scholarly journals Bokashi compost and biofertilizer increase lettuce agronomic variables in protected cultivation and indicates substrate microbiological changes

2020 ◽  
pp. 640
Author(s):  
Fernando Teruhiko Hata ◽  
Felipe Alvares Spagnuolob ◽  
Maria Tereza de Paulaa ◽  
Amanda Aleixo Moreiraa ◽  
Mauricio Ursi Venturaa ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Total Mass ◽  
Microbial Biomass Carbon ◽  
Quality Measurement ◽  
Metabolic Quotient ◽  
Quality Data ◽  
Microbial Quality ◽  
Head Diameter ◽  
Soil Microbial ◽  
Basal Soil Respiration

The aim of the study was to evaluate agronomic productive variables of iceberg lettuce and soil microbiological variables for two crop cycles by using organic inputs. The treatments were as follows: control (no fertilization); Bokashi compost (20 g per plant); Penergetic-k plus Penergetic-p bio-activators (both at 1.5 g per litre of water, applied to the substrate and plant, respectively); and biofertilizer at different concentrations (2.5, 5.0, 7.5, and 10% dilutions in water). Biofertilizer concentrations were applied during five fertigation times per day in the first crop experiment and in single daily fertigation in the second crop experiment. Agronomic productive variables evaluated were: total mass, commercial mass, discarded leaves mass, stem diameter, commercial head diameter and plant height. Soil microbial biomass carbon, basal soil respiration and metabolic quotient were evaluated for substrate microbial quality measurement. In the first cycle, plants treated with Bokashi or Penergetic presented superior total mass, commercial mass and commercial head diameter of lettuce, while plants treated with biofertilizer did not exhibit improvement and presented tipburn in some plants, when compared to control. In the second cycle, the use of Bokashi and biofertilizers improved the total mass and commercial head diameter, compared to control. Higher than control microbial biomass was achieved with biofertilizer concentrations and Bokashi. Lower metabolic quotient (qCO2) was observed for all the treatments, when compared to control. Soil microbial quality data corresponded to better lettuce yields.

scholarly journals Microbial activities, carbon, and nitrogen in an irrigated Quartzarenic Neosol cultivated with cowpea in southwest Piauí

2017 ◽  
Vol 38 (4) ◽  
pp. 1765
Author(s):  
Larissa Castro Diógenes ◽  
José Ferreira Lustosa Filho ◽  
Alessandro Franco Torres da Silva ◽  
Júlio César Azevedo Nóbrega ◽  
Rafaela Simão Abrahão Nóbrega ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Soil Respiration ◽  
Microbial Biomass Carbon ◽  
Metabolic Quotient ◽  
Biomass Carbon ◽  
Microbial Activities ◽  
Carbon And Nitrogen ◽  
Cowpea Cultivars ◽  
Basal Soil Respiration ◽  
Microbial Quotient

The aim of this study was to evaluate microbial biomass and total organic carbon and nitrogen of an irrigated Quartzarenic Neosol cultivated with two cowpea cultivars in Bom Jesus, Piauí, Brazil. The experiment was conducted in a randomized experimental block design in split plots. The plots consist of two cowpea cultivars (Aracê and Tumucumaque) and the subplots were composed of five different irrigation regimes (L1 = 108.2; L2 = 214.7; L3 = 287.9; L4 = 426.1, and L5 = 527.7 mm). Soil samples were collected at a depth of 0-0.20 m in order to evaluate basal soil respiration, microbial biomass carbon, metabolic quotient, microbial quotient, content, and storage of soil carbon and nitrogen. Basal soil respiration, microbial biomass carbon, microbial metabolic quotient, and microbial quotient are influenced by the interaction between cowpea cultivars and irrigation. The cultivar Aracê showed greater stimulus to the microbial community, while the irrigation regimes with 214.7 and 287.9 mm (60 and 90% of ETo, respectively) provided the best moisture conditions for microbial activities.

scholarly journals Soil Aggregation and Organic Carbon Dynamics in Poplar Plantations

