Af/ricultiiral Chemist ry — Titrnips. 



561 



matter were once placed upon a farm exportino^ on\y corn and 

 meat, the loss in these two substances would not be greater than 

 what would be supplied in return by the atmosphere; but the ex- 

 periments of Boussingault and Dr. R. D. Tiiomson show that 

 the amount of such matter respired by an animal^ and therefore 

 lost to a farm, is very great ; indeed we should not be far wrong 

 if we said that in feedhig a crop of turnips by stock one-half of the 

 carbonaceous matter in it is lost to the farm. To restore the loss 

 of organic matter most economically, various processes are recom- 

 mended : some advocate the consumption of artificial food with the 

 turnip ; some the employment of ammoniacal substances to collect 

 carbon from the atmosphere ; and some maintain that if the mine- 

 ral substances composing the ash of the turnip were restored to 

 the soil, it could supply itself with organic matter. To commence 

 with the mineral manures, — Analysis has shown that a great por- 

 tion of the ash of the turnip consists of the alkalies, potass and soda, 

 and of magnesia — and these substances have been recommended 

 in the formation of mineral manures ; we think, however, that a 

 careful examination of the position which the turnip-crop holds 

 in a rotation, and the manner in which its organic and inorganic 

 matters are applied in farm practice, will show that the artificial 

 supply of alkalies can rarely if ever be advocated. A fair crop of 

 turnips would contain in leaf and bulb about one ton and a half of 

 dry matter, of which 250 lbs. would consist of minerals. Omit- 

 ting those minerals which are of less importance, we may consider 

 the composition of the crop as follows : — 



Dry organic matter . 3110 



Potash . . . 127 



Phosphate of lime . 50 



Sulphate of lime . . 40 



Of the organic matter, more than one half of the carbon, but 

 probably scarcely one fourth of the nitrogen, is lost to the farm 

 by the respiration and increase of the stock.* The amount of 

 phosphate of lime removed would vary greatly with the nature of 

 the stock consuming the turnips. A breeding flock or young 

 growing animals abstract large quantities to be employed in the 

 production of bone, while full-grown animals require very much 

 less. Of the alkalies contained in the ash of the turnip the 

 stock return to the soil all they take up. Barley generally fol- 

 lows after turnips, the greater part of which is taken to market. 

 A crop of 40 bushels carries off phosphoric acid equal to about 

 28 lbs. of phosphate of lime and 9 lbs. of potash. The clover 

 following the barley, being consumed by stock, causes a further 

 loss to the farm of organic matter and phosphate of lime, but no 



• This retention upon the farm of nitrogen specially demands more notice 

 than our space permits. 



