Total population (1990 census): 17585
County seat: Spencer
Crop Statistics (1997 US Census of Agriculture)
| Cereals | Farms | Acres | Yield | |
| Maize=Corn | 508 | 118457 | 15713582 bu | |
| Oats | 38 | 649 | 45468 bu | |
| Grain Legumes | Farms | Acres | Yield | |
| Soybean | 532 | 120511 | 5411651 bu | |
| Forages | Farms | Acres | Yield | |
| Total Hay* | 184 | 5110 | 10164 tons, dry | |
| Alfalfa Hay | 110 | 2135 | 4631 tons, dry | |
| Small Grain Hay | 15 | 225 | 413 tons, dry | |
| Tame Hay | 62 | 2000 | 3950 tons, dry | |
| Wild Hay | 32 | 604 | 819 tons dry | |
| Grass Silage | 4 | 146 | 1052 tons, grn | |
| Corn for Silage | 56 | 1896 | 31517 tons, grn | |
| Vegetables | Farms | Acres | Yield | |
| Sweet Corn | 6 | 14 | ||
| Nursery and Greenhouse Crops, Cut Christmas Trees Harvested, Mushrooms, and Sod Grown for Sale | Farms | Sq. ft. under glass or other protection | Acres in the open | Sales ($1,000) |
| Nursery and Greenhouse Crops | 4 | 53778 | D | 530 |
*Alfalfa, grass silage, green chops etc.
D=Withheld to avoid disclosing data for individual farms.