AND RURAL ECONOMIST. 201 



That its effect is graduated by the quantity of vegetable 

 matter on which it is sown. That on closely grazed land it 

 does Httle good at first, and repeated would become perni- 

 cious ; and that it must be united either with long manure 

 of the winter, or the ungrazed vegetable cover produced in 

 the summer. That all crops are ultimately improved bj its 

 improving the soil, even when its effects are not imniediately 

 visible ; but he does not recommend it as a top-dressing, ex- 

 cept for clover. 



M. Canolle, a French writer, observes, that plaster, act- 

 ing chietiy on the absorbent system of plants, its effects are 

 not like those of manure buried in the soil, which act prin- 

 cipally on th ^ roots. The latter, according to their particu- 

 lar nature, divide, soften, enrich, warm or stiffen ihe sods 

 with which they are mixed. The quantity of plaster spread 

 upon the land is so trifling that it can have little effect on 

 the soil. I speak from experience. Plaster buried in the 

 earth where sainfoin has been sown, has produced little al- 

 teration ; whilst the same quantity of plaster spread over the 

 same surface of sainfoin has produced the most beautiful 

 vegetation. 



' From this experience, so uniform in the application of 

 plaster, I am led to believe, that one must consult as w^ell 

 the nature of the soil, as the kind of pkmts to which we ap- 

 ply plaster. Thus, whatever may be the soil, on which clo- 

 ver, lucerne, and sainfoin naturally flourish vigorously, or 

 with that vigor whicli encourage us to apply manure, there 

 is no risk in trying plaster. 



' It is to be remarked, that plaster operates on plants in a 

 direct ratio to the size and number of their leaves. I have 

 spread plaster on land where sainfoin was mixed with the 

 common grasses which compose our meadows. The growth 

 of the sainfoin and wild honey-suckle has been beyond com- 

 parison greater than that of the common grasses. It is to 

 this cause I attribute the failure of success on grass ground 

 chiefly filled with common grasses. I have a field of lucerne 

 separated from a natural meadow only by a brook. I have 

 greatly increased the lucerne by the plaster, whilst the effect 

 of a like quantity on the adjoining grass land was scarcely, 

 if at all perceivable. 



It has been ascertained by repeated experiments that a 

 liberal application of plaster to clover, at the time of turning 

 it down and preparing for a wheat crop, is by far the most 

 advantageous to the crop, and much preferable to turning in 



