SOILS — FEETILIZEES. 129 



at the Iowa Station in 1904 with a view to studying the designing, construction, 

 and operation of sewage disposal plants adapted to private houses, and describes 

 with detailed plans and specifications a model plant which is recommended for 

 this purpose. 



SOILS— FERTILIZERS. 



Soils of the Ozark region, C. F. Marbut (Missouri 8ta. Research Bui. 3, pp. 

 151-273, pi. 1, map i).— This is a report on the soil groups of the Ozark region 

 of Missouri. The soils are broadly classified, and each kind of soil is described 

 as to origin, character, distribution, and general fertility. 



Regarding the soils in general the author states : 



"These soils are all silts of varying colors, running from black, through 

 various shades of reds and yellow, to white or gray. The proportions of clay 

 and sand never or very rarely run high in any of these soils. They are, 

 therefore, usually mellow, or are easily made so with fair treatment. They are 

 well drained, also, and are moderately early and warm. These characteristics 

 are due in part to the greater or less abundance of stone or gravel in the soil. 

 It is almost universal in its occurrence and in some of the types it is very 

 abundant. 



"The subsoils are universally reddish in color. The intensity of the color 

 varies somewhat but is everywhere greater than that of the soil. Like the soils 

 they contain a considerable proportion of silt, very little sand, but also a con- 

 siderably higher percentage of clay than the soils. The average percentage 

 of clay in the soil runs from 10 to 20 and that of the subsoil is a little higher 

 as a rule but rarely running above 20. 



" Like the soil, the subsoil has a varying proportion of stones and gravel 

 intimately mixed with the other constituents. Where the soil is extremely 

 stony the subsoil is slightly less stony. Where the soil has very few stones 

 the subsoil usually has a higher proportion. The stone content in the subsoil 

 is more constant over the region as a whole than in the soil." 



A comprehensive discussion on the agricultural conditions and possibilities 

 of the Ozark region and of the systems of farming adapted to the region is also 

 presented. 



Soil management in the Ozark region, M. F. Millek (Missouri Sta. Bui. 88, 

 pp. 163-189, figs. 9, map 1). — The work here reported was supplementary to 

 that recorded in the general report on the soils of the Ozark region noted above, 

 and consisted of chemical analy.ses of the different soil types, a study of the 

 agricultural conditions of the region, and investigations on a number of soil 

 experiment fields established on typical soils of the region, for the purpose of 

 determining the best methods of soil management for the soils on which they are 

 located, from which conclusions regarding the most practical methods of fertil- 

 izing and cropping these soils are drawn. 



" The soil management problems of a considerable part of the Ozark border 

 lands are on the whole not greatly different from those of north Missouri, since 

 these soils include some of the best agricultural sections of the State. There 

 are, however, large areas where the land is so badly eroded and where the soils 

 are so lacking in fertility that the problems approximate those of the Ozark 

 Plateau and Center regions. In the better region, particularly in the Barton 

 and Springfield groups, the lands are devoted largely to the growing of corn, 

 wheat, oats, and hay. and stock farming has reached a high degree of perfection. 



" Unfortunately, the fact that wheat and corn have given such good returns 

 on a great deal of this land has led to the excessive culture of these crops with- 

 out proper systems of crop rotation, resulting in many cases in a greatly 



