54 



DRY FARMING 



pleting the humus and the nitrogen content has been 

 shown by Shutt, Dominion Chemist, from the folloAving 

 figures* : 



Table X. — Nitrogen-content of Virgin and Cultivated Soils, Indian 

 Head, Saskatchewan. 



Doneghue of the North Dakota Experiment Station 

 arrived at similar conclusions with the fertile Red River 

 Valley soil, under a system of continuous wheat-growing, 

 as indicated in table XI. 



Table XI. — Composition of Old Wheat Soil in Comparison with 

 Virgin Sod.f 



Doneghue concludes that, "The black clay soil of the 

 Red River Valley has deteriorated in fertility and crop- 

 producing capacity under a continuous system of single 

 cropping with wheat. Such land on the Experiment 

 Station contains approximately one-fourth to one-third 



* Western Prairie Soils. 



tFrom North Dakota Experimental Station Bulletin 126. 



