Effects of different amendments on aggregate stability and microbial communities of coastal saline–alkali soil in the Yellow River Delta

Abstract

Organic amendments have been widely used in coastal saline–alkali soil remediation; however, the mechanisms involved and the interactions between organic and inorganic amendments are still unclear. In this work, furfural residue (particulate; C/N ratio: 51.87; O‐alkyl C + di‐O‐alkyl C: 42.35%, aromatic C: 40.89%) and black liquor (dissolved; C/N ratio: 3.11; O‐alkyl C + di‐O‐alkyl C: 32.20%, aromatic C: 28.32%) were tested to examine their effects on chemical properties, water‐stable aggregate fractions, chemical compositions of solid‐state soil organic matter (SOM), gloaming‐related soil protein contents, and microbial communities of coastal saline–alkali soil under a 400‐day incubation experiment. Furthermore, organic amendments mixed with mineral amendment (4:1) were employed to explore the interactions between organic and inorganic amendments. Furfural residue had stronger and longer effects on soil macroaggregate stability (~240 days, intense) than black liquor (~15 days, weak), and mineral amendment addition had a positive effect on the stability of microaggregates. Our results revealed that qualities (primary form, C/N ratio, and chemical composition) of organic amendment which can change microbial communities by increasing soil C/N ratio and effective chemical compositions of solid‐state SOM, are the key factors in promoting the rapid formation and longer stability of coastal saline–alkali soil aggregates. Moreover, inorganic amendment addition can further improve the formation and stability of microaggregates rather than those of macroaggregates. This study provided a much‐needed technical basis for remediation of coastal saline–alkali soil.

Poly‐γ‐glutamic acid enhanced the yield and photosynthesis of soybeans by adjusting soil aggregates and water distribution

“…The microbial secretions can stimulate soil aggregate formation. 45,46 Combining our results on the reduction of soil clay particles by the application of γ-PGA, this phenomenon potentially contributed to the amelioration of soil microorganisms' habitat through γ-PGA application, 47 thereby promoting increased secretion of polysaccharides and peptides by soil microorganisms. 48,49 In addition, Na + ions induced dispersion of aggregates by inhibiting colloid flocculation.…”

“…The γ ‐PGA application in this study enhanced the stability of water‐stable aggregates. The microbial secretions can stimulate soil aggregate formation 45,46 . Combining our results on the reduction of soil clay particles by the application of γ ‐PGA, this phenomenon potentially contributed to the amelioration of soil microorganisms' habitat through γ ‐PGA application, 47 thereby promoting increased secretion of polysaccharides and peptides by soil microorganisms 48,49 .…”

Effects of Environmentally Friendly Materials on Saline Soil Improvement and Sunflower Yields in the Hetao Irrigation Region, China

“…The undisturbed soil cores were obtained using sharpened steel cylinders of 100 cm 3 volume (5 cm inner diameter and 5 cm height) at the soil surface layer (10-15 cm) and were ovendried for 24 h in a ventilated oven to measure BD. The water-stable aggregate (>0.25 mm, R 0.25 ) was determined by wet sieving, as described by [31]. The mean weight diameter (MWD) and mean geometric diameter (GWD) were each calculated by the following equation [31]:…”

“…The water-stable aggregate (>0.25 mm, R 0.25 ) was determined by wet sieving, as described by [31]. The mean weight diameter (MWD) and mean geometric diameter (GWD) were each calculated by the following equation [31]:…”

Effect of Straw Mulching and Deep Burial Mode on Water and Salt Transport Regularity in Saline Soils

“…Furthermore, the thorough integration of straw into the soil can enhance the content of soil organic matter, thereby ensuring consistent crop yields [24]. This practice also facilitates the deceleration of water infiltration, as well as the optimization of water and salt distribution and soil structure within the tillage layer [25]. The integration of straw mulching and deep incorporation of soil strata substantially enhanced soil moisture at a depth of 0-40 cm and markedly diminished salinity in the surface layer (0-20 cm).…”