386 



EW ENGLAND FARMER 



JVNE7, 1813. ll 



GYPSUM OR PLASTER. 



Plaster, first introduced into the United States 

 from Paris by Dr. Franlilin, liaa effected tlie most ^ 

 important improvement in agriculture perhaps that 

 has ever been made. Extensive districts in this 

 and other countries, have been benefited by its 

 introduction to an extent which, considerinfr the 

 comparatively smati amount of the substances em- 

 ployed is truly astonishing. In Germany, says 

 Lampodius, one of her own agricultural writers, 

 " It may with certainly be stated, that by the use 

 of D-ypsum, the produce of clover, and the conse- 

 quent amount of live slock have been increased at 

 least one third." 



"There are, however, some tracts of country 

 where the use of plaster has been attempted with- 

 out success. But this arose from its being one of 

 the original constituents of the soil, which derived 

 no advantage from the addition of a new riuantity. 

 The existence of this salt naturally, in those lands 

 upon which plaster produced little or no eflTect, has 

 been proved by analysis." — Chaptal, p. 7.3. 



Much mystery has heretofore enveloped the 

 modus operandi of this manure ; but before the 

 light of science the cloud is vanishing away. — 

 Many have supposed its efficacy to arise from the 

 specificfooJ which is furnished to certain plants, as 

 to clover, for instance, which seems especially bc- 

 neBted by its application. But when we consider 

 that by the application of a handful, as it were, of 

 this manure, upon an acre of good ground, the 

 product is increased from a few hundreds to Ions 

 of grass, it is at once apparent that, on such a sup- 

 position, the cause is wholly inadequate to the ef- 

 fect. It was reserved for the gifted and honored 

 Liebig to lift the veil, and to produce a theory, 

 not only plausible in itself, but fully sustained in 

 all its parts by the experience of practical men. 



His theory is this : that' the efficacy of plaster 

 consists in its a-rresting, as it rises in exhalations 

 from the soil, or descends in rain, dew or snow 

 from the atmosphere, the ammonia which is gener- 

 ated by the decay of animal matter and apprcpria- 

 ting it to the use of the growing crop. We will 

 permit him to present his own views, howevei;, in a 

 few extracts from liis Organic Chemistry. 



" Nitrogen exists in every part of the vegetable 

 structure." — p. 88. " All animal," [and vegeta- 

 ble] " bodies, during their decay, yield the nitro- 

 pen which they contain, to the atmosphere, in the 

 form of ammonia." — p. 72. " The evident influ- 

 ence of gypsum depends only upon its fixing in 

 the soil the ammonia of the atmosphere, which 

 would otherwise be volatilized, with the water 

 which evaporates." — p. 7.5. " In order to form a 

 conception of the efl^ect of gypsum, it may be suf- 

 ficient to remark, that 100 lbs. of burned gypsum 

 fixes as much ammonia in the soil as f)250 lbs. of 

 horse's urine would yield to it." — p. 88. "If a 

 field be strewed with gypsum, and then with putri- 

 fied urine, or the draining of dung hills, all the 

 carbonic of ammonia will be converted into the 

 sulphate, which will remain in the soil." — p. 184. 

 " If we strew the floors of our stables, from time to 

 time, with common gypsum, they will lose all their 

 oflTensive smell, and none of the ammonia which 

 forms can be lost, but will be retained in a condi- 

 tion serviceable as a manure." — p. 18.5. " But 

 this is not all. When we give a plant nitrogen in 

 considerable quantity, we enable it to attract with 

 greater energy from the atmosphere, the carbon 

 which is necesssary for its nutrition." — 138. Now 



'• carbon enters into the composition of 

 plants." — 3. So that, by strewing a field with, 

 gypsum, we enable plants to supply themselves 

 from the atmosphere, not only with nitrogen, on 

 which their most nutritious principles depend, but 

 also with carbon, the chief constituent of all their 

 frame work. 



This theory is confirmed by several circum- 

 stances which have long attracted the attention of 

 the observing farmer. 



1. It has been observed that plaster acts with 

 increased efficacy when applied in connection with 

 manures, or recently manured lands. The solu- 

 tion of the phenomena by our theory is easy and 

 satisfactory. The ammonia, which would other- 

 wise escape from the decimiposing manure into 

 the atmosphere, is seized upon by the plaster, de- 

 tained ill the soil, and wholly converted to the use 

 of the growing crop. 



2. It has been observed that plaster acts with 

 greater power on soils which have been recently 

 stirred, than on those which have lain for a long 

 time unmoved. Solution — By stirring the soil its 

 porosity is increased ; consequently it absorbs 

 more freely the dews that fall upon it — from 

 which the plaster separates and hoards up in the 

 soil the rich deposits of the atmosphere. In proof 

 of the extent to which' the atmosphere with fer- 

 tilizing matters, which the rains and dews are 

 constantly depositing upon the surface of the 

 earth, we will here introduce the substance of a 

 statemerit made to the American editor of Liebig, 

 by Mr. E. Tufts, of Charlestown. 



