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THE FARMER'S MAGAZINE, 



element ; or as much as would be removed by five-and- 

 thirty wheat-crops. Our culture will be, therefore, far 

 from permanent unless we can add to the staple as much 

 nitrogen as we abtract from it in a course of years. We 

 can get little from the subsoil ; for, rich as it may be as 

 a source of additional minerals, it contains only a third 

 or fourth as much nitrogen as the upper soil. 

 Perhaps we may develope a considerable quantity 

 from another source, namely, by the decomposition 

 of the humus or organic matter of the soil in 

 contact with the atmosphere ; it being supposed 

 that nitric acid is formed through the agency of the 

 ozone occasioned by this decay. Be this as it may, 

 there is yet another source of nitrogen, which is per- 

 fectly able to furnish all that we require. Nine years 

 ago, Professor Way made the following experiment, 

 wonderfully simple in itself, yet marvellous in the in- 

 sight it afforded into the properties of soil. He filled a 

 bottle with air impregnated with carbonate of ammonia 

 so as to be highly pungent to the smell. He threw in 

 a little ordinary dry soil, and then shook the bottle 

 once or twice. What was the effect ? Why, the am- 

 moniacal smell was entirely destroyed : the dry soil had 

 instantaneously absorbed from the air every trace of the 

 ammonia. He also filled a tube with small fragments 

 of dry clay, and passed through it air highly charged 

 with volatile carbonate of ammonia ; and the whole of 

 this gas was arrested. Subsequently, Professor Way 

 spread a very thin layer of clay soil on a sheet of paper, 

 at the bottom of a large cupboard. In this cupboard 

 a small open dish, containing water and lumps of car- 

 bonate of ammonia (smelling-salts), was kept heated by 

 means of a little gas-flame. Sufficient air was admitted 

 to cause a gentle circulation ; the result being that the 

 cupboard was filled with a moist atmosphere consider- 

 ably charged with carbonate of ammonia. The soil was 

 exposed to the ammoniacal fumes for several hours, and, 

 upon analysis, was found to have absorbed ammonia at 

 the rate of 3 tons per acre of 10 inches' depth — equiva- 

 lent to 20 tons of guano. Hence it appears that a 

 roughly-upturned fallow or a pulverulent seed-bed 

 sacks from the passing breezes the ammonia which they 

 bear in minute but ever-present quantity ; and as often 

 as we replace the charge of air in the interstices of the 

 soil, it is robbed at once of the nitrogenous element. 

 So that the more extended superficies we can expose, 

 and the greater indraughts of atmospheric air we can let 

 down into the ground, the more nitrogen will our land 

 acquire for our crops. Only till ; and you shall have 

 ammonia in plenty : Ceres will not faint for want of 

 the smelling-bottle. How much nitrogen may be ab- 

 sorbed in this way, has never been ascertained ; but one 

 thing is certain — the crops that are grown prove that 

 enough and to spare is really obtained. Then, how 

 much tillage is required to ensure this result ? Well, 

 Mr. Lawes grew 6 successive crops of barley on unma. 

 nured ground, each taking away, in grain and straw, 

 1701bs. of nitrogen per acre— considerably more than 

 the quantity supplied to the soil in the ammonia and 

 nitric acid of the rainfall. And the annual cultivation 

 which supplied the 1701b. consistld in once scarifying, 



once ploughing at ordinary depth, and a number of 

 harro wings. At Lois Weedon, the yearly increasing 

 magnitude of the yield, both in straw and corn, shows 

 that the store of nitrogen is augmenting rather than di- 

 minishing. And the forking, scuffling, and horse-hoeing, 

 which have caused this accumulation of plant-food, are 

 abundantly cheap, in comparison with the riches thus ob- 

 tained. I say that, after all these years of wheat-cropping, 

 both the heavy and light-land fields at Lois- Weedon 

 (so far from being exhausted of their native stock of 

 nitrogen) now possess a larger amount of nitrogen than 

 before. Chemical analysis proves it. The subsoil of 

 the light piece contains (according to Mr. Lawes) 3,128 

 lbs. of nitrogen per acre, in a stratum of 1 foot thick- 

 ness; while the upper staple contains 6,200 lbs. — ^just 

 double. Well, the staple has been deepened to 13 

 inches — more than twice its original depth — the 7 inches 

 of additional staple taking the place of as much subsoil ; 

 so that there must be, say 1,500 lbs. more nitrogen per 

 acre in the field than existed there before. The staple 

 of the clay piece contains a proportion of 7,000 lbs. of 

 nitrogen per acre, in a stratum reckoned 1 foot thick ; and 

 the subsoil contains only 2,C0O lbs. in a similar quantity 

 of earth. As the staple has been deepened from its 

 original 5 inches down to 20 inches, there must have 

 been 15 inches of subsoil replaced by staple soil — that 

 is, there is now a 15-inch stratum, containing nearly 

 three times as much nitrogen as it did before. And the 

 latter wheat-crops are so luxuriant and heavy, that Mr. 

 Smith dare not manure them. Science, then, corrobo- 

 rates the expectation of the practical experimenter that 

 wheat may be grown year after year, for a considerable 

 period of time, without appreciable deterioration of the 

 soil. And it is now for you to consider whether an in- 

 troduction of two or three successive wheat crops into 

 the rotation, upon heavy or loamy lands, would not se- 

 cure a handsome profit from the business of husbandry, 

 in spite of cheap corn, and the competition of wealthy 

 gentlemen for every available farm, 



Mr. Greene (Mortivals, Essex), being generally 

 called for, said that he had not attended for the 

 purpose of making any elaborate statement, nor had 

 he risen to advocate the general adoption of the Lois- 

 Weedon systeih ; because he considered that the main ob- 

 jection to it was the large amount of labour that was 

 required at one particular period of the year (Hear, hear). 

 Still, he believed the system did establish or maintain a cer- 

 tain fundamental principle, and was, therefore, interesting. 

 He also thought that it might be carried on advantageously 

 upon a small scale. He should be very happy to answer any 

 questions that gentlemen might like to put to him ; but he 

 feared he could add but Uttle to what was stated iu Mr. 

 Clarke's paper. 



Mr. Corbet; May we take Mr. Clarke's account aa 

 correct ? 



Mr. Greene : Yes, with the exception of one field, which 

 did not yield quite so much as he mentions. It had not 

 been thrashed at the time, and the yield was not so much as 

 it appeared likely to be. 



Mr. Williams : You, Uke Mr. Clarke, then, were deceived 

 in it ? 



Mr. Greene : Yes. 



