^96 BOARD OF AGRICULTURE. 



not gain anything beyond that. In the clover, at the time of 

 budding, their length was eighteen inches ; in bud, sixteen inches. 

 That looks like going back ; but you must remember that the roots 

 measured in the one case were not the same as those measured in 

 the other, but were from another plot of ground. In blossom, 

 they were fourteen and one-half inches ; when ripe, fifteen inches. 

 The grand result is simply this : that wherever rye roots were 

 eight inches, clover roots were twice that length ; and this in 

 soils which I suppose were quite similar in character. That is a 

 piece of information of great value. 



Mr. Lyman. I have heard old men express the opinion that the 

 principal benefit of clover arose from the large amount of root 

 which is left in the ground, even after it is plowed under. I sup- 

 pose that to be the fact. 



Prof. Johnson. Undoubtedly so. 



Mr.- Lyman. If we grow a plant which has a very small root, 

 of course the vegetable matter to supply the succeeding crop is 

 comparatively small. 



Prof. Johnson. I have heard old farmers, and young ones too, 

 say that they would give more for that part of the clover crop 

 below ground than for the part above ground. You have here an 

 accurate setting forth of the proportions. Look at the figures 

 which represent the weight of the top and of the roots. You see 

 there is a rapid increase in the amount of top in the rye plant — 

 from fifty up to two hundred and fifty ; but you observe that the 

 absolute amount of roots diminishes. Whether that is due to any 

 actual decay of the root, or whether to the fact that each result 

 came from a different plot of ground, or because of different care 

 in extricating the roots from the soil, we have no information. It 

 may be due to the fact that there was less development of root in 

 one place than in another. 



Question. Might it not be owing to an absorption of the root 

 into the top ? 



Prof. Johnson. It may be. I had supposed that old roots 

 would have the greater absolute weight. If these figures are 

 correct, they are interpreted by your suggestion, which is sup- 

 ported by some observations that have been made regarding the 

 mode of growth of the underground organs. 



In the next column of figures we have the ratio of root to top. 

 The root is taken as a fixed quantity, ten. In the case of rye we 

 have, in the first place, 10:17 ; then 10:45, 10:59, 10:136. In the 



