386 Nitrate of Soda as a substitute fo?' Guano. 



quisite, potash, for grass ; we have striking evidence from Scot- 

 land for the profitable application of nitrate even singly to grass- 

 land. Thus Mr. Main, of Mid-Lothian, in his Prize Essay,* 

 tells us ; — 



" Top-dressing on grass, whether for hay, soiling, or pasture, is of immense 

 advantage. A remarkable instance occurred in my own experience three year^ 

 since. A field of 1 5 acres had been laid to permanent pasture some six years 

 before. It is not naturally a grass soil, indeed the very reverse. For three 

 years, however, it yielded well and kept a large amount of stock. In the 

 fourth it began to fail, the fifth w^as still worse, and in the sixth it may be said 

 that 12 cows starved on it. In the seventh it was top-dressed with* a ton of 

 nitrate in April, and the results were astonishing. The stock pastured on it that 

 year was 13 milk cows (2 with calves suckling), 5 stirks, 3 colts, and at inter- 

 vals 60 sheep. I have continued to benefit by this experience. A large 

 amount of roughness (rough grass) was left lor wintering ewes, which I could 

 not in the two previous winters fold in the same field." 



On the average then of seasons nitrate, aided by superphosphate 

 if need be, appears preferable to guano for top-dressing grass, 

 and in this application of it no risk can arise from over-luxuriant 

 growth. 



Not so in its use upon wheat, for which purpose a com- 

 bination with salt can alone render it safe. But there are two 

 modes of supplying wheat with pulverized manures — autumnal 

 drilling and spring top-dressing. An experiment tried here this 

 year throws some light upon both methods, and may be the more 

 useful as involving the total failure of one. 



The trial ground had been purposely exhausted by white crops 

 for three previous years. Four different manures were drilled 

 with the wheat in the autumn ; one-half of each lot was dressed 

 with nitrate and salt, at two dressings, in spring. The produce 

 was threshed out on the field, separately, after harvest. Contrary 

 to the experience of others, and to my own upon the same land, 

 none of the drilled manures took any effect. The soil is a sandy 

 loam, and they must all have been washed down by the unusual 

 rains. But the spring dressing with nitrate took a singularly 

 powerful effect, as the following table will show : — 



Yield on Yield on Top Increase 



Manure. Undressed. dressed by 2 cwt.- 



2^ acres. 2§ acres. IS itrate. 



Turns of ■ 



the Drill, Cwts. Bushels. Bushels. Bushels. 



10 Guano . 



10 Blood . 



10 Eapedust 



10 Nitrate 



2 Nothina: 



3 6i 13 



3 6f 12* 



6 4* llf 



3 5i 11-i- 



0 1 2f 



Five acres. 23-|- 51 i 



* Transactions of the Higbland Society, July, 1853, p. 16. 



1. 



