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Remote sensing techniques based on soil spectral characteristics are the key to future land management; however, they still require field measurement and an agrochemical laboratory for the calibration of the soil property model. Visible and near-infrared diffuse reflectance spectroscopy has proven to be a rapid and effective method. This study aimed to assess the suitability of multispectral data acquired with the agricultural digital camera in determining soil properties. This 3.2-Mpx camera captures images in three spectral bands – green, red and near-infrared. First, the reference data were collected, which consist of 151 samples that were later examined in the laboratory to specify the granulometric composition and to quantify some chemical elements. Second, additional soil properties such as cation exchange capacity, organic carbon and soil pH were measured. Finally, the agricultural digital camera photograph was taken for every soil sample. Reflectance values in three available spectra bands were used to calculate the spectra indices. The relationships between the collected data were calculated using the independent validation regression model such as Cubist and cross-validation model like partial least square in R Studio. Additionally, different types of data normalisation multiplicative scatter correction, standard normal variate, min–max normalisation, conversion into absorbance] were used. The results proved that the agricultural digital camera is suitable for soil property assessment of sand and silt, pH, K, Cu, Pb, Mn, F, cation exchange capacity and organic carbon content. Coefficient of determination varied from 0.563 (for K) to 0.986 (for soil organic carbon). Higher values were obtained with the Cubist regression model than with partial least squares.

Smoothing rough ploughed soils increases their albedo, which results in a lower amount of shortwave radiation being absorbed by their surface layer. That surface emits less longwave radiation, leading to a reduction in its temperature, which in turn can affect the climate. This article presents a multistage procedure using remote sensing and geostatistical data sets for quantification of the annual dynamics of shortwave radiation reflected from air-dried bare soils within arable lands of the European Union and its associated countries, Norway and Switzerland. The soils, being cultivated under conventional tillage, were treated as bare formed by a plough (Pd) and a smoothing harrow (Hs), when the major crops were planted there. Information about the areas of the soils and periods when they are bare was obtained from vectorized and rasterized geostatistical data sets. The spatial diversity of the spectral reflectance of the soils, characterized by thousands of their reflectance spectra (stored in the European Land Use and Cover Area frame Survey Top Soil Database), were used to predict the halfdiurnal albedo variation of the soils on a given day of the year. The shortwave radiation reaching the examined soils was obtained from satellite data of the Spinning Enhanced Visible and Infrared Imager instrument. It was found that the maximum radiation levels reflected from the soils occur between the beginning of April and the end of May. During these periods, the radiation reflected from the soils formed by Pd and Hs can reach about 220 and 250 PJ d-1 in the western part of the EU, 150 and 190 PJ d-1 in the central part, and up to 280 and 330 PJ d-1 in the southern part. [ABSTRACT FROM AUTHOR]

Little is known about the problem of soil contamination with antimony in Poland. Soil samples examined in this study represented two different kinds of Sb-enriched areas: military shooting ranges and historical mining sites in south-western Poland. Total Sb concentrations in soils, determined after fusion with lithium borate, were in the range 17.3-427 mg kg-1. The amounts of Sb recovered as "near total concentrations" were determined after soil digestion with concentrated nitric acid and aqua regia. The study confirmed very low recovery of Sb in soils digested with nitric acid (mean 20.9% of total), significantly lower in mine soils (7.6 ±3.4%) than in shooting range soils (34.2±17.5%). Aqua regia digestion proved to ensure satisfactory recovery of Sb, circa 90% of its total concentrations, independently of the soil origin. Additionally, toxicity characteristic leaching procedure (TCLP), developed by the US EPA, was applied to determine leachability of Sb from soils. The concentrations of Sb in TCLP leachates: 0.001-0.281 mg L-1, remained at a level considered as ecologically safe, but considerably exceeded the threshold values for underground and drinking water. The amounts of Sb leached from the shooting range soils in the TCLP procedure, expressed as percentage of total Sb, were determined as 6.2±2.0%, i.e. significantly higher compared to mine soils (0.74±0.42%). These results should be considered as a premise for further risk- and remediation-oriented examination of shooting range soils. [ABSTRACT FROM AUTHOR]