MANURES, AND MODE OF APPLYING THEM. 417 



events lead us to infer that it is far better to plough in 

 the manure for our mangold land in the autumn, than to 

 apply it at the time of sowing in the spring, when it 

 could have but little chance of giving its full value to 

 the coming crop. Organic manures, such as farmyard 

 dung, are always found to increase the yield ; but the evi- 

 dence in reference to the use of special ammoniacal manures 

 is, that although they increase the bulk, the increase is 

 mainly due to the extra proportion of water contained in 

 the root. Boussingault 1 recommends that the land in- 

 tended for mangold should be kept in high condition by 

 farmyard manure. Count de Gasparin 2 states, that the 

 cultivators in the u departement du Nord," the great sugar- 

 preparing district of France, consider that the addition 

 of farmyard dung increases the weight of the crop in the 

 proportion of 1/65 ton for every ton of dung applied. 

 M. de Dombasle, 3 farming a poor soil, estimates the re- 

 sulting increase at only about half as much; while M. 

 Crud,* upon a naturally good soil (Bas Boulonnais) ob- 

 tained an average increase of 2 tons to his crop, over and 

 above the natural produce of the land, for each ton of 

 farm dung he applied. Mr. Pusey's experiments 5 on the 

 action of dung and artificial manures upon beet-root, 

 show that upon a soil whose natural produce, unmanured, 

 was 15J tons per acre, an increase was obtained of 1 ton 

 for each load of manure applied, up to a certain yield, 

 28J tons, after which the addition of more dung produced 

 no effect. By combining highly nitrogenized manures 

 Peruvian guano or woollen rags with the dung, the yield 

 was forced up to 36 tons per acre no bad return on land 

 which only four years before, when he took it in hand, 

 was reputed to be incapable of growing a turnip. 



1 Economic Rurale. 2 Cours d' Agriculture, tome i. p. 655. 



3 Annales de Roville, tome vii. p. 255. 4 Economic de I' Agriculture, 205. 

 5 Roy. Agri. Soc. Jour., vol. vi. p. 531. 



