The season is the year
Demand arrives in a compressed window and collapses afterwards, which makes the pre-season order the single decision that determines the year. It cannot be corrected mid-season, because by the time you know you are short the sowing window has passed. Movement over the same weeks last year is the only sensible basis, and the same report shows what did not move, which in seed is capital sitting on something with a shelf life.
Lot, batch and germination
Seed carries a lot number, a packing date and a germination percentage, and if a farmer's crop fails those are the first things asked for — by him, by your supplier and potentially by an inspector. Recording them on the item and the bill takes seconds and cannot be reconstructed afterwards. It is also what lets you identify every customer who bought from a particular lot if a problem emerges.
Credit until harvest
Farm credit runs to the harvest rather than to a date, which makes it longer and far more concentrated than any other trade — the whole village settles in the same few weeks. Your exposure therefore peaks predictably, and knowing the total and its ageing before the season is what tells you how much more you can safely give. A statement ready at settlement time turns those weeks from fraught into orderly.
Packets and loose weight
Seed sells in branded packets by the piece and loose by the kilo, often to the same farmer in one visit. Holding the unit on the item means both go on one bill without arithmetic, and the stock figure counts what is actually in the shop. Pack size belongs on the item because the rate per kilo differs between sizes and farmers compare.