The Proper Use of Artifieial I\Iaiiures on a Far, 



545 



phates are present in a moderate degree — generally 

 from 20 to 23 per cent. — mostly in an insoluble form, 

 but are gradually rendered soluble in the soil by the 

 action of rain water, due to the presence of carbonic 

 acid. This maybe accelerated to a remarkable extent 

 by the addition of a small quantity of sulphuric acid 

 (oil of vitriol). From experiments made by Dr 

 Vcelcker, it appears that the addition of only 5 per 

 cent, of vitriol causes fully one-half of the phosphate 

 to become soluble, whereas Ijarely one-fifth occurs in 

 a soluble state. An increase of acid causes increased 

 solubility, and it is probable that 25 per cent, 

 would render the whole soluble ; but the effect is not 

 in proportion to the outlay, and the smaller quantity 

 is most practical. The action consists in converting 

 oxalate of ammonia into sulphate of ammonia, the 

 latter possessing a solvent action on the phosphate of 

 lime. The directions for making this addition are so 

 simple, the expense so trifling, and the effect, espe- 

 cially upon root crops, likely to be so beneficial, that 

 we strongly recommend a trial. Dilute the acid with 

 an equal weight of water (soft preferable), sprinkle the 

 liquid over dry sawdust or sand, the former best, as 

 most absorbent ; the guano, reduced to a fine powder, 

 is mixed intimately with the damp sawdust, and may 

 be used in the course of a day or two. Good Peruvian 

 guano suffers no loss from exposure to the air, and 

 hence may be kept under cover from one season to 

 another. The pungent smell arises, not from salts of 

 ammonia, but from certain gaseous products which 

 have no value as manure. 



Guano has a tendency to cake ; hence careful sift- 

 ing and pounding the lumps is necessary, and the 

 neglect of this simple precaution is often attended with 

 serious loss. The guano should be passed through a 

 fine wire sieve, and the lumps that remain mixed with 

 dry sand, beat with a mallet, and again sifted until all 

 is fine. Sand prevents caking. When fine, salt may 

 be added, especially for light soils. Peruvian 

 guano is valuable on nearly every kind of soil, 

 and benefits most crops. We have heard of 

 particular soils, where its action was not seen. 

 Fully alive to the value of really good Peruvian 

 guano, w'Q warn our readers against depending too 

 entirely npon it. Already warning notes have 

 reached us that the supplies are becoming exhausted, 

 and there can be no doubt that the quality is less 

 regular than formerly. Great as were the original 

 deposits — the accummulations of thousands of years — 

 it is quite evident that a time must come when the 

 supplies will altogether cease, or be greatly reduced. 

 What are we doing to economise our own resources 

 all this time ? Will it be believed in the future that, 

 whilst paying millions for birds' dung, we are allowing 

 our own excreta, not only from large centres where 

 collection may be difficult, but on individual farms, to 

 be lost — not absolutely, but relatively to us. Moule's 

 earth closets should be in use everywhere. The fi)l- 

 lowing analysis of three samples by Dr Yrelcker will 

 VOL. I. 



shew the composite nature of Peruvian guano, and ex- 

 plain the reasons for its great value as a fertilizer : — 



Moisture 18.42 15.14 16.56 



■''Organic matters and salts of 



ammonia 52.11 52. 8r 51.70 



Phosphates of lime and mag- 

 nesia (bone earth) 21.99 20.26 23.55 



+Alkaline salts 6.37 10.52 6.44 



Insoluble silicious matters 



(sand) I. II 1.27 1.75 



100.00 100.00 100.00 



•Containing nitrogen 15-34 iS-4i 15.13 



Equal to ammonia 18.62 18.69 18.37 



i-Containing pliosphoric acid 2.23 2.48 1.08 



Equal to bone earth 4.83 5.36 2.34 



The above are very uniform, and we shall do well if 

 we can always get as good. To ensure this as far as 

 is possible, deal only with those who buy direct from 

 the importers, and whose character is above reproach. 

 Avoid all allurements in the form of cheap guanos, 

 not quite equal to the best. The following is the 

 analysis of such a guano, sold by Liverpool brokers at 

 ^11 a ton, and worth about ;^8 : — 



Moisture 14-95 



♦Organic matter and salts of ammonia 31.30 



Phosphate of lime, &c. &c 25.95 



Plydro-sulphate of lime 9.85 



Alkaline salts 7. 70 



Sands, &c 10.25 



''Nitrogen, 5. 28 ; ammonia, 6. 38. 100.00 



NITRATE OF .SODA, ETC. 



Nitrate of soda and sulphate of ammonia are cheap 

 forms of nitrogen, which, acting much in the same 

 way, may be considered together. There is, however, 

 one important distinction. Sulphate of ammonia, in 

 common with all ammoniacal products, is retained and 

 stored up by soils for plant use, whereas nitrate of soda 

 passes through, and unless absorbed by the plant is 

 lost. Hence the latter should be applied only to the 

 growing crop, and sown on the top, so as to pass 

 through the whole depth of soil ; whilst the sulphate 

 of ammonia may be incorporated with the soil, and 

 applied either before the crop is sown or during growth, 

 as is most convenient. 



Both these manures have a special action on cereals, 

 and their fitness depends upon the presence in the soil 

 of available mineral food to meet the greatly increased 

 demand . On limestone marls we found nitrate of soda 

 invariably a success. The addition of l^ cwt. per 

 acre, in conjunction with 3 cwt. of salt, gives an in- 

 crease of from 10 to 14 bushels of grain and 5 to 6 cwt. 

 of straw per acre. On thin weak soils these manures, 



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