We measured the long term changes in soil carbon and pH on three trials in the Riverina. The accumulation of soil C required a matching accumulation of N and was accompanied by a decrease in soil pH. The release of N to crop plants will require a rundown in soil C whereas a build up in soil C will lead to a requirement for liming.

The fast, continuous and accurate assessment of soil salinity is very important to guide management of irrigated lands from the plot to the catchment scale. The reference for soil salinity appraisal, that is the saturated paste extract electrical conductivity, was simulated with accuracy using a chemical equilibrium model, whose data requirements are contents of extractable ions, cation exchange capacity and the anion exclusion. The use of this methodology will be useful in applications that need to obtain soil salinity data with limited amounts of soil.

Farming systems in Western Australia traditionally revolved around growing annual crops like wheat and annual pastures like subterranean clover. Recently, farmers have started growing perennial pastures to provide feed for livestock during the summer, when annual pastures have expired. An obvious question emerged; has this move to perennial pastures changed the nutrient and carbon levels in the soil? We surveyed fields with annual crops and pastures and fields with perennial pastures to explore this issue. There were many differences in nutrient and carbon levels between farms, but there were minor and inconsistent differences between the perennial pastures and the annual crops and pastures. We conclude that it is difficult to alter the nutrient and carbon content of soil in this region by just changing the pasture species from an annual to a perennial.

Soil contamination with heavy metals draws great attention due to its potential threat to food safety and human health, the binding capacity of fulvic (FA) and humic acid (HA) influences metal behaviour in soil. This research studied changes in HA and FA and the distribution of copper, lead, and zinc in HA and FA affected by cultivation. The results suggest that cultivation may potentially increase the mobility and pollution risk of heavy metals.

Water called ‘white gold’ is an important natural resource in Lesotho. Alpine wetlands are the main water source and critical to the sustainability of water supply in the country and South Africa. However, they have been over threatened since the 19030’s by excessive human activities. These wetlands capture, store rainfall and ensure sustained water flow and contribute to high water quality. Results indicated considerable spatial variation existed in these properties, which suggests different management interventions should be preffered for a sustained and continuous utilization.

Selenium (Se) is a trace element of enormous public interest and economic significance. Many areas are Se-deficient, but our study shows that breeding seabirds can contribute substantially to soil Se even though this Se is not necessarily taken up by plants. These results are particularly important for continental islands such as mainland New Zealand and Hawai’i where seabirds were widespread until human colonisation.

Nitrous oxide (N₂O) is an important greenhouse gas and contributes to global warming. The challenge of modelling N₂O is that using utilize readily available robust information to infer causal relationships and improve the accuracy of predicting N₂O emissions from soil. Taking into account seasonal variability and temporal persistence in N2O emissions associated with environmental factors may lead to a reduction in the uncertainty surrounding estimates of N₂O emissions based on limited sampling effort.

Crop utilisation of fertiliser P is low and the improvement of P-use efficiency has become an agronomic-research focus. The combined application of inorganic P fertilizer and manure was proved to be an effective and sustainable way of improving P-use efficiency through increasing labile and moderately labile Po, decreasing Fe-P and occluded-P, and promoting microbial biomass P and phytase activity. The 80/20 ratio of inorganic P fertilizer and manure application is the most appropriate on a wheat–soybean rotation in eastern China.

This paper analyzes the mechanics of slope stability in regard to the hysteretic flow of unsaturated soil and its vegetation’s root system. The integrated model allows for the selection and comparison of combinations and densities of vegetation species, in order to find the optimum location for increased Safety Factor. The simulation results illustrated the importance of the vegetation’s spatial distribution in determining whether or not a remedial cover will have a favorable impact on stability.