Know Your Soil

Learning what type of soil you have, including what levels of nutrients are in your soil will greatly assist you in improving your soil organically. Learning to know your soil is as simple as taking a soil sample to your nearest produce store or laboratory for testing to find out nutrient levels.

This will give you accurate results on each individual nutrient, plus pH and organic matter levels in the soil; knowing your soil will enable you to select the right type of fertilisers to apply, and greatly increase the yield and health of your vitamin rich produce.

Basics for Plant Growth

Plants need sunlight, moisture, air and nutrients. Plants are living things that are made up of carbon compounds, understanding the carbon cycle is the basis of organic gardening.

Plant photosynthesises and converts carbon dioxide (co2) from the atmosphere into oxygen and organic matter. Animals and micro-organisms consume most of this using up the oxygen and returning co2 to the air in a recycling process.

Before chemical fertilizer crops were grown, crops were grown by recycling manures and wastes to replace nutrients that were lost during the growing process. Over time we have moved to a chemical (artificial) way of growing crops and because of repeated ploughing and the use of chemical fertilizers on the soil this has caused soil degradation.

One of the results of this is an increase of pest and disease which has then caused a further increase in the use of more chemicals and pesticides on crops....

It’s also known now that repeated cultivation of fields exposes the top soil to harsh sun rays which causes the soil to be baked (dried out) and that kills the all important micro-organisms and earthworms that live in the soil.

That is why it is important to get to know your soil and progressively build the soil back up to its original/natural state by applying plenty of manures, green manure crops, compost and mulch.

Good soil for optimum growing conditions contains 25% air, 25% water, 45% minerals and 5% organic matter. Soil depths of about 12 cm (6 inches) can support a vegetable garden. However 20-40cm (8-16 inches) of good open soil, high in organic matter is preferred to grow healthy vegetables and deep rooted fruits.

If you take a look at a natural system like a virgin forest, recycling is the basis of its sustainability and has been the heart of organic soils for millions of years, what grows there dies there.

Organic soil matter is plant and animal residues in decomposition, dead bodies of beetles, grubs, earthworms, bacteria, fungi and decomposing plants are all consumed by millions of micro-organisms and earthworms.

An Earthworm can eat 10kg per square metre and increase the nitrogen level by a factor of 5, phosphorus 7 and potassium 11.

Earthworms also open the soil, improve root and water penetration as well as free up nutrients for plants organically.

Using Organic System instead of chemical fertilizing results in micro-organism rich organic soil, which is teeming with organisms that can sustain the soil for years.

Humus is the final result of decomposition and is the best slow release fertilizer as it remains in the soil for years. Most soils only contain about 2% organic matter but that 2% can support human civilation for years if managed correctly, if managed incorrectly fertility levels will decrease resulting in human civilisation struggling to maintain good health.

Have a look at how much money pharmaceutical companies are making from the sale of nutritional supplements, these same companies also manufacture chemical fertilisers the very reason there isn’t any nutrients in commercial produce, resulting in people needing to buy nutritional supplements – go figure....

While you can grow vegetables without soil in hydroponic systems this type of system is totally dependent on non renewable sources to maintain good growth in plants.

Hydroponic tomatoes are said to require 20 times more energy to produce fruit.

As you get to know your soil, the life blood of your garden, you should aim to raise your organic soil levels to 5-6%. This is achieved by minimising tillage, growing green manure crops, recycling manure and mulching in summer to keep soil organisms and earthworms active in breaking down these materials and making them available for plant use.

Ideal garden soil

should contain up to 50% pore spaces (good aeration, given from our friend the earthworm) and half of the space is filled with water.

Soil texture refers to the size of the mineral particles from which the soil is made and the proportion of particles of each size:

Small particles = clay Medium particles = loam Large particles = sand

The best garden soils contain a variety of pore sizes that allow the roots, water and organisms to move freely through the soil. That is why loam soil is the best because it has small spaces that trap the water as well as provides habitat for soil micro-organisms.

Larger particles (sandy) soil allows free drainage and passage ways for roots and organisms and fit together in an open structure with very wide spaces. Although sandy soils drain freely which results it allot more watering.

Small particles (clay) soil has much smaller particle size so packs down (together) very tight. That is why clay soils are very heavy, become bogy under wet conditions and can dry out and can be difficult to penetrate.

Soil structure is an important component in getting to know your soil.

Soil particles are bound together by organic matter, plant roots, fungi and bacteria to form larger clumps. Humus and exudates form organisms that are gummy so they form the strongest and longest lasting bonds to hold soil particles together to form aggregates.

The shape and size of these aggregates determine the soil animals and water and oxygen movement around your soil.

There’s a lot to learn about soil but if you can keep to the basics, feeding the soil the right types of foods like compost, manures, green manures and mulch the micro-organisms in your soil will take care of the rest, working hard to convert these materials into available nutrients for your plants, providing you with ample supply of nutrient/vitamin rich produce all year round.

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