Pedologists need to be able to match local soil classifications to international systems or other local classifications. Well-established multivariate statistical methods, in particular principal components analysis, enable them to do so. In this example, the Australian Soil Classification system is matched successfully with that of the FAO–UNESCO international system.

Soil erosion by water impacts soil organic carbon migration and distribution, which plays critical roles in measuring ecosystem carbon sources and sinks. However, there is limited knowledge of quantifying soil carbon erosion in the three major basins in China – the Yangtze River, Yellow River and Pearl River Basins – which contain the most eroded areas. In this study, we used an empirical model to quantify the lateral movement of soil organic carbon in these three major basins for 1992–2013.

Effects of rice straw ash on sulfosulfuron and wheat straw ash on pretilachlor fate in soils were studied. Ash reduced mobility and persistence of herbicides, but the effect varied with soil type. Even 0.1% of rice straw ash reduced availability of sulfosulfuron to mustard seedlings.

This paper presents MERGE (modelling erosion resistance for gully erosion), a new model to describe how much sediment will be delivered to streams because of gully erosion. The model is process-based and is able to represent actions taken to rehabilitate gullies and reduce erosion. MERGE will help improve decisions about gully remediation to protect coastal ecosystems.

Higher rhizospheric respiration was recorded in the flowering stage of rice crops contributing to a higher carbon dioxide flux to the atmosphere. The regulation of rhizospheric respiration can be achieved through change in soil nutrients and enzyme activities in the rhizosphere by physiological modification of rice plants or soil carbon sequestration.