Agricultural Land Resource Assessment of Coalstoun Lakes
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dnrq00096 S.M. McCarroll and D.M. Brough 276 Land Resources Bulletin Agricultural land resource assessment of Coalstoun Lakes SM McCarroll and DM Brough Resource Management Department of Natural Resources, Queensland Brisbane 2000 ii DNRQ00096 ISSN 1327-5763 This publication was prepared by officers of the Resource Management Group, South East Region to assist with the planned development of the Inland Burnett River Catchment. It may be distributed to other individuals and organisations. The Department of Natural Resources Regional Infrastructure Development Group, and Natural Heritage Trust (NHT) provided financial support for this study which is gratefully acknowledged. This report is intended to provide information only on the subject under review. There are limitations inherent in land resource studies, such as accuracy in relation to map scale and assumptions regarding socio-economic factors for land evaluation. Before acting on the information conveyed in this report, readers should ensure that they have received adequate professional information and advice specific to their enquiry. While all care has been taken in the preparation of this report neither the Department of Natural Resources and Mines nor its officers or staff accepts any responsibility for any loss or damage that may result in any inaccuracy or omission in the information contained herein. ã The State of Queensland, Department of Natural Resources 2000 Department of Natural Resources Locked Bag 40 Coorparoo DC Qld 4151 iii Contents Page List of Tables iv List of Figures iv Summary v 1. Introduction 1 2. Study area 3 Climate 3 Geology 3 Landform 4 3. Methodology 5 Soil survey 5 4. Soils 7 Soil landscapes 8 Chemical and physical attributes 10 5. Agricultural Land Evaluation 15 Current land use 15 Land suitability 15 Limitations to agriculture 16 Discussion 20 Management and development issues 25 6. References 27 Acknowledgments 28 Appendices I Soil Profile Classes 29 II Morphological and analytical data for representative soil profiles 41 III Land suitability classification scheme for irrigated crops 55 iv Page List of Tables Table 1. Mean daily temperature and rainfall recorded at Gayndah Post Office 3 Table 2. Distinguishing attributes of soil types 7 Table 3. Areas of land suitability classes for crops in each mapping unit 22 List of Figures Figure 1. Locality map 1 Figure 2. Typical land use photograph, wheat crop in foreground and one of the craters in the background 2 Figure 3. Photograph of a typical rockpile on the edge of cultivated lands 2 Figure 4. Soil landscape units of the basalt landscape 9 Figure 5. Soil landscape units of the Biggenden Beds landscape 9 Figure 6. Soil landscape units of the Alluvial landscape 9 Figure 7. Average field pH values of soil types Crater, Witton, White, Fletcher and Hind 10 Figure 8. Average field pH values of soil types Sandy, Fowler and Hunter 11 Figure 9. Average field pH values of soil types Bellert, Bellert Gradational variant, Blair and Dove 11 Figure 10. Average field EC values of soil types Fletcher and Hind 12 Figure 11. Average field EC values of soil types Hunter, and Fowler 13 Figure 12. Average field EC values of soil types Bellert, Bellert Gradational variant, Blair and Dove 13 Figure 13. Area of land which is potentially suitable for each crop assessed 21 Accompanying map rear pocket “Coalstoun Lakes Soils” (Scale 1: 50 000) DNR Ref No: 99-BRRL-I-A13238 v Summary Coalstoun Lakes is a local area of about 8000 ha within the Central Burnett region of Queensland and is currently dominated by broadacre cropping. The need for detailed land resource information within the Coalstoun Lakes area has increased in priority due to the proposal to pump irrigation water from a proposed dam on either the Burnett River or Barambah Creek. This study will support strategic planning and sustainable use for the Coalstoun Lakes area by identifying areas prone to or affected by land degradation, land suitable for existing and potential industries, good quality agricultural land and by developing land management guidelines. The existing land system mapping is too broad to supply the information to address these issues. Land Resource Officers from Resource Management in South East Region have completed a medium intensity (1:50 000) soil survey of 7655 ha and assessed the suitability of these soils for a range of irrigated agricultural and horticultural crops. A total of fifteen different soils have been identified and their distribution mapped. The dominant soils are black and grey cracking clays (Vertosols) and non-cracking red clay soils (Ferrosols), red and brown structured gradational soils (Dermosols) and sodic texture contrast soils (Sodosols). Over 50% of the area mapped (3995 ha) are Ferrosols developed on basalt. These soils are suited to a wide range of agricultural and horticultural