402 A NATIONAL PLAN FOB AMERICAN FORESTRY 



The heavy contribution the Ozark region makes to the Mississippi 

 floods indicates that a part at least of the Ozark area should be in 

 public rather than in private hands. The situation is more largely 

 one of Federal than of local interest, and the values at stake are too 

 high to permit continued malpractice to threaten extensive public 

 works and the safety of a large population. About 150,000 acres of 

 abandoned farms and denuded lands need reforestation. Special 

 control measures are necessary on about 50,000 acres. 



ABANDONED AGRICULTURAL LANDS IN THE UPLAND LOAMS 



The agricultural lands of the upland silt loams have reached a 

 critical stage. Clean cultivation, largely for corn, has resulted in 

 erosion so serious as to make a large area of formerly prairie land of 

 doubtful agricultural value. Much of this area is drained by the 

 Grand River. According to H. H. Bennett of the Bureau of Chemis- 

 try and Soils: 



Under continuous cropping to corn the rich top soil (Shelby silt loam of north- 

 ern Missouri) has been swept away from innumerable areas by erosion, down to 

 a yellow clay subsoil, within a period of about 50 to 60 years on 4 percent slopes, 

 and in about 10 to 20 years on 8 percent slopes. The exposed stiff, yellow clay 

 produces little grass of any value and only about 20 bushels of corn per acre 

 (no corn in dry years) as against more than 50 bushels for the best years on the 

 less severely washed soil. The vegetative changes resulting from erosion on this 

 extensive prairie soil have been most violent, a change from almost exclusive 

 stands of bluegrass, in density of 100 percent ground cover, to scattering weeds 

 and dwarfed grasses of very low grazing value. 



At the Bethany (Mo.) Soil Erosion Station, the water loss from an 

 8 percent slope in corn during 1931 was 30 percent of the total pre- 

 cipitation and the soil loss 84 tons per acre. The corresponding losses 

 from a similar area planted to alfalfa were 0.36 percent of the precipi- 

 tation and 2 tons of soil per acre. Since forest has been shown by the 

 investigations of the Lake States Station to be more effective than 

 grass or hay cover crops in controlling run-off and erosion, it can be 

 readily realized that forestation on at least some of these badly erod- 

 ing lands would help to control flood flows and erosion. As forests 

 originally existed on about 40 percent of the abandoned farm land area 

 in southern Iowa and northern Missouri, it is not, therefore, a ques- 

 tion so much of putting forest where it has not previously grown, as in 

 restoring it. In 1919 the Iowa Agricultural Experiment Station said : 



Much of the rolling and rough land in southern Iowa that is subject to erosion, 

 especially that near the rivers, was originally in timber and should probably be 

 reforested or seeded down to grass. If this were done little erosion would ever 

 occur. 66 



Recent data from the University of Missouri indicate that 6 

 million acres of agricultural lands in Missouri are seriously eroding, 

 with gullies 6 to 10 feet deep not uncommon. Dr. M. F. Miller and 

 Dr. C. Hammer of the university estimate that some 2,250,000 acres 

 of these eroding lands need forest planting. Based on an incomplete 

 survey of the whole State, the Iowa State Soil Survey now in progress 

 is revealing that between 2 and 3 million acres of eroding land in Iowa 

 should be permanently taken out of cultivation and planted to trees. 

 The Nebraska Agricultural Experiment Station estimates that more 



6 Eastman, E. E., and Glass, J. S. Soil Erosion in Iowa. Iowa Agric. Exp. Sta. Bull. 183, 1919. 



