The Food of our Agricultural Crops. 
79 
are seeking with regard to the influence of the leguminous 
crop, but some very valuable knowledge has been obtained. 
Altogether, six bean crops and four crops of red clover have been 
grown. Comparing the wheat which followed the beans with 
that which followed the fallow, it may be said that the latter was 
the better crop ; and, the better the season for wheat, and the 
larger the general yield, the greater was the superiority of the 
fallow wheat. This was clearly shown in the year 1863, when 
the wheat crop was one of the largest ever grown in this country. 
The following table gives the produce of the wheat after a 
summer fallow and after a bean crop : 
Buslicls per acre 
Unmanured Mineral manures Uighly manured 
After fallow , , . 45 46 52£ 
After beans .... 34 34§ 46 
Fallow more than beans .11 11 f 6£ 
This was the sixteenth year of the experiment, during 
which period the whole of the crops grown upon the land 
had been carried away. As we know with something like 
certamty that the yield of a wheat crop depends greatly upon 
the amount of nitric acid at its disposal in the soil, it appears 
probable that the large increase of the wheat crops upon the 
fallow-land, compared with the bean-land, was due to the beans 
having taken up nitric acid from the soil. In 1871, the wheat 
crop was as bad as that of 1863 was good. The yield upon the 
unmanured land after fallow was 11^ bushels per acre ; after beans, 
2(H bushels. Upon the land receiving minerals after fallow it 
was 16 bushels ; and after beans, 24 bushels. The season was 
very wet ; and though we may assume that a large amount 
of nitric acid was washed out of both the bean- and fallow-lands, 
the wheat upon the bean-land was benefited by the nitrification 
of the crop-residue of the beans, which would take place during 
the spring and summer. 
It is somewhat remarkable that, upon land which has received 
no manure for forty years, and from which the whole produce 
upon it has been carried away, the average of ten crops of 
barley has been 30 bushels, and of wheat, 28^ bushels. While, 
therefore, grain crops can manage to find sufficient food in the 
soil to grow well, none of the so-called "restorative" crops 
could thrive. The turnips, after the first crop had been carried 
off, were little larger than radishes, and the next nine crops 
were valueless. The beans gave only 12 bushels per acre, while 
the clover in 1874, cut three times, only yielded 1£ tons of hay, 
although no clover had been grown upon the land for twenty- 
