OCR Text |
Show ture and range provide about one-third of the total supply of animal feed. The productivity of much of the permanent pasture and most grazing land is low compared with cropland, and much of it is not suitable for cultivated crops or other intensive uses. From 1940 to 1949 the land devoted to pas- ture and grazing averaged 1,052 million acres. In terms of feed units produced, this land was equivalent in productivity to 142 million acres of cropland; that is, 7.4 acres of pasture and grazing land produced the feed equivalent of 1 acre of cropland. crop yields started to increase sharply, the rise continuing during the forties. Weather was a favorable influence, and its effect was augmented by mechanization, which made planting, culti- vating, and harvesting operations more adapt- able to weather conditions. Improved varieties of crops have also reduced weather hazards be- cause of shorter maturity periods or drought- resistant characteristics. More important have been the increased use of fertilizer and lime, control of insects and dis- ease, and the improved soil-building and con- servation practices used on many farms. In millions of acres 400 300 200 100 acres per capita 1910 m Production of 'export products . Feed for horses, mules Food, fiber, etc., * for domestic consumption 20 30 40 50 Source: Department of Agriculture FIGURE 9.-Cropland use millions of people 200 1910 20 30 40 50 Source: Department of Agriculture FIGURE 10.-Population, and cropland per capita Forests.-Farm woodlands, commercial for- ests, and other forested areas total about 611 mil- lion acres. Slightly over two-thirds of the for- ested area is commercial forest land, while the remaining third is valuable chiefly for fuel wood, posts, and noncommercial woodland. Much of the forested area has multiple uses, involving live- stock grazmg on some 350 million acres, and recreation, wildlife, and watershed protection. Productivity Changes From 1910 until the late thirties, there were no substantial changes in per acre yields. Then addition, the high-producing crops have been shifted to better lands, both area-wise and on in- dividual farms. As a result of varying combinations of these factors, average wheat yields during 1945-49 were one-fourth higher than during 1920-39; corn yields were up about one-third; and hay yields showed a 10 percent increase. The feed value of hay has also increased due to the de- velopment of new high protein legume hays. As a result, livestock productivity has increased by some 15 to 20 percent per animal unit. The increased output of food in the last decade has permitted an increase in per capita consump- tion of around 15 percent above 1935-39. For 155 |