68 EXPERIMENTS UPON OATS AND WHEAT. [Appendix, 



jfluence of great heat and drought, I select the more simple and striking cases 

 of diminution. tThe undressed part of the field produced 54 bushels per acre 

 Common salt diminished this produce by 6 bushels. 



Nitrate of soda 12^ " 



Sulphate of soda 15| " 



Rape-dust 9 " 



Soot I2i " 



while 2 cwt. of guano raised the produt 3 to 70 bushels, being an increase of 16 

 bushels. 



These results not only confirm the deductions which we have already drawn 

 from the preceding experiments upon potatoes and turnips — that guano will act 

 even in our driest seasons, while rape-dust requires at least occasional rain — but 

 they go further in showing that, like the saline substances, rape-dust, and even soot, 

 will viateriaUy diminish the oat crop, if the season be distinguished try remarkable 

 drought. 



2°, Moss oats. — The experiments upon moss oats (p. 53) are a continuation 

 and extension of those of 1841 with greater attention to accuracy in the determi- 

 nation of the produce. The last column in the table speeiks for itself. The 

 general produce of the field being 43 bushels per acre. 



Increase. Cost per bush. 



Sulphate of ammonia gave ... 9 bushels 2s. 3d. 



Sulphate of soda with nitrate of soda gave 18 bushels Is. 7d. 



Bones in muriatic acid gave ... 18 bushels Is. 6d. 



Silicate of potash, mixed with the above, gave 22 bushels 2s. Od. 



m the last two cases the straw, which is usually imperfect in oats grown upon 

 Mioss land, was strong and healthy. It is obvious, therefore, that all these exper- 

 iments deserve repetition, though, as here set forth, the increase of grain by Nos. 

 2 and 3 was obtained at the least cost, and, therefore, to the economist will ap- 

 pear most important. 



E, — The Experiments upon Wheat. 

 I, Effect ofdro^ight. — The first series, tliose made at Lennox Love, afford in- 

 teresting illustrations of the effect of great drought in modifying the action of sa- 

 line manures and of rape dust, upon the wheat crop. The more prominent 

 results are distinctly brought out when thrown into the following form. The 

 produce of the undressed part of the field being 47^ bushels an acre, this produce 

 was affected by the several substances employed in the following manner: — 



Decrease per acre. Increase per acre. 



Common salt, 1 cwt H bush. — 



. 9i bush, — 



slight. — 



— slight. 



— 3i bush. 



— J bush. 

 Thus, the nitrate of soda and the soot did no harm, though the drought did 



not permit them to do any good. Common salt slightly, and sulphate of soda 

 largely diminished the crop of grain — while of these four substances the sulphate 

 was the only one which diminished the yield of straw. Nitrate of soda and 

 soot largely increased it. 



On the other hand, guano slightly increased the yield of grain, and rape-dust 

 added 3| bushels to the natural produce, both also augmenting the weight of 

 the straw by about one-tenth of the whole. 



In this case, then, the rape-dust surpassed in beneficial effect the natural 

 guano, though, as we have already seen, it proved greatly inferior to the latter 

 when applied in similar proportions to oats, potatoes, and turnips. 



2°, Suggestion VIII. — This fact suggests an interesting inquiry. It is known 

 that :>ne of the most lucrative modes in which rape-dust has been hitherto 



Sulphate of soda, 1 cwt. 

 Soot, 32 bush, . 

 Nitrate of soda, I cwt. 

 Rape-dust, 16 cwt. 

 Guano, 2 cwt. 



