Discretion Needed In Application Of Lime

Press, Volume CII, Issue 30193, 26 July 1963, Page 6

Discretion Needed In Application Of Lime

Regular liming of soil is beneficial on most soils and results in improved fertility. It must, however, be applied with discretion because it can easily be overdone and result in serious troubles. Heavy dressings of lime applied each year can build up so that the soil becomes heavily alkaline. Certain plants such as rhododendrons, azaleas, and camellias will not tolerate even mildly alkaline conditions. These plants are limehaters and if lime is added to the soil in which they are growing it will cause them to sicken, turn yellow and eventually die. Organic matter in a soil abundant In lime breaks down very quickly and the soluble mineral nutrients released are quickly lost Certain diseases favour an alkaline soil such as potato scab. Loss of Minerala The most serious trouble of all is the induced mineral deficiencies. Certain elements can be abundant in a soil and are readily available to the plant under acid conditions but when the soil becomes alkaline these elements are converted to complex compounds which are unavailable to a plant Of these elements iron is the most important and the one most seriously affected Iron deficiency is a fairly common complaint on alkaline soils. Iron is necessary for the plant to produce chorophyll. the green colouring pigment of plants. When iron is not available it induces a chlorotic or yellowing effect on the young leaves which, when severe, can result in the dieback of the growing tip. Another element which becomes locked up in soil rich in lime is manganese. The deficiency symptoms here are similar to iron except that the older leaves show the

chlorosis instead of the young leaves. All plants are not equally sensitive to these troubles for there are plants which naturally grow on soils that are rich in lime. In the home garden use lime with caution and do not give regular heavy dressings. Lime has most value in the vegetable garden and needs adding with care in the flower garden or orchard. If in any doubt have a soil, test taken to determine the acidity and apply lime accordingly.