I did that for 3yrs... I could write a whole book.
A summary:
I did French beans and chilli.
Depending on the contractor they might give you inputs deductible from your dues. Some give you seeds deductible and free agronomic support.
They are very specific on the chemicals you can use and if a farmer is caught with prohibited chemicals as a group all of you lose.
Produce per acre depends on the seeds/variety and can range from 2.5 to 6tons. Use of goat manure will increase your produce by up to 1.5 to 2 tons.
Pump installation and irrigation is a huge cost. If possible lease farm land in a place with more rainfall, it saves on irrigation costs.
Once they start harvesting some crooked companies/brokers will harvest once and claim the rest are bad give flimsy reasons/some good companies will sell to the local market or co-contractors when export market is low.
Like any other agricultural produce, they have their peak low season/price. Leo ni 120per Kg next month ni 40 bob. Timing is key.
Some companies will take your produce and claim it didn't meet export standards... You lose more than a ton.
Sale of farm chemicals, mbolea etc are a cash cow for your employees... You need to be hands on.
Cartels are real.