Nitrate of Soda as a substitute for Guano. 



381 



It will be seen that the natural produce of this land is very 

 low — only 9 bushels of wheat per acre, and that owing- to the 

 season the drilled manures were all but thrown away. The profit 

 by the top-dressing of nitrate was, on the contrary, exceedingly 

 high. On about 2t acres of wheat, 2 cwt. of nitrate and 4 cwt. of 

 salt, costing less than 2/., gave about 3t quarters of grain, which 

 at 576'. sold for nearly 10/. — in exact figures 9/. 175. Last year 

 I ventured to say that if nitrate could be reduced in price by 

 one-half^ a large additional home supply of wheat might be 

 grown at 12,s. per quarter. This year, at the same price of 

 nitrate, these extra 3J quarters stood me in less than that sum. 

 It is curious that poor land, producing merely 9 bushels per 

 acre, was enabled by 90 lbs. of nitrate, costing with the salt 

 155., to grow 20 bushels per acre. So great an increase is how- 

 ever exceptional, nor w^ould it be safe to take the average increase 

 of wheat by the use of Nitrate at more than 6 bushels per acre,, 

 but the poorer the land the greater will be found its efficacy. 



Being satisfied as to the superiority of nitrate to guano as a. 

 top-dressing, I have made no further comparative trial, but 

 have been fortunate enough to receive from the high authority of 

 Mr. Hope the following decisive experiment carried out by him 

 in the two last seasons : — 



*^ I have only applied nitrate for two years to wheat, and that after seeing 

 the account of your own experiment in Mr Caird's Enghsh Agricuhure. In 

 April, 1852, I top-dressed wheat after potatoes ; the soil a dry gravehy loam. 

 At the time the wheat was not very promising in appearance. I sowed on 

 part 1 cwt. nitrate mixed with 1 cwt. salt per imp. acre ; on another por- 

 tion 3 cwt. Peruvian guano was applied, and a part got nothing. The 

 nitrate of soda soon took the lead, and kept it. A portion of each was., 

 threshed separately, when they were found to yield as follows ; viz. — 



Per Imp. Acre. 



Straw. Wheat. 



Cwts. 



1 Nitrate of soda . 37f cwts 53 bushels. 



3 Guano . . . 36 , , . 49 , , 



Nothing . . 33 ,, . 39 , , 



" In 1853 I tried the same thing on wheat after beans; I never, however/ . 

 could detect any difference with the eye except where the crop got nothing, 

 though in the former year the difference between the two manures could be 

 seen at a glance ; and having cut the crop with a reaping-machine, which rather 

 intermixed the lots, I was prevented threshing them separately. I have 

 bought 5 tons nitrate for next year, and mean to apply a portion to potatoes." 



Here it appears that tliree cwt. of guano, costing about 30.?., 

 were surpassed in 1852, and equalled in 1853, by one cwt. of salt- 

 petre, costing with the salt but 18^. Indeed, guano is so liable to 

 escape in dry weather upon a hot surface, that it cannot compete 

 W'ith nitrate as a top-dressing. For autumn sowing it is pro- 

 bably better than nitrate ; but then the question arises, ought we. - 



VOL. XIV. 2 D 



