For me, one of the most fascinating aspects of gardening is the 'soil'. I think it's one of the least misunderstood parts of gardening, and that's why in the past, growers started to use 'chemicals' as a way to 'control' the environment of the crops. The use of chemicals has been used as a 'short cut' or fast track way to control pests such as insects, weeds, plant disease, and also to be used as fertilisers to give the plant food (typically nitrogen, phosphorus, potassium) all used in aid to save 'time', 'money' and to produce a 'bigger harvest'.
Whilst the use of chemicals to control these areas might at first appear to be effective, ultimately over time they categorically 'destroy' the soil (mainly the soil life) which in turn produces smaller yields, which then ends up losing money, consequently buying more 'product' (chemicals) to rectify the problem, spending more time - a cyclical disaster!
Thats why I believe 'Organic' gardening is the way forward. With Organic gardening, or at least by my standards, zero chemicals are used to control pests, weeds, plant disease or to be used as fertiliser. I only recommend trying to replicate 'natures way'.
Without human interference, 'nature' does not use any chemicals at all in the plant kingdom, and just look at how lush our forests, jungles and countrysides grow, they thrive... but how is that so?
There are lots of factors which help plants grow in nature, but in terms of soil, we have to take our attention to the 'soil life'. Healthy Soil contains microorganisms (fungi and bacteria ect), and larger creatures like earthworms, beetles and grubs to name a few.
Soil life is one factor that a lot growers do not consider, they often see soil as just particles of 'dead soil', chiefly made of 'sand, silt and clay'. However, 'living soil' is teaming with living creatures which make up the 'soil food web', and maintaining the soil food web is critical for healthy soil, and thus healthy nutritious plants, which result in healthy humans, can you see the link?
The soil food web explained
In simple terms, when plants need nutrients from the soil to grow, they use their roots to draw up nutrients from the earth. However, not all nutrients in the soil are in a readily available form for the roots to take up, disaster you might say? But wait, this is where 'bacteria' and 'fungi' (microorganisms) come to the rescue. Each plant attracts to its 'rhizosphere' (the area around the roots) a whole host of fungi and bacteria. The plant doesn't simply attract these microorganisms by accident, oh no, it scientifically and specifically attracts, monitors and controls with exact ratios, the specie and number of fungi and bacteria needed to perform a very unique job. It attracts these microorganisms by sending out 'food' through its roots in forms of sugars, protein and carbohydrates, this is food for the bacteria and fungi which help create certain enzymes within the microorganisms, which will later help with extracting nutrients from organic matter
The picture below is a soil sample observed under a microscope detailing the microorganisms and other matter.To give you an idea of size, there are approximately a million, million (not a typo) of bacteria per 1/4 teaspoon of soil around the rhizoshpere.
'GETTING A GOOD MICROSCOPE FOR ON FARM MONITORING OF SOIL DEVELOPMENT' [19/12/2013] [online]
Once full of food, it is the role of the bacteria and fungi to go out 'to work', and use the specific enzymes to 'mine out' and eat all kinds of nutrients from the sand, silt, clay, rock and pebbles. Eventually the bacteria and fungi become satisfied and loaded with the nutrients from ingesting the extracted minerals and the exudates (sugars) from the plants.
But wait... if the bacteria and fungi now have all the nutrients in the their stomach that which the plants ultimately need, how do the plants access those nutrients from the bacteria and fungi?
Well, this in when the 'predators' come onto the scene, centralised around the rhizosphere. Microorganisms such as protozoa, nematodes, micro-arthropods, earthworms are the predators that come along and eat the fungi and bacteria. The concentration of nutrients from the fungi and bacteria is so high, that once eaten, the protozoa, nematodes, micro-arthropods and earthworms eventually have to 'poop out' the contents, if not, the nutrients actually poison them. This poop is now loaded with nutrients, and it is in a form that the plant roots can now take up and use, and the cycle is complete (genius).
Soil life being active in my compost heap. Microorganisms are too small to see.
My compost heap teaming with life after being broken down by microorganisms after approx 2 years. The dark brown colour and crumbly texture is a good sign of compost being broken down. (This compost pile was made from of all kinds of garden waste such as weeds, old crops, plant food waste, grass and leaves. Diversity in organic matter will create a diversity in fungi and bacteria)
Using chemicals on soil 'kills' soil life, chemicals kill the fungi and bacteria. Without the fungi and bacteria, the plant doesn't have a 'work force' to go out and mine nutrients. Without nutrient rich fungi and bacteria around, there will be no food for the protozoa, nematodes, micro-arthropods, earthworms. Without these predators feeding on fungi and bacteria, there will be no nutrient rich poop. Without nutrient rich poop, there will be no nutrients for the plants. Without nutrients in plants, there will be no nutrient rich foods for us to eat. With out nutrient rich foods for us to eat - we get sick... or die! So thats why it's important to not use chemicals on our plants and soil, and to instead create an environment where microorganisms can thrive. Hope that has given you a better understanding of why it is so crucial to grow or buy organic food. For more information about soil visit