57 



(S) Foot rot, although not primarily due to improper methods of 

 fertilisation, is no doubt considerably influenced by this cause. 



(9) Insect diseases are also apparently influenced, by the use of ferti- 

 lisers, organic manures rendering the trees more liable to injury from 

 this source than chemical fertilisers. 



MANURES AND COFFEE. 



SIR JOHN LAWES ON THE MANURING OF PLANTS. 



The great English agricultural authority, Sir John Lawes, in answe 1 " 

 to some queries of ours regarding the manuring of coffee and tea, ha 8 

 given expression to opinions that will go far to convince the old styl® 

 of planters of the correctness of their long-establi?hed contempt o 1 

 chemical manure. 



This is what he says : — 



"Our investigations leave very little doubt in regard to the pioper 

 manure for plants of the Graminaceous order, such as wheat, barley, 

 oats, maize, &c. That is to say, plants which ripen their seeds in the 

 course of a few months require their food in the most active condition ; 

 and by means of salts of ammonia, or nitrate of soda combined with phos- 

 phates, we have grown continuous crops of wheat and barley for more 

 than half a century without change. The same substances will pro- 

 duce sugar in the root crops such as mangolds, turnips, sugar beet, &c. 

 These manures do not give the same results when applied to plants of 

 the leguminous order, and we have still a great deal which is quite un- 

 explained in regard to the method by which these plants derive their 

 food, as is the case with the crops named above. We cannot grow our 

 leguminous crop continuously. Referring now to the subject of your 

 letter, I should say most decidedly that the active artificial manures 

 would not be suitable for the coffee tree, and I should be much more 

 disposed to trust to the indirect action of some leguminous plant. I 

 have not much faith in the loppin»s and leaves of leguminous trees. I 

 have several growing Acacias in my pasture, and I could never see that 

 the grass was better under them. I should select any annual legumi- 

 nous plant, pea, bean, or any one which grows most luxuriantly in the 

 district, and dig or plough them under the soil when they are most 

 luxuriant. These leguminous plants do not flourish well except in a 

 soil where there is plenty of lime and potash. I have a letter before 

 me from a gentleman in the Mauritius where they grow d'acharia 

 beans to plough in as a manure for the sugarcane. He sends me a sam- 

 ple of coral sand which he says has a wondeiful effect upon the beans 

 when used with lime, when Jime alone will not act. It is the potash 

 in the sand which acts as a manure for the bean, and it is the nitrogen 

 which the beans collect, partly from the atmosphere and partly from 

 the subsoil, which manures the cane. Should you ft el inclined to try 

 the effect of direct manures, I should use very finely ground bone dust 

 either alone or mixed with rape or other cake, or dried blood. But 

 avoid nitrates, salts of ammonia, and if you use phosphates, employ basic 

 slag in preference to superphosphate." 



The chief point of the above letter is without doubt the strong dis- 

 trust of evanescent chemicals as manures for perennials, such as coffee 

 or tea. The next in importance is the recognition of the value of le- 

 guminous plants, though perhaps Mr. Nelson may feel sore at the 



