UPPER INDIA. 07 



overcropping the land ; crops being taken from the land in 

 more rapid succession than was formerly the case; and the fact 

 of its never being allowed to lie fallow has exhausted the land. 

 If, however, this were the real reason, land must very soon 

 become exhausted by bearing crops; but experiments have 

 been carried on in England where land has been cropped with 

 wheat for twenty years in succession, without manure, and 

 on which there has not been any material diminution of the 

 crop. 



These experiments were made with the express purpose of 

 finding out to what extent the soil was deprived of its elements 

 of fertility by continuous growth of crops without being ma- 

 nured, and the result has shown that under cropping lands do 

 not so rapidly become exhausted as was formerly believed to 

 be the case. 



The real reason of the falling off in the produce of canal- 

 irrigated lands appears to be the consolidation of the pan by 

 the treading of the cattle in ploughing and the hardening of 

 the upper soil by irrigation. This causes shallower ploughing, 

 the roots of plants have less depth of soil in which to search 

 for food, and cannot force their way into the hardened pan ; 

 and there is the alternate soaking and drying of the land, 

 during which the natural salts of the earth are gradually 

 brought nearer the surface by capillary attraction. 



This process may go on for some years before the land 

 shows any excessive amount of reh on the surface ; but the 

 soil is steadily being poisoned by its accumulation in the 

 upper soil, which accounts, together with the increased hard- 

 ness of the soil, for the diminished fertility of lands some time 

 under irrigation. 



Irrigation merely acts as a stimulant for a short time, and 

 eventually reduces the productive powers of the laud. This 

 could be tested by comparing the produce of lands for the 



F 2 



