632 



THE TROPICAL AGRICULTURIST. 



[Maech I, 1884. 



ent countries, and carefully tried against the native seeds 

 of each disti'ict. The results are anxiously looked for. 

 Lastly, figures are adduced from official statistics to prove 

 that the area of cultivated land is rapidly increasing, and 

 that, if experience confirms these views as to the value 

 of Swedish cereals, production will he found equal to the 

 demand. It would be very desirable that our national 

 society should investigate this question, and institute ex- 

 periments at Woburn or elsewhere, in order to determine 

 whether the introduction of seed corn from the northern 

 parts of Sweden woidd be beneficial. 



JVeressiti/ for Phijsioloijical Stv.dy. 



" Nobbe has recently shown that if food-materials other- 

 wise complete but possessing no potassium are supplied 

 to plants (as buck wheat) they behave as if they were 

 ab.sorbing only pure water." — Sachs. 



" The combinations of food-materials must be subject 

 within the tissues to progressive changes of position in 

 addition to and in consequence of their chemical ti'ans- 

 formations." 



" The nutrition of aU plants hitherto examined for this 

 purpose is impossible or abnormal if any of these elements 

 are wanting." 



" The constant occurrence of compounds of phosphoric 

 acid in company with albuminoids as well as of potassium 

 salts in organs containing starch and sugar- points towards 

 definite relations which tbey may possess to those chem- 

 ical processes that immediately precede the processes of 

 construction of plants." — Sachs. 



" They do not assimilate and show no increase in weight, 

 because no starch can be formed in the grains of chlorophyll 

 without the assistance of potassium." (Nobbe.j — Sachs. 



" Lime is partly of use as a medium for conveying 

 sulphuric and pho-sphoric acids in the absorption of plant- 

 food, and partly for its jjower of fixing the oxaUc acid 

 \vhich is poisonous to the plant." — S.\chs. 



yecessity for Vliemical Manures. 



•' The modern system of scientific agriculture has for its 

 foundation the artificial production of plants by the help 

 of simple chemical compounds in defiance of all the tra- 

 ditions which the old system has handed down to us. From 

 the day on which the modein system was first practically 

 adopted, chemists, far from forbidding the use of farmyard 

 maiuire, have simply advised farmers to abstain from using 

 manures which are too strong for their particular pur- 

 pose, but to rectify and complete the imperfect compos- 

 ition of farmyard manure by the addition of chemical 

 compounds, which is a very different matter. Finally, we 

 cannot pass over in silence the new means that the as- 

 sociation of chemical manures with farmyard manure gives 

 to the agriculturist. Let us suppose a sowing of colza 

 and of wheat well manured ; the winter has been rigorous, 

 the spring late, and the plants have suffered. AVith farm- 

 ynril manure only you could do nothing, and the yield 

 would be bad. It is not possible to spread on the land 

 more farmyard manure during the mouth of March, be- 

 .sides, if it "could be done, its action wdl be radically nil. 

 The farmer is thus condemned to remain an impassive 

 spectator to an inevitable mistake. But if, on the con- 

 trary, chemical manure be added, all will be changed ; 176 

 lb. of ammonic sulphate per acre will suffice to give a 

 sudden impulse to the colza and the wheat, and the re- 

 sult is certain." — Ville. 



Keceasiiy for £.rperiments. 

 DIFFERENT MANURES IN POTATO CULTURE. 



An article in 'I'lir Field last year, relating the results 

 of an important series of experiments on the use of various 

 manures in the cultivation of potatoes, conducted in 1881 

 at the Muuster Agricultural and Dairy School, near Cork, 

 attracted a good deal of interest throughout England. 

 During the past year a similar series of experiments were 

 conducted at the Albert Model Farm, Glasnevin, near 

 Dublin, and the results obtained ought to be made widely 

 known. The experiments were carried out under the super- 

 intendence of Dr. C. A. Cameron, Dublin, well known as 

 an able and experienced agricultural chemist. 



The manures tested were kainit. nitrate of sodium, 

 sulphate of ammonia, and mintral superphosphate, and 

 they were tried .singly and in various combinations. The 

 results obtained will be most clearly shown by the follow- 

 ing table, in which the plots are arranged in order of 

 the highest marketable yield: — 



oS "S 



II 





.1. <l. T.O.Q. T. C.Q. 

