128 IIORTUS GRAMINEUS WOBURNENSIS. 



growth, offer sufficient proofs to decide that it is not to the great 

 leno-th of time they require to arrive at perfection that the want 

 of success, in attempts to renew rich pastures, is to be imputed. 



On converting this land into tillage, the first crops are generally 

 too luxuriant. Were we to conclude, from this circumstance, 

 that the superior pasture grasses require a much richer soil to 

 produce them in perfection than what is required for the produc- 

 tion of grain crops ; and, consequently, that a course of white 

 crops, by lessening considerably this degree of fertility, would 

 proportionally render the land less fitted for the re-production of 

 its former valuable grasses, it would not be just; because it is 

 evident that this over-richness of the land for the first crops of 

 grain, does not arise solely from that degree of richness in the soil 

 which produced the superior grasses in such abundance, but rather 

 from the accession of so large a quantity of vegetable matter, 

 which is at once supplied to the land by ploughing in the turf 



Havino- met with no specific information in any agricultural 

 works within my reach, respecting the change produced on the 

 nature of rich pasture land by a course of grain crops, I made 

 several experiments to supply the apparent defect. The results 

 of one of these experiments I may be permitted to detail. 



A space of two square yards of rich ancient pasture land was 

 duo- to the depth of the surface soil, which was eight inches, and 

 removed to a place more convenient for making the experiment, 

 but placed on a subsoil of the same nature as that on which it 

 was before incumbent. Three inches from the bottom of the mass 

 were first placed on the subsoil, and the turf was then reversed on 

 this, to the depth of five inches : this mode was adopted, to place 

 the oround under circumstances as similar as possible to that of 

 ploughing it five inches deep, in the usual manner of breaking up 

 pasture land. 



The nature of the soil was now ascertained, by taking up a 

 portion of it to the full depth, only rejecting the green living 

 vegetable parts of the turf. 



400 o-rains, freed from moisture and the plants of grass, con- 

 sisted of — 



Calcareous and siliceous sand, of different 



degrees of fineness - - - 102 grains. 



Decomposing vegetable matter, and par- 

 ticles of roots - - - 55 

 Carbonate of lime, or chalk - - 160 



