Land resources of the Bencubbin area

This survey of the Bencubbin area is part of the Agriculture Western Australia\u27s regional land resource mapping program, and covers approximately 1.5 million hectares in the Merredin, Trayning, Koorda, Mount Marshall, Mukinbudin, Westonia and Nungarin Shires of Western Australia. The climate is Mediterranean, with hot dry summers and cool winters. Land is used for winter cereal production and grazing, and about 60% is cropped each year. Wheat is the main crop and is grown in rotation with lupins, field peas, barley and medic pasture. This report provides primary and interpreted information on the character and capability of the land, for use at regional, catchment and farm levels. The five major outputs or datasets are: • a site database of soil and landforms • description of map units • description of soil series • a soil landscape map at a scale of 1:250,000 • interpretation of the data. The 1:250,000 scale map and 14 soil landscape map units at subsystem level indicate the landform pattern and enable prediction of soil property variation at a regional level. Land capability interpretations can be made for broad regional planning. For farm scale use, the survey identifies and describes 18 soil series. This provides a basis for more detailed mapping and land use interpretation. Soils are identified within a common framework throughout the region and this grouping will aid the extension of local experience and experimental research results

Land resources of the Bencubbin area - map

Map from - Grealish, G J, and Wagnon, J. (1995), Land resources of the Bencubbin area. Department of Agriculture and Food, Western Australia. Report 12.https://researchlibrary.agric.wa.gov.au/lr_images/1065/thumbnail.jp

Land resources of the Bencubbin area - map

Map from - Grealish, G J, and Wagnon, J. (1995), Land resources of the Bencubbin area. Department of Agriculture and Food, Western Australia. Report 12.https://library.dpird.wa.gov.au/lr_images/1065/thumbnail.jp

National Scale 3D Mapping of Soil pH Using a Data Augmentation Approach

Understanding the spatial variation of soil pH is critical for many different stakeholders across different fields of science, because it is a master variable that plays a central role in many soil processes. This study documents the first attempt to map soil pH (1:5 H2O) at high resolution (100 m) in New Zealand. The regression framework used follows the paradigm of digital soil mapping, and a limited number of environmental covariates were selected using variable selection, before calibration of a quantile regression forest model. In order to adapt the outcomes of this work to a wide range of different depth supports, a new approach, which includes depth of sampling as a covariate, is proposed. It relies on data augmentation, a process where virtual observations are drawn from statistical populations constructed using the observed data, based on the top and bottom depth of sampling, and including the uncertainty surrounding the soil pH measurement. A single model can then be calibrated and deployed to estimate pH a various depths. Results showed that the data augmentation routine had a beneficial effect on prediction uncertainties, in particular when reference measurement uncertainties are taken into account. Further testing found that the optimal rate of augmentation for this dataset was 3-fold. Inspection of the final model revealed that the most important variables for predicting soil pH distribution in New Zealand were related to land cover and climate, in particular to soil water balance. The evaluation of this approach on those validation sites set aside before modelling showed very good results (R2=0.65, CCC=0.79, RMSE=0.54), that significantly out-performed existing soil pH information for the country