Nov. r, 1886,] 



THE TROPICAL AGRICULTURIST, 



345 



the longer lived species is not accurately known, but 

 fifty years is probably the extreme. Individual stems 

 thus dry up and die in succession without seeding, 

 but the clump lives out its normal period, when it 

 flowers, seeds, and dies ; all stems then living, what- 

 ever their age or size, seeding and dying together. 

 As each stem matures separately, and, once matured, 

 will never becomes any larger, it may be thought that 

 when a clump has attained sufficient age to produce 

 stems fit for .sale, such clums might at once be cut 

 out and utilized. But this would stop the increase 

 of the clump, for it is only the young stems that are 

 less than four years old that send up fresh shoots 

 from their rhizomes. It thus follows that the younger 

 stems should be left till at least their fifth year, 

 while the older stems may be removed, for they are 

 matured are no longer reproducing themselves and 

 are saleable- 



This peculiarity of the bamboo makes it a matter 

 of some little difliculty to decide whether a block of 

 bamboos is, or is not, being overworked. The con- 

 dition of the separate clumps, or of a large proportion 

 of them, must be studied, and measures must be adopted, 

 and enforced, to prevent the reproducing stems being 

 cut out. They are often among the finest in the 

 clump, and often al.so the handiest to the a.xe of the 

 cutter. They must be preserved, while if too many 

 old stems are left, the young shoots will be hampered 

 in their growth and become much twised in their lower 

 portions. Owing again to this peculiarity the closing 

 of blocks of bamboo forest against cutters for a term 

 of years may indeed protect the newer culms, but 

 will also lead to many of the older ones being wasted. 

 Each case must be settled on its own merits, but 

 where good supervision can be enforced the closing 

 of blocks is not advisable. 



In Bengal, in parts of the North-West Provinces, 

 in the Deccan, in Mysore and Madras, and possibly 

 elsewhere in India, it is an article of common belief 

 among natives and acted up to in practice, that bamboos 

 cut in the bright half* of the month are sure to be 

 attacked by insects and to turn quickly to powder ; 

 while those felled in the dark half of the moon's 

 course will last for a long time. It is also held that 

 the new shoots are not sent up, even if rain falls, 

 till the thunderstorms that precede the monsoon have 

 set in ; and, further, that the more the thunder, the 

 larger will be the number of new shoots sent up that 

 year, — Indian Foreste}'. 



THE VALUE OP SULPHATE OF AMMONIA 

 AS A MANUEE. 



By Mr. F. J. Lloyd, F.O.S., Lecturer on Agriculture 

 at King's College, &c, London. 



Writing to the Journal of Gas Lir/htiiuj, Mr. Lloyd, 

 F.OS., says :— Of late the Journal has contained some 

 interesting matter in reference to sulphate of ammonia. 

 Perhaps, therefore, a few words on this subject from 

 an agricultural point of view might not only prove 

 of interest to its readers, but, while dispelling from 

 their minds the false views regarding the future of 

 this product, enable them to rightly estimate the true 

 relative merits of nitrate of sisda and sulphate of 

 ammonia as manures. Each of these substances has 

 a manurial value ; and both owe this value to the 

 same fact, viz., that they contain nitrogen. In the 

 one the nitrogen exists combined with hydrogen as 

 ammonia; in the other, combined with oxygen as 

 nitric acid. It is a well-known fact that 100 parts 

 of commercial sulphate of ammonia, of 94 refraction, 

 such as is now usually sold for manurial purposes, 



* An experiment to decide this, ,vas carried out at 

 Dehra in 1884, and the popular theory was fully con- 

 firmed, the 100 bamboos cut in the bright moon being 

 riddled by insect borings, whilst the 100 cut in the 

 dark half of the month are almost untouched. It 

 is probable that, the insects which cause the borings 

 only deposit eggs ou bright nights.— Ed. /, F. 



contains about 20 parts or more of nitrogen ; while 

 the detrimental impurities, the various cyanides, which 

 used twelve or more years ago to be somewhat prevalent 

 in sulphates of aumonia, are now seldom met with. 

