388 



Nitrate of Soda as a substitute for Guano. 



on light soils* to use at that season either one or the other? 

 When we consider how soon the growth of autumn-sown wheat 

 comes to a standstill, to provide it with manure, in the hope that 

 the food may remain safe for its use in the spring, seems at best 

 a venturous precaution, like placing beneath an infant's pillow 

 the cates intended for its morning repast. 



There remains only to be considered the application of guano 

 to turnips, but here the comparison of the two manures is less 

 easy, because a previous question arises whether either one or 

 the other should be applied to turnips at all, or whether in the 

 culture of those roots we should not rather rely upon bone-earth. 

 From experience I have long done so on my own farm ; there 

 are on record experiments clearly showing that on some land 

 superphosphate is not only cheaper than guano, but more effec- 

 tual ; and as the consumption of guano for this purpose is very 

 great, especially among the spirited farmers of East Lothian, it 

 will be worth while to recall one or two of those experi- 

 ments, and first a very striking one made by Mr. Drewett, near 

 Arundel :t — 



"Weight of Turnips 

 per acre. 



Purchased manure — Tons. Cwts. 



None 5 18 



2th cwt. Peruvian guano 9 2 



3^ cwt. African guano .13 1 



Superphosphate from 6 bushels bones 17 10 



It is observable here that not only has the superphosphate 

 excelled the guano, but the cheap African has surpassed the 

 dear Peruvian guano, because it contains less nitrogen indeed, 

 but more of the phosphates. Mr. Caird also states that the 

 inferior and cheaper Bolivian guano is better for turnips than 



* On strong soils the case is different, as the following experi- 

 ment made by Mr. Caird at Baldoon, in the same wet autumn of 

 1852, clearly shows. The result was as follows : — 



^Experiment with Guano on Wheat sown after Fahow on drained alluvial Clay, 

 the Guano (Peruvian) harrowed in with the seed, 20th Sept., 1852. 



Gain after 

 deducting 

 Cost Yield in cost of 



per Acre. Bushels. Increase. Manure. 



Wheat at 7s. 



1. One acre without manure . . 35 



2. „ 2 cwt. guano . 20 44 9 43 



t Journal, vol. i. p. .582. — Each lot received also 20 bushels of dung, and 200 to 

 250 bushels of turf-ashes. 



