Agricultural Cliemistnj — Turn ips. 



509 



growth of turnips or other green crops by means of manure, the 

 attempt to grow such restorative crop without supplied aid, — that 

 is, manure, — is quite unavailing. We see that agency as well as 

 supjjhj is an essential element to be considered in the choice of 

 manures, and that unless such agency or condition of healthy 

 function be secured, a liberal provision of the materials of which 

 the plant is built up may frequently, to a great extent, be 

 useless to it. The matters which are most favourable to the 

 healthy action and rapid accumulation and assimilation by the 

 turnip, are the so cdi\\e(\. ''' mineral manures'' under the influence 

 of which a great regularity of plant and vigorous power of growth 

 are attained. At any rate, in the soil in question, w hen in a 

 condition of agricultiLral exhaustion, the supply of by direct 



manures seems unessential. But the direct supply of phosphoric 

 acid, whether by its reaction upon the soil or a special effect upon 

 the young plant, or from a combination of these influences, seems 

 to enhance the assimilating actions of the turnip to a degree much 

 beyond what could be attributed to it as a mere constituent, rather 

 than in some sort an agent also. We shall recur further on to 

 this interesting subject. 



Of the substances which we may term pure constituents, or- 

 ganic matters,'' and especially such as abound in carbon, must be 

 supplied for the production of agricultural crops of turnip-bulbs. 

 These manures, as well as those which are chiefly nitrogenous, 

 should never be concentrated near to the plant in its earliest stages 

 of growth, but only within its reach, when, under the immediate 

 influence of mineral manures, the young plant has so far developed 

 its organs of accumulation, and its healthy vigour, as to be com- 

 petent to grow faster than the natural atmospheric and soil re- 

 sources of nitrogen and carbon enable it to do. These are, we 

 conceive, the most prominent indications afforded by the results 

 of this our first season of experimenting upon the cultivation of 

 the turnip. As we proceed in our inquiry we shall see how far 

 they are confirmed by those which succeeded them, and w^hich we 

 shall now endeavour to detail. 



The whole produce, leaf and bulb, of 1843, was carted off" the 

 land. In the second year the manures had some reference to the 

 condition of soil as effected by the first year's treatment, and the 

 same division of the land, and the numbering of the plots, was 

 adopted. The manures were again drilled w ith the seed, and the 

 mechanical culture of the land before and after sowing, the estima- 

 tion of the crop, and its entire removal, were conducted as before. 



The entire series of results of this second season (1844) are 

 given in the following Table at one view, but we shall make se- 

 lections as before, for the convenience of detailed examination. 