Forests ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 508 ◽  
Author(s):  
Zhiwei Ge ◽  
Shuiyuan Fang ◽  
Han Chen ◽  
Rongwei Zhu ◽  
Sili Peng ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Organic Carbon ◽  
Soil Microbial Biomass ◽  
Fine Root ◽  
Microbial Biomass Carbon ◽  
Critical Role ◽  
Stand Age ◽  
Biomass Carbon ◽  
Soil Microbial ◽  
Soil Microbial Biomass Carbon

Soil resident water-stable macroaggregates (diameter (Ø) > 0.25 mm) play a critical role in organic carbon conservation and fertility. However, limited studies have investigated the direct effects of stand development on soil aggregation and its associated mechanisms. Here, we examined the dynamics of soil organic carbon, water-stable macroaggregates, litterfall production, fine-root (Ø < 1 mm) biomass, and soil microbial biomass carbon with stand development in poplar plantations (Populus deltoides L. ‘35’) in Eastern Coastal China, using an age sequence (i.e., five, nine, and 16 years since plantation establishment). We found that the quantity of water-stable macroaggregates and organic carbon content in topsoil (0–10 cm depth) increased significantly with stand age. With increasing stand age, annual aboveground litterfall production did not differ, while fine-root biomass sampled in June, August, and October increased. Further, microbial biomass carbon in the soil increased in June but decreased when sampled in October. Ridge regression analysis revealed that the weighted percentage of small (0.25 mm ≤ Ø < 2 mm) increased with soil microbial biomass carbon, while that of large aggregates (Ø ≥ 2 mm) increased with fine-root biomass as well as microbial biomass carbon. Our results reveal that soil microbial biomass carbon plays a critical role in the formation of both small and large aggregates, while fine roots enhance the formation of large aggregates.

scholarly journals Defining a realistic control for the chloroform fumigation-incubation method using microscopic counting and 14C-substrates

1996 ◽  
Vol 76 (4) ◽  
pp. 459-467 ◽  
Author(s):  
William R. Horwath ◽  
Eldor A. Paul ◽  
David Harris ◽  
Jeannette Norton ◽  
Leslie Jagger ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Soil Microbial Biomass ◽  
Microbial Biomass Carbon ◽  
Soil Depth ◽  
Temporal Trends ◽  
Biomass Carbon ◽  
Soil Microbial ◽  
Microbial C ◽  
Parameter Values ◽  
Chloroform Fumigation

Chloroform fumigation-incubation (CFI) has made possible the extensive characterization of soil microbial biomass carbon (C) (MBC). Defining the non-microbial C mineralized in soils following fumigation remains the major limitation of CFI. The mineralization of non-microbial C during CFI was examined by adding 14C-maize to soil before incubation. The decomposition of the 14C-maize during a 10-d incubation after fumigation was 22.5% that in non-fumigated control soils. Re-inoculation of the fumigated soil raised 14C-maize decomposition to 77% that of the unfumigated control. A method was developed which varies the proportion of mineralized C from the unfumigated soil (UFC) that is subtracted in calculating CFI biomasss C. The proportion subtracted (P) varies according to a linear function of the ratio of C mineralized in the fumigated (FC) and unfumigated samples (FC/UFC) with two parameters K1 and K2 (P = K1FC/UFC) + K2). These parameters were estimated by regression of CFI biomass C, calculated according to the equation MBC = (FC − PUFC)/0.41, against that derived by direct microscopy in a series of California soils. Parameter values which gave the best estimate of microscopic biomass from the fumigation data were K1 = 0.29 and K2 = 0.23 (R2 = 0.87). Substituting these parameter values, the equation can be simplified to MBC = 1.73FC − 0.56UFC. The equation was applied to other CFI data to determine its effect on the measurement of MBC. The use of this approach corrected data that were previously difficult to interpret and helped to reveal temporal trends and changes in MBC associated with soil depth. Key words: Chloroform fumigation-incubation, soil microbial biomass, microscopically estimated biomass, carbon, control, 14C

scholarly journals Reviews and syntheses: Soil resources and climate jointly drive variations in microbial biomass carbon and nitrogen in China's forest ecosystems

