358 COMPARATIVE EFFECTS OF STRAW AND STRAW ASH. 



great skill in the practical farmer to apply for a time the ashes only of 

 his stravs"- — or some other saline mixture to his land. 



The practice of burning the stubble on a windy day has been found 

 in the East Riding of Yorkshire to produce better clover, and to cause 

 a larger return of wheat, (British Husbandry, ii., p. 333) — for this 

 purpose, however, the stubble must be left of considerable length. In 

 Germany, rape straw — which the above table shows to be rich in saline 

 and earthy matter, and, therefore, exhausting to the land — is spread 

 over the field and burned in a similar maimer. The destruction of 

 weeds and insects which attends this practice, is mentioned as one of its 

 collateral advantages, (Sprengel, Lehre vom Diinger, p. 355.) 



In the United States, where, according to Captain Barclay, the sti:aw 

 is burned merely in order that it may be got rid of, (Agricultural Tour 

 in the United States, pp. 42 and 54,) it would cost little labour to apply 

 the ash to the soil from which the straw was reaped, while it would 

 certainly enlarge the future produce — and in Little Russia, where from 

 the absence of wood the straw is universally burned for fuel, and the 

 ashes afterwards consigned to the nearest river, the same practice 

 might be beneficially adopted. However fertile, and apparently inex- 

 haustible, the soils in this country may appear, the time must come 

 when the present mode of treatment will have more or less exhausted 

 their productive powers. 



It is not advisable, as I have already said, wholly to substitute the 

 ash for the straw in ordinary soils, or in any soils for a length of time, 

 yet that it may be partially so substituted with good effect — or that straw 

 ashes will alone give a large increase of the corn crop, and therefore 

 should never be wasted — is shown by the following comparative experi- 

 ments, conducted as such experiments should be, during an entire rota- 

 tion of four years. The quantity of manure applied, and the produce 

 per imperial acre, were as follows : 



15 cwt. barley 3 tons stable dung 2 tons of rotten 

 No manure. straw burned in the straw dung eight 



on the ground. state. months old. 



1°. Turnips, 22 lbs. 8^ cwt. 18| cwt. \^% cwt. 



2°. Barley, 14f bush. 30i bush. 30^ bush. 30f bush. 



3°. Clover, 8 cwt. 18 cwt. 20 cwt. 21 cwt. 



4°. Oats, 32 bush. 18 bush. 38 bush. 40 bush. 



The kind of soil on which this experiment was made is not stated, 

 (British Husbandry, ii., p. 248,) but it appears to show, as we should 

 expect, that the effects of straw ash are particularly exerted in promot- 

 ing the growth of the corn plants and grasses which contain much sili- 

 ceous matter in their stems — in short, of plants similar to those from 

 which the ash has been derived. 



Theory of the action of straw ash. — That it should especially pro- 

 mote the growth of such plants appears most natural, if we consider 

 only the source from which it has been obtained, but it is fully ex- 

 plained by a further chemical examination of the ash itself. The so- 

 luble matter of wood ash in general contains but a small quantity of 

 silica — while that part of the straw ash which is taken up by water 

 contains very much. Thus a wheat ash analyzed by Berthier contained 

 of— 



