Area Covered per Tank

This is the arithmetic that decides whether you run dry three-quarters of the way down a headland, and it is worth doing before the field rather than during it. A 1,000 litre tank at 100 L/ha covers 10 hectares; drop the carrier volume to 80 L/ha and the same tank covers 12.5. That is the whole calculation, and its usefulness is entirely in the planning it enables.

The number to be careful with is the tank volume, because the nameplate figure is not the usable one. Sprayers carry a sump and a suction line that cannot be drawn down, and boom plumbing holds several litres that never reach the nozzles as a properly mixed solution. On a mounted sprayer the unusable remainder can be 20 or 30 litres. Rinse tanks are separate and should never be counted. Use the volume you can actually apply, which you find by filling to the mark and spraying until the pressure drops.

Matching tank loads to field size is a real optimisation rather than a tidiness preference. A field that takes 2.1 tank loads means mixing a second batch for a tenth of a tank, and leftover spray solution is a genuine problem: it cannot be stored, cannot legally go down a drain, and the standard disposal route is to dilute it and apply it to a labelled crop, which means finding more of that crop. Growers routinely adjust carrier volume within the label's permitted range specifically to make the loads come out even.