Total population (1990 census): 327140
County seat: Des Moines
Crop Statistics (1997 US Census of Agriculture)
| Cereals | Farms | Acres | Yield | |
| Maize=Corn | 442 | 90408 | 13423582 bu | |
| Wheat for Grain, Total | 4 | 93 | 4381 bu | |
| Oats | 22 | 435 | 28390 bu | |
| Popcorn | 4 | D | D | |
| Grain Legumes | Farms | Acres | Yield | |
| Soybean | 448 | 87971 | 4004990 bu | |
| Forages | Farms | Acres | Yield | |
| Total Hay* | 241 | 6972 | 16409 tons, dry | |
| Alfalfa Hay | 210 | 5698 | 14654 tons, dry | |
| Small Grain Hay | 10 | 118 | 224 tons, dry | |
| Tame Hay | 39 | 698 | 1234 tons, dry | |
| Wild Hay | 4 | D | D | |
| Grass Silage | 3 | D | D | |
| Corn for Silage | 18 | 558 | 8455 tons, grn | |
| Vegetables | Farms | Acres | Yield | |
| Snap Bean | 6 | 13 | ||
| Pumpkins | 3 | D | ||
| Squash | 3 | 1 | ||
| Sweet Corn | 17 | 120 | ||
| Tomatoes | 9 | 9 | ||
| Fruits | Farms | Acres | Yield | |
| Apples | 12 | 84 | 12777 trees | |
| Peaches | 3 | D | D | |
| 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 | 42 | 369492 | 495 | 3737 |
| Nursery, Floriculture, Vegetable and Flower Seed Crops | 8 | X | 62 | X |
| Florculture Crops | 14 | 358752 | D | 2536 |
| Bedding/Garden Plants | 13 | 268312 | 3 | 1758 |
| Foliage Plants | 3 | D | D | D |
| Potted Flowering Plants | 4 | 75000 | D | 625 |
| Cut Christmas Trees Harvested | 16 | X | 56 | 156 |
| Nursery Crops | 17 | D | 181 | 797 |
| Sod Harvested | 3 | X | D | D |
| Other Nursery and Greenhouse Crops | 16 | D | 196 | D |
*Alfalfa, grass silage, green chops etc.
D=Withheld to avoid disclosing data for individual farms.
X=Not applicable.