MIXTtTEE OP SOILS. 363 



liquid manure impregnated with lime, were used as a top- 

 dressing on diflFerent parts of the same field. The mud 

 was hauled out in the autumn and thrown in heaps, and 

 there left to the action of the frosts and snows of win- 

 ter. In spring it was spread about the same time the 

 other manure was applied. Strange as it may seem, the 

 top to which the mud was applied appeared to far the 

 best advantage. The grass was heavier, and, after the 

 crop had been removed, that part of the field on which 

 the mud was applied came in more quickly and luxu- 

 riantly than the rest. This field was a light, gravelly 

 soil, which had not been under very high cultivation. 



Many of our soils are gravelly, with a mixture of 

 sand. These soils need a mixture of marl and meadow 

 mud. Marl and mud contain the carbonate, or in some 

 cases the sulphate of lime, or plaster of Paris, and often 

 a mixture of clay, which sandy or gravelly soils need. 

 On these soils clayey mud has been found to do the 

 best. Peat mud is a rich vegetable food ; and if a 

 small proportion of potash, or ashes, be added, it is val- 

 uable as a manure. 



Light soils are always improved by any substances 

 which make them firmer and more compact. Stiff clay 

 soils, on the other hand, are benefited by applications 

 which make them lighter and more permeable. No one 

 of the three kinds of earth, sand, clay, and lime, when 

 unmixed with the other varieties, would be capable of 

 supporting vegetation. The mixture of them, when any 

 one predominates, will correct and improve them; since 

 it is well known that the fertility of soils depends upon 

 the relative proportions of their difierent constituents. 

 In some marls the clay predominates, and these should 

 be used on the light, sandy soils ; in others, the sand 

 predominates, and these are adapted to stifier lands. 

 The practice of mixing soils has always been attended 



