Characterization of soil organic matter by near infrared spectroscopy – determination of glomalin in different soils

Abstract

8Determining and characterizing soil organic matter (SOM) cheaply and reliably can help to support 9 decisions concerning sustainable land management and climate policy. Glomalin, a glycoprotein 10 produced by arbuscular mycorrhizal fungi, was recommended as a promising indicator of SOM quality. 11But extracting glomalin from and determining glomalin in soils using classical chemical methods is too 12 complicated and time consuming and therefore limits the use of this parameter in large scale surveys. 13Near infrared spectroscopy (NIRS) is a very rapid, non-destructive analytical technique that can be used 14 to determine many constituents of soil organic matter. 15Representative sets of 84 different soil samples from arable land and grasslands and 75 forest soils were 16 used to develop reliable NIRS calibration models for glomalin. One calibration model was developed for 17 samples with a low content of glomalin (arable land and grasslands), the second for soils with a high 18 content of glomalin (forest soils), and the third calibration model for all combined soil samples. 19Calibrations were validated and optimized by leave-one-sample-out-cross-validation (LOSOCV) and by 20 the external validation using eight soil samples (arable land and grassland), and six soil samples (forest 21 soils) not included in the calibration models. 22Two different calibration models were recommended. One model for arable and grassland soils and the 23 second for forest soils. No statistically significant differences were found between the reference and the SOIL Discuss., doi:10.5194/soil-2016-9, 2016 Manuscript under review for journal SOIL 24

The effect of thinning on humus conditions in spruce and beech stands in the Highlands area of the Czech Republic

“…Chemical analysis: Carbon and nitrogen were determined using samples cleared from coarser particles after they were finely ground; the determination was made using the automatic analyser LECO TruSpec /MI USA/ (Zbíral 1997). Humic substances were extracted from the fine soil by a solution of sodium pyro-phosphate in an alkaline mixture + NaOH using short fractionation by Kononová and Bělčiková (Podlešáková et al 1992).…”

Evaluation of chemical properties of througfall, forest floor and seepage water in Spruce and Beech stands in the Highlands area of the Czech Republic

“…Available nutrients in the forest floor horizons (L, F, H) and the organomineral horizon (A) were determined after extraction via an acid solution of ammonium nitrate and ammonium fluoride (Zbíral 1995), (Mehlich 1984) using the method of flame atomic absorption spectrometry (Ca and Mg) and the method of atomic emission spectrometry (Na and K). Cation exchange capacity (CEC) was determined using the summation method (Zbíral et al 1997). The determination of the soil adsorption complex by hydrogen was carried out using the method of double measurement (Zbíral et al 1997).…”

“…Cation exchange capacity (CEC) was determined using the summation method (Zbíral et al 1997). The determination of the soil adsorption complex by hydrogen was carried out using the method of double measurement (Zbíral et al 1997). The total content of Al in the forest floor (L, F, H) and organomineral horizon (A) was determined by the method of flame atomic absorption spectrometry (FAAS) (Zbíral 2002).…”

Determination of the Titanium Contents in the Winter Oilseed Rape Plants (Brassica napus L.) by the Application of Fertilizer Containing Titanium

“…I. They were determined by the following methods: N min = N-NH 4 + + N-NO 3 − , N-NH 4 + -colorimertically by Nessler's agent, N-NO 3 − -colorimertically by the phenol 2.4 disulphonic acid, P -colorimertically (extract Mehlich 3 -Mehlich, 1984), K and Cafl ame photometry (extract Mehlich 3 -Mehlich, 1984), Mg -AAS (extract Mehlich 3 -Mehlich, 1984), S -spectrometrically ICP OES (water extract - Zbíral et al, 2011a), Ti -spectrometrically ICP MS (extract Mehlich 3 -Zbíral et al, 2011b). C ox -oxidometrically by Ťjurin in modifi cation of Nikitin (Dziadowiec and Gonet, 1999), N t -by distilling (Kjeldahl -Bremner, 1960), pH/KClpotentiometrically (1.0 mol/dm 3 KCl).…”