Generally there are three main reasons to automated, to increase quality, to increase oversight or accountability, and tor reduce costs.   Let’s look at these from standpoint of the challenges to manual processes.  According to Michael Caliel, CEO of Invensys Operations Management, there are six barriers to Human Reliability :

1. Stress-induced fatigue.  Agriculture is hard work, and the work continues day and night.  Tired workers make mistakes.
2. Poor-coordination among team-members.  Just the geography of agriculture increases this challenge.
3. Inadequate operating procedures. 
4. Inadequate or insufficient access to information.  For example, knowing about temperature, pump status, fuel levels are all information pieces that if missing, can add to growers costs and risk.
5. Limited ability to derive context from disparate information sources.   As real-time data becomes more utilized, deriving information from complex data-sets needs to managed by information systems.
6. Insufficient practice or rarely seen scenarios and work processes.  There are standard development methodologies for developing automated systems, which require the developer to define or bound all possible scenarios.  A properly designed automated system does not care if a particular event only happens once in several years, and so it will handle that event jsut as any others.