CHAPTER XI. SOILS 
Losses on Cropland 
Agricultural losses due to soil deterioration, while of considerable 
lecal importance in many areas of rangeland and timberland, reach 
significant national proportions primarily on land used for culti- 
vated crops. For the period 1942=51 this cropland area, including 
rotation pasture, averaged about 50 million acres. 1 
In this discussion consideration is given primarily to losses 
which arise essentially from physical soil deterioration, not ine 
cluding the unrelated losses of replaceable organic matter and plant 
nutrients which are the normal rest of crop production. These 
types of soil deterioration include erosion by runoff water, blow= 
ing (wind erosion), deterioration of structure, alkali accumulation, an¢ 
waterlogging, Such losses are assumed to be preventable. (Table 29) 
As serious as are the production losses arising from these causes, 
they are minor in comparison with the tremendous increase in pro= 
duction attainable were all farmers to make the fullest efficient 
use of all the land, labor, and capital available. 
Additional agricultural losses involving cropland, wien are not 
considered here, include the extensive areas deliberately inundated 
by permanent dam backwaters and the estimated 250,000 acres of 
cropland absorbed annually by urban and industrial expansion and 
by highway and airport construction. Nor is consideration given 
here to areas where low soil productivity is a natural consequence 
of an original state of infertility, alkalinity, droughtiness, 
acidity, high water table, massive structure, even though such 
soil deficiencies can often be corrected by proper soil management. 
Losses from flooding and sediment deposition on cropland are dis- 
cussed later in this chapter under "Watershed Damages, Including 
Floodwater and Sediment." 
The different causes of soil deterioration generally occur, not 
singly, but in combination. Alkali accumulation, for example, is 
commonly associated with waterlogging and with impaired soil struc- 
ture. Similarly, soil erosion nearly always involves loss of 
organic matter. Therefore, in evaluating broadly the effects of 
soil deterioration, it is not possible to make any sharp distinc- 
tion as to the specific individual effects. Although the various 
1/ Cropland in 1950 is reported by the U. S. Census as 09 million 
acres, including idle and unharvested land but "exclusive of cropland 
used only for pasture in 19:9." The 450 million acre average for 
19h2=51, referred to in this chapter, includes such rotation and irri- 
gated pastures on farms as are sometimes used for the production of 
cultivated crops. In other chapters reference is made to 358 million 
harvested acres, a term that excludes idle and unharvested land. 
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