636 



tHE TROPICAL AGRICULTURIST. [March i, 18W. 



salts (mixecl either with rape cake or sawdust) used 

 18 a eross-dressing. In the experiments on sugar beet, 

 larmyard mnmu'e proved far superior to all others; 

 :,ad nitrate of soda was more successful, when used 

 lor cross-dressing, than ammonia salts. But although 

 the actual produce was larger, the best grown from 

 ammonia salts contained a large percentage of sugar 

 than that from nitrate of soda. Th« experiments on 

 iiangel-wurzel agree mainly with those with beet, 

 oxcept that in some cases the ammonia salts show 

 a marked advantage over nitrate. As in the case of 

 turnips, the best results are obtained from farmyard 

 manure, with ammonia salts and rape cake as a top- 

 dressing. By these means, a yield of about three- 

 fold, as compared with that from unmanured land, 

 is obtained. lu some other experiments excellent 

 results were obtained by using superphosphate and 

 sulphate of potash as a manure, with a cross-dressing 

 of ammonia salts and rape cake. But a considerable 

 amount of variation is noticeable in all these e.tperi- 

 meuts even under similar conditions of manuring, &c., 

 showing that, after all that can be done, the weather 

 has a more potent effect upon the crop than any 

 artificial conditions. A regards potatoes, it appears, 

 from the average of ten years' experiments, that 

 nitrate of soda is sometimes more suitable, boiih 

 singly and in mixtures, than ammonia salts ; whilst in 

 other seasons the latter yield the better results. As 

 with the other roots, the yield is increased sometimes 

 more than threefold by the use of manures. 



A serii-s of experiments was commenced in 1848, 

 and is still in progress, on a regular course of rotation 

 of turnips, barely, leguminous crop, and wheat. In 

 these, an extraordinary increase of yield Las been ob- 

 tained by the use of manures composed of pearlash, 

 superphosphate, ammonia salt.s, alkaline sulphates, and 

 rape cake. The average for the first nine courses — 

 1848 to 1883 on unmanured land is a production of 

 Sik cwt. of turnips, 3,f)93 lb. of barley, 37 cwt. of clover, 

 1,867 lb. of beans, and 4,510 lb. of wheat. By the use 

 of the manures as just mentioned, on plots of equal 

 extent, a yield of 336J cwt. of turnips, 4,883 lb. of 

 barley, 75 cwt. of clover, 3,330 cwt. of beans, and 

 5,308 cwt. of wheat was obtained. The turnips were 

 incrt^ased about tenfold ; the clover twofold ; and the 

 other crops to a considerable extent. 



The most striking fact elicited by these experiments, 

 is the importance of nitrogenous manures to the farmer. 

 Used singly, they arc as ifficacious as much greater 

 quantities of superphosphate and other alkaline salts. 

 And when judiciously applied as mixtures, they not 

 only make two, but three or four blades grow where 

 only one grew before. If these extensive and costly 

 experiments, which have been arranged and conducted 

 with remarkable care, skill, and application, by .Sir 

 J. B. Lawcs and his assistants, had done no more 

 than to elucidate tliis f.nct, the benefit to agricult- 

 urists generally 'woidd be such value as to entitle this 

 gentleman to the proud position of a public benefactor. 

 But, even from the imperfect outline of them which 

 we have gi(en, our readers will be able to ,iu<lge 

 that their value is incalculable to those direetly in- 

 terested in agriculture. It is most satisfactory to 

 know tliat these experiments are to be continued ; for 

 it is only by taking the average of a large number 

 of seasons that the effects of the variations due to 

 climatic conditions can be eliminated. 



In addition to setting forth the value of nitrogen- 

 ous manures, these experiments conclusively show 

 that sulphate of ammonia is by far the best of this 

 class of manures in the market, at present prices. 

