Soil Sampling and Sample Preparation

Abstract

Soils are sampled and analysed in order to characterize a range of attributes and provide a value (or range of values) that is indicative of a specified area. For trace elements, sampling may be undertaken for the purpose of providing their soil concentration, which can then be used to assess the degree of site contamination. Trace elements are introduced in soils through a variety of sources which differ widely in their composition. Typical delivery is to the soil surface through a combination of passive (for example, atmospheric deposition) or active (for example, spreading of contaminated materials) mechanisms and supplement background 'geochemical' sources. The change in total content (dG/dt) over a time period (t) of a soil contaminant (G) depends on the input rate at the soil surface (plough) layer (A), the leaching rate at the lower boundary of the system (L) and the removal by harvesting plants (U) [1]:The source plus delivery mechanism influence not only the absolute metal concentrations likely to be present in soil, but also a combination of the spatial distribution and chemical form/species present. Some historical knowledge of the contributing sources and site management can be of considerable help to the design of a sampling plan, sample collection and preparation stages. An indication of the degree of accumulation or loss of Trace Elements in SoilsEdited by Peter S. Hooda

Trace metal enrichment observed in soils around a coal fired power plant in South Africa

“…The STSI is a systematic design-based approach whereby the area is divided into several sub-regions, or strata, after which simple random sampling is conducted within each of the strata (Brus and De Gruijter, 1997). The stratification process typically divides the site into smaller strata based on specific properties of the stratum whereby the variance of a parameter within a stratum should, if accurately applied, be smaller than the variance between strata (Edwards, 2010). Primarily STSI was employed to reduce the error associated with simple random sampling or bias introduced with other traditional sampling schemes such as following an X or W pattern (Edwards, 2010).…”

Legume-grass mixtures increase forage yield by improving soil quality in different ecological regions of the Qinghai-Tibet Plateau

“…Soil near the crop roots was collected from 28 test plots using an auger. We randomly collected 5 soil sub-samples (0-10,10–20 cm depth) from each experimental plot and integrated them into one soil sample to reduce errors due to soil heterogeneity ( Edwards, 2010 ). This approach is commonly used in soil microbiology and for determining the physico-chemical properties of soil ( Huhe et al., 2017 ).…”

Herbivore assemblages affect soil microbial communities by altering root biomass and available nutrients in an alpine meadow

“…The samples from each quadrat were mixed thoroughly to form one composite sample for the determination of relevant indicators. Mixing multiple soil samples reduces errors due to soil heterogeneity (Edwards, 2010), and many studies on soil microbiology and phyisco-chemical properties often use such an approach (Chen et al, 2010;Huhe et al, 2017;Xiao et al, 2020). These 36 soil samples were stored at 4°C and immediately brought back to the laboratory.…”