The Importance Of Lime

Press, Volume CV, Issue 31018, 25 March 1966, Page 6

The Importance Of Lime

Lime is an important factor in soil fertility due to its effect on acidity. Its application is of most importance in the vegetable garden and, to a less extent, in the orchard and flower garden. Soils vary widely in their need for lime while light, sandy soils, and those in areas of heavy rainfall, need it most as lime is quickly leached from them.

Lime is a rather loose term, being used to refer to many compounds of calcium. In horticulture, however, it usually applies to either limestone and chalk, or to hydrated lime. It fulfils a number of functions in a soil. Calcium is an essential plant nutrient, although the amount necessary varies from plant to plant Leguminous plants, such as peas and beans, require large amounts, white members of the Ericaceae family resent it It reduces the liability of some plants to attack by certain diseases. Club root of brassicas is common on acid soils and application of lime will do much to control this disease.

Broken Down The organic matter is more readily broken down when lime is present due to the stimulation of micro organisms in the soil.

Affected, also, is the availability of mineral nutrients. Nitrogenous compounds released in the decomposition of organic matter are converted into forms more

readily taken up by plants. Phosphates, too, are becoming more readily available to plants when there is lime present. In acid soils they are more likely to be changed into the insoluble forms. On heavy soils it improves the crumb structure, making such a soil less sticky, easy to work and improves soil surface drainage. Soil Test The need of a soil for lime is best ascertained by having a soil test taken to determine its pH. The term pH implies the degree of acidity of a soil; 7 being neutral, above 7 is alkaline and below is acid. A soil that Is slightly acid, between 6 and 7, seems most suitable for plant growth in general. Other signs of acidity in a soil is by the weeds it supports; sorrel and spurrey are indicative of an acid soil.

Ir. the vegetable garden lime should be applied every three or four years in association with the crop rotation at a rate of from 2-4 ounces a square yard or according to the recommendation of the soil test. Light soils and soils in areas of heavy rainfall lose lime quickly and should receive annual dressings.

In the fruit garden lime should be applied more carefully and a soil test should be used as a guide for application.

In the flower garden every four or five years should be sufficient for general application. The plants themselves should be the guide. Limehaters should never have lime applied, while quantities applied to carnations, pinks and rock roses should be increased.