Effect of Freezing–Thawing Cycle on Soil Active Organic Carbon Fractions and Enzyme Activities in the Wetland of Sanjiang Plain, Northeast China

Abstract Freeze-thaw cycles (FTCs) are an important element of mid and high latitude ecosystems, and significantly influence soil physicochemical properties and microbial activities in the soil active layers. With the global warming, the effects of FTCs on the dissolved organic carbon (DOC) concentration and soil enzyme activity of different types of soil were still uncertain. In this study, soil of undisturbed Deyeuxia angustifolia wetland (UDAW), disturbed Deyeuxia angustifolia wetland (DDAW) and rice paddy field (RP) from three soil layers of (0–10, 10–20 and 20–30 cm) in Sanjiang Plain, Northeast China, were collected, and then subjected to various FTCs with a large (10 to -10℃) and a small (5 to -5℃) amplitudes, respectively. The results indicated that FTCs increased the soil DOC concentration but reduced the concentration of MBC and activities of cellulase, invertase and catalase. Increase in the freeze-thaw frequency, resulted in the DOC concentration increasing initially and then decreasing, and the MBC concentration and soil enzyme activities were opposite. The DOC concentration increment resulting from the freeze-thaw effects was different across different layers and soil type: as the soil depth increased, the average DOC increments decreased, and the average DOC increments varied across different soil types: UDAW > DDAW > RP. The average MBC concentration and soil enzyme activity decreased from 0-10 cm > 10-20 cm > 20-30 cm soil depth; MBC concentration and soil enzyme activities varied across the different soil types: UDAW > DDAW > RP. The freeze-thaw amplitude and soil moisture content interaction had an effect on soil active organic carbon fractions and enzymatic activity. Small amplitude FTCs and higher water content had the greatest effect on DOC concentration, while larger amplitude and higher water content had the greatest effect on MBC concentration and enzymatic activity. In wetland soil, the significant correlations between active organic carbon fractions and enzyme activities indicate that the increased DOC by FTCs plays an important role in soil microbes and enzyme activities. However, active organic carbon fractions and enzyme activities had little correlation in RP, indicating that FTCs has more influence on wetland than farmland.

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Soil labile organic carbon fractions and soil enzyme activities after 10 years of continuous fertilization and wheat residue incorporation

Scientific Reports ◽

10.1038/s41598-020-68163-3 ◽

2020 ◽

Vol 10 (1) ◽

Cited By ~ 1

Author(s):

Ligan Zhang ◽

Xi Chen ◽

Yujun Xu ◽

Mengcan Jin ◽

Xinxin Ye ◽

...

Keyword(s):

Organic Carbon ◽

Enzyme Activities ◽

Soil Enzyme ◽

Soil Enzyme Activities ◽

Carbon Fractions ◽

Labile Organic Carbon ◽

Soil Labile Organic Carbon ◽

Organic Carbon Fractions ◽

Residue Incorporation

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Wheat straw and biochar effect on soil carbon fractions, enzyme activities, and nutrients in a tobacco field

Canadian Journal of Soil Science ◽

10.1139/cjss-2019-0092 ◽

2021 ◽

pp. 1-12

Author(s):

Yi Wang ◽

Jianxin Dong ◽

Xuebo Zheng ◽

Jiguang Zhang ◽

Peilu Zhou ◽

...

Keyword(s):

Organic Carbon ◽

Soil Fertility ◽

Wheat Straw ◽

Enzyme Activities ◽

Mineral Fertilizer ◽

Soil Enzyme ◽

Hot Water ◽

Available Phosphorus ◽

Carbon Fractions ◽

Organic Carbon Fractions

Annual removal of tobacco residues and insufficient input of organic materials have exacerbated total organic carbon (TOC) depletion and soil degradation in a tobacco field in the Huanghuai area. Straw residue and biochar application may be effective ways to increase TOC accumulation and improve soil fertility. In this field experiment, wheat straw (WS) and wheat-straw-derived biochar (BC) with mineral fertilizer were compared with mineral fertilizer alone (CK), and we assessed their effects on soil organic carbon fractions, enzyme activities, and nutrients in Shandong Province, China, during 2016 and 2017. At 0–20 cm depth, the WS treatment had a greater overall effect on the measured soil properties. Compared with the control, the WS treatment significantly increased the concentrations of microbial biomass carbon (MBC), hot-water-extractable carbon (HWC), and permanganate-oxidizable carbon concentrations (POXC; by 252.41%, 107.02%, and 65.53%, respectively); the activities of sucrase, urease, and phosphatase (by 112.52%, 7.81%, and 34.33%, respectively); and the contents of alkaline hydrolysable nitrogen, available phosphorus, and available potassium (by 92.22%, 100.78%, and 10.57%, respectively). Compared with the control, the BC treatment significantly increased TOC content, MBC content, light fraction organic carbon (LFOC), and potassium (TK) concentration (by 74.93%, 86.24%, 153.73%, and 21.92%, respectively). Most soil enzyme activity and nutrient parameters were significantly correlated with MBC. Thus, straw application improved soil fertility by increasing the concentrations of high labile organic carbon fractions (HWC, MBC, and POXC), stimulating soil enzyme activities, and releasing more soil available nutrients, and BC addition contributed to the accumulation of TOC, MBC, LFOC, and TK.

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