Precision farming is bringing about a new revolution in agricultural farming systems with its high potential of reducing the environmental impact and increasing the productivity, based on the high efficiency of advanced technology. Variability management is the key approach in precision farming, using field maps and real-time sensing for temporal and spatial variation in soils, plant growth and yield, and other parameters related to cultivation. Site-specific field management can be implemented based on accurate information. Scale-free precision farming approaches are suitable for small-scale Japanese agriculture. Prospects and strategies for Japanese precision farming are introduced, followed by the results derived from investigations on soil mapping and the use of soil sensors.