Information
Level 2 Detail of experimental conditions (what might be found in a journal paper or project brief in Hydstra)
Description
What?
The study monitored physicochemical parameters, nutrient and sediment loss associated to varying fertiliser application rates and land management practices on banana crop lands
When and Where?
From November 2002 to July 2006 a study was undertaken on a number of banana fields in the Tully River region. The watershed for the study region was approximately 2 ha and the land use composition comprised of a homestead, one complete banana plot and small proportions of three other banana plots. The cropping area of the watershed was approximately 1.5 ha and the slope of the watershed for the cropping zone ranged between 5 to 40%, though was on average approximately 20%
The soil type was categorised as moderate to strongly structured red clay loam to clay soil formed from basic dykes within granitic hills. This plot was chosen due to the relatively small catchment area and because drainage was directed into a single channel, which was suitable for the establishment of a weir structure.
How?
Crop fertilisation was undertaken using a variety of application methods, which evolved over the study period. In general, nitrogen (N) and phosphorus (P) were applied via routine fertigation, which commenced during the 2003/04 growing period. The fertiliser sources varied from year to year, with varieties including potassium nitrate and mono-ammonium phosphate. In a number of cases, blends of fertiliser were used, some of which were specifically for nitrogen, potassium, sulfur and / or other trace elements application. Foliar fertiliser application was also used, particularly in the colder months when root uptake of the soil is reduced. Further detail of fertiliser application to the study plot is provided in Table 2.
Best management practices undertaken by the landholder included inter-row vegetation and minimum tillage techniques. Grassing the inter-rows within the banana plants and slashing (fortnightly) also took place. However, herbicides were used in place of slashing on a number of occasions throughout the study period. Furthermore, liming took place on the banana plot in order to maintain soil permeability and productivity.
A crump weir was installed at both sites in November 2002. The weir was a TB3 (1.16 cumec, 1.4 m throat width, 1:10 crest slope crump weir) with a 1 mm tipping bucket rain gauge. Core instrumentation consisted of a 3.5 m range Druck PTX1830 pressure transducer coupled to an RRDL-AN datalogger through a locally fabricated vent box. Depths and discharges were measured to the nearest 0.0001 point and were recorded every two minutes, but reporting data was limited to 15 minutes.
A portable field meter (WTW Portable 340i, Weilheim, Germany) was used for physicochemical water quality measurement (pH, dissolved oxygen, temperature and conductivity) of drainage flow water. Over the course of the project a number of sampling strategies were used. During the 2002/03 and 2003/04 seasons, water samples were collected by the landholder and project catchment coordinator. In the 2004/05 season, modified rising stage samplers were collected by the landholder and project catchment coordinator. In 2005/06 an autosampler was used to collect event flows.
Samples for Total Suspended Solids (TSS) analyses were collected in 1 L polypropylene bottles and aliquots filtered through pre-weighed Whatman GF/C filters (pore size 1.2 µm). Samples of total nitrogen and phosphorus analyses were collected in 100 mL polyethylene bottles and frozen immediately. Total filterable nitrogen and phosphorus samples were filtered with a 0.45 µm into a 10 mL Starstedt polypropylene vials and frozen immediately.
TSS filter membranes were oven dried at 103 - 105°C for 24 hours and re-weighed to determine the dry TSS weight. Total and total filterable nitrogen and phosphorus were digested using an alkaline persulfate technique and the resulting solution simultaneously analysed for nitrate and FRP by segmented flow auto-analysis using an ALPKEM Flow Solution II. Samples containing >50 mg/L of suspended solids were serially diluted prior to digestion. Particulate nutrient concentrations were measured via the subtraction of the total filterable concentration from the total nutrient concentration. The analyses for nitrate, nitrite, ammonia and FRP were also conducted using standard segmented flow auto-analysis techniques. The difference between the total filterable nutrient concentrations and filterable inorganic nutrient provided an estimate of the filterable organic nitrogen and filterable organic phosphorus fractions.
Project administration
Site identifier code: na
Principal investigator: Faithful J.W
Principal data manager: -na
Principal organizations: Queensland Department of Natural resources and Water.
Data custodian: Department of Environment and Resource Management (DERM)
Key co-operators: -na
Data access policy: Research has not been published. Government report
Planned pathway for data: completed study (there is no evidence of formal database records)
Data warehousing: for ongoing studies -na
Planned data upload frequency: for ongoing studies –na
Key references and sources of this data synthesis
Faithful JW, Brodie J, Hooper A, Leachy P, Henry G, Finlayson G and Green D. 2007. Plot-scale runoff of nutrient and sediment under varying management regimes on a banana and cane farm in the wet tropics.
Key words
Horticulture, bananas, Tully River, nutrient, sediment, hydrology