Field-Wide Furrow Infiltration Variability
ABSTRACT Control of furrow irrigation systems is influenced by field-wide infiltration variability and, thus, the ability to characterize and model it is germane. Field-wide variability of infiltration in furrow irrigation was investigated. Infiltration estimates were obtained from neutron probe measurements at 100 sites on a rectangular grid. Infiltration functions developed using blocked-furrow infiltration tests at 100 corresponding sites, were coupled with field measured intake opportunity times to obtain the infiltrated depths. Statistical methods were used to quantify sources of infiltration variability and combine variances in infiltration parameters with variances in intake opportunity times to estimate the field-wide infiltration variability. The effect of reducing the number of field measurements on the estimated field-wide infiltration variability was investigated. The two-point volume balance method was found to underestimate field-wide infiltration variability.