154 ACTION OF SOIL ON FOOD OF PLANTS IN MANURE. 



tliat liitherto the practical farmer has troubled himself 

 very Httle about the causes of those facts, as, indeed, the 

 investigation of causes is not his proper business ; while 

 those who have undertaken this task show, by the way in 

 which they attempt to discharge it, that they are but little 

 acquainted with the plant as an organised being, having 

 pecuhar requirements which must be accurately known 

 by all who would cultivate it properly. 



In the following remarks I shall compare a pea-plant 

 with a cereal, and shall call the attention of agricidtur- 

 ists to certam peculiarities which have to be considered 

 in the cultivation of both plants. 



A moderately moist, strong soil, not too cohesive and 

 perfectly free from weeds, is particularly suited for peas 

 and barley ; a well-tilled, calcareous loam or marl is the 

 best for both plants. An arable surface soil 6 inches 

 deep suffices for barley, which, with its fine-matted roots 

 spreading in tufts, finds a loose subsoil rather injurious 

 than beneficial. Fresh manuring just before sowing acts 

 powerfully on the growth of barley. Whilst the barley- 

 corn should not he lower than 1 inch, the pea thrives 

 best if the seed is put 2 or 3 inches deep in the soil. The 

 roots of the pea-plant do not spread sideways but go 

 deep into the eartli ; hence peas require a deep soil tilled 

 down, to the lower layers, and a loose subsoil. Fresh 

 manure has scarcely any influence upon the growth of 

 peas. 



It results from these pecuharities of both plants, that 

 the barley derives the conditions of its growth principally 

 from the arable surface soil, the pea principally from 

 the deeper layers of the soil. What the ground may 

 contain below the depth of 6 inches is a matter of indif- 

 ference for the barley ; the contents of these deeper 

 layers are everything to the pea. 



