@Zamali
I believe the info given in this forum is enough to get you started. More will keep flowing in.
Opex and capex only works in accounting,not farming. In farming,there is something called rainfall and drought,pests,e.t.c. No accounting books can balance nature,only God can. Therefore,my advice to you..... Leave the comfort of your computer (i do not mean you resign),then get your hands dirty and pray (don't ignore good farming practices). This can be done on a trial basis using a smaller portion of land. When you get to see results and learn the lessons (sometimes a bit harsh),you will be making progress. Soon,you will be the one giving advise on SK.
Otherwise,enjoy your books man!