ACIDITY IN SOILS

Wairarapa Times-Age, 12 November 1941, Page 3

ACIDITY IN SOILS

LIME LACKING. Acidity in garden soils is most likely when lime is lacking and large quantities of bulky animal manures are used. Certain chemical fertilisers are also likely to cause it if used in excess. Sulphate of ammonia is one of these. Basic slag on the other hand, tends to correct acidity, as does lime in any form. Carbonate of lime is, of course, just another form of lime which works rather more slowly than freshly slaked lime. Any soil that is close in texture or tends to get pasty or beaten down on top, or to remain waterlogged for long periods, is likely to become sour, though it is not certain that it will do so. The remedies in such cases will obviously depend to a large extent upon the initial causes of the acidity which must be rectified, but it will almost always be necessary to apply lime in addition. Land that is not naturally well endowed with this constituent and is heavily manured, is almost certain to become acid. The remedy in this case is simple, namely, a thorough liming every second or third year. A very slight degree of acidity in the soil is no great detriment. In fact, some crops seem to prefer it, notably potatoes, which are rarely scabby under such conditions. On the other hand, winter greens are much more likely to suffer from club root if the soil is acid. On the lawn, the change from alkalinity to acidity is particularly interesting, for the clovers and coarser grasses tend to die out and are replaced by finer grasses. Consequently, a moderate degree of acidity is desired by all greenkeepers.