How to Improve the Quality of the Soil
There are a number of ways to improve the quality of the soil; drainage can be made more efficient and the substance and fertility of the soil enhanced. Drainage The most important consideration on any land that is to be productive is drainage. This fact has been recognized almost as long as gardening has been a practise. The ancient Roman poet Virgil, a keen horticulturist, waxed lyrical about it. While soil must contain water if it is to sustain plant growth, satu¬ration or waterlogging can be as harmful as drying out. This can be fatal. If water fills all the interstices between the soil particles there is no room for air, and so the essential oxygen, and the plant roots begin to rot. Good drainage enables water to pass through the soil and run away to its natural level. In well-drained soils, root development is unimpeded and roots will grow to surprising depths, improving the plant’s effi¬ciency at absorbing nutrients and therefore maximiz-ing growth and vigour.
Some soils drain naturally, but not all can be relied upon to do so. In a particularly damp garden it may be worth considering installing a drainage system. The most effective consist of underground pipes laid in trenches at regular intervals and backfilled with gravel, but this is an expensive procedure. Cheaper but less effective methods include digging organic material or sand and gravel into the soil. Such measures may not assist deep drainage, but they do improve soil condition just below the surface. Raising borders slightly to produce a trench along their edges also improves drainage, particularly for shallow-rooted plants. Some species are more tolerant of wet feet than others, but there is still no substitute for truly efficient, beneficial drainage.
Building up the soil – Soil that has been well managed will be rich in organic matter and therefore rich in beneficial micro-organisms. If you are lucky enough to inherit a garden in good condition then rejoice, but remember you have got to keep working at it. If the soil is poor do not despair, but start digging in what¬ever rotted or rotting vegetation you can find -manure, leaf mould, compost, and so on. Thereafter, treat your soil as a hungry beast and feed it with com¬post or manure every year. After three summers you should notice a considerable difference.
Fertility – This is different from soil condition, though often confused with it. To thrive, plants need adequate levels of every essential plant nutrient, but in the act of gardening you automatically remove vital plant material, such as crops and prunings, so these lost minerals need replacing. Furthermore, many gar¬den plants have been bred to grow faster and larger than their wild counterparts and therefore need higher levels of nutrients.
Manure used as a soil conditioner also tackles this problem, but it is not always available. Fortunately plant foods are easy to come by, either organic (such as fish or bone meal) or inorganic (in the form of pro¬prietary products). The concentration of nutrients in inorganic fertilizers varies, the exact ratio sometimes being indicated by the letters NPK. The accompany¬ing numbers, say 10:11:27, indicate 10 percent nitro-gen, 11 percent phosphorus, and 27 percent potas¬sium. Nitrogen promotes leaf growth, phosphorus ripens fruit, and potassium produces good fruit and flowers. Generally a balanced, all-in-one fertilizer is adequate, but sometimes a plant needs extra quanti¬ties of one nutrient. For example, leafy vegetables such as spinach require heavy nitrogen application.
High fertility, once achieved, needs to be kept at that level. I use dried poultry waste at roughly a double handful per square yard (square metre) once a year on my mixed borders. This works well as a source of nitrogen, phosphorus and potassium.
Tags: beneficial micro organisms, borders, drainage system, fertilizer, gravel, plant growth, plant roots, sand and gravel, soil condition, soil drainage, soil particles, soils