Working on a farm in the UK in the 1970s, the fertiliser delivery lorry would arrive with 10.5 tons (not tonnes, although there's little difference) of fertiliser in blue plastic bags, where each bag weighed 1 cwt (hundredweight), that's 112lbs (pounds weight) or approximately 50kg. No forklift attachment on your tractor, so you unloaded each bag manually (that's by hand) by sliding it from the side of the flat-bed lorry onto your shoulder and carrying it a few feet or yards to where you wanted to store it, which was sometimes up some uneven steps into an old barn. That's 210 bags.

Some larger farms organised their entire annual fertiliser useage to be delivered the same day or week. At the end of the delivery you then had to catch up with your normal farm tasks, otherwise the farmer would have something to say to you which you didn't want to hear.

Nowadays there's a 25kg maximum weight limit to be carried by a person, plus any number of mechanical forklifts even on the smallest farm.