THE FARMERS' COLUMN.

Bruce Herald, Volume XI, Issue 108, 31 January 1879, Page 7

THE FARMERS' COLUMN.

From the 'American Agticul-urut ' EOME FACTS ABOUT LIME. Several correspondents i>k for information concerning the use of lime on land, and all o them contain evidence of several commo-dy accepted but false theories. First lime is not plant-food ; or rather it, is to common in most soils, and incid ntaUy comprises so la*ge a portion of many fertilizers, ihas its application as plant- food is unnecessary. We have not seen a Boil analytic from whioh this constituent was miasma- and there is nearly always considerable of it present in available form ; all true huperphosphates are composed of oue-fourth part or more of lime, and it is prominent iv Peruviao and fish guano, in nearly or quite all manufactured fertilizers, as well as iv barn-yard manure. Lime, ho fever, has an important effect aside from its action as plant-food. Freshly burned lime (known as '* caustic lime " and " quicklime '•) has a strong affinity for carbonic acid, so that when it and organic matter (which always contains a large proportion of carbonic acid) are mixed together, the lime and carbonic acid unite, promoting the decomposition of the organic matter. Newly "slaked lime" — which ia lime united with water — has an effect similar to quicklime, though slower, and hence is better for farm use. Fresh, undecomposed organic substances, especially dung, contain the most valuable ingredient of plant -food, nitrogen, in its simple form ; but it ia very soon changed into ammonia, which in turn unites at once with carbonic acid. Then when lime is brought in contact with the mass, it at once combines with the carbonic acid, and the valuable ammonia escapesand is los* . When, however, the lime is applied before the ammonia is formed, the nitrogen is oaydized to nitric acid, which unites with the lime to produce nitrate of lime, and the nitrogen is saved. Therefore, lime may be used in stables and house privies, or in composting carcases of dead animals, to advantage ; but if mixed with manure a day or tw > old, the result .is a loss of valuable material. The above alsoahou-s why, when lime is put into a c>mpoat, ifc has such beneficial ae'i >n i.i hastening decomposition, and why it is necessay to use plenty of fresh earth to ab--B'>rb the escaping ammonia. Free acids, and tliose i-iea-ily decomr.osihle Bubß!ances. are also readily taken up hy lime, and many injuri us comp utids as of iron in wet lands, are rendered harmless In home soils insoluble sdica-es, of potash, e*c, accumulate ; but the action of iime w 11 break up the combination and Bet the potash free for use as plant- food. Theabove statements show that the main action of lime in the sod is in making available plant-food what waa before unavat able Therefore, while it miy incrnase the cropyield of poor land, it will tend to bring about ita early exhaustion, unless plant-food is added. In heavy clay soils, the above mentioned chemical reactions of lime, des roys their tenacity and makes them friable and porous. Soils containing a large proportion of organic matter are benefited by its application* Wet lands are less benefited by. lime than tbe same when drained, on accouut of the water. Light soils are improved by it when accompanied by a liberal application of muck or other organic matter; clays should also have the same treatment. As the best effects of lime are not apparent until the second year, it is best to apply it early in the fall ; then, if tbe land is. not rich enongb, manure or other fertilizer put on the following spring will help to produce a good crop, other conditions being equal. The auzount used is from 10 to 50 bushels per acre, according to circumstances, the condition of the ■oil, etc.