Vol. VII. No. 170. 



THE AGKICULTUKAL NEWS. 



341 



DOMINICA PRODUCE AT THE COMING 

 COLONIAL FRUIT SHOW. 



It has been ileoiileJ that the ishmd of Dominica 

 shall participate in the Colonial Fnilit and Vegetable 

 Show, to be held under the anspiices of the Royal 

 Horticultural Snciety in London, an November 2(J and 

 27 next, and the Dominica Ojfjcii'l Gftzctfe of October 

 17 contains a letter from Dr. U. A. Alford Xicholls, in 

 which he states the classes at the .Show under which 

 produce from the isl.-ind may be exhibited, and mentions 

 the arrangeuK'iits that have been made. 



Tlie classes in which Dominica producp may compete 

 are those for {n) piiie-a])iilt;s, (//) bananas, (r) oranges, 

 (d) limes, (() sliaddocks, poinelows and other sm;li fruit, 

 (/) yams, sweet potatcs, and other tubers, (//) vegetables 

 other than tubers, (/i) bottled fmit in clear glass bottles, 

 .(/) jams, jellies, and sj'rups, shown in clear glass bottles. 



Mr. .1. A. Brooks, Acting-Secretary of the Permanent 

 Exhibition Committee, is carrying out the arrangements for 

 collecting and despatching the exhibits, which will be sent 

 forward by the Royal .Mail steamer leaving Dominica (in 

 November 1. The exhibits will lie consigned to Mr. A. E. 

 As]iinall. the Londou representative of tlie Permanent 

 Exhibition Committee of Dominica, wh(» will arrange for 

 tlieir display at the Show. 



Medals and other prizes will be given in each class at 

 the discretion of the Council of the Koyal Horticultural 

 Society. 



Dr. Xicholls, in the course of his letter, ex[)resses a hope 

 that growers of fruit and vegetables will help in making 

 known the capabilities of the island by sending on tine 

 exhibits of their best jiroducts, which, as he points out. will 

 greatly aid the persistent efforts that are now being made to 

 poptilarize Duminica limes in (Jreat ISritain. 



CITRATE OP LIME AT DOMINICA. 



The Curator of the Botanic Station, Dominica, in 

 his latest Aininat Rcpnrt ('!)07-fS) ifiakes the follow- 

 ing reference to the progress of the' citrate of lime 

 industry in the isbuul ■ — 



Cimsuleiiibie [iicigrcss has Deeu maile in iJie nianuiaciure 

 of citrate of lime in Dominica during the pkst year. Dui-ing 

 1901), the year in which citrate of iime was first exported 

 from the island. 72iS ewt. of this product were produced. In 

 1907, 2,388 cwt. of citrate of lime were shipped, showing an 

 increase of 1,(5(50 cwt.--a very .satisfactory advance. 



The great drawback in making citrate in Dominica at 

 present is the cost of drying the product. What is recpiired 

 is efficient machinery for cheaply and quickly drying the 

 •citrate without loss of acid. When such an apparatus can 

 be obtained without necessitating the expenditure of too 

 great a sum, the chief obstacle in the making of citrate of 

 liirie by estates will have been removed. 



Should such machinery be of too costly a character for 

 estates making 80 to 100 bogheads of concentrated juice, then 

 the development of fai'tories may be expected at suitable 

 points in the several districts for the purchase of lime 

 juice from ailjoining estates, to be made into citrate of 

 lime. 



No doubt many dittieulties are met with in new enter- 

 prises of this kind. These are usually overcome as experience 

 is gained. It is hoped that the cost of drying citrate may be 

 greatly reduced and that this product may shortly rank as 

 one of the chief exports of Dominica. 



SULPHATE OF AMMONIA AND ACIDITY 



IN SOILS. 



A note in a recent issue of the 'Turdcncn 

 aiinn) ic[f' draws attention to the ' curious .appearance 

 of the herbage ' in a grass plot at the R^jthainsted 

 Agricultural Experiment Station. England, which has 

 been manured continuously with sulphate of ammonia 

 and chloride of ammonia for 'a long period of years. 

 The vegetation on this plot! is described as being 

 composed almost entirely of three grasses, while the 

 surface soil consists of a peat-like mat of senii-decaye<l 

 plant remains. The following particulars are given of 

 investigations carried out in connexion with the condi- 

 tion of the soil of this plot : — 



Kecent investigations that have been made in the 

 laboi-atory sliow that the soil has become acid, a result that 

 often may occur as a consequence of the long-continued use 

 of ammonium salts. It was found tliat tlie organisms whicii 

 ordinarily oxidize the ammonia to nitrates were only present 

 in small ijuanities, and their action w.is almost "inhibited 

 owing to the acidity of the soil. The slight amount of 

 nitrification ob.served, together with other facts, which need 

 not be considered here, point to the conclusion that the 

 oxidation is attributable t<.i the beneficial action of the small 

 residual quantity of lime present in the .soil. This acts 

 |iartly, no doubt, as locally neuti-alizing the acidity, and it is 

 possible that further investigation may show that its iutiuence 

 may also be connecteil with other jiliysiuhigical properties 

 wliich this substance is known to possess. The acidity of the 

 siiil is, at least mainly, brought about by the action of various 

 micro-fungi, which are able to utilize ammonia, setting free 

 the acid in the soil. The general re.sult of the investigation, 

 which has a practical value of considerable importance, 

 indicates that ' the decline in fertility of the acid plots may 

 I'c attributed to the repression of the normal bacterial 

 activities of the soil, and the encouragement of the growth of 

 moulds.' 



It will be remembered that the question of acidity 

 in soils brought about as the result of long-continued 

 applications of sulphate of ammonia was referred to at 

 the West Indian Agricultural Conference held at Barba- 

 dos in January last, by Professor J. B. Harrison, C.M.(;.,in 

 connexion with the sugar-cane experiments carried out 

 in British Guiana. As the result of suggestions ma<le 

 to Professor Harrison that the falling off in the 

 productive power of some of the cane fields in which 

 experiments were carried out might be due to the 

 lengthy period over which sulphate of ammonia had 

 been regularly applied, the subject was investigated 

 and experiments were conducted which lasted over 

 three years. 



The results of the experiments, however, did not 

 support the theory put forward, as a change in the 

 manurial treatment from sulphate of ammonia to nitrate 

 of soda brought about a further lowering of the yield 

 of cane, and Professor Harrison stateil it as his opin- 

 ion, that on heavy clay soils, such as those of the 

 experiment fields of British Guiana, and under tropical 

 meteorological conditions, the <lctloccul."ition or pudd- 

 ling, caused by long-continued dressings with nitrate 

 of soda, is likely to prove more injurious to the produc- 

 tive power of the soil than is the souring action, either 

 direct or indirect, of sulphate of ammonia. 



