Jam. I, 1887.] 



THE TROPICAL AGRICULTURIST. 



463 



The fertility of a soil is dependent on other things 

 besides its chemical composition. We must consider 

 the office it performs is twofold, namely, (1) to re- 

 tain the plant firmly in the position most favourable 

 to its growth, and (3) to supply a certain amount 

 of food. Hence mechanical texture becomes a matter 

 of great importance ; it must be firm enough to afford 

 the proper degree of support, and at the same time 

 loose enough to allow the delicate fibres of the root- 

 lets to extend themselves and also access of air to 

 take place, without which the plant cannot live. It 

 must be of such a texture as to retain, for a cosiderable 

 period, the water which falls on it au.l at the same 

 time porous enoMgh. to suffer the excess to drain away: 

 otherwise the roots of the plants will rot. It is for 

 these reasons that the nature of the solid substratum 

 at some depth beneath the soil must be borne in 

 mind. These and other things, such, for example, as 

 the condition of the surface with respect to its 

 absorbent power for heat, all tend greatly to complicate 

 the subject, and render decisions concerning the com- 

 parative value of different lands, founded on merely 

 chemical evidence, exceedingly prone to error. 



The great essential principle to be sought for in 

 manures is this great law of nature, that substances 

 strengthen vegetation mainly by their contents of nitro- 

 gen. 



In dung and in liquid manures, the nitrogenotis matter 

 is partly combined with hydrogen, and has thus become 

 ammonia. Farm-yard dung contains all the principles 

 withdrawn from the soil by the growth of plants : the 

 decomposed strata furnishes silica in a minute state 

 of division, still having with it a little potash and various 

 saline substances. The solid animal extrements contain 

 abundance of earthy phosphates, while the vj-ine gives 

 up by its putrefaction at once carbonate of ammonia 

 and more phosphate, besides smaller portions of other 

 principles. The only thing at all defective is potasli, 

 and that frequently exists plentifully in the soil, and 

 is gradually liberated by disintegration. 



Solid animal manures should not be allowed to 

 putrefy in hea.-ps above ground, because a great portion 

 of the manuring matter, in that case, assumes the 

 state of yas and is wasted. In the heap, previous to 

 fermentation, the nitrogen, the essential element of 

 ammonia, and of supreme value to the planter, is 

 variously combined with carbon, oxygen and hydro- 

 gen; but when it leaves its former arrangement in 

 obedience to the action of decaying bodies, it uni- 

 formly adapts one and only one, new one. Every 

 nitrogenous compound exposed to air and moisture liber- 

 ates its nitrogen to unite ivith free hydrogen and form 

 ammonia. This is a principle of fermentation which 

 admits of no exception. The true economy of farm- 

 yard manure may be thus indicated; nothing must 

 be allowed to run away in the forin ef a fluid, or to fly 

 away in the disguise of a smell. Therefore, we must 

 store the dung daily in proper pits under shelter. 

 The cow-sheds, of whatever material the walls and 

 roof may consist, as long as ventilation is ensured, 

 must be floored with pucca terrace flooring, paving 

 stones, tiles, bricks, concrete, and Portland cement, or 

 planks, and must have a gentle slope towards a gutter 

 running down the centre. In this manner not a 

 particle of dung or drop of urine and washings can 

 run to waste. At a convenient distance, though as 

 close as possible, let the manure pits may be made. 

 The best plan is to have tbe manure shed parallel 

 to the cow-shed, on the slope of a hill immediately 

 above or below it. The pits, arranged side by side, 

 should if possible be floored and lined with masonry, 

 if not possible with hard moss, being previously well 

 puddled. They should be made as water-tight as 

 possible. The cowherds should daily collect the dung 

 and litter, and spread it evenly in a pit, also spread- 

 ing a few inches of dry earth, of which a heap 

 should be collected and stored in an adjoining shed 

 in dry weather, over the mass, then tread it well 

 down. The gutter running down the middle of the 

 cow-shed, should either be connected with the manure 

 shed or end in a spout, under which tubs, or large 

 earthen bowls should be placed. The urine and 

 washings, thus collected, should be poured over tlie 



dung and litter previous to the dry earth being 

 stamped in. If no litter is used, any grass will do, 

 though paddy straw is the best. When one pit gets 

 filled up with these daily layers of dung, litter, aud 

 earth, corer all up with another good layer of earth 

 and turves, and commence filling up the nest pit. 

