Soil chronosequence data may easily be interpreted in a too straightforward and simple a way if some relevant theoretical background is not kept in mind. This paper discusses pedological concepts that are considered relevant for soil chronosequence studies. Implications of each of the mentioned concepts are pointed out, in order to provide some guidance for establishing soil chronosequences and interpreting obtained data.

Error sources in predictive modelling are described and a distinction is made between statistical variability (aleatory uncertainty) and lack of information (epistemic uncertainty). Examples of uncertainty analysis are provided and discussed, including reference to error disaggregation and geostatistics. A systems-based analytic framework for uncertainty analysis is proposed in the form of a flow diagram to assist in identification of various uncertainties in the modelling process.

Soil organic matter has been shown to affect a range of important soil properties that are responsible for the functioning of soils. The direct links of soil organic matter levels to yields and returns are more difficult to demonstrate. However, many soil properties do improve with increasing levels of soil organic matter, resulting in improved soil health.

It is widely suggested that soil organic matter (carbon) in grain production systems can be increased by using practices such as reduced tillage, stubble retention and alternative rotations. We measured soil carbon levels in three long-term (12, 28 and 94 year old) field experiments in Victoria. We found that these practices may not reliably increase carbon on their own, but that significant increases are possible in some circumstances through long-term use of multiple practices such as stubble retention + reduced tillage + legume + elimination of fallow.

The space–time observation system for soil organic carbon (STOS-SOC) is a novel approach which is driven by satellite-derived inputs and readily available geospatial inputs, such as digital soil maps. These satellite-derived inputs and other geospatial data characterise space–time variations in management and land use. The STOS-SOC primary use is monitoring changes in soil organic carbon which is important for a carbon accounting system and as an indicator of soil quality.

The Permanent Top-Dressed (PTD) pasture experiment was established in 1914 at the Rutherglen Research Station in Victoria, Australia, to demonstrate the value of adding phosphorus fertiliser to increase pasture productivity for lamb and wool production. This paper reports on the status of the PTD soils after 100 years, investigating the long-term implications of continuous grazing and fertiliser management on the soil. After 100 years these soils would be in a state of quasi-equilibrium, with the history of superphosphate addition and grazing leading to a decrease in soil pH while increasing the carbon, nitrogen, phosphorus and exchangeable Al compared to the control.

In a long-term cattle grazing trial in northern Australia on Brown Sodosol–Yellow Kandosol complex, we analysed soil organic matter and mineral nitrogen 16 years after trial establishment on moderate and heavy stocking. Higher soil organic matter was found under heavy stocking, although grazing treatment had little effect on mineral and total soil nitrogen. Interannual variability had a large effect on soil mineral nitrogen, but not on soil organic matter.

The management of land within its inherent physical capability is vital to prevent land degradation and maintain productive soil and land resources. A new scheme, land management within capability (LMwC), that semi-quantitatively categorises the level of sustainable land management in relation to a range of soil and land hazards is presented. It can help to target priorities and guide sustainable soil and land management at local, regional and state levels.

A report card was published in 2013 summarising the current condition and trend of 10 soil- and water-related themes relevant to agriculture in the south-west of Western Australia. This paper focuses on the assessment methodologies and results for the seven soil-related themes. The results indicate that the situation and outlook for soils is mixed, with improvements in wind and water erosion but adverse trends for soil acidity, soil compaction and water repellence.

This paper provides an insight into changes in some basic properties of Dermosols in Tasmania between two sampling rounds five years apart. The results suggest that soils under cropping are undergoing the greatest changes with most sites showing an adverse change in one or more of the measured soil properties.