Improve Soil pH, Acid Soil, Alkaline Soil.

If you like this page then please tell google by clicking the +1 button  

Soil pH

The pH value is a measure of the acidity of a soil and is based on a set of numbers ranging from 1 to 10 that are universally recognised scale. The number 7 has been given to a soil that is neutral, that is it is neither acid or alkaline. Numbers above 7 indicate an alkaline soil and numbers below 7 indicate an acid soil. Soil testing kits are easy to use and can be obtained from most garden shops or your plant nursery may even offer a free testing service. The following values are generally accepted as the degree of acidity.

Strongly Acid Soil.  pH  5.0 - 5.5  Plants for acid soil in this range include Parsley, Potato, Tomato, Sweet Potato, Maize, Millet, Oars, Tye, Radish, Azalea, Ferns, Iris, Orchids, Rhododendron, Camellia, Daphne and Boronia.

Moderately Acid Soil. pH 5.5 - 6.0  Plants for a moderately acid soil include Bean, Brussels Sprouts, Carrot, Choko, Endive, Kohl Rabi, Peanuts, Rhubarb, Soyabean, Crimson Clover, Aster, Begonia, Canna, Daffodil, Jonquil, Larkspur, Petunia, Primrose, Violet and most bulbs.

Slightly Acid Soil.  pH 6.0 - 6.5  Plants that prefer this soil include Broccoli, Cabbage, Cauliflower, Cucumber, Egg Plant, Pea, Sweet Corn, Pumpkin, Squash, Turnip, Red Clover, Sweet Clover, White Clover, Candytuft, Gladiolus, Iceland Poppy, Pansy, Rose, Snapdragon, Viola, Wallflower, Zinnea and Strawberry.

Very Mildly Acid. Soil  pH 6.5 - 7.0  Plants that favor very mildly acid soil are Asparagus, Beet, Celery, Lettuce, Melons, Onion, Parsnip, Spinach, Lucerne, Carnation, Chrysanthemum, Dahlia, Stock, Sweet Pea and Tulip.

Acid Soil Treatment

Lime has the ability to assist in breaking down heavy clay soils and it will also reduce the acidity level of a soil. The breaking down of clay soils occurs becaus the presence of lime in a wet clay soil causes the fine clay particles to flocculate, that is they tend gather together in small clumps, and this produces the crumbly texture that is desired.

However, lime will also help to release some chemicals from the soil for the plants to use but it will also tend to lock up others, and this should be taken into account when adding lime to reduce acidity. Potash, magnesium, molybdenum and perhaps nitrogen are more readily soluble in a slightly alkaline soil, while slightly acid soils assist solubility of iron, copper, zinc and manganese which may become insoluble and unavailable in an alkaline or over-limed soil.

As we have seen, the lower the pH reading the more acid the soil, and most plants prefor a neutral to a slightly acid soil, that is, a pH from 6.0 to 7.0. The addition of lime will raise the pH, and materials such as sulphate of ammonia, and sulphate of iron will lower the pH.

The safest type of lime for the home gardener to use is ground limestone, also known as agricultural lime, which has a mild action that may take many weeks to have an appreciable effect on acidity or soil structure, but other fertilisrs can be spread,  seeds can be sown and seedlings planted at the same time.

Adding Lime to Soil

For good results the lime should not be left on the surface, but raked in and then lightly forked to a depth of five or six inches.
While the application rate when adding lime to soil is not critical, a degree of care should be taken. A level breakfast cup holds about three-quarters of a pound of lime, and this amount should be adequate for one square yard of garden bed that has not ben limed for several years and is to be used for vegetables and flowers that like a slightly acid soil. An extreemly acid soil could be treated with up to one and a half pounds to one square yard. Most soils do not need frequent liming and periodical testing for the pH level should be done to prevent over liming

In over limed soil it is common to find plants suffering from chlorosis. They may show symptoms ranging from paler than normal green foliage to yellow or cream varigated leaves. While other factors can cause these symptoms, over liming is the most likely cause when heavy or too frequent applications of  lime has occurred. This change of leaf coloring is due to an iron deficiency caused by the locking up action of the lime.

When adding lime to soil it should not be left on the surface, but raked in and then lightly forked to a depth of five or six inches.

Lowering Soil pH

The addition of sulphate of iron, or sulphate of ammonia will lower the pH level and so increase the acidity of a soil, as will the addition of copious amounts of decayed vegetable matter, compost, stable manure and straw etc.. When adding soluble sulphates they should be evenly spread over the soil surface and then well watered in. While no firm advice can be given to the application rates, sulphates should be thinly applied, and after watering in and given light cultivation the pH level should be checked. By repeating this at say monthly intervals you will learn the characteristics of your particular garden soil and be able to maintain the required pH level for the particular plants that you wish grow.

Happy gardening, and the following is an  interesting gardening link for seeds, plants and shrubs that you might like to check out while you are here.


 .allergy free home.

.garden soil preparation.
. .

Buy Groceries Online.
Copyright 2012. All rights reserved.