All good soils may be alike but each type of poor soil is poor in it’s own unique way. Some plants thrive in poor soil but what kind of plants thrive in what kind of poor soil is worth investigating when you know what kind of soil you are dealing with.
If you are struggling to grow a variety of plants, it’s a good idea to get your soil tested and understand the pH, type of soil and whether you have an imbalance of nutrients.
Bemlab in Strand will do a soil test for about R250 and assist by also giving an analysis interpretation.
If you have a small yard like me, you only need one soil sample. If you have stoney soil, you will need 1kg. For other soils, 500g will be sufficient. Using a spade, dig out a sample of soil going the length of the spade (about 30cm deep).
I knew our soil wasn’t good but I wanted to see specifics so I have an idea of where I am starting from. Although I have been adding compost, liquid fertiliser and mulch over the past year, I decided to take a sample from soil that I haven’t treated.
The first thing Bemab analyzes here on this test is the type of soil texture class which is either sand, loam or clay. The ideal type being loam. Here, my soil type is sand which means it is well aerated, well drained and fairly easy to work with however water tends to flush through sandy soils and so it makes sense to to try gardening with sunken pits as I have done in our time of drought. The best advice I can give to sandy or clay soil is to add lots of organic matter.
The second part of the test is the pH. The perfect pH for most garden soils is a pH between 6 and 7. Unless you are growing plants which like acidic soil like blueberries and azaleas, a pH of less than 6 will be an issue for plants and a pH of above 7.5 will also be an issue. My analysis states we have a pH of 7.6 which means our soil is too alkaline. We will most likely have a boron deficiency due to our high pH. The picture below illustrates availability of nutrients to plants based on pH.
If your soil is too acidic, you can ‘sweeten’ it or increase the pH by adding lime however lowering the pH is more complicated. The gardener can add sulfur which can be costly and takes a while to work. Most soil scientists only recommend adding sulfur to a garden if you are planting crops that like an acidic soil like blueberries. Again, adding lots of organic matter increases the availability of all nutrients.
The next block on the test is the soil resistance which is an indication of soil salinity. Anything less than 300 ohms is regarded as saline.
The next part measures the percentage of stone in the soil and stone reduces the reactive volume in the soil.This percentage must be taken into account when gypsum and lime requirements and P fertlisations calculations are done.
We now look at how much phosphorus is available to a growing plant in milligrams per kilogram. There are two tests that Bemlab uses and each test is specific to the type of region where the soil sample was taken. If you come from an arid region where the pH is 7 and above, the phosphorus is mostly bound to calcium and if your pH is low, then the phosphorus would be bound to iron and aluminum. The Olsen test would be for high pH soil level and the Bray method would be for low pH soil levels. This test uses the Bray II method which tests for total phosphorus which is available in this year’s crop and also what is left in reserve which won’t be available for this year’s crop.
If we are using the Olsen method, we would want our phosphorus levels to be between 15 and 20. Our score of 14 is on the low side meaning our soil needs some TLC with compost and organic matter.
If you are using the the Bray test, you would want to do the Bray I or weak Bray to see how much phosphorus is available and you would want your levels to be between 20 and 30 with anything between 25 and 30 to be a good result. The Bray II or strong Bray is usually double the Bray I unless there are special conditions.
Phosphorus is essential to plant growth and is involved with energy transfer, photosynthesis, transformation of sugars and starches, nutrient movement within the plant, and transfer of genetic characteristics from one generation to the next. Phosphorus is also critical in root development, crop maturity and seed production. Phosphorus is an immobile nutrient meaning that it doesn’t move readily with water.
Potassium is then measured and our score of 94mg per kg is very low. Good postassium levels are around 200mg per kg however these numbers vary depending on the cation exchange of the soil and the ability of soils to hold onto these nutrients. You would want a higher number for heaveir soils (220 – 250mg per kg) and a lower number for lighter soils. As our soil is sand with a high pH, a good number would be 170 – 180 mg per kg.
Potassium is very mobile in sandy soils but binds to exchange sites of clay. Potassium increases crop yield and quality. It maintains turgor, reduces water loss and wilting.
Sodium is a basic cation that is a non-essential nutrient that destabilises soil structure.
Potassium as mentioned above increases quality and yield of crops and binds to clay exchange sites. A reading of 0.510 cmol per kg or 200mg per kg is considered very high.
