TRANSACTIONS OF SECTION D. 



741 



4. Note on the Nitrogenous Nutrition of the Bean. 

 By S. H. Vines, B.Sc, F.R.'S. 



[Preliminary communication.] 



I give here the results of some observations on water-cultures of the bean 

 ( Vicia faba) as a contribution to a subject which has already been much dis- 

 cussed, but without any generally accepted decision having been arrived at. 



It is generally admitted that a leguminous crop does not impoverish the soil as 

 regards combined nitrogen but rather enriches it. It occurred to me to observe 

 the effect of growing beans in solutions, some of which did and some of which did 

 not contain combined nitrogen. 



Young bean-plants, about a week or ten days old, were placed, on June 25, 

 1887, with their roots in the following solutions (three in solution I., three in solu- 

 tion II.) :— 



Analysis of solution II. showed that no combined nitrogen, other than a trace 

 of free ammonia, was present. 



After being ten days in the water-cultui-e the cotyledons were removed from 

 two plants of I. and II, respectively. 



The plants all grew well, but those in solution II. grew better than those in I. ; 

 they all flowered, but in no case, possibly owing to non-fertilisation, was any seed 

 formed. 



After flowering, the plants began to dry up: the experiment was closed on 

 August 12. 



After the removal of the plants the liquid in the six pots was examined. The 

 liquid in the three pots of II. was turbid and of putrescent odour, whereas that in 

 the three pots I. was comparatively free from turbidity and from smell. The tur- 

 bidity in pots II. was largely due to bacteria. 



For the purpose of tabulation the pots may be distinguished thus : — 



yy' \ with Cotyledons. yy- 



II.3 



They were examined qualitatively for ammonia and albuminoid nitrogen, and 

 quantitatively for nitrates. No nitrites were foimd. 



without Cotyledons. 



The solutions I.j, I..,, I.3, each contained originally 14 mgrs. N m 100 cc. It will 

 be noticed that rather less of the combined nitrogen supplied was absorbed by the 

 plant which retained its cotyledons than by those which were deprived of them. 

 The general result of the experiment seems to indicate that a bean-plant can obtain 

 suppUes of nitrogen even when growing in a soil in which no combined nitrogen is 

 originally present. 



It may, however, be objected that plants 11^ and IT, which retained their 



