634 
Rotation of Crops. 
superphosphate without potash. It would thus appear that 
the beneficial effects of the phosphatic manure on the clover 
were largely connected with the increased capability of the plant 
to take up more potash. 
With the mixed manure, supplying a large amount of potash, 
the amount of it found in the clover crops was, however, much 
greater still. Both in the beans and in the clover the amount 
of potash in the crops grown under the influence of the direct 
supply of it was about twice as much as those grown with 
superphosphate without potash. But whilst, under the influ- 
ence of the supply of it, the shorter-lived, more meagrely root- 
ing, and less successfully grown bean crops stored up only 
22T6 and 24 - 4-6 lb. of potash, the clover crops contained in 
one case 123*12 lb., and in the other 132 - 62 lb. 
The very much larger proportion of the total potash of the 
bean crops which is found in the corn than in the straw would 
seem to indicate its greater importance in connection with the 
maturing than with the merely vegetative and accumulating 
tendencies of growth ; yet the increased amount of it taken up 
by the beans coincidently with increased growth, and the much 
larger amounts of it in the clover with its much greater amounts 
of growth and produce, and harvested as it is in the unripened 
condition, are on the other hand indications of a direct connec- 
tion between potash supply and the luxuriance of growth or 
vegetative activity of these leguminous crops. Indeed, as already 
referred to, potash manures are well known to be frequently 
beneficial to such crops. To these points further reference will 
be made presently, when calling attention to the amount of 
lime taken up by leguminous crops. 
The Potash in the Wheat Crops . — The results on this point 
are given in the bottom division of Table IX. 
It has been seen that by far the larger proportion, both of 
the nitrogen and of the phosphoric acid of the wheat crops, was 
accumulated in the grain. But the figures relating to the potash 
show that of it there was very much more in the straw than in 
the grain. There was also much more, but not in so great a 
degree more, in the straw than in the grain of the other cereal 
— the barley. It bas been pointed out that potash is at any rate 
essentially connected with the formation of the carbohydrates. 
Consistently with this it was found that by far the larger pro- 
portion of the potash of the turnip crop was in the roots, where 
was the great accumulation of sugar. Again, of the total potash 
of the barley crop, the larger proportion was found in the straw 
where there was the greatest accumulation of carbohydrate — as 
cellulose : and now, in the wheat, with a larger proportion of 
