This work was carried out at the Experimental Farm of the Universidade Federal do Ceará, Curu River Valley, in the State of Ceará, Brazil, from October 4, 1999 to March 10, 2000, to calibrate, under field conditions, the so called soil moisture model for agricultural activities (MUSAG) determining the parameters associated to the model functions (infiltration, percolation and evaporation).The measurements of soil water storage were done with a neutron probe, and compared with that predicted by the model. The MUSAG provided values of storage water, statistically not different from the values determined by the neutron probe for the depth of 0 - 0,30 m. The model did not provide reasonable estimates of the soil moisture during periods with larger precipitation frequency, however, the predictions followed the tendency of the observed values, but underestimating them.
model; soil water; neutron probe
