Contents 
Introduction - - 5 
The outlines of agricultural regions in the northern hemisphere 6 
The effect of heat upon the acreage of crops treated as annuals.— 11 
A classification of field crops, 11. The six principal types of an- 
nual cropping, 15. Table of six principal types of annual crop- 
ping, 16. Month-degrees above freezing, 21. Boundary lines de- 
termined largely by heat, 22. The effect of factors other than 
heat, 26. 
Size of farm in relation to rainfall and other factors in the Great 
Plains - 28 
Definition of the term “farm,” 28. Table of the size of the farm 
calculated from Nebraska farm management surveys compared 
with census figures, 30. Table of the size of farm as affected by 
the number of farms within a given area, 32. Method of map- 
ping the data, 34. The western' edge of 160-acre farming, 35. 
Two-section farming, 35. Size of farm in relation to rainfall 
and heat, 36. Size of farm in relation to soil, 37. Size of farm 
in relation to rainfall and. economic conditions, 37. Size of farm 
in relation to plant growth, 38. 
Farm types in Nebraska . 58 
Boundaries of type areas, 58. The determination of farm types, 
59. Table of the number of all farms compared with the number 
reporting domestic animals, 61. Farm types grouped for the 
purpose of study, 62. The principal uses of farm land, 63. 
The acreage and yield of crops, 63. Table of corn per farm in 
1909, 64. Table of coarse forage (large corn and “cane”) in 
1909, 65. Table of wheat per farm in 1909, 65. Table of oats per 
farm in 1909, 66. Table of rye per farm in 1909, 66. Table of 
barley per farm in 1909, 67. Table of potatoes per farm in 1909, 
67. Table of millet per farm in 1909, 68. Table of alfalfa per 
farm in 1909, 68. Table of timothy and clover per farm in 1909, 
69. Table of wild hay per farm in 1909, 69. Table of apple trees 
per farm and also the per cent of all land covered with woods, 
70. 
The harvest value of crops, 70. Table of the harvest value of all 
crops grown on cultivated lands in 1909, 71. Table of the esti- 
mated harvest value of pasture per farm in 1909, 71. Table of 
the value of crop and pasture growth per farm in 1909, 72. 
