I am looking to build a model, Mathematical, that under certain conditions, I can estimate the production and costs, depending on the type of soybean planting method.
It sounds like you mean a simulation model not a statistical model. If so, first ask if you really need a model? I would say 'yes' only if you expect yields/economics to vary with season, rainfall temperature etc, as well as 'planting method'. If inter-annual and inter-site variation are not big considerations, then use a simple field experiment.
But if you do want to use a model, be prepared to run field experiments so it can be parameterised. No simple task.
Search for APSIM SoyBean, a plug-in module for the APSIM cropping system simulator. It may not simulate the economics, but it will simulate yields and you can work out the gross margins. APSIM covers numerous crops and management options
The softwares available are amazing - thanks for the awareness - but still if I understand the question correctly it says how to plant the crop first - so that would require statistical model assuming you have a number of varieties to work with - once that is done and you get some data next would be analysis which these software by the initial look would take care of quite well I suppose. And yes - I agree with Dr Cornish "No simple task"