 Sulphate is now quoted at but little more than nitrate ; 

 and 80 pa' t of the former supply as much nitrogen 

 as 100 pa;,-, uf the Litter. With some kinds of crops 

 the nitrate produces the more striking immediate 

 results. But we have s«en that, for securing these, 

 a great deal of cni-e in the matter of drainage is 

 necessary; and, further, after every possible exercise 

 soniare and skill, a smart shower or two of rain, or 

 ently i-f auow, may not only cause a considerable 

 in it to of nitrate to go to waste, but the mischief 

 f,irthirinre^|.p,j,j g, fgj jjs the destnictioB of the 

 tv tbu U'tui 



entire crop. So it is satisfactory to observe that 

 these extensive and authoritative trials support the 

 claims that have recently been made in our columns 

 on behalf of sulphate of ammonia as a manure. Ad- 

 mitting the nitrate of soda to be theoretically the 

 better — and this is by no means proved — it is evident 

 that the mechanical properties of sulphate are such 

 as to render it the best for general use, as recently 

 urged in our " Correspondence " columns by " A Farm 

 Bailiff and Valuer under the Agricultural Holdings 

 Act," even if its price were considerably higher than 

 at present. In saying this, we repeat that these two 

 nitrogenous manures, if competitors at all, are only 

 so in a limited sense, as there are special applications 

 for each. 



But, if this is true, why has sulphate lately fallen 

 in value in the market nearly to the level of nitrate ? 

 One reason frequently set forth is that nitrate hai 

 proved to be the better for beet and root crope 

 generally. These are the class of crops that appear 

 to be least benefited by the use of nitrogenous manures, 

 for the simple reason that they have plenty of leaf 

 surface, and by this means take up nearly all the 

 nitrogen they require in the form of ammonia, a 

 minute proportion of which is always present in the 

 atmosphere. The special advantages offered by the 

 use of sulphate for grass and grain crops have been 

 pointed out in these articles ; and we can only accept 

 one of two conclusions from the marked effect which 

 the discarding of sulphate in connection with beet 

 crops appears to have exercised upon its market prioe. 

 These are, that the use of sulphate for grass, grain, 

 or general purposes is not sufficiently understood (or, 

 at any rate, not sufficiently acted upon) ; or that the 

 market \alue of it is artificially kept down by the 

 operations of speculators. Both are probably true to 

 a great extent. Looking at the quantities of grass 

 and grain grown in our own country, it would appear 

 that the bulk of the .sulphate made at an ordinary 

 gas-works should be purchased at good prices by 

 farmers in the vicinity. Under these circum- 

 stances, there is evidently room for the Sulphate of 

 Ammonia Producers' Association which is now in course 

 of formation. And if this body goes energetically to 

 work in the direction of making known the value of 

 sulphate for the various purpose, which have here been 

 noticed, and also the establishment of direct communic- 

 ation between the producer and the consumer, results 

 will be obtained that will prove beneficial to all parties 

 concerned. — Journal of Gas lAghiinyy fVoti-r Supiily 

 and Sa/iitar/i [mprowinent. 



SEED UEKINUNATION. 



Sir, — Referring to Mr. Cirierson's letter in last week's 

 Journal, I would remark that it is a well-known fact 

 that when fresh soil is exposed by deep railway 

 cuttings, or otherwise, plants either quite fresh to a 

 locality, or previously uncommon, frequently make their 

 appearance in profusion. 



A notable instance occurs in this neighbonrhood. A 

 few years since, having time on my hands at a country 

 railway station not far off, I wandered on to the line, 

 and was surprised to find not one, but several plants, 

 which, although I had explored the neighbourhood 

 fairly well, I had never previously seen. Since then, 

 however, in collecting together and compiling all the 

 information I could get at upon our local flora for the 

 Essex Field Club, I have ascertained that all these plants 

 had been found previously in small quantities within 

 a few miles of the station. Now, as they were to be 

 found only in special places and in small quantities, 

 it is highly improbable that the seeds of all should have 

 been carried to this one spot ; nor was it likely that 

 the seeds of all should in recent years have become 

 spread over the whole country. I was therefore led 

 to suspect that all these plants had, some time or the 

 other, been more or less profuse, but had become rare 

 through the soil becoming unsuited to them by ex- 

 haustion, cultivation, or some other cause ; and that in 

 making the railway cutting, both seeds and suitable 

 soil had been exposed, and again the plant had become 

 profuse. 



