404 



NEW ENGLAND FARMER. 



Sept. 



EFFECTS OF PIjA.8TEK ON THE SOIL. 



HAT effect 

 has Plaster, 

 or Gypsum, 

 on the soil, 

 after having 

 been used 

 for many 

 years ? Will 

 it exhaust 

 the suil ? If 

 so, can fer- 

 tility be re- 

 stored by 

 other agen- 

 cies ? In N. 

 ~ " Brunswick, 

 not far from 

 Fort-F airfield, 

 there is a moun- 

 tain of gypsum of 

 superior quality. Tnis rock is 

 taken to our mills and ground, 

 and is used quite extensively as a fertilizer by the 

 farmers of Northern Aroostook, producing great 

 results, increasing the crop of grass and grain two 

 or three fold. Yet some abstain from using it, 

 fearine it will ruin their land in the end. 

 Lyjidon, Aroostook Co., Me., 1870. h. d. c. 



^'Mi 



Remakks. — The question asked in the open- 

 ing of this note is of too much consequence to 

 be answered by one or two brief remarks. 

 Piaster has become an article of importance 

 for agricultural purposes. Hundreds of tons 

 are annually used in the vicinity of Boston on 

 various crops, but especially for clover, and 

 potatoes. We have seen old pastures cov- 

 ered with a luxuriant growth of white clover, 

 by a simple application of ground plaster of 

 about fifty pounds to the acre. And this has 

 occurred where scarcely a head of clover had 

 been seen before for many years. Scattered 

 upon potatoes before covering the seed, it 

 keeps off worms, prevents decay, and essenti- 

 ally proves the crop in other respects. 



In order better to understand how, and to 

 what extent, plaster affects the soil and the 

 crops, its composition should be clear to the 

 mind. 



As we understand it, plaster or gypsum, is 

 lime in combination with sulphuric acid, or 

 what is familiarly known as oil of vitrol. 



The elBcacy of plaster will depend much 

 upon the hind of soil to which it is applied. 

 On clayey soils, which are stiff and impervi- 

 ous to the rains, the plaster would be retained 

 for a long time without being much affected ; 

 while it would operate beneficially on soils 

 that are light, dry, and sandy, or open, as 

 they soonest admit the rain water which dis- 

 solves and conveys it to the roots of the 

 plants. 



In some cases, plaster will not produce any 

 effect, on account of the soil being already 

 sufficiently supplied with it, or the soil 

 may be deficient in other substances up- 

 on which the plaster must act in order to 

 make it productive. As an illustration, we 

 may add that red clover requires several sub- 

 stances to perfect its growth, and among them 

 potash. If this is lacking, the others would lie 

 inactive, so far as the clover is concerned, and 

 no clover would grow. 



We have observed that different writers as- 

 cribe the fertilizing properties of plaster to 

 different qualities. While Baron Liebig gives 

 it to the fact that it possesses the property of 

 fixing the ammonia in the rain water, Davy 

 ascribes it to the sulphur which it contains, 

 and Chaptal, to its regulating the solubility 

 of salts in the soil. Dr. Muse, of Marj land, 

 many years ago started the theory that the 

 chief efficacy of plaster arose from its tenden- 

 cy to produce phosphoric acid. 



It seems to be clearly ascertained now, 

 however, that "while it acts directly as nutri- 

 ment to a certain class of plants, it also acts 

 indirectly by fixing the ammonia contained in 

 the atmosphere, and in the dew, rain and 

 snow, and thus furnishes additional food of a 

 stimulating nature to the same plants." 



It has been stated by some that leaves of 

 plants serve not mere y as lungs, but as 

 mouths also, absorbing the food supplied by 

 the atmosphere, j'lst as the fine fibrous roots 

 collect the food supplied by the soil. This 

 seems to be proved by the fact that plaster 

 acts more beneficially upon clover when its 

 leaves are fairly expanded, than it does when 

 applied directly to the soil. 



In order to be clearly effiacious, the appli- 

 cation of plaster must be alternated with ani- 

 mal manure ; otherwise, the fertility which it 

 produces will not be sustained, and in a few 

 years of repeated plastering, the product will 

 descend lower than before. Therefore, it 

 should not be too often repeated upon the 

 same soil, as most soils require a change in 

 manures, as well as in crops, once in five or 

 six years. 



We are glad our correspondent asked the 

 question, because we observe a tendency to 

 make a too free use of a good thing. 



Suckers from the base of fruit trees are 

 most effectually removed when in full leaf. 



