Soil nutrient limitations characterise savanna soils and are one constraint on establishing productive tree plantations and enhancing economic opportunities in tropical regions. We found positive tree growth responses to phosphorus, nitrogen and sulfur fertilisation, yet unhealthy trees developed in which zinc limitation and small-scale variation in soil characteristics was confirmed. Nutrient additions to enhance tree growth will need to encompass trace elements in addition to phosphorus, nitrogen and sulfur, and consider small-scale variability in cation exchange capacity and composition.

Irrigation and farming practices can increase nutrient leaching losses, which affects water quality. Under zone-specific management of variable rate irrigation and mixed cropping, over 5 years, drainage flux meters worked well for the well-drained sandy loam; nutrient concentrations and leaching loads generally had greater uncertainty in the poorly drained silt loam. Drainage flux meters are more reliable in the sandy loam than the silt loam.

Soil and groundwater around the world are salt affected. Saline water can be used effectively for irrigation by salt leaching to despatch the accumulated salts back to groundwater. We examine the rootzone efficiency and groundwater impacts of salt leaching to remove salts from the rootzone.

The erosion of gullies degrades the local landscape and contributes to poor water quality in receiving bodies. Consequently, considerable effort is invested to rehabilitate gullies and prevent erosion. This study investigates the use of the MERGE gully erosion model to test different rehabilitation options to help land managers determine what the best combination of actions will be at different sites. This study considers three different gullies, demonstrating that different actions will work better at different sites.

Greenhouse gas emissions from agriculture contribute 15% of the official national account. Nitrous oxide is a major greenhouse gas and is primarily emitted from soils. With a Global Warming Potential nearly 300 times that of carbon dioxide, it has major impact on climate change. Nitrogen applications in the form of fertilisers, crop residues, urine and dung are the primary contributors to these emissions. The study assembled nitrous oxide emissions data from Australian agriculture that has been collected over the past 2 decades to provide accurate emission factors for the national account.

This paper discusses the spatial and temporal variation of the soil erosion degree in the regions of southern Shanxi and Guanzhong Basin, China, based on Universal Soil Loss Model, RUSLE. In the new era, the ecological and environmental problems caused by soil erosion are receiving more and more attention. The analysis in this paper can elucidate the seriousness of the soil erosion problem so that the government can strengthen the key management of soil and water conservation and achieve the purpose of reducing soil erosion.

Cotton fields are prone to soil erosion. The WEPP model has advantages for predicting erosion, but parameters are rare for Australian cropping soils. We measured WEPP interrill erodibility (Ki) for five cultivated soils. Ki was ~3 000 000 kg.s m⁻⁴ for Emerald and Gatton soils and 3 900 000 kg.s m⁻⁴ for three clay soils, in the high end of the range of USA cropping soils. Soil surface and sediment particle sizes, and settling velocity distributions, were similar between soils but sediment sizes were finer.