Modern Organic Farming Without Soil [Part2]

Click here for part one of this article.


We will start off with the results. Here are some photographs of the result of my experiments. This particular batch of photos are from a fully automated system that I designed for growing my vegetables on the third story terrace, far away form the ground soil. The power required to drive the system is generated from solar panels.

Tomato

Mint

Spinach

Long Beans

Bitter Gourd

After running this system for two years and studying the plant behavior I decided to implement it on individual smaller systems, which might be more practical on balconies and the like. Here are some photos of the result.  I did not try to tame these but let it grow as wild as they pleased, but without soil. Have put down the growth medium used below each photo. The medium select is a neutral medium.

medium: 3/4 inch gravel

medium: machine waste cloth, gravel, cleaning sponge pieces

medium: cocoa peat , 3/4 inch gravel

Working Principle:

The plants use soil to build the root structure and absorb the nutrients required for its growth. The soil also provides support for the plant to stand upright. As the plants grow taller the main root goes deeper and the the branched roots spread further away. The minor roots tend to look for moisture and nutrients. Since too much water can rot the roots the plants prefer moist soil to wet soil.  Moist soil has enough air for the plant roots.

My experiment was based on these main attributes [ and some minor attributes would make this blog boring ] and I formulated a theory. It was my belief that plants are happy when:

• they have just enough moisture
• the right amount of nutrients
• right amount of aeration of the roots
• have a medium where they can spread their roots
• a medium that can support the weight of its steam and leaves

p.s: Most vegetables are happy in a medium that is 12 inches deep.

Selecting Growth Medium:

Based on what I mentioned, I found that the medium should essentially process three major qualities. Firstly it should have the ability to retain moisture and the nutrients we provide externally, secondly it should be able to hold the plant steady and thirdly it should be an inert medium. By inert I mean that it should be neutral by itself. Some of the mediums that I have tested are:

• cloth rags
• gravel
• charcoal
• broken clay tiles
• coco peat [ surface layer ]
• coconut shell
• coconut husk 

Different plants show different growth patterns and varying root structure. For example tomato has a main root area  going down and the rest spreading outward, while in the case of mint the roots run all over the place and so does the plant. So we could safely infer that we can use a shallower and more spread out growing bed for the mint and a deeper smaller surface area growing area for the tomato. So when selecting the pots or growing container choose accordingly.

Building a simple system:

I have designed a construction which uses readily available PVC pipe and joints to make a light weight soil less vegetable garden  for small spaces and balconies. I have done the calculations with 12+ inches of growing bed height.
This will be covered in part 3.

Modern Organic Farming Without Soil [Part1]

Introduction:

Farming or agriculture has been an integral part of the human race since time immemorial. Years went by and  population grew. The basic human nature to live in clusters or groups saw the concentration of the major chuck of population in specific geographical locations, forming cities and towns. Most of the modern day cities have very little vegetation and very little fertile soil. No one is to be blamed, but when one population increases it takes up the space of another, sadly it is the trees and vegetation that we chop down starting a chain reaction. I have no intention to bring out any melodrama here so let me cut to the chase.

The best way to put forth the topic would be through a series of question and answers, and here it goes.

Q: Is soil absolutely necessary for cultivation ?
Now, that sounds like a stupid question. The plain and simple answer is NO, cultivation can be done without the use of soil.

Q: How is it possible ?
The answer is not in the soil,the answer is in the plants. Just like humans adapt to varying dwelling conditions, so do plants. The more comfortable the living conditions, the happier the plants. To understand this further, let us look as what the plants need for a healthy growth.

Q: What do plants need ?
Lets keep this very simple. Plants need food to grow and this is taken in through the roots, the leaves use sunlight and process the food. The stem as we know helps in transportation and also in giving form to the plant.

Coming back to the soil, it is a variable mixture which changes from region to region. Soil primarily contains substances such as silica (silicon dioxide), rock powder, minerals and organic and inorganic substances. It has two primary functions as far as the plants are concerned,  firstly it provides the nutrients and secondly it helps build a foundation so that the plant can stand upright.

Both these functions are made possible by the plant roots. Which brings us to the next question...

Q: What do the roots need ?
The root is a very interesting part of the plant. Silently working underground, cut off from out naked eye this intricate labyrinth decides whether the plant should live or die. It would be quite apt to say that the roots are the heart of the plant. If the leaves or stem are under attack they resist quite well and they are quite hardy to environmental changes. In the case of roots, too much water can rot the roots and too little can kill the roots. Once either happens it is very difficult to revive the plant because the whole system shuts down. The more complex the plant the more complex the situation. The roots also need aeration in healthy quantities.

Q: What is the ideal condition for the root?
Roots need nutrients, a strong foot hold to keep the plant upright, moisture and air. If we provide a condition congenial to this then we have a healthy plant.

If we can provide such a condition without using soil and if we use only organic nutrients, then we have a perfect and healthy plant. In part two we will see how this can be achieved so that we can grow our vegetables on our balconies or terraces.