Soil organic carbon is an important part of overall world carbon stocks. The measurement techniques for soil organic carbon that have evolved over time can measure quite different species and suffer various interferences. An understanding of the techniques used is required to assist further research opportunities for soil organic carbon due to both its importance to world carbon stocks and the techniques used to measure it.

The Fundamental Soil Layers (FSL) contain a range of New Zealand’s soil attribute information held in a spatial database. This study assesses the accuracy of the FSL by comparing observed data for Profile Available Water (PAW) and Potential Rooting Depth (PRD) with FSL estimates for these two attributes. FSL estimates for PRD and PAW were inaccurate, and allowance for variation in underlying data and estimation methods did not improve their accuracy.

Status of soil organic carbon was evaluated in olive orchards in Mediterranean Lebanon. Vertical distribution of SOC contents was studied in depth in pairs of abandoned/actively managed fields. Stocks of SOC were also compared in relation with the duration of abandonment.

Wet chemistry and spectroscopy methods assessed the functional groups in the carbonaceous surface of wood biochars. The amount of acidic groups in biochar decreased with increasing pyrolysis temperature. Besides, the presence of a low amount of inorganic fraction caused a “masking effect” on the determination of surface acidity of biochar. This can be partially solved by using potentiometric titrations after acid-washing pretreatment to quantify biochar acidity.

We evaluated the change in water extractable organic carbon (WEOC) and microbial PLFAs of biochar during incubation with an acidic paddy soil, suggesting that the WEOC quickly change and interact with soil components, and that the PLFAs profile is significantly affected by biochar chemical properties. The findings contribute to revealing the interaction mechanism between biochar and soil, and to the proper utilisation of environmental residues.

This study uses cladistics to assess the naturalness of the Australian Soil Classification (ASC). The results suggest that the ASC is not a natural classification, however, Soil Orders of Organosols, Podosls and Vertosols are natural. The results also indicated that to make ASC more natural revision of soil colour and characters located in the Great Groups as well as Soil Orders such as Chromosols, Ferrosols and Dermosols are necessary.

It is known that adding biosolids changes the characteristics of the receiving soil, including pH. How this affects the bioavailability of any heavy metals contained in the biosolids was tested by measuring the ratio of DTPA-extractable to total metal concentrations in composted and anaerobically digested biosolids, and in the soil before and after application. Uptake of Cu and Zn was measured in leaves of two indicator crops, canola and oats.

The goal of this study was to investigate the spatial and temporal distribution of annual rainfall erosivity in New Zealand. High-resolution data from 35 weather stations from both islands were used to calculate the R-factors. Based on these results, region-specific equations were developed and applied by using long-term precipitation records from 597 stations in order to produce a rainfall erosivity map of New Zealand.

New Zealand soils have low concentrations of rare earth elements. Across a range of rare earths, only La increased yield and decreased uptake of Cd in ryegrass for one harvest after application and for one soil type. There was not enough evidence to recommend the use of La to increase yield or decrease CD uptake in ryegrass-dominated pastures.