" Eight years since, about three quarters of an 

 acre ot land, situated on one side of a lane and on 

 a declivity, were broken up. About the same time, 

 the proprietor of a field on the opposite side of the 

 lane, and above the land of Mr. T., commenced 

 gardening on a large scale, and formed an immense 

 bed of compost in the lane. This heap was made 

 up of animal and vegetable matters, and from re- 

 ceiving constant additions is continually undergo- 

 ing fermentation, and the gases and vapors emana- 

 ting from it are always perceptible. Four years 

 ago Mr. T. observed, that in some inexplicable 

 way, his land l)ad become so fertile as to induce 

 him to dispense with the use of manure, he has not 

 since used it, and is now fully persuaded that its 

 fertility is owing to certain vapors arising from the 

 heap and then descending on his land. None of 

 the soluble matters of the heap are carried to I\Ir. 

 T.'s field, no manure has been applied, and its fer- 

 tility continue unimpaired." — Appendix to Liebig, 

 p. 3(Jfi. 



3. Plaster has been observed to produce but 

 slight effects upon old, dry and hide-bound mead- 

 ows. Says Liebig, (p. 87,) " Water is absolutely 

 necessary to efiect the decomposition of gypsum, 

 and also to assist in the absorption of the sulphate 

 of ammonia by the plants : hence it happens that 

 gypsum is not observable on dry fields and mead- 

 ows." To which may be added, that but a small 

 quantity of putrescent matter existing in such ca- 

 ses, the exhalations are inconsiderable ; and what 

 is deposited from the atmosphere by dews cannot 

 be absorbed by the soil in consequence of its com- 

 pact, impenetrable surface. On old, and even dry 

 pasture lands, the effect is much greater, there be- 

 ing ever present on their surface, a portion of ma- 

 nure to serve as a basis for its action. 



4. It has been universally observed that the most 

 striking effect of plaster is on the clover crop. 

 Reason — " Red clover contains double the quanti. 



ty of nitrogen that common hay docs." — Gray, 

 158. 



5. It has occurred, in the experience of diffi 

 cnt farmers, that where one part of the field issp' 

 with plaster immediately before a thunder show in 

 and another directly alter the same shower, i 

 portion sown first was benefited in a far higher ! 

 gree than the other. Reason — " Rain water mo 

 at all times, contain ammonia, though not alwi 

 in equal quantity. It must be greater in Bumr 

 than in spring or winter, because the intervals 

 time between the showers are greater. The ri 

 of n thunder shower after a long protracted drouj 

 contains the greatest quantity which is convej 

 to the earth at any one time." — Lkhis;, p- 73. 



r>. Considering the beneficial effects of plas 

 at large, it has been observed that they depend, 

 general, not so much on any peculiarity in the 

 cation, or composition of soils, as on those phj 

 cal conditions which render the surface of the E 

 an easy medium for the transition of soluble 

 ter : all of which must go to corroborate the thi 

 ry in question. 



From the views thus presented, we are led 

 infer — 



1. That the atmosphere ia an incxhausti 

 source of food for plants. 2. That the most avi 

 able agent for securing the benefit of this food 

 plants is plaster. 3. That viewed in this lig 

 the value of plaster in agriculture can hardly 

 over-rated. 4. Then it may be safely recommei 

 ed for general use on all soils containing a port 

 of fermentative matter?, and not so compact or w 

 as to prevent the process of exhalation and abso 

 tion. 5. That it should always be applied to 

 surface of the soil, or at least wilhin the influei 

 of the atmosphere. €>. That it should be sown 

 an early date in tho season, before the period 

 the most abundant dews and exhalmions has ct 

 mcncod. 7. That it should always accoiiip! 

 manures used as a top dressing, or only sligl 

 buried in the soil : and 8. That il should be ' 

 erally employed about our barnyards, slables,vau 

 manure heaps, compost beds, &c, — not however 

 compost under the supposition ihal it will has 

 the fermentation of the mass. " Davy has rel 

 ed this opinion by direct experiment, placing it 

 yond a doubt, that the mixture of plaster with i 

 nures, whether animal or vegetable, does not fai 

 itate decomposition." — Chaptal, p. 74. 



The proper quantity to be used when so 

 broadcast upon the field, has been decided by i 

 perience, as also by chemical science, to be fr 

 one to one and a half bushels per acre. 



WOOD ASHES. 



Ashes, whether " live" or leached, consider! 

 the certainty, uniformity and power with wh 

 they act, as well as the permanency of their i 

 tion upon vegetation, may well be ranked amo 

 the very best manures. The fact of this superi 

 ity over other manures is very generally und 

 stood : the reason of this superiority appears qu 

 obvious when we reflect that they are compos 

 entirely of organised matter, reduced to the ni' 

 consolidated form, and when, further, we learn fr 

 chemistry that their chief bulk consists of the vt 

 material which enters most largely into the fit 

 grains and grasses. Yet, strange as it may bo, 

 inconsiderable portion of this priceless article 

 suffered to be lost to all the purp ises of cultii 

 tion, being permitted to lie waste about our dwi 

 lings, and to disappear na useless rubbish. '. 



