Evaluation of Soil Tests for Measuring Potentially Mineralizable Soil N in Southern Idaho Soils

Abstract

Developing rapid soil tests to predict N availability could improve management strategies for irrigated crops and would assist in sustainable production. No rapid soil test has been evaluated for applicability in irrigated systems in the semiarid western united States. Soils were collected at two sampling depths (0-30 and 30-60 cm) from irrigated fields across southern Idaho representing predominant soil classes, crops, and irrigation management systems; a 0-60 cm depth was calculated. Anaerobic incubations were used to estimate N mineralization (NMIN) in the sampled soils. The tests were positively correlated with NMIN: the amino sugar N (ASN) test was strongly correlated at 0 to 30 cm (r = 0.73) and 0 to 60 cm (r = 0.79). The flush of CO 2 from soil after capillary rewetting (FL_CO 2 _C) was also strongly correlated at the 0-to 30-cm depth (r = 0.73) and 0-to 60-cm depth (r = 0.67). The loss on ignition (LOI) test was strongly correlated for the 0-to 30-(r = 0.65) and 0-to 60-cm (r = 0.67) depths. Removal of sites with high soil organic matter resulted in improved r 2 for LOI and ASN but not FL_CO 2 _C. The relationship of several tests with NMIN warrants further investigation of their ability to predict crop responses in the region. The ASN test uses a standard 2 M KCl extract, can be automated, and is easily implemented with only minor changes. These results should be expanded to field correlation calibration trials before any test is recommended. Abbreviations: ASN, amino sugar N test; DSD, direct steam distillation; FL_CO 2 , flush of CO 2 ; FL_CO 2 _C, flush of CO 2 after rewetting dried soil via capillary wetting; ISNT, Illinois Soil N Test; LOI, loss on ignition test; NMIN, mineralizable N calculated via anaerobic incubations; OC, organic C; SLAN, Solvita labile amino N; SOM, soil organic matter; TC, total C; TN, total N; WB, Walkley-Black oxidizable soil C test.

Can an amino sugar test estimate potentially available nitrogen from biosolids?

“…For soils, similar results were obtained by Bushong et al. (, ) and Rogers, Schroeder, Rashed, and Roberts (): the ISNT was a relatively poor predictor ( R 2 = 0.41–0.61) of inorganic N from 14‐ or 7‐d anaerobic incubations of diverse agricultural soils.…”

“…Presuming that anaerobic incubation produces reasonable estimates of PAN from biosolids, the relatively low R 2 of these relationships indicates that the AST-N probably would not. For soils, similar results were obtained by Bushong et al (2007Bushong et al ( , 2008 and Rogers, Schroeder, Rashed, and Roberts (2018): the ISNT was a relatively poor predictor (R 2 = 0.41-0.61) of inorganic N from 14-or 7-d anaerobic incubations of diverse agricultural soils.…”

Comparison of nutrient management recommendations and soil health indicators in southern Idaho

“…The SHT uses a combination of a measure of microbial activity, determined from release of CO 2 –C following a 24 h incubation period and the active organic N fraction in the soil (determined with a water extraction) along with the number of wetting and drying periods throughout the season to estimate mineralizable N. The measurement of CO 2 –C release has been found to vary greatly depending on the procedure used (Franzluebbers, 2016, Haney et al., 2008, Rogers, Schroeder, Rashed, & Roberts, 2018, Wade et al., 2018), which can result in large variations of estimated N mineralization. To evaluate this rapid test, we compared the N mineralization estimated using the SHT (Equation ) with that measured in either the laboratory or in the field (Study 1, Figure 4).…”

Predicting Cool‐Season Turfgrass Response with Solvita Soil Tests, Part 2: CO2–Burst Carbon Concentrations

“…As an assessment of soil CO 2 respiration, the SSCB test has been evaluated in various crop and grassland systems (Goupil and Nkongolo, 2014; McDonald et al, 2014; Castro Bustamante and Hartz, 2016; Sadeghpour et al, 2016; Sciarappa et al, 2017; Mureva and Ward, 2017; Ward et al, 2017; Bamber et al, 2018; Chahal and van Eerd, 2018; Norris et al, 2018). The SSCB test is positively and significantly ( P < 0.05) correlated with SOM (McDonald et al, 2014; Castro Bustamante and Hartz, 2016; Sadeghpour et al, 2016; Rogers et al, 2018), soil total organic C and N (Haney et al, 2012; McDonald et al, 2014), soil N mineralization (Haney et al, 2008b; McDonald et al, 2014; Castro Bustamante and Hartz, 2016; Rogers et al, 2018), plant‐mineralizable N (Norris et al, 2018), soil water‐extractable organic C and N (Haney et al, 2012; Castro Bustamante and Hartz, 2016), soil P mineralization (Haney et al, 2008b), and chloroform fumigation extraction microbial biomass C (Chatterjee and Acharya, 2018).…”