A SIMPLE TEST FOR SOIL ACIDITY.

Shannon News, 17 April 1925, Page 2

A SIMPLE TEST FOR SOIL ACIDITY.

An accurate simple test, which any farmer can make in ten minutes' lime at almost no expense, to determine how acid his soil is, and how much lime it will take to correct this acidity, lias been discovered by the lowa Experimental Station. A number of test tubes, some test solution, a colour chart and land whose acid content is to be found, are all that isr required for this test. The composition of the soil test solution, which is the secret of the test, is relatively simple, says "The Farmer." It consists of 9.5 grams of potassium thioeynatc dissolved in a quart of acetone. That is all there is. To make the test, a test-tube onefourth full of this solution is taken. Then enough of the soil which is to be tested is added to make the tube half full. After being- shaken vigorously for half a minute. Ihe tube is allowed to stand for from two to five mmutcs. If the solution is colourless. the soil is neutral or sweet, and does not require lime in order to stow clovers or alfalfa. If it is pink; or a very light red. it is slightly acid and ought to have from one to one-half tons of limestone. If the solution Is red it needs one and one-half to two tons of limestone, and if it is dark, red or maroon, it will probably take from two and one-half to three tons !o neutralise the acid condition. Colour charts have been prepared, indicating Ihe ranges of colour which may be found, and a comparison can be mado with one of these charts to determine just how acid the soil is. Men with considerable experience in testing soils by this method rely entirely upor. ,i iiKMnorisalion of the chart in determining- Ihe amount of acidity in a soil. The soil should not be too moist, as that seems to destroy the effectiveness of the test. If the soil is sandy, it is better to use twice as much soil as solution. Tn an effort to test the stability of the lowa soil test solution n. bottle of it was stored away eleven months ago, and at regular J intervals tests have been made with it, Ho far it has shown no indica--(ions of deterioration. ■ *