LIME NEEDED FOR FERTILITY

Southland Times, Issue 23828, 27 May 1939, Page 18

LIME NEEDED FOR FERTILITY

PASTURES IN SOUTH ISLAND REACT BENEFIT TO CLOVER AND GRASSES Adequate liming is a basic step in building up and maintaining the fertility of considerable areas of farming land. The quantity of lime applied to a sou depends upon the properties of the soil, its management and the crop to be grown. Soils which are deficient in lime should be given a heavy initial dressing of from one to one and a-half tons for heavy soils and half to one ton for light soils This should be followed by light annual maintenance dressings or heavy applications spaced at longer intervals, states a Canterbury Chamber of Commerce Agricultural Bulletin The most generally suitable iorm is the ground limestone rock. Guaranteed standards of quality and fineness of grinding are desirable. On cultivated land lime is most effectively applied during the final stages in the preparation of a seed bed for a lime-loving crop. On established pasture lime may be applied at any convenient period of the year. Farmers could help to ensure themselves of prompt deliveries from the works by ordering supplies throughout the year Lime tends to encourage clovers which build up the soil fertility. Pastures grown on well-limed land are richer in both lime and phosphate. HELPS FERTILIZER To obtain the greatest value from fertilizers, the lime content of the soil should be adequate, and conversely the greatest benefit from lime is received when the soil is well fertilized. A big percentage of South Island pastures need lime to encourage the development of desirable grasses and clovers. Clovers are essential for low cost feed production and the nitrogen which they fix in their roots under favourable soil conditions is required by all non-legume crops, cereals, root crops, and grasses. . On sour soils, therefore, liming is essential for the later production of the regular rotation crops, wheat, oats, clover, and ryegrass, and turnips. Since clover builds up the fertility of the soil it is the most important ot these crops, and lime helps to grow clover. , , . _ , Experiments conducted at Canterbury Agricultural College show that liming tends to stimulate the pastures most strongly during summer and autumn period that are normal of low production. Also they have shown that pastures grown on limed land are richer in both lime and phosphate than are similar pastures grown on unlimed land. LIME AND SUPERPHOSPHATE Any form of lime in a ready mixed fertilizer reacts with the soluble phosphoric acid, causing it to revert or change from a readily soluble form to a less soluble form, thereby reducing the availability and efficiency of the superphosphate used in the mixture Mixing limestone with superphosphate immediately before spreading has no disadvantages. The mixing of lime with superphosphate also counteracts the tendency of superphosphate to burn seeds sown in contact with it. Accordingly, limestone mixtures are usually used when sowing swedes, turnips, and similar seeds. If maximum returns and efficiency from superphosphate are desired, it is essential that lime be applied to sour soils either before the phosphate is applied, or with phosphate. If phosphate is added directly to sour soils a big amount of the soluble phosphate is fixed in a form unavailable to crops by iron, aluminium and other substances which are not active in well-limed soils. Experience has shown that the value of lime is usually increased by the use of fertilizers, and also that fertilizers give the best results when lime is adequate.