Vol. XVII 



Xo. 434. 



THR AGhICrLTLT.AL NEWS. 



387 



in this connexion. Tbiis line of enquicy opens up th*^ 

 who'.e qoeetion of the influence of org^acic matter in 

 the soil: its effect in increasing tte retention of 

 moisture in dry times, and aiding draioage in times 

 of excessive rain; its effect in iricreasiog fertility, and 

 in maintaining that condition of openness and tilth 

 upoE which high prodnctivity dependsu 



AnsiQg again oat of thus, come the questiooa con- 

 nect^ with manuring, and the fundamental points con- 

 cerning the production of pen manuie and *•{ green 

 dressingo. These matters lead to endless others. For 

 instance, what is going to be the effect on estate 

 practice, in the matter of manuring — of the increasing 

 use of mechanical power in place of animal power? 

 Mechanical haulage of produce as exempiided in the 

 facuiry railways, mechanical ploughing, which is being 

 increasingly a/Jopted, the use of motor ears in place of 

 horse-drawn carriages, and other similar changes all 

 affect the question, and careful planters will study the 

 outlook. Anything which tends tn reduce the qwan- 

 tity 01 pen mtnnre available for aa estate is, from that 

 poii:: of view, detrimental, b;it the advantages of 

 mechanical traction are so great thit tins will assuredly 

 be persiste-l in and extended, in spite of this incidental 

 defect 



The iibfeci ctn be remedied t<» a considerable 

 exteuit by the intelligent application of scientific 

 principles^ It is essential t'aa.i feftQe aoik shall 

 be supplied widi the requisite quaotaty of organic 

 master, nothing will eflBciently replace tliat. The sources 

 of this organic matter are either the pen manure 

 which we are ctHisidering, or gieen dressings. 

 Now the green dressings are either those which the 

 planter deliberately grows for the pnrpoee, or they 

 arise from the crop residues, such as the cane trash and 

 tiie cane tops which remain on the land, or from the 

 weeds which grow there, an<l are ultimately ploughed 

 in. Carefully handled, these things- will supply the 

 amount of organic matter which may soffiee to keep 

 the iaod in good condition. A little consideration will 

 diow that few prc^rties spend much on imported food 

 for animals, and that sncfa espeoditure as is made is 

 laid oat on ccoeentBated foods which, irhile enriching 

 the lesnltaot mannre in the matter of nibrogen ar ] 

 other constdtnenta. do not add greatly to the bulk :: 

 organic matter, which is the thing we are immediately 

 OHisidering. The loss of fertilizing material arising 

 from lessened por^hasing of imported concentrated 

 foods can be made good by tbe purchase of chemical 

 raaoures, axtd no grea: ' .•n .f a.^y, r^nlta. The mater- 



ial uised for the feeding of theanimals on a r. . . .- ;-uie, 

 largely cane tops and giaas, stiil remains on i:.t prop- 

 erty, so that the question is to make best use of them. 

 It ia a matter of common ex{.erienc« tha( these things 

 when tnmed into the Land prove less effective as manures 

 than when they have been fed to animals, ki that 

 there seems to be here some loss of efficiency, if these 

 crop residues and similar nuterials are simply allowed 

 to remain on the ground to be ploughed in. It has 

 been suggested that the increased efficacy of pen man- 

 nre, as contrasted with the raw material used for the 

 animals' food, lies in the presence in the pen manure of 

 beneficial bacteria, which pr nbttbly assist in the break- 

 ing down of the plant structures, thus permitting their 

 free mingling wi>h th^.^il, and their more ready availa- 

 bility to the growing crop. At the same time some of the 

 bacteria may be such as are ca{»ble of aasimilacing 

 atmospheric nitrogen, thus adding appreciably :o the 

 fertility of the soil. There are grotuids for thinking 

 that such bacteria p:ay an important part in maintain- 

 ing fertility in the tropics. 



It is not diffienit to apply the principles thus 

 referred to. Should the introdoction of mechan cal 

 means of haulage leai-l to an nndesicable diminuuoa 

 of animals oa any p'antation. every effort should 

 be made to produce as much pen manure fiom 

 the reduced number of animals as was formerly 

 obtained from the fall number. - To this end, as 

 much fodder as iormeAj should be brought to- t.he 

 pens, the quantity should be as greatly as p)jeib!e 

 in excess of the actual f'jod requirements of the 

 animals, the object being to make as much compost as 

 poaatUe. In scioitific langa tge this might be de»- 

 scribed as making a culture of the beneficial i»cteria. 

 This may seem a simple suggestion, but it is certain 

 that its nae will be attended with good results. 



Still continuing to think of the sug«r crop, it may 

 be sn^giested that increased efficiency in prodnctioa 

 will result from the more extensive use of nitro- 

 crentms manures in g^rowing rttoon canes, prorided 

 that the jdant canes have been adequately heated 

 widi pen manure. This is the ou'xome of the teaching 

 of the manurial experiments conducted in the Leeward 

 I=.i- ■- • elsewhere. 



The increased efficiency in prodnetioo to be 

 doived from the use of improved vuieties of sogar- 

 canes is having careM attention, acd. doabdesa, wiO 

 con&nne to be a master of seiioas concern on the part 

 of planters. 



