Effects of amendments on carbon and nitrogen fractions in agricultural soils of Yellow River Delta

Abstract Although various measurements (including organic amendments) have been used to ameliorate saline–alkaline soils, soil organic matter (SOM) remains low in most salt-affected agriculture soils. It was hypothesized that lower SOM level was partly attributable to weaker SOM stability (thus grea...

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Main Authors: Lipeng Wu, Kaijing Zhang, Xingyu Zhu, Tongping Lu, Xiujun Wang
Format: Article
Language:English
Published: SpringerOpen 2023-05-01
Series:Geoscience Letters
Subjects:
Online Access:https://doi.org/10.1186/s40562-023-00276-9
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author Lipeng Wu
Kaijing Zhang
Xingyu Zhu
Tongping Lu
Xiujun Wang
author_facet Lipeng Wu
Kaijing Zhang
Xingyu Zhu
Tongping Lu
Xiujun Wang
author_sort Lipeng Wu
collection DOAJ
description Abstract Although various measurements (including organic amendments) have been used to ameliorate saline–alkaline soils, soil organic matter (SOM) remains low in most salt-affected agriculture soils. It was hypothesized that lower SOM level was partly attributable to weaker SOM stability (thus greater desorption) in the salt-affected soils. To test this hypothesis, we conducted a 16-week incubation experiment using low- and high-salinity soils to evaluate the effects of soil ameliorants (gypsum, CaCO3, rice straw and biochar) on SOM labile fractions, i.e., water extractable organic carbon (WEOC) and nitrogen (WEON), together with microbial biomass carbon (MBC) and nitrogen (MBN). Our results showed an increase in MBC and MBN under all amendments in both low- and high-salinity soils, reflecting improvements in soil properties. Gypsum amendment led to a decrease in both WEOC (by 15–21%) and WEON (by 14–31%). CaCO3 amendment only caused a decrease in WEON (by 14–27%), with a greater decrease found in the high-salinity soil. There was an increase in WEOC (by 13–66%) but a decrease in WEON (7.6–46%) under biochar and straw amendments in both low- and high-salinity soils. WEOC:SOC ratio (an indicator for SOC desorption) showed a decrease under gypsum and biochar amendments but an increase with CaCO3 and straw treatments. There was a decrease in WEON:TN ratio (an indicator for ON desorption) under all amendments, with the greatest decrease under biochar treatment. Our analyses demonstrated an enhancement in SOC or ON adsorption under all amendments, indicating that SOM stability might be enhanced in association with soil amelioration. Our study also highlights that there is strong decoupling between carbon and nitrogen cycles and further studies are needed to examine the impacts of such decoupling on SOM stability.
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spelling doaj.art-80c04c650620433aa3adf7ff1a3616962023-05-14T11:18:58ZengSpringerOpenGeoscience Letters2196-40922023-05-0110111210.1186/s40562-023-00276-9Effects of amendments on carbon and nitrogen fractions in agricultural soils of Yellow River DeltaLipeng Wu0Kaijing Zhang1Xingyu Zhu2Tongping Lu3Xiujun Wang4College of Global Change and Earth System Science, Beijing Normal UniversityCollege of Global Change and Earth System Science, Beijing Normal UniversityCollege of Global Change and Earth System Science, Beijing Normal UniversityCollege of Global Change and Earth System Science, Beijing Normal UniversityCollege of Global Change and Earth System Science, Beijing Normal UniversityAbstract Although various measurements (including organic amendments) have been used to ameliorate saline–alkaline soils, soil organic matter (SOM) remains low in most salt-affected agriculture soils. It was hypothesized that lower SOM level was partly attributable to weaker SOM stability (thus greater desorption) in the salt-affected soils. To test this hypothesis, we conducted a 16-week incubation experiment using low- and high-salinity soils to evaluate the effects of soil ameliorants (gypsum, CaCO3, rice straw and biochar) on SOM labile fractions, i.e., water extractable organic carbon (WEOC) and nitrogen (WEON), together with microbial biomass carbon (MBC) and nitrogen (MBN). Our results showed an increase in MBC and MBN under all amendments in both low- and high-salinity soils, reflecting improvements in soil properties. Gypsum amendment led to a decrease in both WEOC (by 15–21%) and WEON (by 14–31%). CaCO3 amendment only caused a decrease in WEON (by 14–27%), with a greater decrease found in the high-salinity soil. There was an increase in WEOC (by 13–66%) but a decrease in WEON (7.6–46%) under biochar and straw amendments in both low- and high-salinity soils. WEOC:SOC ratio (an indicator for SOC desorption) showed a decrease under gypsum and biochar amendments but an increase with CaCO3 and straw treatments. There was a decrease in WEON:TN ratio (an indicator for ON desorption) under all amendments, with the greatest decrease under biochar treatment. Our analyses demonstrated an enhancement in SOC or ON adsorption under all amendments, indicating that SOM stability might be enhanced in association with soil amelioration. Our study also highlights that there is strong decoupling between carbon and nitrogen cycles and further studies are needed to examine the impacts of such decoupling on SOM stability.https://doi.org/10.1186/s40562-023-00276-9BiocharStrawGypsumCaCO3Water extractable organic matterSaline–alkaline soils
spellingShingle Lipeng Wu
Kaijing Zhang
Xingyu Zhu
Tongping Lu
Xiujun Wang
Effects of amendments on carbon and nitrogen fractions in agricultural soils of Yellow River Delta
Geoscience Letters
Biochar
Straw
Gypsum
CaCO3
Water extractable organic matter
Saline–alkaline soils
title Effects of amendments on carbon and nitrogen fractions in agricultural soils of Yellow River Delta
title_full Effects of amendments on carbon and nitrogen fractions in agricultural soils of Yellow River Delta
title_fullStr Effects of amendments on carbon and nitrogen fractions in agricultural soils of Yellow River Delta
title_full_unstemmed Effects of amendments on carbon and nitrogen fractions in agricultural soils of Yellow River Delta
title_short Effects of amendments on carbon and nitrogen fractions in agricultural soils of Yellow River Delta
title_sort effects of amendments on carbon and nitrogen fractions in agricultural soils of yellow river delta
topic Biochar
Straw
Gypsum
CaCO3
Water extractable organic matter
Saline–alkaline soils
url https://doi.org/10.1186/s40562-023-00276-9
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AT xingyuzhu effectsofamendmentsoncarbonandnitrogenfractionsinagriculturalsoilsofyellowriverdelta
AT tongpinglu effectsofamendmentsoncarbonandnitrogenfractionsinagriculturalsoilsofyellowriverdelta
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