20 VOELCKEE on the Scouring Lands 



forcing effects of the fertilizers employed and the consequent 

 luxuriant growth of the young herbage. 



In scouring pastures there is abundance of plant-food, and 

 hence in the drier summer months the herbage on such pastures 

 grows with great luxuriance. The direct use of manure in- 

 creases still further this luxuriant growth of the herbage, but 

 at the same time retards its getting mature soon enough before 

 it has to be made into hay. Hence the use of manures generally 

 aggravates the scouring properties of the herbage. An excess of 

 manure under all circumstances retards the ripening process, and 

 tends to produce less wholesome and less nutritious roots, green 

 and fodder crops ; whilst a scanty supply of manure on naturally 

 poor soils tends to push on plants to early maturity. It is upon 

 this principle that gardeners act when they require to force 

 flowers into .early bloom. 



Again, the fact that the complaint ceases almost entirely after 

 the first November frost finds a ready explanation by my 

 views on the character of the herbage from scouring pastures. 

 Like the unripe wood of our fruit-trees, the unripe young 

 clover-leaves and grass-shoots in ' our meadows are killed much 

 more readily or changed in composition than the older and more 

 matured portions of the herbage. But as the immature young 

 leaves and grass-shoots only have medicinal effects, the pasture 

 becomes either altogether sweet after the first autumnal frost, or 

 the evil is seen in a much more mitigated form on land which 

 scours during the summer months. 



It -now remains for me to point out how it is that scouring 

 land frequently does not bring the herbage to a sufficient degree 

 of maturity. 



In the first place I would observe that lias-clays contain an 

 excess of mineral food, and, being retentive even after draining, 

 they also often contain a large quantity of water. The excess 

 of water and coldness of the soil retard the early develop- 

 ment of the herbage. The upland position of all hill-pastures, 

 on which the evil generally preponderates, of course is also 

 unfavourable to an early growth of the herbage. But, more 

 than this, the peculiar tenacious character of the lias-clay sub- 

 soils on scouring land, the great depth of these clay-beds, and 

 their near approach to the surface soil, tend to retard vegetation, 

 and to make it very gradual during the colder and wetter months 

 of the year. In many cases under-drainage, besides taking off the 

 surface water, produces little alteration in the condition of the 

 surface soil, for the simple reason that it is too thin, and the 

 clay subsoil bed too tenacious and too deep to be penetrated by 

 the ameliorating influence of the atmosphere. 



