Because new crops are harvested partway through the calendar year, many statistics are built on a period other than the calendar year. The start differs by crop and country. For US corn and soybeans, the crop year runs from September 1 to the end of August of the following year.
For example, "2026/27" refers to the period from September 1, 2026 to the end of August 2027, and the new crop harvested in 2026 is counted in that year.
Partway through the crop year, the old crop harvested in the previous year gives way to the new crop. Each futures contract month is also tied to either the old crop or the new crop.