Information
Level 2 Detail of experimental conditions (what might be found in a journal paper or project brief in Hydstra)
Description of study
What?
A practical approach for obtaining an estimate of the root-zone hydrology on a sodic duplex soil was undertaken from the BRIA where no infiltration and deep drainage measures were available.
When and Where?
Data was obtained from the Gaynor research site in north Queensland. Soils on site display weak cracking upon drying.
How?
The study site was deep ripped to 0.35-0.4m. The study area was then landformed and laser graded to a down slope gradient of 0.00106m-1 before being sown to consecutive furrow irrigated crop.
The study area was 325m long and 62.5m wide. The furrow length was 315m and furrow spacing was 0.75m. Prior to planting the second crop, the study area was split to give two un-replicated experimental plots. Gypsum (20 t/ha-1, by product grade with 14.5% S and 18.5% Ca) was incorporated into the surface (0.1m) of one of these plots. All plots were sown to maize.
Irrigation was scheduled when cumulative Class A Pan evaporation reached 60-65mm this reflected a soil water deficit of 50-55mm in the area without gypsum. The furrows were open ended to minimise waterlogging. Runoff, channels through 100mm Parshall flumes for the second crop only, was recorded for up to 6 hours after each irrigation event. Furrow discharge rates were graphically integrated over time.
Infiltration of irrigated water was estimated using the computer model KIM. KIM is a model of furrow irrigation that predicts advance, recession and infiltration. The model assumes that a fixed inflow rate is applied for a given time, during which water advances towards, and eventually reaches the end of the furrow where it flows out.
Furrow geometry- Surface geometry was recorded at right angles to the direction of the furrows.
Irrigation advance- Time distance relations describing the rate of irrigation water advance down furrows were measured.
Methods for determining water and solute fluxes rely on localised measurements which must be extrapolated to larger areas. The chloride profiles sampled provide a simple means of calculating localised deep drainage fluxes at four distances down furrows with and without gypsum.
Project administration
Site identifier code: N/A
Principal investigator: AJ Dowling
Principal data manager: N/A
Principal organizations: Queensland Department of Primary Industries and CSIRO
Data custodian: Queensland Department of Primary Industries
Key co-operators: N/A
Data access policy: Research has been published but base data is not archived
Planned pathway for data: completed study, no evidence of formal database records.
Data warehousing: for ongoing studies –N/A
Planned data upload frequency: for ongoing studies – N/A
Key references and sources of this data synthesis
These data summaries have been extracted from:
- Dowling AJ, Thorburn PJ, Ross PJ and Elliot PJ. (1991). Estimation of infiltration and deep drainage in a furrow-irrigated sodic duplex soil. Australian Journal of Soil Research 29: 363-75.
Keywords:
Infiltration, deep drainage, cropping