438 



MR. J. B. LAYVIX J;R. GILBERT, AND DR. PUGH OH 



parativcly large amount of Nitrogen, is one of the best preparation! for tin- after-growth 

 of wheat. On the other hand, it is equally true that fallow — one important eff< • 

 which is to accumulate within the soil the available Nitrogen of two or mere yean for 



the growth of one — and addimj nitriKjruons manures, have eaeh mnch the -ame effect in 

 increasing the produce of the Cereal crops. 



B. — Yield of Nitrogen per acre when Wheat is grown in alternation "•///< 



Beans, or with Fallow. 



The striking and interesting fact, that the growth (and removal from the land) of a 

 highly nitrogenized Leguminous crop, and fallow, have each the effect of increasing the 

 amount of produce, and with it the yield of Nitrogen per acre, of a succeed ii._ I 

 crop, is briefly illustrated by the summary of direct experimental results given in the 

 following Table : — 



Table III. 



Showing the Amount of Nitrogen obtained per acre, in "Wheat grown consecutively, in 

 "Wheat alternated with Beans, and in "Wheat alternated with Fallow. 



Period of Experiment ten years, 1850 — 1859 inclusive. 



It is seen, then, that ten consecutive crops of beans, without manure of any kind, 

 gave an average annual yield of Nitrogen, per acre, of 34*7 lbs. ; and ten consecutive 

 crops with "mineral" but without nitrogenous manure gave an average annual yield, 

 per acre, of 511 lbs. 



Note. — At page 439, line 3 from bottom, after " 



average annual amount, per acre, of 42-6 lbs." insert 

 The second and third courses gave, however, much less 

 than the first, and hence a less average per annum 

 than that stated for the twelve years. 