 On the other hand, commercial nitrate of soda, of 

 95 refraction, contains little less than .16 parts of 

 nitrogen. Hence, unless it can be shown that the 

 nitrogen in sulphate as ammonia is less valuable to 

 the farmer than the nitrogen in nitrate of soda, it 

 is evident that, so long as a ton of nitrate of soda 

 can be bought for £10 (which is approximately its 

 present price), sulphate of ammonia is worth £12-I0s. 

 a ton. Now, is the nitrogen of ammonia as valuable 

 to the farmer as the nitrogen of nitrate? In order 

 to answer this question, which lies at the root of 

 the wba'e subject, it is necessary to briefly state some 

 facts regarding the function of the roots of the plant, 

 atsd the properties of the soil. The majority of plants 

 take most, if not all their nitrogen from the soil 

 as nitric acid. There cin be no doubt, therefore, 

 that nitrate of soda will act upon vegatation more 

 rapidly than sulphate of ammonia. But it is equally 

 certain that every properly cultivated soil possessses 

 to a high degree the power of nitrification — that is, 

 it converts all nitrogenous substances gradually into 

 nitric acid. Ammonia is one of the substances most 

 easily so converted. Hence it is certain that, when 

 sulphate of ammonia is used as a manure, the soil 

 will gradually convert the ammonia into nitric acid, 

 and supply to the plant nitrogen really in the very 

 same form as is supplied by nitrate of soda. So far 

 it is evident, then, that nitrate of soda is only more 

 beneficial than sulphate of ammonia, inasmuch as it 

 acts upon vegetation more rapidly. 



Next let us consider the action of the soil on 

 these two substances respectively. The late Dr. 

 Voelcker, among his valuable additions to agricultural 

 chemistry, left none more valuable than his researches 

 upon the action of soils on manures. By analysing 

 the water flowing from the drains of large fields, 

 where crops were cultivated under varying conditions 

 and manures, he proved that nitrate of soda is washed 

 rapidly through the soil by rain, so that a largo 

 qaantity of the nitrogen so applied to the soil is 

 never taken up by the roots of the plants ; and during 

 the time there is no crop growing the nitrate of 

 soda is being merely washed away. Not so with sul- 

 phate of ammonia. Only once or twice in all his 

 experiments, did he find ammonia being washed through 

 the soil into the drains, and then only in minute 

 quantities, and this was found to be the case even 

 where the land had been manured with 4 or 5 cwt. 

 of sulphate of ammonia — far larger quantities than 

 are usually employed. What then became of the 

 ammonia ? It was found that all fertile soils had 

 the power of retaining ammonia, which became only 

 gradually converted into nitric acid ; and then only, 

 and not until then, was it washed out of the soil. 

 Meanwhile any plant growing in the soil would be 

 well able to take up the nitric acid as it was formed, 

 so that less would be lost, than where the nitrogen 

 had been applied as nitrate of soda. If then nitrate 

 of soda is more active than sulphate of ammonia, 

 still the latter is more lasting and less wasteful. It 

 is evident that manure manufacturers are well aware 

 of this fact, for one seldom finds nitrate of soda 

 admixed in compound manures, except for special 

 and forcing purposes, while sulphate of ammonia is 

 largely and rightly used for mixing with pho.sphatic 

 manures. If I have made my meaning clear, it will 

 be evident that the producers of sulphate of ammonia 

 have nothing to fear, from theoretical reason, as to 

 the supposed inferiority of this manure, when com- 

 pared with nitrate of soda. 



As might be anticipated, practice in the field con- 

 firms these scientific conclusions. Thus the renowned 

 experiments of Sir J. B. Lawes and Dr. Gilbert at 

 Rothamsted, and the experiments by the late Dr. 

 Voelcker at Woburn, for the Eoyal Agricultural Society, 

 yielded the following results, where equal quan- 

 tities of nitrogen were applied as sulphate of ammonia 

 and nitrate of soda respectively:— 



