Information
Level 2 Detail of experimental conditions (what might be found in a journal paper or project brief in Hydstra)
Description of study
What?
Nine plots, 550 m long and 8 m wide were oriented down a 1.0% slope. Each plot consisted of permanent one or 2 m wide beds. Traffic was restricted to the furrows between these beds. Dryland cotton, wheat and sorghum were grown as rotation crops to produce a range of antecedent water contents and ground cover levels at all times.
When and Where?
The study was undertaken near Emerald, central Queensland, in the Emerald Irrigation Area (“Elsden Farms”). The region has a semi-arid sub-tropical environment, with summer dominant rainfall. Long term mean annual rainfall and evaporation are 639 mm and 2265 mm, respectively. The soil was a shallow black cracking clay (Vertosol), with a particle size distribution in the 0-10 cm depth of 20% sand, 18% silt, and 62% clay.
How?
Runoff was measured through San Dimas flumes, with the water height recorded on Campbell Scientific CR10 data loggers at one minute intervals. A discharge rating curve was used to calculate discharge rate and runoff. Soil loss was measured in two components: the coarse bedload material was collected in a trough, and the finer suspended material was collected by a flow based integrated sample. A bilge pump was located at the end of each flume. This was controlled from the data logger – for every 1000L that flowed through the flume, the pump would run for 2 seconds and pump a sample into a 20L plastic container. This would provide an integrated suspended sediment sample per event. Rainfall volume was measured on a daily basis at two locations within the study area. Rainfall intensity was recorded by a pluviometer.
During 1998/9, Macquarie Instruments pumping samplers were installed at two monitoring sites. When the bilge pump started, the pumping sampler would also take a sample. These samples were multiplexed (4 samples/bottle). Sub-samples were also taken from the bed load traps for nutrient analysis. All samples were collected from the field as soon as possible after the runoff event, frozen, and sent to the DNR Indooroopilly laboratories for analysis.
Soil surface cover was measured after each runoff event in three locations per treatment. A similar technique to that described by Sallaway et al. (1988) was used to quantify projected soil cover.
Project administration
Site identifier code: CTDC
Principal investigator: Rohde K
Principal data manager: N/A
Principal organizations: Cooperative Research Centre for Sustainable Cotton Production, Department of Natural Resources
Data custodian: Department of Natural Resources
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:
- Rohde K. (1999). Controlled traffic and crop rotations for dryland cotton including control of erosion and sediment movement. Hydstra Brief.
Keywords:
Runoff, soil erosion, crop rotation, controlled traffic