V.JL. VIII. Xo. 181. 



THE AGRICULTURAL NEWS. 



lOS 



At a mceliug of the Euard of Jlanageiucut of tin.- 

 Jamaica Agricultural Society held ou January 28 last, the 

 above evidence wa.s considered, and although its discouraging 

 nature wa.s recognized, it was decid<^d to expend a sum of 

 £10, in the coming financial year, on experiments in 

 cotton growing carried out on peasants' plots, under the 

 guidance of the Agricultural Instructors, in suitable parts of 

 the island. 



Although present conditions in regard to this 

 matter rn.iy not now appear promising at Jamaica, yet, 

 undoubtedly, no pains should be spared, and every 

 effort made to ascertain the possibilities of Sea Island 

 cotton cidti\ation in the island, before deciding to 

 abandon all attempts to establish so valuable an 

 industry. 



GUANO. 



The varying prices at which guano may be 

 purchased on the market indicate the varying quality 

 of the material, and this form of manure is one which 

 should only be purchased on the results of analysis. 



Guano — as is generally known — is the more or less dried 

 excrement of sea birds, and the largest deposits of this 

 valuable fertilizing agent are found on the coasts of Peru and 

 of the adjacent islands. (Juanos are also found on certain 

 islands off the south-west coast of Africa. The manure in 

 question is peculiarly useful, in that the best grades supply not 

 only phosphates to the soil, but also nitrogen and a small 

 l>roportion of potash.. The original deposits always contained 

 a fairly rich percentage of nitrogen. If the guano was 

 deposited in the dry, rainless districts of Peru, the nitrogenous 

 matter remains indefinitely in the e.vcrement, but in rainy 

 regions, this is decomposed and washed away in course of 

 time, and the resulting material is, of course, in.soluble, and 

 valued almost .solely for the [ihosjihate content. 



In pa.ssing, it may be said that the best Peruvian 

 deposits of guano have been exhausted, and as a consequence, 

 the grades now exported are inferior !■> those shippe^l twenty 

 and thirty years ago. As already indicated, the composition 

 of the manure varies greatl}' ; and pre.sent imports from 

 Peru may contain from 2 to 10 per cent of nitrogen, 10 to 30 

 per cent of phos[ihoric acid, and from 0'2 to 3 4 per cent of 

 potash. Such material as sand may exist in the manure to 

 from about 8 to as much as 30 per cent. 



In a nitrogenous guano, the nitrogen present exists in 

 a number of forms, e.g. uric acid, and the ammonium salts of 

 oxalic, uric, sulphuric, pho.sphoric, and carbonic acids, etc., as 

 well as in compounds of organic nature. As a result of this 

 complexity of composition, it follows that while some of the 

 contained nitrogen is inunediately available as plant food, 

 other compounds will have to undergo bacterial changes in 

 he soil before Ijecoming available for this purpose. This 

 peculiarity renders nitrogenous guano a manure e.'pecially 

 •well suited for application to a crop for which it is desiral)le 

 to provide a supply of nitrogen that will gradually become 

 available as the growing plants require it. 



What is known as ' ecpialized ' or ' rectified ' guano repre- 

 sents an attempt on the part of manufacturers to bring up 

 the composition of guanos of lower grade, more esjiecially 

 those from which the .soluble nitrogenous constituents have 

 been \>ashed out by rain, to that of the richer grades deposited 

 in dry districts, by the addition of nitrogen compounds such 

 as sulphate of ammonia. Such manures, while containing 

 nitrogen in good forms, cannot entirely .substitute the original 

 guanos, owing to the imi>ossibility ot adding forms of nitrogen 



identical with those existing in the natural product, and 

 which, as already indicated, give a peculiar value to the best 

 guano, by their gradual availability. 



The phosphates in this manure are chiefly jiresMit as 

 phn.sphates of calcium. lu nitrogenous guanos, hovever, 

 a proportion exists as ammonium [ihosphate, which is a salt 

 readily soluble in water. 



Since the great proportion of the calcium phosphate 

 present is the in.soluble, tribasic form, guanos are frequently 

 treated with small quantities of sulphuric acid. In the 

 ' dissolved guano ' which results, the phosphate is clianged 

 into the .soluble form, .similar to that which e.'iists in super- 

 [ihosphate. The nitrogen, too, has become fixed as sulphate 

 of ammonia, and is in no danger of being lost by passing oil 

 as a gas. 



Connuercial Peruvian guano sliould be in a dry, finely- 

 divided state, and if squeezed in the hand should not cling 

 together in a sticky mass. The colour' should be rather light,- 

 and the smell not very pungent, for if so, a loss of ammonia 

 is taking place. 



LIME AND CACAO EXPORTS FROM 

 DOMINICA. 



In the course of the address given b\'the Adminis- 

 trator of DoiTunica(Hon. Douglas Young, C.M.G.) to the 

 Legislative Council of the island on ifarch 18 last, it 

 was mentioned that the }"ear 1909 had been a prosper- 

 ous one for Dominica, and that there were abundant 

 signs of the steady development of the island's fei'tile 

 resources. The total trade had increased from £2.52,893 

 in 1907 to £26.5,127 in 1908. There had been an 

 advance in value of £19,621 in the imports for local 

 consumption, while the e.\ports of local produce showed 

 a falling off of £26,462 compared with the previous 

 year. This decline in value of the export shipments is 

 explained in the following extracts from the address ■ — ■ 



Of the e.xports from Dominica in 1 908, lime product.s 

 represented i.'.")0,9.jl, and cacao, £30,362. The reduction 

 fnjm £77,4:07 in the previous year in the value of the lime 

 products shippeil is not due to a le.ss yield in 1908, bui to 

 the reduced market prices obtained during that year conqjared 

 with 1907, when the price of lime juice was exceptionally 

 high. The average figure realized for concentrated juice in 

 1907 was about £22 per hog.shead, while in 1908 it fell to 

 about £15 per hogshead. 



The lime crop of Dominica for 1908 reached about 

 310,000 barrels, an increase of 38,000 barrels on the previous, 

 year. To no small extent may this increase be attributed to 

 the yield of increased areas under cultivation. As in previous 

 years the value of the shipments has been computed at the 

 time of export on the net estimated value of the produce, but 

 if the price realized in the overseas market be taken, the lime 

 products of Dominica for the past year may be valued at 

 £80,000. The citrate of lime industry shows a small 

 advancement on the previous year. During 1908, 2,520 cwt., 

 valued at £8,164, were shipped abroad. 



The amount of cacao ex|)orted from Dominica in 1908' 

 was 9,820 cwt., compared with 11,628 cwt. in the previous 

 year. The Administrator was not prepared to say that the 

 .shortage thus shown is entirely due to a .short crop for the 

 year The crop 'was not so full as tliat of 1907, but it is 

 thought that the lateness of the ' Christmas ' crop is 

 partly responsible for the shrinkage, and that in consequence 

 a part of the 1908 crop will be included in the export of the 

 present year. 



