Field Capacity is the amount of soil moisture or water content held in the soil after excess water has drained away and the rate of downward movement has decreased. This usually takes place 2–3 days after rain or irrigation in pervious soils of uniform structure and texture. The physical definition of field capacity (expressed symbolically as θfc) is the bulk water content retained in soil at −33 J/kg (or −0.33 bar) of hydraulic head or suction pressure. The term originated from Israelson and West and Frank Veihmeyer and Arthur Hendrickson. [Wikipedia 2014-12-10 https://en.wikipedia.org/wiki/Field_capacity]