LIME DEFICIENCY

Sun (Auckland), Volume III, Issue 708, 6 July 1929, Page 13

LIME DEFICIENCY

PRACTICAL TESTS Practically every farmer can tell, by observation of the natural herbage of his farm, whether the soil is deficient in lime, states an exchange. The occurrence in excess of such plants as sorrel, and of others like bhacken and gorse, is generally a sign of lime deficiency. Inability to grow clover and lucerne successfully is another indication of a similar condition. Apart from an actual chemical analysis of the soil, a number of tests has been devised to determine whether the soil contains a sufficiency of lime for agricultural needs. A somewhat rough and ready method is to test the soil by drying a small quantity of it and adding to it a little dilute hydrochloric acid. Effervescence indicates the present of a carbonate, most probably limestone. In neutral or sour soil no such effervescence takes place. Blue litmust paper (obtainable from the chemist) may be used to find out if the soil is sour. A little of the boi! should he taken from several places in the area to be examined and the whole should be thoroughly mixed on a clean surface without handling A small quantity of this mixture should be placed in a clean cup and stirred into a paste. A piece of blue litmus paper should then be pressed into the paste by means of a piec of stick, leaving about half the paper not in contact with the soil. After some 15 minutes the paper should be withdrawn and an examination made of that part which has been i n the soil. If the blue colour has changed to red, the soil is acid. It is suggested by some chemists that an idea of the degree of sourness is indicated by the depth of the red colour.