October i, 1882.] 



THE TROPICAL AGRICULTURIST. 



277 



are very slowly converted into nitric acid, but the 

 soil yields up a certain quantity eveiy yi-ar," bnt 

 I take It this refi ru to old or subsuilx, iiud car\uot 

 apply to the fresh surface soil of a new clearing — 

 vntualiy uotliitig more or less than a top ilressing 

 ol' manure in the form of or<rauiu matter ; though 

 alboit a inauiire h 33 rapidly susceptible to tlie form- 

 ation of nitrates ; and it is in some sense satis- 

 factory to know. that the same rule to some and a 

 greater ixteut than I fancied, applies to rape and I 

 suppose, therefore, tootherdescriptions of poonao. But on 

 the other hand are not tlie hopes thus extendi d com- 

 pletely cancelled, by the ruinous activity , Mr. 

 Warington's remarks would lead us to suppose, a clim- 

 ate such as ours exerts in tlie creation of nitrates ? 

 And this view is supported by Mr. Lawes ; — " Under 

 favourable condilions of temperature and moistuie, nitric 

 acid is produced with rapidity." (See page 114 7'. A.) 

 Further on we are told " the nitrifying plant cannot 

 carry on its work unless it is furnished with 

 a'kaline substances," and it is nwjgculed that phosphates 

 may also be necessary- In all our soils alkalies of some 

 sort Ij fancy abound ; though should it be that phos- 

 phates are also required it perhaps miy be inferred 

 that poor soils, on being deprived of vegetation, lose 

 their nitrogen less rapidly than rich ones. Also, that 

 the appliciition of phosphoric acid, in the form of 

 bonedust or otherwise, in excess, may have a tend- 

 ency to exhaust the existing nitrogen. As regards 

 conserving the latter : how would it do to eat-ott 

 any green crop it might be decided to grow amongst 

 the coffee &o. ? But 1 woUld say with pigs in pre 

 ference to .•'keep — for I do not remember pigs loose 

 about the lines ever doing any material damage to 

 old cotTee, and in crop time they could be housed ; 

 and not only do they give a very rich manure, but 

 I am not sure that they wi'uld not be a comple'e 

 antidote to grub. With other vegetable matter besides 

 the coffee roots to feed on the latter would not prob- 

 ably confine their attention to these only : and 

 anyhow I believe the pigs would ruthlessly and 

 quickly grub out every one of them. And the harm 

 thus occasionally done to the coffee would I feel sure 

 prove but a vtinor evil ! No old tree would be, hut 

 partially, uprooted — and the cause removed — to he 

 set straight again, and a little fiesh earth stamped 

 round would speedily rectify all semblance of injury. 

 Grubbiug about with their snouts, ihe manure and 

 rotting vegetable matter too would be worked into 

 the .sod. This is an idea that I know will be laughed 

 at — and welcome ! All 1 ;isk is accompany the laugh 

 with a substantial reason. If none are fortheoming 

 an acre, to be snrionudtd by movable hurdles as 

 at home, thus treated would not be a ruinous ex- 

 periment. X. 



THE LOSS OF NITRATES QUESTION. 



Sib, — A letter signed " X.," appearing in your issue 

 of 5th instant, has hitherto attracted no attention. 

 It is based upon a lecture by Mr. Wariugton, re- 

 produced in the .July Tropical At/rirulturist. I ain 

 indebted to "X." for drawing my attention to this 

 very concise, clear and pithy paper, from which I 

 gather that nitrification or the formation of nitrates, 

 which constitute the most suitable form in which 

 nitrogen is absorbed by plants, takes place chiefly 

 on the surface soil, and that these from their great 

 solubility are readily washed through the soil, unless 

 there is plant life present to take them up and use 

 them. I learn further that nitrates are as readily and 

 regularly produced as they are easily lost, and that 

 the loss is diminished by the presence of a crop. 

