Water extractable organic matter in arable soils: Effects of drought and long-term fertilization

1994 ◽  
Vol 26 (9) ◽  
pp. 1257-1261 ◽  
Author(s):  
A ZSOLNAY ◽  
H GORLITZ
2021 ◽  
Vol 9 ◽  
Author(s):  
Yinghui Wang ◽  
Qiang Zhang ◽  
Hamed Majidzadeh ◽  
Chen He ◽  
Quan Shi ◽  
...  

Water-extractable organic matter (WEOM) in soil is the critical substrate that fuels microbial-driven biogeochemical cycles. However, questions remain regarding whether and how expanding impervious surface area under global urbanization may alter soil WEOM cycling. Based on absorbance and fluorescence spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), we compared the content and chemical signatures of soil WEOM under impervious surfaces with those in adjoining open areas and evaluated the impacts of types (complete sealing by concrete and partial sealing by house structures) and durations (1.5, 27, and 114 years) of impervious surface coverage. The content of soil WEOM and its chromophoric and fluorescent fractions were not significantly changed (less than 20%) after 1.5 years of coverage by concrete and house structures. However, these parameters decreased by more than 30% with 27 and 114 years of coverage by the residential home structures. The microbial-humic-like and protein-like fluorescent WEOM persisted preferentially over the terrestrial-humic-like and nonfluorescent WEOM. FT-ICR MS results suggest various degrees of depletion of biochemical groups in WEOM. While the water-extractable lipid-like compounds increased with 1.5 years of coverage, all studied biochemical groups were depleted with long-term coverage, which might reduce the microbial processing of suberin-derived compounds. This study highlights the remarkable impacts of soil sealing on reducing substrate availability for microbial carbon processing in urban environments.


2021 ◽  
Vol 777 ◽  
pp. 146127
Author(s):  
Peng Zhang ◽  
Chun Cao ◽  
Ying-Hui Wang ◽  
Kai Yu ◽  
Chongxuan Liu ◽  
...  

2018 ◽  
Vol 13 (No. 3) ◽  
pp. 140-149 ◽  
Author(s):  
Šimanský Vladimír ◽  
Lukáč Martin

Soil structure is a key determinant of many soil environmental processes and is essential for supporting terrestrial ecosystem productivity. Management of arable soils plays a significant role in forming and maintaining their structure. Between 1994 and 2011, we studied the influence of soil tillage and fertilisation regimes on the stability of soil structure of loamy Haplic Luvisol in a replicated long-term field experiment in the Dolná Malanta locality (Slovakia). Soil samples were repeatedly collected from plots exposed to the following treatments: conventional tillage (CT) and minimum tillage (MT) combined with conventional (NPK) and crop residue-enhanced fertilisation (CR+NPK). MT resulted in an increase of critical soil organic matter content (St) by 7% in comparison with CT. Addition of crop residues and NPK fertilisers significantly increased St values (by 7%) in comparison with NPK-only treatments. Soil tillage and fertilisation did not have any significant impact on other parameters of soil structure such as dry sieving mean weight diameters (MWD), mean weight diameter of water-stable aggregates (MWD<sub>WSA</sub>), vulnerability coefficient (Kv), stability index of water-stable aggregates (Sw), index of crusting (Ic), contents of water-stable macro- (WSA<sub>ma</sub>) and micro-aggregates (WSA<sub>mi</sub>). Ic was correlated with organic matter content in all combinations of treatments. Surprisingly, humus quality did not interact with soil management practices to affect soil structure parameters. Higher sums of base cations, CEC and base saturation (Bs) were linked to higher Sw values, however higher values of hydrolytic acidity (Ha) resulted in lower aggregate stability in CT treatments. Higher content of K<sup>+</sup> was responsible for higher values of MWD<sub>WSA </sub>and MWD in CT. In MT, contents of Ca<sup>2+</sup>, Mg<sup>2+ </sup>and Na<sup>+</sup> were significantly correlated with contents of WSA<sub>mi </sub>and WSA<sub>ma</sub>. Higher contents of Na<sup>+</sup> negatively affected St values and positive correlations were detected between Ca<sup>2+</sup>, Mg<sup>2+ </sup>and Na<sup>+</sup> and Ic in NPK treatments.


ael ◽  
2016 ◽  
Vol 1 (1) ◽  
pp. 160023 ◽  
Author(s):  
Zhongqi He ◽  
Mingchu Zhang ◽  
Aiqin Zhao ◽  
O. Modesto Olanya ◽  
Robert P. Larkin ◽  
...  

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