Very dry soil moisture conditions enhanced particulate phosphorus losses in surface runoff from an Organic soil and from a Brown soil under very wet conditions. A high hydraulic conductivity resulted in more P being lost in subsurface flow than surface runoff from the Organic soil, whereas surface runoff losses dominated the Brown soil. The quantity of P lost was inversely related to the anion storage capacity of the soil.

The nitrification inhibitor 3,4,-dimethylpyrozole phosphate (DMPP) may be effective in minimising environmental degradation caused by NO₃^– leaching from excessive N fertiliser use. DMPP has not been widely investigated on coarse-grained soils containing a low abundance of nitrifying microbes. In this study, using such soils, DMPP conserved NH₄⁺ and inhibited nitrifying microbial populations for 100 days, which is longer than observed previously for heavier soil types. In addition, DMPP was more effective than another nitrification inhibitor (nitrapyrin) in inhibiting nitrification. These soils also contained low Cu, a cofactor in ammonia mono-oxygenase (AMO), which facilitates nitrification, suggesting an interaction between DMPP and Cu availability controlled this process. Thus, DMPP has the potential to be an important tool in minimising nitrification in areas where these soils are common (e.g. Western Australia’s agricultural zones).

The use of gypsum to amend tropical soils rich in toxic aluminium can effectively increase soil carbon stocks. Total carbon stock in the soil and its fractions were estimated after four growing seasons of sugar cane under gypsum application. Of the total increase in C stocks resulting from gypsum application, 80% occurred in the 40–100-cm layer.

Sea-level rise and saline water intrusion have caused a shortage of fresh water and affected agricultural areas globally. The findings of an incubation experiment to examine the effects of salinity on soil carbon and nitrogen cycling indicate that salinity has altered carbon and nitrogen cycles in the acid sulfate soil. Future fertiliser and crop management will need to account for the changed nutrient cycling caused by saline water intrusion and climate change.

Rhizosphere effect on nitrogen transformation in Australian native plants was investigated. Ammonium oxidizing bacteria and nitrification potential were lower in rhizosphere soils than that in non-rhizosphere soils. Some Australian native plants were found to inhibit nitrification in their rhizosphere.

In the present study, over a 5-year period (2008–2013), 740 kg N ha^–1 fertiliser was applied to an irrigated cotton–wheat–maize rotation on a cracking clay (grey Vertosol). The N in the drainage was composed of 12.8 kg NO_x-N ha^–1, 8.7 DON-N and 0.1 NH₄⁺-N kg ha^–1. This result shows that DON is an important component (40%) of the deep drainage N from irrigated Vertosol cotton production systems.

Carbon occurs in small concentrations to very great depths in many soils. However, its distribution is poorly understood. This study examined two readily available techniques for measuring soil carbon content. An equation was developed that allows prediction of total carbon in deep regolithic soils.

We quantified the charcoal content of artificial soil samples of defined quantities of rock, charcoal and litter, spanning a wide range of organic carbon contents (0.1–15%). Using attenuated total reflectance mid-infrared spectroscopy combined with randomForest modelling, we overcame traditional limitations (e.g. non-linearity) of infrared analysis and accurately quantified the charcoal content of the standards, enabling rapid, low-cost and efficient charcoal analysis in soil.

Activated biochar exposed to H₂S and contained 36.5% S (S element and SO₄^2–), confirming its potential to adsorb significant amounts of H₂S. SulfaChar significantly increased corn plant biomass when used as an S fertiliser.