SOILS AND THEIR TREATMENT 



377 



porous, and fertile. Air sweetens and crumbles them. Appli- 

 cations of manure render them capable of supplying plant 

 food. They serve also to assist crops in dry weather in find- 

 ing root room and moisture ; they enable heavy surface rains 

 to pass away freely ; and as air always follows the retreating 

 moisture, these once useless, worthless subsoils in time 

 become of the most valuable description. There seems to 

 be absolutely no description of subsoil that cannot in this 

 way be made fertile. A most important product of deep 

 working or trenching ground is that, not only does it tend 

 in winter to keep the soil in which crops may be growing 

 drier than shallow soils do, but is also much warmer. In the 

 summer, when drought so commonly prevails, the deep 



Shows a deep or vertical section of deep trenching 

 after the ground has been previously well worked. 

 Both top and bottom spits of 12 inches of soil, A 

 and B, are thrown out, and the hard bottom soil, C, 

 is forked and broken up 12 inches deep. The en- 

 tire body of 2 feet of soil from the next trench, D, 

 is thrown out, and so on throughout the plot. 



working enables the roots of crops to go so much deeper, 

 where the soil is at once cooler and moister, and thus con- 

 tinue productive much longer. Remarkable illustrations of 

 the differences found in crops grown on deeply-worked and 

 shallow-dry soils are often seen on groups of allotments, 

 where the soil is quite of the same nature or texture. In the 

 first case the crops are robust and luxuriant ; in the latter 

 they are poor, soon ceasing to be productive. 



Operations. The process of trenching is simple enough, 

 but should be invariably performed during the winter months, 

 on plots that are for the time uncropped, and have not been 

 deeply worked previously or for several years. In good 

 class gardens the work is done about every third year, but 

 if done in gardens where labour is less abundant it is 

 carried out once in from four to five years. The first effort 

 of the cultivator in trenching where soils have not been so 



