Good gardeners know that 90% of the success of their produce comes from the soil. While the care you take for your plants is important, you will have to put huge amounts of work in controlling and keeping the soil in proper growing condition. The perfect soil varies for the different plants you grow. Some plants like soil on the more acidic side, while others enjoy neutral or sweeter pH. But first, let’s talk about the essence of soil.
Basic Soil Knowledge
Probably you haven’t thought a lot about the soil under your feet. However, you may be surprised by its complexity. The soil varies in its composition and the structure of its particles.
These factors are closely examined by farmers who need the appropriate soil for planting crops, as well as engineers who may need to understand how soil is going to hold up under different demands. The soil is also vitally important to the sustainability of an ecosystem because it serves as a natural medium for the growth of vegetation.
What is Soil?
The soil is a living substance containing different elements whose interaction determines the health of the plants. Soil contains minerals, such as sand, silt and clay.
The proportion of minerals in the soil determines the texture. It is the organic matter called humus that determines the soil’s fertility.
The hummus is constantly being regenerated by the living organisms, contained in the soil. The ground is full of microorganisms. The microorganisms facilitate the absorption of carbon in the soil, producing the polluting effects which contribute to climate change. By merging with roots bacteria and fungi, protect the plant from disease and provide it with water and all the nutrients it needs.
What are Soil Layers?
Now, if you look down at the soil under your feet, you can’t tell very much about it. So, when you study soil it’s helpful to grab a shоvel and dig a hole that’s big enough to reveal a vertical section of soil that ranges from the surface to the underlying rock – referred to as a soil profile.
The soil profile is somewhat like the soil’s fingerprint. It will differ from other soil samples based on factors like its colour, texture, structure and thickness, as well as, its chemical composition.
Each layer of a soil profile is referred to as a soil horizon. These horizons are identified by letters. Horizon “A” is the upper layer, closest to the surface. You can think of this horizon as the topsoil.
As you move deeper into the layers of the soil profile you have horizon “B” and “C”, giving us the three main horizons.
One gram of plant-covered soil contains about 1 billion bacteria from between 5 000 and 25 000 species. The other star of the soil is the earthworm, of which there are around 25 000 per hectare.
In one year several thousand tons of earth pass through the digestive tract of just a single earthworm. Worms also create tunnels, which help plants access the nutrients and speed up the absorption of water, which also prevents soil erosion.
Soil health has a direct impact on human health, but the ground beneath our feet is in danger. The use of pesticides and chemical fertilizers is sterilizing soil and killing living organisms.
Deprived of organic nutrients, plants are becoming dependant on chemicals. Their natural defences are weakened and they need even greater amounts of artificial inputs just to survive.
Farmers, who until recently benefited from the free and natural service provided by soil are in turn at the mercy of chemical inputs. A vicious circle develops where a great amount of money is required to buy more and more products. Plants that are deprived of natural nutrients produce fruits and vegetables of inferior quality, which are low in vitamins and the central nutrients. They also contain potentially harmful pesticide residue. Urgent action is needed and there is a solution – agroecology.
What is Agroecology?
Agroecology respects the soil’s natural life cycle. It can also re-inject new life in infertile soils by counteracting the harmful effects of chemicals.
By feeding the soil with compost, fertilizing it with green manure, practising crop rotation and by not harming its underground organisms by digging or ploughing it up. Agroecology allows us to practice a form of agriculture, which respects soil life whilst providing healthy, varied and tasty food for everyone.
It is crucial to remember that living and healthy soil is good for our health, good for farmers, good for the environment and the climate, and good for the earth.
There are three basic types of soil – Sand, Silt and Clay, but most soils are composed of a combination of the different types.
The mixture determines the texture of the soil, or in other words, how the soil looks and feels.
In addition to the three basic soil types, gardeners can benefit from peat and saline soils.
And, of course, the loam soil, which we consider a type of soil, even though it is really a combination of sand, silt and clay. The soil that will fit best your needs is determined by the type of plants that you’re growing.
Sandy soil is greyish-brown in colour. It is very dry, and it’s also one of the soil types that are hardest to grow in. It consists of small, weathered rocks and because of this, it can’t retain water well. Sand is fairly coarse and loose so water is able to drain through it easily. While this is good for drainage, it is not good for growing plants because the sandy soil will not hold water or nutrients.
In fact, sandy soil is used to improve the drainage for other soils. Sand warms up much quicker than other soil types and it can be used as a way to warm up the ground after winter.
Silt is another type of soil, which is commonly found next to riverbeds. It’s transported by the moving currents of water, and it’s one of the most fertile natural types of soil out there. Silty soil retains water well and it’s even used to fertilize other types of soil.
Silt can be thought of as fine sand, and it will hold water better than sand. If you were to hold a handful of dry silt in your hand, it would feel almost like flour. If you add water to the silt in your hand, it would do a fair job of holding the water and feels slick and smooth.
This type of soil has a fine texture and fine quality. Because silt soil retains water so well the soil retains lower temperature year-round.
Clay soil is brown in colour. It has the finest particles among other soils. The downside of clay soils is that they retain too much water. Because of the dense and fine texture of clay, water can’t drain.
Clay is very fine-grained soil. Its particles are even smaller than silt, so there is very little space between the fine grains for air or water to circulate. Therefore, clay does not drain well or provide space for plant roots to flourish. Clay isn’t the best pick for farming. However, if you are potting, clay soil is the one to pick.
When moisture is added to clay, it can be moulded into shapes, such as a pottery bowl or a building brick.
Peаt is a type of soil, which is dark brown or black in colour. It contains аcidic water, but it is used to regulate soil chemistry or pH levels, аs well as an agent of diseаse control for the soil.
Peaty soil is soft and eаsily compressed because of its high wаter content. It is also rich in orgаnic matter. Although peat soil tends to be heavily saturаted with water, once drained, it turns into a good growing medium.
During the summer though, peat could be very dry and it cаn even become a fire hаzard.
Peaty soil is desired because of its аbility to hold water in during the dry months аnd its capаcity to protect the roots from dаmage during the rainy season.
Sаline soil cаn be found in extremely dry regions аnd is usuаlly brаckish becаuse of its high sаlt content. The sаlinity is due to the buildup of soluble sаlts in the rhizosphere—high sаlt contents prevent wаter uptаke by plаnts, leаding to drought stress.
It can cause damage to the plants and stаll plаnt growth, impede germinаtion, аnd cаuse difficulties in irrigаtion.
It’s eаsy to test if you hаve saline soil. You’ll probаbly see a white lаyer coаting the surfаce of the soil. As well as poorly growing plants and signs of leaf tip burn on young leaves.
The type of soil аll gardens and gardeners love. Loam soil is a combination of the three basic soil types – sand, silt and clay, it also contains hummus. This soil has a higher pH and calcium levels because of its organic matter content.
The fertility of the loam soil will vary depending on how much of each component is present, but generally, if you are a gardener, this is the type of soil you want because loam retains moisture, but also allows for good drainage.
Loamy soils could be moulded into a ball, but the ball should easily crumble when disturbed.
This soil is the ideal material to work with, but you can’t have an even amount of all present particles. So don’t despair if you don’t have it in your garden. There are many ways to condition your soil—adding beneficial soil inoculants, covering your soil with compost, or simply spraying leaves and soil with compost tea.