Soil Biological Fertility and Bacterial Community Response to Land Use Intensity: A Case Study in the Mediterranean Area

Abstract

The current study was performed to investigate the effects of three different long-term land use intensities on adjacent soil plots, namely a winter wheat field, a grass-covered vineyard, and a cherry farm, on soil biochemical, microbial, and molecular parameters. The results showed the maximum content of soil organic matter (SOM) and microbial biomass carbon (MBC) observed in the grass-covered vineyard. Basal respiration (BSR) and the cumulated respiration (CSR) after 25 days of incubation were significantly higher in the grass-covered vineyard and cherry farm, respectively (BSR 11.84 mg CO2–C kg−1 soil d−1, CSR 226.90 mg CO2–C kg−1 soil). Grass-covered vineyard showed the highest soil biological fertility index (BFI) score (20) and ranked in the class IV (good) of soil biological fertility. Cereal field and cherry farm had lower BFI scores and the corresponding BFI class was III (medium). In addition, the maximum ribosomal RNA copy number and the highest abundance of oligotrophic bacterial groups (25.52% Actinobacteria, 3.45% Firmicutes, and 1.38% Acidobacteria) were observed in the grass-covered vineyard. In conclusion, the grass-covered vineyard is a more conservative system and could have a large potential to improve total carbon storage in soil, mainly because of the cover crop residue management and the low soil perturbation through the no-tillage system.

Changes in Photo-Protective Energy Dissipation of Photosystem II in Response to Beneficial Bacteria Consortium in Durum Wheat under Drought and Salinity Stresses

“…The responses of drought-stressed plants to the microbiological and chemical fertilization treatments were slightly different. Accordingly, the highest grain yield was found by the application of PGPB inoculants (I), which had no statistically significant difference with CF (+17%), I + 1 2 CF (+6%), and I + CF (+21%) treatments, while was significantly higher than 1 2 CF(+60%) and control (+82%) treatments (Figure 1). Grain yield in all experiments was affected by PGPB inoculation and chemical fertilization.…”

“…Durum wheat (Triticum durum Desf.) is a very important worldwide food crop widely cultivated all over the Mediterranean basin, where it often suffers from multiple and coincident environmental stresses such as drought and salinity [1][2][3]. The primary negative effects of such abiotic stresses appear on the photosynthesis process and photosystem II (PSII) activity [2], by over-reducing of reaction centers in PSII, especially in plants without the ability to dissipate the excess energy [4].…”

“…Estimation of fraction of light absorbed by PSII that is used in photochemistry (P); quantum yield of thermal dissipation in the dark-adapted state (L) and quantum yield of thermal dissipation in the light-adapted state (D) in response to the chemical/microbiological fertilization management under non-stress, drought and salinity conditions, as well as their change rates as compared to the non-fertilized plants.Means in each column and each experiment followed by the same letter(s) are not significantly different based on the least significant difference (LSD) test at 0.05 probability level. +I: Seed inoculation with the selected plant growth-promoting bacteria (PGPB) consortium (bacterial suspension was also added to pots every 3 weeks); −I: No PGPB inoculation (durum wheat seeds were treated with non-inoculated NB medium before planting); CF: Soil treated with full dose of chemical fertilizer;1 2 CF: Half dose of chemical fertilizer; −CF: No chemical fertilizer; SD: Standard deviation.…”

Comparative Genomics and In Vitro Plant Growth Promotion and Biocontrol Traits of Lactic Acid Bacteria from the Wheat Rhizosphere

“…Among these factors, soil type is the main force driving changes in the community, followed by growth stage [ 51 ]. LAB represent only a small part of the wheat rhizosphere microbial community [ 52 , 53 ], therefore, enrichment methods are necessary to isolate them from soil [ 18 ]. In addition, LAB are fastidious microorganisms and are more easily detected in soils cultivated with fruit trees or, more in general, soils rich in carbon sources [ 54 ].…”

Soil fertility and bacterial community composition in a semiarid Mediterranean agricultural soil under long‐term tillage management

“…Similar findings, describing the decrease of soil respiration during the incubation period because of the lack of organic C resources, were reported by Birge (2013). It has also proved that soil microbial respiration is strongly influenced by SOM availability to microbial decomposers (Yaghoubi Khanghahi, Murgese, Strafella, & Crecchio, 2019). This supposition has proved that the amount of microbial respiration could be restricted by the availability of SOC, and not the MBC content (Brige, 2013).…”