occasionally especially on our avocado and citrus trees, and when growing potatoes. However most of our plant nutrients come from the compost piles that adorn every corner of the garden.

Rainbow worm farm experiments

Rainbow worm farm experiments evaluates the effect of the liquid manure on a corn crop.

These three rows of corn were planted about six weeks ago. As you can see they look very much the same.

The two rows on the left will be given a dilute mixture of worm wee, roughly a half, and that on the right will be given an equal amount of water that is harvested from rainfall; it acts as a control. 

It is recommended that your use the worm wee once a week to feed your plants.

It probably will not be too rigorous, but the aim is to give two waterings a week. The first was on the 20th December; that is midsummer in the southern hemisphere. The second photo, see below, was taken on 5 January, two weeks later.

I am quite interested to see what effect the worm wee has, if any. I expect the plants will be healthier, but will there be a visual distinction? Will it be dramatic, or will one have to use the imagination to see the difference? And what effect on the cobs?

The question may well be asked, what was planted here before? Was it the same crop throughout? Were there green beans where the two left rows are growing, providing more nitrogen?

There was a crop of broccoli plants a few of which remain as they are still producing a few florets, and down the left side there was a row of the good wife's famous poppies. I doubt they would have much effect.

If there are interesting results, then perhaps in the next rainbow worm farm experiments we will be a little more rigorous about these details.


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This is more of a fun exercise than a scientific experiment. If there appear to be some interesting results then perhaps a serious agriculturist might like to set up some trials.

I might add here that the wee is something of a byproduct for us; we got into the wonder of worm farms to generate food primarily for our hens.

In cramped quarters where they can only copulate and feed, the worms produce explosive growth. This I can attest to; we started with a few hundred worms and now have hundreds of thousands, perhaps millions. I'm not counting! But they reputedly double in numbers every month, munching their way through their own weight of organic material every day.

Finding enough food for them is the limiting factor.

Week 1

Week 1 of our rainbow worm farm experiments.

The bees will collect pollen from the corn, but I don't believe they will have much effect on the pollination. This is week 1 of our experiment. Now to fertilize the two left rows with worm wee.

Week 3

Worm wee experiments with corn two weeks later

Week 3, or 16 days later to be precise, here's the growth. Can you see you a change in our rainbow worm farm experiments? I confess I can't; at the far end, in front of the bee hives, the corn plants in the two left rows seem to be ahead of that on the right, but in the foreground, the controls seem to be doing better.

Keep watching, and at the end of the day it is whether the cobs are larger and tastier. We will do some blinded tasting experiments.

Week 5

It's now week 5 in our rainbow worm wee experiments with corn. We have had plenty of rain and heat and the plants are bolting up. In the distance the two rows on the left seem to be marginally taller, but those in the foreground not.

Worm wee experiment with corn at week 5.

Week 7

From the side where the other photos were taken, there's really little to be seen the corn is so tall, but at week 7 from the other end, it's clear that the two rows on the right that get the worm wee are surging ahead.

However, I'm more interested in the size of the cobs, and that is a good few weeks off.

Rainbow worm farm experiments week 7

Week 14

And now it is week 14, and time to check the results of our rainbow worm farm experiments.

Corn grown with worm wee

 I tried to be objective, and I think these two cobs are representative of the those from plants grown from worm wee, and those not. I should have weighed them, but it was in the pot before I thought of it.

At an estimate, the cobs from plants grown in worm wee are about 25% bigger; I could not detect a difference in taste.

Both cobs were a little old; those enjoyed a couple weeks earlier were more juicy and sweet.

This can hardly be described as a rigorous experiment, but I'm convinced; the worm wee does seem to make a remarkable difference.

How to grow corn

Corn ears nearing maturity.

How to grow corn is of course very basic for even the beginner gardener. You purchase a packet of seeds, prepare a piece of ground and plant them about a foot apart, one inch deep. Over and above that of course we're going to be doing some rainbow worm farm experiments.

You might thin them if you are feeling strong. I do not; the production per plant might be greater then, but the overall weight of maize rather less.

This is going to be an ongoing page; I will only add new photographs when there is something worth seeing. Come and visit our rainbow worm farm experiments every couple weeks if you are interested.

How often should you feed your worms?

There is plenty of room for rainbow worm farm experiments, but in short do not starve them. You cannot feed them too much; they may not eat it all, but it will not hurt them like too little.

I have six containers of about half a cubic metre; each is fed about every six weeks - with a very large amount of food; twenty to forty litres of rotting food.

Recently I went on holiday for a month, which meant that some were not fed for nearly two months; they thrived, perhaps even better than a six weekly feed.

Just as important is to make sure they remain damp, but not sopping wet.

Dip a fork into your worm farm at least every couple weeks; you will soon see if they are thriving.

Do remember that water is the greatest enemy of the worm farm; keep the rain out.

Insect pests

The worm wizzard tells me that without a doubt, wormwee makes a great insecticide, inhibiting for example aphids and red spider mites; use a 10:1 ratio.

  1. Bernard Preston
  2. The wonder of worm farms
  3. Rainbow worm farm experiments

Bernard Preston

Bernard Preston is a semi-retired chiropractor who's other passion is for a sustainable planet; a place where our children's children will be able to thrive and enjoy a full life as we have. Or will they be cursing us for so polluting and destroying their world that they have no future; a silent Spring? These rainbow worm farm experiments are part of his tiny contribution. It's also been a lot of fun!

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