SOIL CONDITION EVALUATION AND MONITORING (SCEAM), TASMANIA KIDD1, D., Cotching3, W.E., Dolbey2, B., Gay2, Q., Grose2, C., Hawkins2, H., Hawkins2, K., McDonald1, D., Moreton1, R., Novakowski2, A., Priestly1, T., Rodgers1, D., Scholz2, G., Tate2, S. 1. Department of Primary Industries, Parks, Water and Environment, Tasmania 2. Formerly of the Department of Primary Industries and Water 3. Tasmanian Institute of Agricultural Research Email: Darren.Kidd@dpipwe.tas.gov.au Introduction There is now a well recognised requirement to monitor soil condition across the country to determine the long-term effects of different land uses and management practices on soil health. Tasmania was one of the first Australian states to implement a scientifically sound monitoring system, which has established 100 long term reference sites in each NRM Region (300 in total), and a database of Tasmanian state-wide base-line soil condition data. The Soil Condition Evaluation and Monitoring (SCEAM) Project commenced in 2004, and was largely based on the “500 Soils” monitoring program in New Zealand (Sparling et al 2003). It was funded by the Natural Heritage Trust, and is a joint initiative between The Department of Primary Industries, Parks, Water and Environment, the Tasmanian Institute of Agricultural Research, and the Cradle Coast, Northern and Southern Natural Resource Management (NRM) Regions. The intention is to re-visit sites every 5 years to help identify long-term soil health trends for different land uses, when compared against key soil health target values for different soil types. Methods Priority soil/ land use combinations were identified through a work-shop with Tasmanian soils experts and in conjunction with each NRM Region for targeted reference site establishment. Site locations were identified using a combination of desktop analysis and field investigations. Selected sites were chosen depending on where physical investigation had identified required soil orders with appropriate land use, regionally typical and spatially uniform soil profile characteristics were represented, and theland owner was cooperative. Samples were collected and bulked from every 2m along a 50m transect for both surface (0 to 75mm) and sub-surface horizons (75mm cores between 75 and 300mm depth, depending on horizons depth(s)), and chemically analysed using CSBP Wesfarmers laboratories in Western Australia. Physical samples for bulk density and aggregate stability were also taken at both depths at 3 points along the transect, and analysed for bulk density and wet-sieving (Laffan 1996). A soil pit was excavated at each site to 1.2m (where possible) for full description and classification to Australian standards. Targeted soil/ land use combinations included agricultural, horticultural, forestry and conservation land uses, such as Ferrosols-Intensive Cropping, Dermosols-Intensive Cropping, Sodosols-Cropping, Dermosols- Plantation Forestry, Dermosols-Native Forestry, Chromosols-Grazing (North Facing Slopes), and Organosols-Conservation. Soil target values were developed (and are subject to review by Tasmania’s soil expert community) for six key soil health indicators, with range variations dependent on soil order and land use. The targets consider a balance between environmental health and impacts, while maximising the intended land use productivity. No targets were deemed suitable for conservation land uses. Results Table 1 shows a state-wide results for each land use category and the proportion of sites not meeting initially developed soil health targets (variability between soil orders is accounted for within target ranges). Table 1. Proportion (%) of Sites Not Meeting Soil Condition Targets in Tasmania (Surface Samples) Organic % of total Carbon Exchangeable Bulk Aggregate Land Use Category sites pH % Olsen P Sodium % Density Stability Dryland Cropping <1 0 0 n/a 0 0 0 Dryland Grazing/ 19 19 8 51 12 2 15 Pasture Intensive Cropping 40 4 32 n/a 7 11 28 Irrigated Pasture 6 6 0 56 6 6 25 Native Forest 11 0 17 n/a 3 0 10 Organic Cropping 5 23 8 n/a 8 0 31 Perennial 8 5 23 n/a 0 23 14 Horticulture Plantation Forestry 7 0 26 n/a 16 0 0 Conservation 3 n/a n/a n/a n/a n/a n/a Results are being developed into a “soil health report card” for each region, with these indicating different soil health issues relevant in a regional context. State-wide results are generally indicating; One third of intensive cropping and one quarter of perennial horticulture sites across the state are showing signs of organic carbon decline. (Many native forest sites were sampled immediately post-harvest, possibly explaining the 17% of sites low in organic carbon). Declining soil pH has generally been addressed across Tasmania for all land uses, with the exception of of a few dryland pasture sites. Organic cropping sites are also showing slight acidity in about one quarter of sites. A significant proportion of grazing sites have below optimum levels of available P with possible impacts to production, however, some are displaying a risk of off-site impacts with levels exceeding the target range. Results will be subjected to continued statistical and spatial analysis, with all data, such as the on-going collection of detailed land use histories, current land management practices, and additional soil chemistry, to be utilised for further data-mining activities. Cradle Coast NRM sites are currently being sampled for potential organic and inorganic contaminants, as well as soil biological measures, and additional soil carbon analyses using Mid-Infra-Red Spectroscopy (MIR Analysis) have also been undertaken. Acknowledgements Australian Government – Natural Heritage Trust Funding. NRM North, NRM South, Cradle Coast NRM. The land holders who allowed sampling of their soils and agreed to be involved in future soil condition monitoring. References Laffan M., Grant J. And Hill R. 1996. A method for assessing the erodobility of Tasmanian forest soils. Australian Journal of Soil and Water Conservation 9: 4, 16- 23. Sparling R.B., Frampton C. And Cuff J. 2003. National Soil Quality Review and Programme Design. Ministry for the Environment, Doc #807593, New Zealand.