 These pits should be emptied in the .tame order they 

 are filed, and only wjoden rakes aud implements 

 should be used. 



Every description of sweepings, stable litter, ele- 

 phant's dung and litter, and all the ashes from the 

 factory and cooly lines .should be carefully collected 

 and immured in the manure pits along with the dung 

 from the cow-sheds. Dead bodie.s of animals, and 

 excrements objectionable to the caste prejudices of 

 the coolies, can well be disposed of by being burned 

 anywhere about the plantation among the bushes with 

 a good sprinkling of lime if possible. 



Ashes. — The really enormous amount of this valu- 

 able manure daily prepared in the factory, engine- 

 house, cook-room and, last but not least, cooly lines, 

 and generally wasted or frittered away, is lamentable 

 on most plantations. Every particle of ash should be 

 carefully collected, stored along with the charcoal 

 dust and sweepings of the charcoal godowns in a 

 convenient, water-tight shed, for manurial application 

 during the cold season. All the wood of the tea 

 prunings should be gathered and burnt in bare 

 patches all about the plantation, and applied to the 

 neighbouring bushes. This is really returning the actual 

 elements of which the tea bush is composed. 



Lime is abundant and cheap in some tea districts as 

 Sylhet, Cachar, and the Darjeeling Terai, and is Ja 

 most valuable manure. Soils and sub-soils, far below 

 the reach of ordinary cultivation, always contain a 

 very sensible quantity of ammonia. The action of 

 lime, in the presence of water, is to set free from 

 the soil as nearly as possible one-half of the ammonia. 

 The application of lime on cold, spongy marshy soil 

 is most profitable. The chemical action of lime, and 

 the effect which it produces as a manure, appear to 

 be of two kinds. On the one hand it acts upon 

 vegetable mould, accelerating its decomposition and 

 rendering it soluble and then fits it to enter the 

 roots of plants. Lime deprives some mould of its 

 acidity, and renders it fertilizing. But, on the other 

 hand, there is every probability that, by means of its 

 carbonic acid, lime produces some other effect, and 

 furnishes the plants with so^iie nutritive matter. The 

 roots of certain plants, specially tap-rooted ones like 

 the tea plant, appear to have the faculty of depriv- 

 ing lime of its carbonic acid, which it immediately 

 re-absorbs in equal proportion from the atmosphere, — • 

 boring through limestone in its hunger for lime. — 

 Indian Tea Gazette. 



DAVIDSON'S No. I AND T " SIROCCOS." 

 To the Editor of The Home and Colonial Mail. 



Sir. — In the issue of The Indian Planters' Gazette 

 of I9th Oct. ult., there appears a letter signed " Oor,'' 

 in wl.ich my No. 1 "Siroccos" are highly praised; 

 but in referring to the T shaped " Siroccos," " Cor " 

 says that, "although they (the T "Siroccos") ilo 

 more work, they do not do as good work as the 

 No. 1;" and he goes on to say thit he thinks the 

 causes for this are, that in the T " Sirocco " the top 

 row of trays being exposed to the air, their tem- 

 perature in consequence of this remains compara- 

 tively low, and, therefore, the damp leaf coming 

 freshly into the machine does not receive a suflliciently 

 sharp heat to promptly check fermentation. 



Although I do not quite agree with " Cor " as to 

 the particular causes he assigns for the effects 

 described, probably those of your readers who have 

 an interest in the sul)ject, and who may have seen 

 his letter, will be further interested to know that 

 the objections to the T " Sirocco " therein cited are 

 now altogether disposed of in my present make of 

 the apparatus. 



The top of the drying chamber is now closed in 

 with perforated plates, aud a portion of the fresh hot 

 air from the stove is, in the large size of the 



