tonne per hectare

The tonne per hectare is the language of harvest statistics. FAO tables, national yield surveys and agronomy trials everywhere outside North America report in it, and a few reference numbers calibrate the rest: world average wheat sits near 3.5 t/ha, a strong UK or Danish winter wheat crop cuts 9 to 10, Iowa maize reaches 11 to 12, and paddy rice averages about 4.7. The certified world record for wheat is 17.398 t/ha, harvested at Ashburton, New Zealand in 2020, roughly five times what the world's average wheat hectare manages.

Every one of those figures has a moisture content hiding inside it. Grain is weighed wet and standardised to a trading moisture, around 13 to 15 percent depending on the crop, so two fields can differ on paper by dryness alone. The moisture-shrink and dry-matter solvers in this catalog's agronomy section exist for that correction, and its yield converters turn t/ha into the bushels per acre North America trades in, which is where the caution about the factor of two comes home.

Pointed the other way, the unit rates inputs instead of outputs: lime at 5 t/ha, manure at 30. The arithmetic anchor is that 1 t/ha spreads 100 g on each square metre, so a 25 kg bag at that rate covers 250 m², about a tennis court in fertiliser terms.