CEREAL CULTIVATION GREAT PLAINS 341 



rainfall is not sufficient to furnish surplus water, there 

 are no marsh lands worth considering, and, therefore, 

 drainage is nowhere, at present, a serious problem. 

 There are, however, places in the Red River-of-the-North 

 Valley where drainage is needed for the best farming 

 operations. 



367. Soil amendments. As the soil in this area is 

 usually fairly well supplied with plant-food and is seldom 

 or never acid, soil amendments are not so necessary as in 

 the Eastern area. Stable manure, green-manuring, crop 

 rotations, and good cultivation are the chief means of 

 increasing crop production. Whether commercial ferti- 

 lizers are really needed in this area, considering present 

 benefits, cost, and future welfare of the land, is a question 

 not yet satisfactorily settled. According to Ladd (1901, 

 p. 702), soils, fertile as those of the Red River Valley, 

 should, under a system of cropping including 2 humus- 

 producing for every 3 humus-consuming crops, " yield 

 good crops without the aid of commercial fertilizers for a 

 thousand years. This assumes the proper use of all barn 

 manures, and the prevention of unnecessary loss from 

 the soil." However, in Victoria and New South Wales, 

 with a rainfall averaging 10 to 12 inches, applications of 

 superphosphate fertilizers, and, in certain cases, sulfates 

 of potash and ammonia, gave from 20 to 30 per cent in- 

 crease in yields of wheat, an increase nearly twice as great 

 as that resulting from summer fallow (Guthrie, Helms, 

 and Howell, 1901, 1902, 1904). 



368. Barnyard manure. There is very little infor- 

 mation of value on the effects of barnyard manure in the 

 Great Plains area. In some places certain plant-foods 

 may be lacking, and, what may be more important in this 

 area, the organic matter will bring into use mineral foods 



