The topics for this 
Machines and automated farm tools have greatly reduced the human labour in farmlands but they cannot render the human efforts as completely useless. For instance, humans still have a major role to play and these roles cannot be filled by machine effort alone. in this article, we would be looking at the different ways in which human labour is still needed on a farmland.
MACHINES CANNOT WORK THEMSELVES:
this is actually explanatory. it simply tells us that the machines still need humans to operate them. take for instance, the bulldozer or the tractor, these machines need a human do actually drive them. they cant drive themselves and even if they can, there would be a great deal of error. this can be proved following the machine -5 to +5 rule. this simply explains the efficiency levels of a machine. it can either be very efficient or very poor in functions.
FARM MANAGEMENT CANNOT BE DONE BY MACHINES
even if a machine can do all the things needed to be done on a farmland, the farm still needs a human to supervise and oversee activities on the farmland. this isnt a task that can be given to a machine (robot).
CROPS/FARM PRODUCE CANNOT BE MARKETED OR SOLD BY MACHINES
In the eventuality that the machines have succeeded in harvesting all the cross on the farmland, human effort is still required to take these products to the relevant market and to be sold to the buyers. Machines may aid with this task but the execution and success of this is solely human effort. There's no way a machine would market the product even if the machines can go as far as packaging and arranging them, it still wouldn't be able to look for buyers. Humans play the major role for this task.
HUMANS ALSO HELP IN SERVICING MACHINES
It's not argument that machines cannot repair themselves, fuel themselves, and maintain themselves. This is purely done by humans and this task cannot be interchanged.
OTHER HUMAN LABOUR EFFORTS INCLUDE
Knowing when to plant crops
knowing where to plant crops
purchase of landspace
purchase from farm tools/machines
generation of funds for farm maintenance
Regardless of the uses of machined in farms, human labour is still very essential because it's what keeps the entire farming system balanced.