Produce from organic farming is a niche market in first world cities; expensive food grown for rich city people who don’t want pesticides, herbicides or hormones to contaminate their palates. It’s a good market, so let’s not knock it. But organic can also be a far cheaper way for smallholders to farm.
Mike Bosch, well-known chicken producer from Limpopo, South Africa, recently featured on africanfarming.com, has promoted chicken manure as a cheap, organic fertiliser that works extremely well for fresh produce gardens. Livestock farmers know that dung makes very good manure, both fertiliser and compost, contributing nutrients and structure to the soil.
Organic crop production is about using natural materials to improve soil fertility, mainly of humus and micro-organisms that break down the organic material so plants can use it. Humus (an end product of compost) and globulin (produced by mycorrhizal fungi) are very important. Humus retains up to 80% of water; globulin protects plant roots and helps with drought resistance.
The biggest problem in conventional gardening is using instantly soluble nitrogen and phosphate fertilisers. Regular use gives plants lush growth at first, but excessive free amino acids soon build up in the leaves and make it easy for insects to attack. (examples of this are thrips and red spider)
The biggest problem in conventional gardening is using instantly soluble nitrogen and phosphate fertilisers.
Most plants do well in soils with a pH of between 6 and 7. It really is essential to monitor the soil pH. The better the organic matter in your soil, the closer the pH moves to neutral (7). This is because organic material buffers the soil pH and protects it from becoming either too acid (low pH) or too alkaline (high pH). Adding compost to soil is the way to correct soil pH.
Another good practice is to have your soil analysed twice a year. Although once a year is better than nothing. Plants will have few diseases and they will do well in fertile, well-drained soils. See the recipe for a home soil test at the end of the article.
CARING FOR THE SOIL
There are millions of good soil micro-organisms in fertile healthy soil. They need the carbon and nitrogen supplied by nature to survive. By turning the soil regularly and using synthetic fertilisers, man has interfered with the natural process. The soil becomes barren.
Fertile soil is porous. To feed and protect it, the gardener should use compost and mulch.
When done correctly, compost should be ready between 18 and 21 days. It is made up of 50% green material en 50% brown material.
Green material: Nitrogen-rich (N) material, like green grass cuttings, vegetable peels, seed-free weeds, fresh or old cow dung of chicken dung and lucerne (green or dry hay). Don’t add citrus, bones, meat or carnivore faeces.
Brown material: Carbon-rich (C) materials such as leaves, newspapers, wheat chaff or straw, bits of brown cardboard.
Don’t put in anything that has been treated with weed killer. Cut the material into small pieces. Mix everything well and dampen (if you squeeze a handful it should only give out a drop of water). Add a 1% water solution of effective micro-organisms (EM). See the contact detail to get hold of EM below, but if you can not get hold of EM, it is not the end of the world.
Depending on the size of your compost heap, cover with a black tarpaulin, black refuse bags, or a black rubbish bin. Turn the compost every second day and aerate the heap if it gets too hot (over 70°C). Be watchful if you have small children – you don’t want them going into a compost heap and getting burnt, which is possible.
For information on effective micro-organisms write to firstname.lastname@example.org or phone +27118881651
The red compost earthworm eats kitchen waste such as vegetable or fruit peels, tea and coffee bags, newspaper and egg boxes, watermelon. The excreta from these earthworms contains 30% humus.
Always cover the soil with a 10cm to 15cm layer of mulch. Mulch controls weeds, conserves moisture and keeps plant roots cool. The best mulch is lucerne hay which is also a fertiliser. As a mulch the farmer/gardener can also use wheat chaff or pine bark.
SOIL AND PLANT WELL-BEING
Don’t turn the soil often – use a fork to turn the top 5cm of the soil lightly. You can aerate it by digging the fork in and then twisting it slightly. After winter you can dig deeper around plants that don’t have a shallow root system.
Apply good quality compost twice a year and cover it with a mulch.
Fertilise the plants twice a year with an organic fertiliser like Lucerne pellets or meal and organic fertilisers from seed companies or nurseries. Use as little as possible synthetic fertiliser; never use raw manure, which can burn the plant, and spread disease.
Spray plans with organic leaf feed or make your own, using the lucerne pellets or meal. Add two cups to one litre of water, leave overnight and add this ‘tea’ to 10 litres the following day. Spray both sides of the leaf.
You could also use a 1% ‘worm’ compost tea.
Use as little as possible synthetic fertiliser; never use raw manure, which can burn the plant, and spread disease.
Use organic sprays to control pests and stay away from organophosphates and imidacloprids which are harmful to bees and ladybirds. If organic sprays are not effective then use a contact insecticide with minimal impact on the environment.
Use organic fungicides to control fungal diseases. A synthetic copper fungicide that is not harmful to micro-orgamisms and other insects can be used to black spot.
A DIY TEST FOR SOIL PH
You need vinegar, baking soda, soil, and distilled (or boiled and cooled) water.
Collect a cup of soil from different parts of your field and put 2 teaspoons into separate containers. Add ½ cup of vinegar to the soil. If it fizzes the soil is alkaline with a pH of between 7 and 8.
If it doesn’t fizz after doing the vinegar test, then add distilled water to the other container until 2 teaspoons of soil are muddy. Add ½ cup of baking soda. If it fizzes you have acidic soil with a pH somewhere between 5 and 6.
If there is no reaction from your soil – then you have a neutral pH of 7 which is a good place to be.