You get at least 65% of potato you pick on the field

Good payment I guess.
I doubt that any farmer would give you so much potato from his field just for picking it. After-all he planted them, it is his soil, his seeds, he used his manure and now he will give you such a big part of his crop. Actually, in case you will work harder you will get 85%.
Thing is, it is not about potato or any farmer's work. Only numbers are true and yes there is such a great offer. You can rely get such a great payment for trading Forex. Not with your own money which is big difference.
But first thing is you must learn and pass tests. They will teach you how to trade and after they will test you. In case you pass all tests you are in.