Dissolved organic C (DOC) is a small component of soil organic matter that influences soil chemical and biological processes and C accumulation, but variation in DOC in alkaline soils is poorly understood. A survey of alkaline soils from South Australia and Victoria found high DOC concentrations, highlighted regional differences in soil C and DOC and demonstrated how soil pH, soil chemical composition and cropping intensity influence DOC. The work improved understanding of the dynamics of soil C on alkaline soils.

Tillage is an important human activity in agricultural areas, which can cause soil erosion together with the migration of soil constituents. The latter can lead to calcium carbonate replenishment and available phosphorus (AP) dilution in the surface layer of soil derived from carbonate-rich bedrocks. Reducing tillage can help increase AP concentrations in the topsoil layer and therefore improve soil fertility.

To meet national and international demands for ethanol, sugarcane cropping has increased in Brazil in the last years, affecting soil organic matter and subsequently ethanol sustainability. Herein, we quantified aboveground and belowground biomass production, shoot-to-root ratio, and the net and gross annual organic matter increases as a result of sugarcane cropping. Our results showed that the use of a mechanised green cane harvesting system resulted in significant organic matter increases that reduced the impact of land use change due to sugarcane expansion on pastures and Cerrado vegetation.

Soil quality affects atmospheric carbon sequestration of terrestrial vegetation by limiting its growth. We aimed to discriminate between the natural processes and human influence on soil nutrients in a forest fragment and grassland created by afforestation. Afforested areas had lower soil quality and this effect was also observed in neighbouring forested areas.

Movement of phosphorus off farms into waterways is detrimental to the health of downstream aquatic systems through promotion of algal blooms. We measured the concentration of phosphorus, and other elements, in the top 100 mm of soil under a beef farm and a dairy farm and found extremely high concentrations in the top 10 mm of soil. Management practices that lower phosphorus concentrations in surface soil will likely benefit the health of downstream ecosystems by reducing phosphorus movement off-farm.

Soil salinisation harms large areas of agricultural land in Australia and other arid countries. We conducted field trials of how best to remediate saline and sodic (high exchangeable sodium) drought-affected soils in the Lower Murray region using various treatments (gypsum, limestone, seawater, acid) followed by irrigation. The results highlighted that irrigation only, without further costly soil amendment, could be effective in remediating the soils.

Estimating soil hydraulic properties of undisturbed soil samples is of paramount importance in many areas such as hydrology, soil science, and engineering. A new method to estimate the soil hydraulic properties of undisturbed samples is presented. The results showed that this method is a promising technique.

Revegetation of abandoned mine wastes can play a critical role in ameliorating the flux of environmental toxins. We investigated the recalcitrance of barren mine wastes at a long abandoned tin mine and discovered nutrient and structural factors as major limitations to seedling establishment. This study highlights the potential for plant establishment in previously hostile environments.

Soil disturbance following tillage, which is a major issue in crop production, could be mediated by poultry manure application, thereby improving crop yield. Soil physical properties in tilled soil could be improved by combined application of poultry manure and NPK fertiliser; however, high rate of poultry manure under zero tillage should be avoided. To ensure good soil productivity and sustainable maze production, minimum tillage practices and joint application of organic and inorganic fertilisers are recommended.

As commercial nitrification inhibitors (NIs) namely nitrapyrin, 3,4-dimethylpyrazol phosphate (DMPP) and dicyandiamide (DCD) are ineffective at high soil temperatures, it is worth exploring new compounds that can serve as effective NIs under warm climate. Comparing the effectiveness of 4-amino-1,2,4-triazole (ATC), DMPP and DCD to inhibit nitrification of (NH₄)₂SO₄ at 35°C revealed that ATC was more effective than the commercial NIs. Therefore, ATC shows potential for commercialisation as an effective NI for high as well as moderate soil temperatures.