Precision agriculture (PA) as a crop management philosophy was first hypothesised in the early 1990's as a way of utilising the development of technology such as the Global Positioning System (GPS) and variable-rate crop applicators to produce crops in a more sustainable fashion. Historically, fields have been managed as homogeneous units, receiving equal amounts of crop production inputs. The rational behind precision agriculture, or site-specific crop management, is that by identifying within-field variability in crop and soil attributes (e. g. cotton yield, soil nitrogen levels) and their origin, it then becomes possible to optimise crop production inputs such as pesticides and fertilisers on a point-by-point basis. Implicitly, this lowers the potential for the over and under-application of these crop production inputs, thus increasing profitability for the grower whilst simultaneously reducing the probability of adverse environmental impacts such as groundwater or surface water contamination from the over application of agrochemicals. While progress in developing a filmy integrated PA system has been slow over the past decade, research from a number of industries worldwide has highlighted there will be many benefits to be galled from adopting such a system. Secondly, triller technological advances in airborne imagery collection, on the-go sensor development and computer processing techniques means there is an unprecedented number of tools available to aid in crop management. Furthermore over the last decade it has emerged that each country and crop will its own unique requirements within the larger framework of PA.