Calcium (Ca) stabilises soil structure. Plants can tolerate very high concentrations of calcium in the soil. The role of calcium in plants is quite similar to that in people; it is essential for good growth and structure. Insufficient calcium levels lead to deterioration of the cell membrane; the cells become leaky resulting in the loss of cell compounds and eventually death of the cell and plant tissue.
Magnesium (Mg) is an essential element that, if it is in a ratio higher than 1:4 with calcium, can destabilise soil structure. Many critical physiological and biochemical processes, especially photosynthesis, in plants are adversely affected by Magnesium deficiency, leading to impairments in growth and yield. Ideally, we would like 12 – 15 mg per kg.
Moving down the page there is a small table with a heading called Base Saturation. These cations are expressed as a percentage of the total exchangeable cations. The first result is 2.21% of soduim (Na). You don’t want this percentage to be higher than 15% and if it is higher than 1%, it might be a good idea to keep an eye on this reading if you test your soil again at a later stage.
Potassium (K) saturation can change rapidly in sandy soils. In clayey soils a 4-5% saturation is regarded as optimal, except if free lime or salinity occurs. Between 3 and 6% is also good. Our score of 1.91% is not satisfactory.
Calcium (Ca) stabilises soil structure. Between 65 and 75% is the optimum range and is beneficial for soil structural stability, especially in loamy or clayey soils.
Magnesium (Mg) can destabilise soil structure. A high ratio compared to calcium (Mg:Ca ratio > 1:4) indicates to the possibility of poor internal drainage and subsoil salinity.
The T-value is the sum of all the exchangeable cations in the soil, including soluble (free) and those on the exchange sites. It is not equivalent to the S-value, which is the sum of only the basic cations (Na, K, Ca & Mg) while the T-value also includes exchangeable H+ . Neither is the T-value similar to the cation exchange capacity (CEC) since the first mentioned includes all cations in the soil, those on the exchange sites and the free nutrients – the T-value is therefore often larger than the CEC.
Copper (Cu) is an essential metal for plants. Its availability for plant uptake is affected by soil pH, being lower at high soil pH. At excessive levels in soil, micro-organism activity is adversely affected. In plants, copper plays a key role in photosynthetic and respiratory electron transport chains, cell wall metabolism and stress protection.
Zinc (Zn) is an essential micro-nutrient for plants. Usually, a zinc deficiency is expected in calcareous (high pH) soils, sandy soils and soils with a high phosphorus concentration. Zinc deficiencies in plants leads to stunting of growth, chlorosis and smaller leaves, increasing crop maturity period, sterility and inferior quality of harvested products. A good number is 1.5 – 2mg per kg. Our score of 7.9mg per kg for our sandy soil with a high pH is a strange reading and before it is brushed off that we have enough zinc, another soil sample should be taken. I’m nervous to remineralise our soil on my own without a consultant and I shy away from chemical fertilisers as I want to encourage effective microorganisms and earthworms so I am adding as much organic matter and compost as I can. I have already noticed a huge difference since I added my first mulch layering last year.
Manganese (Mn) is an essential micro-nutrient for plants. Manganese reaction in soil is quite complex. The amount of available Manganese is influenced by soil pH, organic carbon content, moisture and soil aeration. Manganese availability increases as the soil pH decreases, with toxicity being common in soil with pHKCl < 4.5. In plants Manganese plays a direct role in photosynthesis because it is involved in chlorophyll synthesis. Ideally we would like a scoring of 12 – 15mg per kg.
Boron (B) is an essential micro-nutrient for plants, but the range between deficient and toxic boron concentration is smaller than for any other nutrient element. One of the most important factors affecting the availability of boron in soils is pH. With increasing soil solution pH, boron becomes less available to plants. Therefore, excessive application of lime to acid soils can result in boron deficiency symptoms in plants. The main functions of boron in plants relate to cell wall strength and development, cell division, fruit and seeds development, sugar transport and hormone development. Between 1 and 1.5mg per kg is good. We definitely have a boron deficiency and that is also indicated by small holes in our radishes and beetroot.
Iron (Fe) is also an essential micronutrient for plants. It is very abundant in soil, but that does not mean it is available for plant uptake. Availability of iron decreases as soil pH increases, with deficiencies starting to occur at pHKCl > 6.0. We would like to target for 20 – 25mg per kg. Excessive concentrations of phosphorus in soil also result in reduced iron availability. In plants, iron acts as catalyst to chlorophyll production and is essential for protein production. Yellowing of young leaves are therefore typical of iron deficiency
Organic carbon (C) in soil is an indication of the organic material content of the soil. Organic matter in soil improves microbiological activity, soil water holding capacity and fertility (cation exchange capacity) as well as soil structure. Less than 0.5% is low, between 0.5% and 1.5% is medium, 1.5% – 3% is high and anything above 3% is very high although I have read that your goal should be at least 5% organic matter.
