FARMERS' INSTITUTES. 2G3 



all-devouring sea, where it will finally be dejiosited in new plaster beds ; and 

 when these are again brought to the surface by some volcanic upheaval, your 

 ever-so-many-millionth grandsons will Avonder where so much plaster came from, 

 and they will use it to enrich their fields, v>'hich Avill then be undergoing a like 

 process of exhaustion by the solvent and transporting action of water. 



I close this lecture with a recapitulation of the action and benefits of plaster 

 as used in ai^riculture. 



Ist. Plaster acts best in dry soils and in moderately dry reasons. 



2d. It is inactive, or at least fails to give the best results in soils deficient in vege- 

 table mold. 



3d. It tends to dissipate tbe vegetable matter in soils by promoting oxidation. 



4th. Plaster benefits plants by directly supplying sulphur and lime, and by indi- 

 rectly supplying potash and magnesia. 



5th. It Jixes or converts the volatile carbonate of ammonia into the non-volatile sul- 

 phate of ammonia. Its office in preventing the waste of carbonate of ammonia in the 

 stable and in fermenting manure is much more important than in fixing the annnonia 

 of the atmosphere. 



Gth, It increases the development of leaves and stalks, without a corresponding 

 increase of seed. The most careful experimenters assert that it is of no benefit to cereal 

 crops. 



7th. It is markedly beneficial to clovers and all leguminous crops. 



8th. As plaster is of sparing solubility in water, a comparatively small dressing is 

 as beneficial as a very large one. A hundred weight is as good as a ton, so far as the 

 crop is concerned to which it is applied. 



9th. Since plaster is rapidly washed out of the soil by the heavy rains of fall and 

 spring, it is best to apply the plaster to the crop we wish to lienefit in the quantity 

 which that crop requires, and at the time it is found to do the most good, viz.: in 

 early spring growth. 



10. There is great diversity of views among farmers in regard to the influence of 

 plaster on Indian corn. Although corn ranks second or third as a market crop, yet 

 for use iipon the farm it stands first in importance among our grains. All doubts in 

 regard to the iufiuence of so important a manural substance on a leading crop should 

 be solved by accurate, careful and repeated experiments by farmers in all parts of the 

 State. 



DISCUSSION OX PLASTER AT ADKIAX. 



J. Iloag. — In regard to liberating the extract of ammonia from muck or 

 soil, does it operate the same on manure? 



Dr. Kedzie. — It only produces decomposition of the manure, and acts as a 

 means of catching the ammonia and holding it. 



H. G. Bradish. — In your opinion would not juilverized muck have very much 

 the same effect as plaster? 



Dr. Kedzie. — As far as catching the ammonia it would have the same effect. 



Mr. Moore. — I have been at a great loss to find any material difference or 

 benefits from plaster, whether applied in small or large ([uantities. I have used 

 it of late years on my corn crop, and I have always thought with the best results. 

 I shall have to try by thorough experiment before I can be convinced that it 

 does not increase the yield of grain. I know that it increases the growth of 

 stalk, and I am pretty well satislled that it increases the seed. I have received 

 the largest benefit on clover. I have experimented in the use of plaster on this 

 crop, in different ways. I have used a bushel, bushel and a half, two bushels, 

 a half a bushel, and a i^eck to the acre, and there was no marked difference, 

 and then I have used none at all and there was a striking contrast. 



J. M. Roberts. — I would like to ask if you have ever experimented Avith j^our 

 corn by leaving a part wdthout plaster. 



Mr. Moore. — Yes, sir ; I have done that Avith very marked effect. I haA'c also 

 mixed plaster with ashes and received very large benefits. 



