March, 1963 



Larimore & Smith: Fishes of Champaign County 



307 



following paragraph (Fehrenbacher 1963 

 and personal communication from Dr. 

 Russell T. Odell, Professor of Soil Pedol- 

 ogy, University of Illinois). 



The dark upland prairie soils can be 

 placed in four general groups. A group of 

 silty loess prairie soils (mainly Drummer, 

 Flanagan, and Catlin soil types) covers 

 about 40 per cent of Champaign County. 

 These soils are loam till covered with 3 

 to 5 feet of loess. Properly managed, they 

 are the most productive in the county, 

 averaging about 95 bushels of corn per acre 

 per year. A second group of prairie soils, 

 mainly Drummer, Brenton, and Proctor 

 soil types, consists of silty outwash soils 

 with greater subsurface flow and higher 

 permeability than the first group men- 

 tioned. They cover about 26 per cent of 

 the county and also are very productive. 

 This group of soils is associated with the 

 former marshes. A third group, made up 

 of medium-textured prairie soils, occurs 

 in rolling areas mostly along the Cham- 

 paign Moraine and covers about 10 per 

 cent of the county. A fourth group, com- 

 posed of fine-textured prairie soils of silty 

 clay loam and silty till, covers a large area 

 in the northeastern part of the county and 

 scattered areas in the northwestern part, 

 a total of 16 per cent of the county. This 

 group is somewhat less productive than the 

 other prairie soils. The small remaining 

 group, consisting of nonprairie soils, is 

 generally associated with the river valleys 

 and constitutes the least productive soils 

 in the county. 



Weather 



Champaign County has a temperate 

 continental-type climate without the mod- 

 ifying influences of a large body of water. 

 In most years, temperature extremes range 

 from well below degrees to slightly 

 over 100 degrees F. The annual mean 

 temperature is 52 degrees F. (Changnon 

 1959:46). Comparison of monthly aver- 

 age temperatures over a 57-year period 

 during which weather records have been 

 kept at Urbana reveals great fluctuation 

 but no significant trend. August, the 

 month of our most intensive collecting in 

 1959, was considerably warmer than the 

 August average. 



The county receives an average of 

 about 36 inches of precipitation per year. 



Although the annual averages for 1929- 

 1958 were similar to those for the 

 preceding 1903-1928 period, judged by 

 data graphically presented by Changnon 

 ( 1959 : 1 1 ) , the 5-year period immediately 

 preceding Thompson & Hunt's study was 

 exceptionally wet, and the years 1930, 

 1953, 1954, and 1956 were exceptionally 

 dry, the annual rainfall being less than 

 30 inches. The years 1940 and 1959 re- 

 ceived subnormal amounts of precipitation 

 and were marked by unusually dry sum- 

 mers. The summer months of 1959 were 

 extremely dry and resulted in low water 

 levels during the time of our intensive 

 field work. 



Agricultural Practices 



Champaign County is one of the most 

 productive grain areas in the world. Dur- 

 ing more than a century of farming, this 

 county has undergone great changes in 

 landscape, in farming methods, and in 

 crops. These changes include the draining 

 of the wet prairies and marshes to convert 

 them to productive farmland, the use 

 of large machinery, and the widespread 

 use of commercial fertilizers and new and 

 improved plant varieties. 



The farming of the first settlers in this 

 county was largely restricted to raising 

 cattle and small crops on the high areas 

 and along the stream courses where drain- 

 age was naturally good. Lands that were 

 dry enough for cultivation were turned 

 by oxen. During the last quarter of the 

 nineteenth century, ditches were dug and 

 tiles laid to drain the wet prairie fields. 

 By 1900, the farms averaged between 80 

 and 100 acres in size. 



With the development of large farm 

 machinery — heavy tractors, combines, 

 seeders, and corn pickers — many farms 

 were merged to form larger ones. Cur- 

 rently, the average Champaign County 

 farm is about 200 acres. Within the past 

 30 years a trend toward less diversifica- 

 tion among farm crops has appeared ; corn 

 and soybeans have become the two lead- 

 ing crops. 



During the 1940's, the widespread use 

 of commercial fertilizers brought about a 

 general increase in average yield. Hybrid 

 plants and improved varieties added to 

 yields. Recently, liquid nitrogen as a fer- 

 tilizer has further increased production. 