The Ultimate Guide to Soil by Anna Hess
MAKING A WORM FARM
What you need:
3 stacking boxes that don’t let in any light and one lid that fits on top
A drill with a 6mm drill bit
Rainwater or chlorine free water (let water to stand for one day so chlorine can evaporate)
Food scraps – Information about what worms like and don’t like can be found here and here
Lets get started! The bottom box does not need to be drilled. This is where you will collect worm tea which when diluted with water will act as a liquid fertiliser for your plants.
Put 2 bricks in the bottom box so that when the second box goes into the first box, it is slightly raised.
Put the second box into the first box and let it rest on the bricks. Draw a line around the second bin on the outside where the two boxes meet. This is to guide you when drilling holes.
Take the second box out and drill a pattern of holes about 50mm apart from each other all around the box including the base. Don’t drill holes above the line that you drew. Repeat the same process for the third box.
Stack the second box into the first undrilled box and let it rest on the bricks. Put 2 bricks into the second box and stack the third box into the second box.
Fill your third box about halfway with shredded newspaper/carboard/paper (avoid glossy paper or glossy cardboard) Add some kitchen scraps and compost that has been soaked in rainwater and add your worms. Tuck your worms in with wet newspaper and roll up some damp newspaper to seal the sides of the box all the way around. This will avoid a flies coming in and interfereing with your worms.
Lastly, put the lid on top as your worms like the dark.
The worm tea will drip to the bottom box. You can harvest this when it is sufficient to collect. You can even install a tap to the bottom box if you like to make this process easier and rasing the whole structure on more bricks. The second box collects the worm castings which you can use for your garden. When you empty this out, you move this box to the top and add bedding, compost and kitchen scraps. The worms will migrate to the top box and follow the food
Have fun 🙂
I never thought much about worms until I started gardening and have learnt that worms have an amazing ability to bring enormous fertility to the ground. These little invertebrates mix soil by moving up and down and wherever they go, eating organic matter like rotting plant material, manure, and deceased bodies and then depositing nutrient rich worm poo into the soil known as castings. Castings contain five times more nitrogen, seven times more phosphorus and eleven times more potassium than ordinary soil. While these blind but light sensitive worms squirm around, they loosen and aerate the soil which allows better penetration of water and also allows aerobic bacteria and oxygen to get to plant roots. Looser soils allows plants roots to penetrate deeper and access more resources as well as provide more draininge.
Earthworm’s bodies are coated with a sticky mucuous called coelomic fluid and this fluid mixed with the bacteria in their castings bind soil particles together forming soil aggregates. This prevents soil erosion and retains water. Healthy soil means healthy plants which are more resistant to diseases and garden pests. Worm castings hold nutrients so they are released slowly to plants and the nitrogen is also readily available.
One way to encourage these hard working composters is to mulch well, avoid herbicides and fungicides, and keep the soil moist. The thick layer of mulch will help loamy soil retain water well. Worms don’t like acidic soil so ensure your soil pH is above 4.5 and avoid compacting the earth by providing walkways around your plants and keep tilling to an absolute minimum unless you really have to.
Another great idea is to start a worm farm and we will show you how to build a simple structure below. Worm farms turn kicthen waste into super compost without letting off greenhouse gases which saves the landfill and ultimately benefits the planet. There are some things to know before you provide a home to red wrigglers (Eisenia fetida) or redworms (Lumbricus rubellus). They are top level worms meaning they live in the top 30cm of soil. This means they will live near the top of your worm farm making them easier to feed.
They eat the equivalent of their body weight in a day thus providing the same amount of worm castings. Their environment should be kept withiin 15 degrees and 30 degrees. They can double their population every 6 – 8 weeks and they need bedding made from wet newspaper or wet shredded paper and cardboard. It’s also good to know that worm bins don’t smell so you can keep them indoors as well.
Did you know that the largest earthworm was found in South Africa in 1967 on the side of the road near King Williams Town and was close to 7 meters long?
