Corn, oats, and the drained land; then corn and soy

1880s — 2022

The rotation that replaced wheat: What took wheat's place was made possible by the ditch. In the 1880s the county's great swamps were attacked in earnest: the Eel River ditch, completed in 1887, ran 11 miles and drained over 3,000 acres, and the Little River ditch, completed in 1889 with all its branches, ran 40 miles and furnished the outlet for the water falling on 200,000 acres. The federal surveyors of 1908 judged the result without hedging — the drained swamp lands "are the strongest corn soils in the county, command the highest price, and are an important factor in the county's wealth," and the corn and truck soils together brought the county's top land prices, $50 to $150 an acre across its farms. The standard rotation on the upland clay loams ran sod to corn, corn to oats, oats to wheat when wheat was kept at all, with timothy sown in the fall and clover in the spring and the land rested in grass two or three years; on the drained black lands corn followed corn for years at a time. Oats, the horse-feed crop, peaked with the horse — 50,715 acres in 1900 — and faded as the tractor came. The second half of the twentieth century consolidated the county into the two-crop system the censuses now record, and the 2022 Census of Agriculture states its proportions exactly: soybeans for beans on 161,375 acres, the county's largest crop by acreage; corn for grain on 103,967 acres; and, behind them, wheat for grain on 17,987 acres — more than the county sowed in 1900, returned as a rotation and cover crop in a system it no longer leads. Irrigated land in 2022 amounted to 527 acres, a reminder that this remains, as it was in 1908, a rainfall-and-drainage agriculture: the county's farm problem was never getting water onto the land, but getting it off.

Sources:

1. U.S. Bureau of Soils, Soil Survey of Allen County, Indiana (1908; issued 1910) — the Eel River ditch (1887; 11 miles; over 3,000 acres) and Little River ditch (1889; 40 miles with branches; outlet for 200,000 acres), the drained swamp lands as "the strongest corn soils in the county," land prices of $50–$150 an acre, the rotations described, and the 1900 oats acreage of 50,715.
2. USDA, NASS, 2022 Census of Agriculture County Profile: Allen County, Indiana — soybeans 161,375 acres, corn for grain 103,967 acres, wheat for grain 17,987 acres, irrigated land 527 acres.