 Mr. Warmgton is lecturing specially on the loss of 

 nitrates in wheat cultivation, and shows that, though 

 a bare fallow hicreases the nitrates, they are better 

 preserved under a crop rotation. It appears then 



that, if wheat — a great absorber of nitrates — were per- 

 ennial, there would be no loss of nitrates because 

 the wheat would always be absorbing them as they 

 were formed.* "X." endeavours to apply the facts 

 and logical conclusions of Mr. Wariugton in refer- 

 ence to wheat to tlie perennials coffee and tea. Now 

 the preservation of nitrates is of vast importance to 

 the wheat-grower, because he knows that wheat is 

 a greedy devourer of this compound, but to the tea 

 and coffee planter the loss of nitrates is of no im- 

 portance, until he kiwicx that there is a deficiency 

 in the soil. What we do know is that we are living 

 in a country where nitrates are rapidly and con- 

 tinuously made owing to the higher atmospheric 

 temperature. "X." ax.'iumes that we are sidfering 

 from loss of nitrogen, and that this is accelerated 

 bv close draining. If this, which is not proved, be 

 the case, it is surely better that some of the nitrates 

 should be washed deeper into the soil and some lost 

 ill the drains, than that the surface soil itself should 

 be carried witii ever-increasing force and rapidity ' 

 down the whole face of a long hill. If "X." would 

 first prove that coffee or tea or any of our new pro- 

 ducts were suffering from loss of nitrogen, there 

 would be some cause for his letter, and, perhaps, 

 some sense in his remarks about mustard and beet 

 crops. He should nut, however, say that Mr. Wariug- 

 ton advises these, as that gentleman is speaking 

 specially of annual crops. " X.," to suit his argu- 

 ment, assumes twice the loss of nitrates Iiere as com- 

 pared with England ; he might witli more certainty 

 assume the production to be four times as large. 

 Mr. Wariugton gives us facts based on actual ex- 

 periment, "X." gives us theories not based on any 

 thmg. Mr. Warington deprecates being considered 

 a practical farmer, "X." says notliing to lead one 

 to suppose that he is practical either as planter or 

 chemist. He speaks, however, as one in authority 

 What a boon he might confer on the planting com 

 mnnity, if he were to supplement Mr. Bosanquet's 

 useful experiments by analyses of the drainage water 

 and soil. Y. 



[These are just what we want and ought to have, 

 for surely this ivriter is not serious in stating that 

 the loss of nitrates is "of no importance " to the 

 coffee and tea planter. In the article in another 

 column, WTitten before the receipt of this letter, we 

 pointed out that, on the older estates, the feeding 

 rootlets of coffee, tea, &c. , ought to absorb the 

 nitrates. It is on new clearings, especially in the 

 lowcountry, that green crops, such as mustard or 

 rape might prove useful. — Ed.] 



THE MADRAS SCHOOL OF A(4RICULTURE. 



The Iwliaii Mirror: — It is unileniable that the Madras 

 School of Agriculture is engaged in doing most useful 

 work. Through the exjjeriments it is can-ying ou 

 with such general success, it is gradually paving the 

 way to the introduction of a thorough reform in the 

 present metliods and implements of Indian a^^ri- 

 culture. It is doing what is better still — it is raising 

 a body of men who can at all times carry out and 

 perpetuate that reform which is so necessary in a 

 country so purely agricultural. The rate at which 

 popidation is increasing in every part of the Empire, 

 is fast outstripping the proiluctive )iowers of a soil, 

 rich it is true, with tropical fertility, but gradually 

 exhausted by a reckless sjstem of cultivation. Doubt- 

 less, much new land remains to be broken up. But 

 it seems to us that such new land may be held in 

 reserve to fall back upon hereafter, while such old 



* Mr. Warington expressly adduces an instance 

 where as great a quantity was lost hi drauiage as was 

 absorbed by the wheat in forming a crop. — Ed. 