2015 ◽  
Vol 12 (22) ◽  
pp. 6751-6760 ◽  
Author(s):  
Z. H. Zhou ◽  
C. K. Wang
Keyword(s):  
Microbial Biomass ◽  
Forest Ecosystems ◽  
Microbial Biomass Carbon ◽  
Mean Annual Temperature ◽  
Biomass Carbon ◽  
Large Variability ◽  
Soil Resources ◽  
Carbon And Nitrogen ◽  
Soil Microbial ◽  
Microbial Quotient

Abstract. Microbial metabolism plays a key role in regulating the biogeochemical cycle of forest ecosystems, but the mechanisms driving microbial growth are not well understood. Here, we synthesized 689 measurements on soil microbial biomass carbon (Cmic) and nitrogen (Nmic) and related parameters from 207 independent studies published up to November 2014 across China's forest ecosystems. Our objectives were to (1) examine patterns in Cmic, Nmic, and microbial quotient (i.e., Cmic / Csoil and Nmic / Nsoil rates) by climate zones and management regimes for these forests; and (2) identify the factors driving the variability in the Cmic, Nmic, and microbial quotient. There was a large variability in Cmic (390.2 mg kg−1), Nmic (60.1 mg kg−1, Cmic : Nmic ratio (8.25), Cmic / Csoil rate (1.92 %), and Nmic / Nsoil rate (3.43 %) across China's forests. The natural forests had significantly greater Cmic (514.1 mg kg−1 vs. 281.8 mg kg−1) and Nmic (82.6 mg kg−1 vs. 39.0 mg kg−1) than the planted forests, but had less Cmic : Nmic ratio (7.3 vs. 9.2) and Cmic / Csoil rate (1.7 % vs. 2.1 %). Soil resources and climate together explained 24.4–40.7 % of these variations. The Cmic : Nmic ratio declined slightly with Csoil : Nsoil ratio, and changed with latitude, mean annual temperature and precipitation, suggesting a plasticity of microbial carbon-nitrogen stoichiometry. The Cmic / Csoil rate decreased with Csoil : Nsoil ratio, whereas the Nmic / Nsoil rate increased with Csoil : Nsoil ratio; the former was influenced more by soil resources than by climate, whereas the latter was influenced more by climate. These results suggest that soil microbial assimilation of carbon and nitrogen are jointly driven by soil resources and climate, but may be regulated by different mechanisms.

scholarly journals The sensitivity of microbial processes in Icelandic soils to increasing temperatures

2009 ◽  
Vol 6 (4) ◽  
pp. 6749-6780 ◽  
Author(s):  
R. Guicharnaud ◽  
O. Arnalds ◽  
G. I. Paton
Keyword(s):  
Microbial Biomass ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Elevated Temperatures ◽  
Microbial Biomass Carbon ◽  
Biomass Carbon ◽  
Labile Carbon ◽  
Soil Microbial ◽  
Arctic Soils ◽  
Temperature Regimes

Abstract. Temperature change is acknowledged to have a significance effect on soil biological processes and the corresponding sequestration of carbon and the cycling of key nutrients. Soils at high latitudes are likely to be particularly impacted by increases in temperature. In this study, the response of a range of soil microbial parameters (respiration, nutrient availability, microbial biomass carbon, arylphosphatase and dehydrogenase activity) to temperature changes was measured in sub-arctic soils collected from across Iceland. Sample sites reflected two soil temperature regimes (cryic and frigid) and two land uses (pasture and arable). The soils were sampled from the field frozen, equilibrated at −20°C and then incubated for two weeks at −10°C, −2°C, +2°C and +10°C. Respiration and enzymatic activity were temperature dependent. Microbial biomass carbon and nitrogen mineralisation did not change with temperature. The main factor controlling soil respiration at −10°C was the concentration of dissolved organic carbon. At −10°C, dissolved organic carbon accounted for 88% of the fraction of labile carbon which was significantly greater than that recorded at +10°C when dissolved organic carbon accounted for as low as 42% of the labile carbon fraction. Heterotrophic microbial activity is governed by both substrate availability and the temperature and this has been described by the Q10 factor. Elevated temperatures in the short term may have little effect on the size of the microbial biomass but will have significant impacts on the release of carbon through respiration. These results demonstrate that gradual changes in temperature across large areas at higher latitudes will have considerable impacts in relation to global soil carbon dynamics.

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