September is the time to plant :
– Angelica seeds
– Basil seeds
– Beans – Pole/runner seeds
– Beetroot seeds
– Borage seeds
– Bronze Fennel seeds
– Cape Gooseberry seeds
– Capiscu,/Sweet Peppers seeds
– Carrot seeds
– Cauliflower seeds
– Chicory seeds
– Chives seeds
– Coriander seeds
– Corn Salad seeds
– Corn Maize seeds
– Cucumber seeds
– Dill seedlings
– Eggplant seeds
– Endive seeds
– Florence Fennel seeds
– French Taragon seedlings
– Jerusalem Artichoke seeds
– Leek seeds
– Lemon Balm seedlings
– Lettuce seeds
– Luffa seeds
– Melon/Cantaloupe seeds
– Mustard greens/Cress seeds
– NZ Spinach seeds
– Onion seeds
– Oregano seedlings
– Parsley seeds
– Parsnip seeds
– Pumpkin seeds
– Radish seeds
– Rhubarb seeds
– Rocket seeds
– Sage seeds
– Salsify seeds
– Shallot seedlings
– Spinach seeds
– Spring onion seeds
– Squash seeds
– Strawberry seedlings
– Strawberry plants
– Summer savoury seedlings
– Sunflower seeds
– Sweet Marjorum seedlings
– Swedes/Rutabagas seeds
– Sweet Potatoes
– Swiss Chard seeds
– Thyme seedlings
– Tomatillo seeds
– Tomato seeds
– Turnip seeds
– Watermelon seeds
– Winter savoury seedlings
– Zucchini/Courgette seeds
The summer seed list is long and now is the time to plant as much as you can. Water only when necessary and give moderate amounts to directly sown crops especially in heavier soils. If crops are overwatered, large seeds will rot before germinating and thickly sown crops could be victims to damping-off. You may loosen the soil carefully around perennial crops like globe artichokes, asparagus, rhubarb, and pole lima beans. Generous dressings of compost will prepare your plants for the summer ahead.
That’s a mouthful but there are so many other words that could be easily slotted into this title. We will expand by explaining how growing your own food will shine your green halo so brilliantly, it will light the way for others to be inspired. I am not surprised that many religious texts and spiritual writings refer to planting and growing. One experiences a little piece of magic when you enjoy the fruits of your own labour from seed to plate.
I cannot think of a more meaningful workout than gardening. Not only does it exercise and build muscles but it is good for your brain and the rest of your body too. Planting greenery brings you out into the fresh air where vitamin D doesn’t need to be swallowed. It stimulates learning and a deeper connection with nature and it has bountiful therapeutic qualities.
The garden is a superb environment to reconnect with nature from the tiniest microscopic organism to the largest wildlife you can accommodate. It doesn’t matter whether you have a large piece of land or just a balcony or enclosed flat, you can still enjoy the healing properties. It relieves stress, it is often a meditative process improving concentration, increasing self awareness, happiness, acceptance and overcoming pain. With some care and attention, your efforts will also bless you with a sense of pride and gratification. It’s a marvellous creative outlet with endless ways to create beauty and self expression and it can also introduce new interests like botany, landscape architecture, nutrition, photography, naturalism and farmers markets to mention a few of many.
Add to the already impressive benefits above, it is purposeful way to spend quality time with loved ones and create a sense of community by connecting with others close by to bulk buy, share information, advice and accomplishments.
Home grown food tastes better and if you grow heirloom (non GMO/non hybrid) varieties in a biologically diverse environment in soil fed with nutrients, your food will be more nutritious.You will also be able to save some seeds from your crops to use for next year. Ta dah! When you save the seeds, you can also swap them for different varieties that you may not have. This is a very important aspect and a right to which we must cling on to for dear life. To read more about why – you can read our previous story about seed biodiversity here.
Growing your own food becomes cheaper and cheaper as you learn more and practice sustainable gardening. As explained above, you can save heirloom seeds for re-use or to swap or gift which means you buy less seeds as your collection grows. There is huge potential to be grow a wide variety of fruit, vegetables and legumes that your local grocery store has never stocked. There is no fresher vegetable than one that is still growing in the ground which means less fridge space and obtaining food is a walk through the garden. This act inspires us to take an interest in the origins of our food and make better choices about what we put on our plates which is a part of conscious eating. Eating more fruit and vegetables can only be a good thing when it concerns your health and the sense of security of knowing whose been near your delicate spinach leaves is invaluable.
