Improving your soil
Many gardens do not have a great soil that a wide variety of plants will thrive in. Because of this you will most likely need to improve the quality of your soil. What do we mean when we talk about improving the soil?
Soil improvement is based upon 2 main ideas, 1) improving the structure of the soil so its water retention properties and oxygen content are improved and 2) improving the nutrient content of the soil so the plants have access to the nutrients they require for strong growth.
If we improve the structure of the soil then oxygen will be able to enter the soil. Oxygen is required by plant roots and without it the plant will die.
Clay soils tend to have very small particle sizes which bind together tightly and therefore little oxygen is found inbetween the soil particles. Because the particles are closely bound water tends to drain poorly from clay soils. The end result is that clay soils tend to be waterlogged and lacking in oxygen. If the plants roots don’t have access to oxygen the plant will die.
Sandy soils have very particles in them and this means the gaps between particles is much larger than the gaps between clay particles. Because sandy soils have large air pockets in these gaps water drains very quickly out of them and so they need watering far more frequently than loam or clay soils. Sandy soils have sufficient oxygen levels in them.
How to improve the soil
So what steps can we take to improve the quality of our soil?
Improving soil structure
To improve soil structure we add and incorporate organic matter into the soil. Organic matter is normally added in the form of well rotted organic manure or garden / shop bought compost. Making your own garden compost is the most cost effective way of obtaining organic matter for improving your soil. Other forms of organic matter that slowly break down to be incorporated into the soil are bark chipping mulches that can double up as weed suppressants.
The compost or manure is dug into the soil and the organic matter helps the water retention properties of the soil as it acts like a sponge drawing water into it without making the soil waterlogged. As well as helping the water retention properties of the soil the organic matter binds to the tiny clay particles and creates larger particles. The effect of these larger particle sizes is that the available air pockets and therefore oxygen in the soil increase so the plant roots will benefit from improved soil aeration.
When organic matter is used as a mulch your friends the garden worms will pull the organic matter down into the soil and help improve the soil structure and aeration.
Digging the soil also helps improve soil structure as it reduces soil compaction, improves aeration and soil drainage and makes it easier for plant roots to penetrate into the soil.
Improving Soil nutrient contents
Plants are like all humans. Without the availability of food and water they will die and with inadequate levels of nutrition they will have reduced growth and be more susceptible to disease and environmental stresses.
As well as its main benefit of improving the soil structure organic matter benefits the soil in another way as it is slowly broken down by soil bacteria and this process releases nutrients into the soil that are then made available to the plant. It is important to note however that the amount of nutrients released by the breakdown of organic matter is not sufficient for getting the soil to have the level of nutrients we want the soil to have.
To improve the quality and quantity of ‘food’ that is available to the plants we must first feed the soil. When we talk about feeding the soil we are talking about adding fertilisers to the soil. There are many forms of soil fertilisers including organic and non organic. An example of an organic fertiliser is seaweed extract, this is frequently used by organic vegetable gardeners as they believe the nutrients is contains are taken in by the vegetable plants and help to improve the taste of the vegetables.