 8 2 H 1 7 -■ 



Kitrate of sodium 'J \ 



Mineral sui)erphoypliatf-I j 



Kainit 6 14 6 2 6 2 



Kaiuit '^ 



Nitrate of sodium 1 



Sulpluiteof ammonia 1 



Miiit^ralsuperpliosphateS, 



Kaiuit ... ... 'Ill ^ ,-, lion 



Miiierulauperphosiihatc-l/^ '" i IJ u 114 

 S 1 12 1 5 

 \\z 19 

 a 3 IJ U 8 



1 1 1 115 3 8 2 11 

 3) 



!i 



3 2 8 



s s. 



T. C.Q. 



.Superphosphate 

 Sulphiite of ammonia 

 Superpliosphate ... 

 .Sulphate of ammonia 



Kiiiiiit 



Milnite of .sodium 

 .Superiiliosphate ... 



Kiiinll 



Sulphate of ammonia 

 .Superphosphate ... 

 Nitrate of sodium... 

 Ko manure 



li 



1 11 B 1 19 1 12 II 



1 19 



2 2 2 

 J 18 



> ■2112 

 10 2 10 2^ 



R 2 



3 7 

 2 li 2 



2 3 8 



3 U 



B 2 2 2 

 3 2 19 2 



1 

 i 



■i 11 1 

 3 9 1 



This taljle is calctdated to teach important lessons. The 

 most striking feattue in the Irish potato experiments in 

 ISSl was the remarkable results brought out by the use 

 of kainit. This year again kainit stands pre-eminent. It 

 produced by itself the highest gross yield, and that, too, 

 at by far the lowest cost. Kainit, applied at a cost of 

 only 14s. 6d. per acre, gave a yield higher in gross weight, 

 and only 4^ cwt. less in marketable tubers, than a mixture 

 of nitrate of soda and superphasphate, costing ,£1 13s. Od. 

 per acre. The marketable potatoes from kaiuit thus cost 

 barely 4d. per cwt. for manure, while those from nitrate 

 of soda and superphosphate cost nearly Is. per cwt. — an 

 advantage to the kainit of more than 13s. per ton. Kainit 

 in use with other mauiues also did well, generally adding 

 to the yield. It will be seen that a mixture of kainit 

 and superphosphate, costing £1 7s. per acre, gave a much 

 higher yield than a dressing of superphosphate alone, 

 costing £,i 12s. per acre. 



The table indicates that superphosphate as a single manure 

 ranks next to kainit, and thereis no doubt that, judiciously 

 applied, it forms a very useful manure for potatoes. lu 

 conjunction with nitrate of soda, superphosphate gave the 

 highest yield of marketable tubers, but with sidphate of 

 . ammonia it did badly. 



Next to the pre-eminence given to kainit, perhaps the 

 most important featm-e brought out is the very poor re- 

 sults realised by the nitrogenous manures, nitrate of soda 

 and sulphate of ammonia. By themselves it will be seen 

 that they gave very small yields — indeed, much below the 

 plot that received no manure at all— in potatoes oV a 

 marketable quahty. When given along with inorganic 

 manures they did no better, ha\dng evidently, to some 

 extent, neutralised the good influence of these. 



Dr. Cameron analysed the sound potatoes from each 

 plot, and the percentage of drj' matter varied somewhat. 

 The idot dressed with nitrate of soda and superphosphate 

 stands highest, with 28'tiO, and the others follow in this , 

 order; — The plot ilressed with kainit, nitrate of sodium, 

 suljihate of ammonia, and superphosphate, 28'12; the plot 

 dressed with sulphate of ammonia alone, 2s-12 ; that with 

 kainit, sulphate of ammonia, and superphosphate, 27'50; 

 that with superphosphate alone, 27'0-l; that with nitrate 

 of sotla alone, 27'00 ; that with kamit and superphosphate, 

 27'OU; no manure, 26'90; sulphate of ammonia and super- 

 phosphate, 2C10; kainit alone, 25'SO; and kaiuit, nitrate 

 of soda, and sujjcrphosphate, 2430. 



The column showing the quantity of diseased tubers 

 does not bring out very startling results. It is curious to 

 note that the nitrogenous manm'es produced little or no 

 disease, while kainit shows about 7 per ceut of disease 

 — a circumstance contrary to previous e.>cperience. 



"By unvi'iliug the sources of plant production, science 

 has done her work ; it is now for the State in conjunc- 

 tion with the farmer to do theirs."— Villk. 



" Notwithstanding all that has been said against exjieri- 

 meutal fields, it is now clearly proved that thiMr testi- 

 mony is the only one th.at can be relied on ; the only 

 practical method of fixing with certainly the composition 

 of the soil with respect to the requirements of agricuit- 

 ure."— VlLiJ!, 



