The plain farmOS way to do this is to navigate to the asset under which the inventory is being tracked. e.g. You might have a “Hay barn” asset (which is a structure) and add/subtract hay bales from its inventory as hay is acquired/created then used. When used this way, the current inventory for the hay barn will be displayed on the asset page and there is a tab at the top to see the history of the inventory logs.
See Inventory tracking | farmOS
You might also find this thread interesting: In cab Inventory display / adjustment & alternate Field Tool It explores alternate interfaces for tracking/recording data that way.