The blooms of flowers that will turn into fruit are gorgeous to look at and one can enjoy the sweet perfumes they emit. There is something very special when you are relaxing in your garden and nearby are hanging grapes or crisp cucumbers, striking red leaves of beetroot or even the flowers from potatoes reminding you of the treasures below. Imagine sitting in the shade of a fruit tree whilst reading a book or watching your loved ones play.
You have been showered with the benefits of gardening for you but let us take a closer look as growing your own food solves many other environmental concerns.
You cut out many carbon emissions by not supporting trade where food is transported to the grocery store by trucks and planes and the fuel you would use driving to the grocery store and driving back again.
By growing organically and maintaining biodiversity in your garden, you can combat soil erosion, cut out pesticides, herbicides and chemical fertilisers. That means less air pollution, less water pollution, less body pollution and less pretty birds and other animals dying. You also create less of a demand for monoculture which is a monopoly of bad farming practices designed for maximum profit and not for the health of those consuming these products or for the giving soil that gives up it’s nutrients for these crops. The seeds these corporate giants use are usually genetically modified and their farming practices rely heavily on machinery, water, chemical fertilisers, pesticides, herbicides and as a result reduce biodiversity and deplete the soil of nutrients. Geoff Lawton explains this process simply and visually in this informative video below this article
|MAKING YOUR OWN COMPOST HEAP
In a natural system, living things die and their deaths allow life to be reborn. Plants and other living things die on forest floors and in meadows, and are broken down over time by water, microorganisms, sun and air.
Compost has two main functions. It improves the structure of the soil, which makes the soil easier to work, providing good aeration and water retention characteristics. It also makes the soil more resistant to erosion. Compost also recycles and provides nutrients for plant growth. In addition, its organic acids make nutrients in the soil more available to plants. Carbon, nitrogen, magnesium, sulfur, calcium, phosphorus, potash and trace minerals maintain the biological cycles of life. Fewer nutrients leach out in soils with enough organic matter.
If soil only consisted of rock meal, it would be infertile. The fertility depends on the amount of organic matter or humus present in the soil as well as the effective micro-organisms and soil nutrients.
Healthy soil means healthy plants and healthy plants are more resistant to diseases and insect attacks. Ensuring you have fertile soil is a far better way to grow food than using poisons that kill beneficial soil life.
Composting is simply speeding up the processes that occurs in nature and it involves some fundamental principles. These principles are the provision of air, moisture and warmth in order to create an ideal environment for the fungi and bacteria that are responsible for the decomposition and breakdown of the raw materials.
There are many methods of making compost heaps and different recipes for layering your pile. Spring and Autumn are ideal times to make a compost heap as biological activity is high during these periods and it should not be too hot nor too cold for microbial life in the pile. We thought it would be a good idea to include this article to give you time to make before the onset of Spring.
Many households throw away things that can be turned into this black gold and this is why we are about to explain how to build a simple and effective compost heap.
You don’t need any fancy equipment or containers, however you may use them if you wish. It is also a good idea to build a compost pile on an unused growing bed so the next crop grown in that bed will pick up and utilize any nutrients that leached out from the pile and into the soil. When the next season comes, you can build a compost pile on another unused bed.
Here’s the process step by step:
1. Loosen the ground, where the pile will be, to about 30cm deep with a fork or hoe.
2. Lay down brush, woody materials and other roughage for air circulation.
3. Add about 5cm of mature material like dry weeds, leaves, straw, hay and old garden wastes. Water it thoroughly.
4. Add about 5cm of immature material like fresh weeds, grass clippings, hedge trimmings, green cover crops and kitchen wastes you have saved. Water well.
5. Cover lightly with about 1 or 2cm of soil to prevent flies and odours.You will want to do this straight after adding the immature material. Moisten the soil.
6. Add new layers of mature vegetation, immature vegetation and soil. Water the pile regularly until it is ready for use. You can also cover your compost heap to protect it from too much rain or too much sun.
7. Let the pile cure for 3 – 6 months while you are building a new pile. Turn the pile once for faster decomposition. A 1.2 meter pile will reduce to 30 – 40 cm when it is ready to use.
When you turn the compost pile, make the base of the new pile smaller than the original base to give the turned pile more internal volume and less surface area.
If you are not ready to use your compost when it is fully cured, stop watering it and spread it out to dry.
Always be sure to add at least 3 different kinds of crops to your compost piles. Different microbes flourish in specific kinds of crops. The result of this crop diversity is microbe diversity in the soil, which ensures better soil and plant life.