The properties of soils are crucial for the successful growth of plants. For plants to achieve their maximum potential, the soil must provide satisfactory conditions. The properties that influence plant growth are:
1. Biological Properties
These refer to the living organisms that are found in soil such as earthworms. They differ in size ranging from slightly larger animals like moles to micro organisms like bacteria. The large organisms create large spaces as they burrow through your soil which helps aerate the soil and improve water drainage. The micro organisms on the other hand break down organic matter in the soil, releasing nutrients to the plants growing in the soil. So don’t be alarmed when you spot living organisms in your soil; they are there for a good purpose. You can even introduce living organisms to your soil when necessary.
2. Physical Properties
The physical properties that influence the growth of plants are soil texture and structure.
● Soil texture is the relative distribution of various sizes of soil particles. It affects the soil’s ability to retain water and nutrients. The texture of soil is dependent on the amount of sand, silt and clay in it. Soils are referred to as either light or heavy. Heavy soils contain higher proportions of clay soil while light soils contain higher proportions of sand.
The 3 primary classes of texture are sand, loam and clay. Sands have at least 70% of sand; clays at least 40% of clay; and loams just the right amount of sand, silt and clay.
● Soil structure is the arrangement of soil particles, that is, sand, silt and clay and spaces in the soil and the capability to form groups of particles held together by chemical forces (aggregates). Spaces between these aggregates allow proper aeration, water drainage and root penetration. Organisms in the soil also benefit from this. A well-structured soil allows proper germination of seedlings and formation of a firm root system.
Changing soil texture is next to impossible so have to make do with what you have but the structure can be changed by adding organic matter which is the decomposing remains of plants and animals, otherwise known as humus.
3. Chemical Properties
Chemical properties that determine the proper growth of plants include: cation exchange capacity and soil solution
● Cation exchange capacity
This is the capacity of the soil to absorb nutrients in form of cations. It’s measured by a soil test. Cations are present on the soil’s surface and the greater their surface area, the greater the ability nutrients. Therefore, the size of soil particles affects the fertility of the soil. Soils with high clay content have a larger surface area for absorption and so are more suitable for gardening.
● Soil Solution
This refers to the soil water with its dissolved salts. Nutrients enter the plants through the soil water so it’s crucial to plant growth.
Salts such as calcium, magnesium, sodium and potassium are also important for the plant’s growth.
Soil pH refers to the neutrality, alkalinity or acidity of the soil solution. It influences the level of nutrients in the soil and the activity of soil organisms.
You can improve your soil’s chemical properties by introducing cover crops, reducing the amount of synthetic fertilisers and pesticides by adopting more natural solutions like organic matter and use of rock dust to restore the phosphorous levels in soil.
Making the most out of your soil
To determine the properties of your soil, you need to carry out a soil test and choose the garden design that is most suitable which will give you bountiful harvest. You can do this with the use of a soil test kit which assesses the type of nutrients available in your soil. If the necessary nutrients(Nitrogen, Phosphorous and Potassium) are lacking or are in low quantities, you can add fertilisers.
Finding out the type of crops that your neighbours grow is also a good idea because their soil is basically the same soil as yours. If a certain crop is successful on their land, there’s also a good chance that it will do well in your land.
You can also adjust the pH of your soil depending on the type of crops you want to grow. For example, you can add lime to make it more alkaline. However, keep in mind that most plants prefer neutral conditions.