Glomalin contributed more to carbon, nutrients in deeper soils, and differently associated with climates and soil properties in vertical profiles

Abstract

Despite vital importance in soil conditioning and a proxy for arbuscular mycorrhizal (AMF), glomalin-related soil protein (GRSP) contribution to soil carbon and nutrients at vertical soil profiles and underlying mechanism were not well-defined yet. Thus, 360 soil samples were collected from 72 farmland 1-m soil profiles in northeastern China, and soil physiochemical properties, nutrients, glomalin characteristics, local climates were determined. Linear decreases of glomalin amounts were observed from the top to deep soils, and glomalin/SOC (glomalin ratio to total SOC) in the 80–100 cm soil (EEG, easily-extracted GRSP, 2.2%; TG, total GRSP, 19%) was 1.34–1.5-fold higher than did in the 0–20 cm soil. Different statistical analyses crosschecked that the lower pH and higher SOC usually accompanied with the higher EEG and TG, while EEG was more sensitive to climates; Moreover, glomalin was more physiochemical-regulated in the deep soils, but more nutrient-regulation was found in the surface soils. Structure Equation Model showed that soil depths and climates indirectly affected TG and EEG features through soil properties, except significant direct effects on EEG. In future, glomalin assessment should fully consider these for identifying the AMF importance in the whole 1-m profile, and our findings also favor degrade soil improvement from glomalin rehabilitation.

Effect of Salinity Stress and Microbial Inoculations on Glomalin Production and Plant Growth Parameters of Snap Bean (Phaseolus vulgaris)

“…To extract glomalin-related soil protein (GRSP), soil samples from 5 replicates of each treatment (e.g., ICSC 1, 4, 7, 8, and 10) were randomly selected, dried at 50 • C for 24 h, and sieved (2.0 mm) prior to protein extraction following the protocol from Wright and Upadhyaya [39] with modification [40]. Easily extractable GRSP (EEG) was extracted from 0.5-g soil samples by adding 4 mL of 20 mmol L −1 sodium citrate (pH 7.0) solution followed by autoclaving at 121 • C for 30 min.…”

Microclimate regulating functions of urban forests in Changchun City (north-east China) and their associations with different factors

“…Urban forests management will greatly benefit from better understanding the relationships between microclimate regulation functions, urban forest structure, and local environmental conditions (Zhang et al 2013, Wang et al 2017b. Recent studies have demonstrated that higher trees have a better regulation capacity in terms of sunlight interception, air temperature and humidity (Giannico et al 2016).…”

Variation in glomalin in soil profiles and its association with climatic conditions, shelterbelt characteristics, and soil properties in poplar shelterbelts of Northeast China

“…We have investigated most shelterbelt characteristics in this paper and parameters included tree size (height, DBH) and age, and community characteristics (tree density and shelterbelt width), as well as ditch width, depth, and distance to neighbouring farmlands. These latter parameters are particularly important for farmland productivity and in preventing nutrient and water losses (Wang et al 2017b). Both the RDA ordination and SEM analysis found insignificant effects on GRSP features (except for ditch width, as shown in the conditional term effects in the RDA ordination).…”