Recovery of organic matter and microbial biomass after abandonment of degraded agricultural soils: the influence of climate

Abstract

After abandonment of agricultural lands (ongoing on 220 million hectares worldwide), degraded arable soils undergo self‐restoration and development towards natural ecosystems. We studied the linkage between microbial properties and density fractions of soil organic matter (SOM) during post‐agricultural restoration of former arable Phaeozems and Chernozems. The chronosequence study was conducted in two contrasting bioclimatic zones of European Russia: deciduous forest (Luvic Phaeozem) and dry steppe (Calcic Chernozem). Each chronosequence included an arable soil, 3–4 soils with increasing periods after abandonment (from 7 to 35 years), and reference sites with native soils. The basal respiration (BR) and microbial biomass (Cmic) were closely correlated with the soil organic carbon (Corg) content as well as SOM density fractions: free particulate organic matter (fPOM), occluded particulate organic matter (oPOM), and mineral–SOM. The greatest increase in most properties was common in the top 0–5 cm and was maximal for fPOM and oPOM fractions (by 1.5–2.5‐times), Cmic (1.9‐times), and BR (1.5–2.5‐times). For the first time, the duration of full recovery of soil properties depending on climate were estimated. Generally, ~40–120 and 20–30 years in the forest and steppe, respectively, are required to restore Corg, total nitrogen (TN), and Cmic contents in the 0‐ to 5‐cm layer after the abandonment of agricultural lands. The maximal restoration rates of all properties are common in the first 15–20 years after abandonment.

Assessing Soil-like Materials for Ecosystem Services Provided by Constructed Technosols

“…Chemical and microbial properties in the studied materials were interrelated, and therefore, the variation in microbial indices and the values of corresponding ecosystem services were partly explained by nutrients' and PTE contents. Commonly, soil C and N contents stimulate microbial biomass growth [68,69]; however, in our study, a positive correlation between C and N contents and qCO 2 was shown. Apparently, the energy costs for microorganisms to maintain their biomass under intensive input of C and N are too high.…”

Tight coupling of fungal community composition with soil quality in a Chinese fir plantation chronosequence

“…The variance in community composition (Figure 5c) demonstrated shifts in fungal community functions as stands aged. The vertical gradients in fungal diversity and composition are common due to the main input of organic materials starting from the topsoil (Chen et al, 2019a; Ovsepyan, Kurganova, de Gerenyu, & Kuzyakov, 2019; Uroz et al, 2016).…”

Spatial Variation Characteristics of Soil Erodibility in the Yingwugou Watershed of the Middle Dan River, China

“…As said before, the study area is canyon-shaped, with horizontally extended mountains. Due to years of afforestation activities, there is significant forest cover on the mountains in the northwest portion of the basin; consequently, there is significant soil organic matter accumulation and low erodibility [42]. Less afforestation has been completed in the southeast mountains; thus, there is less plant root growth and distribution than in the north.…”