crops. In the remaining area, 25% of the area are soils developed on alluvium and colluvium (1996 ha), soils formed on Biggenden Beds (775 ha) or on a range of geologies with slopes greater than 8%. A total of 6290 ha suitable for sugarcane, 5793 ha for asparagus, cruciferae and vegetables, 5713 ha for beans, 5793 ha for cucurbits, 4190 ha for lucerne, 5580 ha suitable for navybean and potato, 4596 ha for sorghum, 4418 ha for soybean, 4596 ha for sweet corn, 5660 ha for sweet potato, 6281 ha for avocado, macadamia, citrus, lychee and mango, 4325 ha for grapes, 4288 ha for stonefruit, 4781 ha for peanuts, 4595 ha for maize and 6591 ha for pasture. Furrow irrigation of sugarcane is suitable on 1284 ha of land. The possibility of future salinisation in some areas will affect future irrigation management within the Coalstoun Lakes area. Widespread inefficient irrigation development of the highly permeable Red Ferrosols may cause seepage downslope with localised or general rises in watertables where these permeable soils contact with less permeable Dermosols and Vertosols soils such as Fletcher and Hind. These hazard areas have been identified. There is evidence of minor seepage occurring in these areas even under rainfed conditions. Future irrigation systems will need to be designed so as the amount of water being applied does not exceed crop uptake needs, and monitoring be undertaken to ensure irrigation management is sustainable. 1 1. Introduction Coalstoun Lakes is located approximately 25 km east of Gayndah in the Central Burnett region of Queensland. Broadacre cropping systems dominate the agricultural production, with a small number of dairies operating within the region. Peanuts, maize and sorghum are predominantly grown in the summer months, while wheat is the main winter crop produced in the area. Local farmers have a perception that there is a large potential for irrigation development within the Coalstoun Lakes area. The existing issues associated with current land uses, such as physical and chemical decline of the Ferrosols, and potential degradation and environmental issues which may be associated with irrigation development, necessitates the need for a detailed land resource information base to ensure sustainable agricultural development. The land resource information from this study will be used to support catchment management planning, strategic planning and for the sustainable use and management of SEQ lands by: • identifying areas prone to or affected by land degradation (salinity/erosion/soil structure/acidification) • identifying land suitable for existing and potential agricultural industries • identifying good quality agricultural land for designation in planning schemes • developing sustainable land management guidelines in cooperation with landholders, Landcare, ICM groups, Government Departments and others. The study area may be seen in Figure 1 and a typical landscape photographs in Figures 2 and 3. Figure 1. Locality map 2 Figure 2. Typical landscape photograph, wheat crop in foreground and one of the craters in the background Figure 3. Photograph of a typical rockpile on the edge of cultivated lands 3 2. Study Area 2.1 Climate The climate for the inland Burnett District is subtropical with long, hot summers and mild winters. The mean daily maximum temperature is 32.6oC in December. Temperatures frequently exceed 35oC during the summer months of December and January. July has the lower mean daily temperature of 5.9oC. Frost does occur in the study area, but only in low lying areas. The average annual rainfall for the area is 772.9 mm. Approximately 70% of the total rainfall occurs in the summer months of October to March. Below average rainfall is a regular feature in the district. On average, the study area is drought declared approximately once every five years (Mahar 1993). Mean daily temperature and rainfall can be seen in Table 1. Table 1. Mean daily temperature and rainfall recorded at Gayndah Post Office Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Mean Daily Max. Temp. (deg. C) 32.5 31.8 30.7 28.5 25.1 22.3 21.8 23.6 26.7 29.4 31.5 32.6 28.0 Mean Daily Min. Temp. (deg. C) 19.9 19.8 18.0 14.3 10.3 7.4 5.9 6.7 10.0 14.0 17.0 19.0 13.5 Mean rainfall (mm) 117.2 106.9 76.6 38.5 41.3 39.8 39.4 29.3 35.5 64.6 77.1 106.8 772.9 Bureau of Meteorology 2.2 Geology The Central Burnett region is a complex mixture of metamorphic, igneous and sedimentary rocks. Basalts are prominent in the Coalstoun Lakes area and are surrounded by sedimentary rocks to the west, and acid volcanics to the east. Small areas of alluvial deposits may be found along creeks. The Barambah Basalt Formation was extruded from the volcanic vents along the Perry Fault line in the Coalstoun Lakes area. The fluid lavas flowed south down the valley of Sandy Creek, into Barambah Creek, and then North into the Burnett River for a distance of approximately 150 km and is up to 20 metres thick (Ellis 1968).