386 



THE SOUTHEKN PLANTER. 



[July 



views of the peculiar action of the salts of 

 ammonia. Whilst some hold that the action 

 can only be referred to the nitrogen, because 

 the acid can be changed without, thereby 

 materially altering the effect ; others assert 

 that the soil already contains so much am- 

 monia, that the increase of produce cannot 

 be attributed to the small quantity of nitro- 

 gen added in the salts of ammonia. They 

 maintain that an acre of ground which con- 

 tains in its upper ten inches of soil 10,000 

 lbs. of ammonia or nitrogen, could not have 

 its fertility increased two-fold by the addi- 

 tion of 30 to 60 lbs. of ammonia. As in 

 such a soil there was no want of nitrogen, 

 the cause of the increased fertility must be 

 sought for in something else. 



The case is much the same with the ac- 

 tion of nitrates as with that of the salts of 

 ammonia. Nitrate of soda exercises a pow- 

 erful effect, in certain cases, on the increase 

 of grain and straw, and in others it is val- 

 ueless. The experiments of Kuhlmann have 

 shown that the bases also of these salts play 

 some part in the action. From a meadow 

 manured with 220 pounds* of nitrate of 

 soda, an increase of crop to the amount of 

 1807 pounds per acre was obtained ; whilst 

 from another portion of the same meadow, to 

 which was applied the same quantity of ni- 

 trate of lime (containing li per cent, more 

 nitric acid), there was an increase of only 

 609 pounds. Consequently the produce from 

 nitrate of lime was I less than from the soda 

 salt. , If we ascribe the increase in the 

 crop to the nitric acid, then the effect of 

 the two salts is quite incomprehensible. 



The action of common salt appears in 

 many cases equally incomprehensible. — 

 In 1846, Kuhlmann obtained from 190 

 pounds of sulphate of ammonia an ^'n- 

 crease of hay, amounting to 2228 pounds 

 per acre; a similar quantity of sulphate 

 of ammonia, with the addition of 116 

 pounds of common salt, gave an increase 

 of 2792 pounds of hay. There were conse- 

 quently 564 pounds more hay obtained (per 

 acre) by the addition of the common salt, 

 than from the employment of the sulphate of 

 ammonia alone. 



It might be supposed, that- the want of a 

 chlorine compound, which is contained in 

 not inconsiderable quantity in meadow plants, 

 was the reason, in the case of the common 



* We drop the foreign denominations of 

 weights and measures. — [Ed. So. Planter. 



salt, of the increase of produce; but a sim- 

 ilar difference, as in the above cases, was 

 found in two other experiments, which 

 Kuhlmann made, in 1845 and 1846, with 

 sal-ammoniac alone, and with sal-ammoniac 

 and common salt. The piece of meadow 

 manured with 190 pounds of sal-ammo- 

 niac gave in the two years 3256 pounds 

 per acre more hay than a piece of the same 

 extent which was unmanured. From an- 

 other portion, to which were applied 190 

 pounds of sal-ammoniac and 190 pounds of 

 common salt, 5004 pounds of hay were ob- 

 tained. Hence, by the use of common salt, 

 there was an increase of a half more than 

 from the sal-ammoniac alone. 190 pounds 

 of common salt alone, without sal-ammo- 

 niac, produced an increase of 1748 pounds 

 of hay, the difference between the two num- 

 bers 3256 and 5004 is not great enough 

 to exclude the idea, that each salt has acted, 

 just as if the other had not been present, or, 

 in other words, that each salt has a special 

 action of its own. 



In the summer of 1857, the effect of salts 

 of ammonia by themselves, and mixed with 

 common salt, on summer barley, was tried 

 by the General Committee of the Agricul- 

 tural Society of Bavaria, in a series of ex- 

 periments made at Bogenhausen, in the 

 neighbourhood of Munich. For this pur- 

 pose, 18 plots, each of 1914 square feet in 

 extent, were marked off in a field which had 

 gone through the usual rotation of crops, 

 having been, three years previously, man- 

 ured with common farm-yard manure, and 

 having borne rye, and then two crops of oats. 

 Four of these plots were manured with salts 

 of ammonia; one remained unmanured ; to 

 four others were applied the same quantity 

 of ammonia salts, and at the same time, to 

 each 62 rfe. of common salt. Each plot re- 

 ceived the same amount of nitrogen in the 

 ammdnia salts. 



In estimating the quantity of manuring 

 matter to be employed, it was assumed that 

 440 lbs. of guano per English acre, corres- 

 ponded to the full measure of farm-yard 

 manure usiu^lly applied ; this gives twenty 

 pounds of guano for one of the plots. A 

 good sample of guano was selected for the 

 experiments, and on being submitted to an- 

 alysis, was found to consist of 14.53 water, 

 33.38 ash, and 52.10 organic matter, of 

 which 15.39 was ammonia. Twenty pounds 

 of this guano, therefore, contained 3.07 lbs. 



