LIME IN THE SOIL.

New Zealand Herald, Volume LXIV, Issue 19558, 10 February 1927, Page 14

LIME IN THE SOIL.

DRESSINGS ON GRASS LAND. EXPERIMENTS IN ENGLAND. RESULTS AT ROTHAMSTED. In a recent issue of the Journal of the Ministry of Agriculture, England, the effects of light and heavy dressings of lime on grass land were recorded. Experiments that have been continued for a considerable time at Rothamsted proved that liming in conjunction with the application of complete mineral manures, was beneficial, both as regards yields, and the quality of the resulting herbage, but under other conditions a different state of affairs resulted. When nitrate of soda or mineral manures were applied to grass lands at Rothamsted, liming proved disadvantageous and reduced the yield. The same effect was observed with organic manures, such as farmyard manure and fish guano. Ihis unexpected result following the moderately heavy dressing of 1001b. of lime an acre, was the subject of careful investigation. It was found that with farmyard manure only, the use of lime in heavy or light dressings was liable to cause a reduction of first and second crops. With farmyard manure and artificial manures a light dressing of lime was found to produce a substantial increase in the first crop, more than counterbalancing a slight decrease in the aftermath. Heavy liming failed to produce the marked increase. The profit or loss due to liming was calculated to show a heavy loss when used in conjunction with farmyard manure alone, but a moderate profit when a light dressing of lime was given with farmyard and artificial manure. The application of lime is so frequently recommended as being periodically essential for the successful production of all crops that farmers will be interested to know that the theory, although it may be said to hold good in general, is subject to modifications in regard to certain crops. The director of the Rothamsted experiment station, Sir John Russell, has pointed out that different arable crops vary in their response to dressings of lime, and that the application of lime should be determined as much by the crop as by the soil. The clovers, white and red, meadow foxtail and barley, are especially sensitive to soil sourness, requiring more lime in the soil than Alsyke clover, oats, or potatoes. These characteristics should be utilised in practice; thus, if a soil is so sour that clovers and barley will not thrive on it, the farmer has two alternatives. He can dress the soil with sufficient time to counteract its sourness, or he may decide to grow oats and potatoes, which require little or no limo. Tests are now being made at Rothamsted, to ascertain with some degree of exactitude how much lime is required for the various crops, and a scheme of experiments has been drawn up to throw light upon the subject.