151 



The Important facts that seem to be established by the re- 

 sult of this experiment are — 



First. That for potatoes it is better to spread the manure, 

 and plough it in four inches, than any other depth, or to apply- 

 ing the manure in the furrow and putting the seed on it — the 

 reason of which I think is that all the growth of the potato 

 plant and of the new tubers is above the seed planted ; hence 

 manure placed below the seed is quite or nearly out of the 

 natural reach of the plant ; but let the manure be placed above 

 the seed, and the growth of rootlets and tubers is among the 

 enriched soil ; the plant draws its nourishment directly from it ; 

 and at every hoeing the enriched soil is thrown directly about 

 the plant, which causes new rootlets and tubers to put forth. 



Secondly. That one-third of the virtue of manure is re- 

 tained in the ground after a potato crop for the next year's 

 crop. For a crop of mangolds, and probably other gross feed- 

 ing plants, the advantage of heavy manuring over no manure 

 is over one hundred per cent, or in other words a crop without 

 manure may not pay expenses, when a crop highly manured 

 would be very profitable. 



Thirdly. That there is no perceptible virtue of manure left 

 in the land the third year for a crop of carrots, though I think 

 it would prove otherwise with some other crops ; and that 

 there is no advantage in high manuring, shown by this experi- 

 ment, for a crop of carrots, as the increase in the crop is com- 

 paratively small, although the growth of tops was very much 

 larger. I conclude that carrots exhaust land much less than 

 most other crops, hence the superior condition of land after 

 carrots for succeeding crops the next year. 



