Water availability regulates negative effects of species mixture on soil microbial biomass in boreal forests

There is little information on the effects of S management strategies on soil microorganisms under zero tillage systems o n the North American Prairies. Experiments were conducted to examine the effects of tillage and source and placement of S on soil microbial biomass (substrate induced respiration) and functional diversity (substrate utilization patterns) in a canola-wheat rotation under conventional and zero tillage systems at three sites in Gray Luvisolic and Black Chernozemic soils. Conventional tillage significantly reduced microbial biomass and diversity on an acidic and C-poor Luvisolic soil, but it had mostly no significant effects on the near-neutral, C-rich Luvisolic and Chernozemic soils, which underlines the importance of soil C in maintaining a healthy soil. Sulphur had no significant effects on soil microbial biomass, and its effects on microbial diversity were more frequent on the near-neutral Luvisol, which was more S-deficient, than on the acidic Luvisol or the Chernozem. Significant S effects on microbial diversity were observed both in the bulk soil (negative effects, compared with the control) and rhizosphere (positive effects) of the acidic Luvisol, but all significant effects (positive) were observed in root rhizospheres in the other soils. Sulphur by tillage interactions on acidic Luvisolic soil indicated that the negative effects of S in bulk soil occurred mostly under zero tillage, presumably because the fertilizer is concentrated in a smaller volume of soil than under conventional tillage. Sulphate S effects, either negative or positive, on microbial diversity were usually greater than elemental S effects. Therefore, S application can have direct, deleterious effects on soil microorganisms or indirect, beneficial effects through crop growth, the latter presumably due to increased root exudation in the rhizosphere of healthy crops. Key Words: Biolog, conservation tillage, microbial biodiversity, rhizosphere, soil biological quality, S fertilizer type and placement

Download Full-text

Effects of liming on the microbial biomass and its activities in soils long-term contaminated by toxic elements

Plant Soil and Environment ◽

10.17221/3451-pse ◽

2011 ◽

Vol 52 (No. 8) ◽

pp. 345-352 ◽

Cited By ~ 9

Author(s):

G. Mühlbachová ◽

P. Tlustoš

Keyword(s):

Microbial Biomass ◽

Soil Microbial Biomass ◽

Respiratory Activity ◽

Soil Microbial Communities ◽

Microbial Biomass C ◽

Negative Effects ◽

Lead Smelter ◽

Soil Microbial ◽

Hydrogen Carbonates

The effects of liming by CaO and CaCO3 on soil microbial characteristics were studied during laboratory incubation of long-term contaminated arable and grassland soils from the vicinity of lead smelter near Příbram (Czech Republic). The CaO treatment showed significant negative effects on soil microbial biomass C and its respiratory activity in both studied soils, despite the fact that microbial biomass C in the grassland soil increased sharply during the first day of incubation. The metabolic quotient (qCO2) in soils amended by CaO showed greater values than the control from the second day of incubation, indicating a possible stress of soil microbial pool. The vulnerability of organic matter to CaO could be indicated by the availability of K2SO4-extractable carbon that increased sharply, particularly at the beginning of the experiment. The amendment of soils by CaCO3 moderately increased the soil microbial biomass. The respiratory activity and qCO2 increased sharply during the first day of incubation, however it is not possible to ascribe them only to microbial activities, but also to CaCO3 decomposition in hydrogen carbonates, water and CO2. The pH values increased more sharply under CaO treatment in comparison to CaCO3 treatment. The improvement of soil pH by CaCO3 could be therefore more convenient for soil microbial communities.

Download Full-text

EFFECT OF WATER AVAILABILITY ON SOIL MICROBIAL BIOMASS IN SECONDARY FOREST IN EASTERN AMAZONIA

Revista Brasileira de Ciência do Solo ◽

10.1590/01000683rbcs20140135 ◽

2015 ◽

Vol 39 (2) ◽

pp. 377-384 ◽

Cited By ~ 1

Author(s):

Lívia Gabrig Turbay Rangel-Vasconcelos ◽

Daniel Jacob Zarin ◽

Francisco de Assis Oliveira ◽

Steel Silva Vasconcelos ◽

Cláudio José Reis de Carvalho ◽

...

Keyword(s):

Soil Moisture ◽

Microbial Biomass ◽

Soil Water ◽

Water Availability ◽

Soil Microbial Biomass ◽

Secondary Forest ◽

Microbial Biomass Carbon ◽

Basal Respiration ◽

Soil Water Availability ◽

Soil Microbial

Soil microbial biomass (SMB) plays an important role in nutrient cycling in agroecosystems, and is limited by several factors, such as soil water availability. This study assessed the effects of soil water availability on microbial biomass and its variation over time in the Latossolo Amarelo concrecionário of a secondary forest in eastern Amazonia. The fumigation-extraction method was used to estimate the soil microbial biomass carbon and nitrogen content (SMBC and SMBN). An adaptation of the fumigation-incubation method was used to determine basal respiration (CO2-SMB). The metabolic quotient (qCO2) and ratio of microbial carbon:organic carbon (CMIC:CORG) were calculated based on those results. Soil moisture was generally significantly lower during the dry season and in the control plots. Irrigation raised soil moisture to levels close to those observed during the rainy season, but had no significant effect on SMB. The variables did not vary on a seasonal basis, except for the microbial C/N ratio that suggested the occurrence of seasonal shifts in the structure of the microbial community.

Download Full-text

Plant mixture balances terrestrial ecosystem C:N:P stoichiometry

Nature Communications ◽

10.1038/s41467-021-24889-w ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Xinli Chen ◽

Han Y. H. Chen

Keyword(s):

Microbial Biomass ◽

Plant Diversity ◽

Soil Microbial Biomass ◽

Meta Analysis ◽

Terrestrial Ecosystem ◽

Terrestrial Ecosystems ◽

C:N:P Stoichiometry ◽

Soil Microbial ◽

Species Mixture ◽

Background Soil

AbstractPlant and soil C:N:P ratios are of critical importance to productivity, food-web dynamics, and nutrient cycling in terrestrial ecosystems worldwide. Plant diversity continues to decline globally; however, its influence on terrestrial C:N:P ratios remains uncertain. By conducting a global meta-analysis of 2049 paired observations in plant species mixtures and monocultures from 169 sites, we show that, on average across all observations, the C:N:P ratios of plants, soils, soil microbial biomass and enzymes did not respond to species mixture nor to the species richness in mixtures. However, the mixture effect on soil microbial biomass C:N changed from positive to negative, and those on soil enzyme C:N and C:P shifted from negative to positive with increasing functional diversity in mixtures. Importantly, species mixture increased the C:N, C:P, N:P ratios of plants and soils when background soil C:N, C:P, and N:P were low, but decreased them when the respective background ratios were high. Our results demonstrate that plant mixtures can balance terrestrial plant and soil C:N:P ratios dependent on background soil C:N:P. Our findings highlight that plant diversity conservation does not only increase plant productivity, but also optimizes ecosystem stoichiometry for the diversity and productivity of today’s and future vegetation.

Download Full-text