338 Transactions of the A2ierican Institute. 



acid, wliich in its turn is absorbed by the leaves of the plants of the 

 succeeding crops, and also acts to some extent in dissolving the 

 minerals in the soil. This is about all the benefit that results from 

 green manuring with shallow rooted plants, like buckwheat and 

 rye. The deep rooted plants, like clover, enrich the soil in addition 

 to this by bringing up mineral constituents, like potash, etc., from 

 the subsoil, where they would not otherwise be reached. 



Mr. A. S. Fuller. — Why not subsoil, in the first place, and bring 

 up these substances in that way. 



Mr. James A. Whitney. — Because tliis would bring up many 

 substances that we don't want brought up. For instance, in those 

 subsoils that contain peroxyd of iron, together with organic matter. 

 The decay of the organic matter abstracts oxygen from the peroxyd, 

 and converts it into what chemists call a protoxyd. This is very 

 hurtful to plants, and if brought to the surface would do more harm 

 than the other results of subsoil would be likely to do good. Besides, 

 clover roots will draw up fertility from the subsoil a great deal cheaper 

 than you do it with a plow. 



Mr. N. C. Meeker. — Some members, horticulturists, are saying in 

 an undertone, that clover is the best thing for an orchard. !N^ow, let 

 us know distinctly whether it is proper to sow a young orchard with 

 clover, or is it not. Hundreds and thousands want this question 

 answered. 



Dr. Isaac P. Trimble. — The great trouble with those who have 

 oi>cliards is, that they want to get two crops from the same ground, 

 "which cannot be done ; certainly not if a permanent and profitable 

 orchard is required. If we are to have apples, we must be content 

 with apples. There are a few orchards in west Jersey where buck- 

 wheat was sown and tm-ned under year after year, other fertilizers 

 were applied, and these are the only orchards I know of which con- 

 trive to bear fruit. On the other hand, the ground of the great mass 

 of orchards has borne in corn, potatoes, grass, and rye, and with the 

 help of the curculio they are ruined. 



Dr. J. E. Snodgrass. — Clover has great value, because it has the 

 property of absorbing phosphorus from the air. 



Mr. James A. Whitney. — The doctor is mistaken with regard to 

 this alleged property of clover. Phosphorus does not exist in 

 the air, but as phosphoric acid is drawn from the soil by the 

 roots of plants. It occurs in the first instance in the older or grani- 

 tic rocks. As the rocks become disintegrated, the phosphorus, in the 



