Soil microbial C and N turnover under Cupressus lusitanica and natural forests in southern Ethiopia assessed by decomposition of 13C- and 15 N-labelled litter under field conditions

2014 ◽  
Vol 388 (1-2) ◽  
pp. 133-146 ◽  
Author(s):  
Marianne Benesch ◽  
Bruno Glaser ◽  
Michaela Dippold ◽  
Wolfgang Zech
Keyword(s):  
Field Conditions ◽  
Southern Ethiopia ◽  
Natural Forests ◽  
Cupressus Lusitanica ◽  
Soil Microbial ◽  
N Turnover ◽  
C And N ◽  
Microbial C

Long-term effects of afforestation with Pinus radiata on soil carbon, nitrogen, and pH: a case study

Soil Research ◽  
2011 ◽  
Vol 49 (6) ◽  
pp. 494 ◽  
Author(s):  
R. L. Parfitt ◽  
D. J. Ross
Keyword(s):  
Pinus Radiata ◽  
Mineral Soil ◽  
Early Spring ◽  
Early Years ◽  
Long Term Effects ◽  
Soil C ◽  
Soil Microbial ◽  
Soil C And N ◽  
C And N ◽  
Microbial C

Planting of Pinus radiata D. Don in previously grazed pastures is a common land-use change in New Zealand. Although carbon (C) accumulates relatively rapidly in the trees, there have been no studies of the annual effect on soil C content during the early years of establishment. Here, we study soil properties under P. radiata and pasture each year over 11 years after P. radiata was planted into pasture that had been grazed by sheep. Under the growing trees, grass was gradually shaded out by the unpruned trees, and completely disappeared after 6 years; needle litterfall had then increased appreciably. By year 9, soil microbial C and nitrogen (N), and net N mineralisation, were significantly lower under pine than under pasture. Soil pH, sampled at 0–100 mm in early spring each year, decreased by ~0.3 units under pine and increased by ~0.3 units under pasture. Close to the pine stems, total C and N decreased significantly for 3 years, while ~100 kg N/ha accumulated in the trees. Soil C and N increased in subsequent years, when litterfall increased. Overall, the mineral soil under pine lost ~500 kg N/ha over 11 years, consistent with uptake by the trees. Leaching losses (estimated using lysimeters) in year 9 were 4.5 kg N/ha.year. These data indicate that ~6 Mg C/ha may have been lost from the mineral soil at this site. The difficulties associated with measuring losses of C are discussed.

Precipitation patterns and N availability alter plant-soil microbial C and N dynamics

2021 ◽  
Author(s):  
Ilonka C. Engelhardt ◽  
Pascal A. Niklaus ◽  
Florian Bizouard ◽  
Marie-Christine Breuil ◽  
Nadine Rouard ◽  
...  
Keyword(s):  
N Availability ◽  
N Dynamics ◽  
Precipitation Patterns ◽  
Soil Microbial ◽  
Plant Soil ◽  
C And N ◽  
Microbial C ◽  
C And N Dynamics

scholarly journals Enzyme activity and microbial biomass in an Oxisol amended with sewage sludge contaminated with nickel

2007 ◽  
Vol 64 (1) ◽  
pp. 61-67 ◽  
Author(s):  
Marcos Donizeti Revoredo ◽  
Wanderley José de Melo
Keyword(s):  
Enzyme Activity ◽  
Sewage Sludge ◽  
Microbial Biomass ◽  
Soil Microbial Biomass ◽  
Soil Microbial ◽  
Tropical Areas ◽  
C And N ◽  
Microbial C ◽  
Positive Correlations ◽  
The Impact

The role of nickel in soils of tropical areas under the application of sewage sludge is still not very well known. This study was carried out under greenhouse conditions in Jaboticabal, São Paulo State, Brazil, with the objective of evaluating the impact of the application of sewage sludge previously contaminated with rates of nickel (329, 502, 746 and 1119 mg kg-1, dry basis) on a soil cropped with sorghum, in relation to soil enzyme activity and soil microbial biomass. Soil samples were collected at the beginning and the end of the experiment. The experimental design was completely randomized, with five treatments (control and four rates of Ni in the sewage sludge) and four replications. C and N of the soil microbial biomass and enzyme activities (acid and alkaline phosphatases) were sensitive indicators for impact evaluation caused by sewage sludge contaminated with nickel. There were positive correlations between "total" and extractable nickel (Mehlich 1) with C-microbial biomass and negative with the microbial C/N relationship. N-microbial biomass correlated positively with "total" and extractable Ni at the last sampling. At the end of the experiment, the acid phosphatase activity correlated negatively with "total" Ni while the alkaline phosphatase correlated with both forms of the metal.

scholarly journals Forest defoliator pests alter carbon and nitrogen cycles

2016 ◽  
Vol 3 (10) ◽  
pp. 160361 ◽  
Author(s):  
Anne l-M-Arnold ◽  
Maren Grüning ◽  
Judy Simon ◽  
Annett-Barbara Reinhardt ◽  
Norbert Lamersdorf ◽  
...  
Keyword(s):  
Climate Change ◽  
Leaf Litter ◽  
Soil Microbial Activity ◽  
Quercus Petraea ◽  
Oak Forests ◽  
Operophtera Brumata ◽  
Winter Moth ◽  
Carbon And Nitrogen ◽  
Soil Microbial ◽  
C And N

Climate change may foster pest epidemics in forests, and thereby the fluxes of elements that are indicators of ecosystem functioning. We examined compounds of carbon (C) and nitrogen (N) in insect faeces, leaf litter, throughfall and analysed the soils of deciduous oak forests ( Quercus petraea  L.) that were heavily infested by the leaf herbivores winter moth ( Operophtera brumata  L.) and mottled umber ( Erannis defoliaria  L.). In infested forests, total net canopy-to-soil fluxes of C and N deriving from insect faeces, leaf litter and throughfall were 30- and 18-fold higher compared with uninfested oak forests, with 4333 kg C ha −1 and 319 kg N ha −1 , respectively, during a pest outbreak over 3 years. In infested forests, C and N levels in soil solutions were enhanced and C/N ratios in humus layers were reduced indicating an extended canopy-to-soil element pathway compared with the non-infested forests. In a microcosm incubation experiment, soil treatments with insect faeces showed 16-fold higher fluxes of carbon dioxide and 10-fold higher fluxes of dissolved organic carbon compared with soil treatments without added insect faeces (control). Thus, the deposition of high rates of nitrogen and rapidly decomposable carbon compounds in the course of forest pest epidemics appears to stimulate soil microbial activity (i.e. heterotrophic respiration), and therefore, may represent an important mechanism by which climate change can initiate a carbon cycle feedback.

scholarly journals Perennial herbaceous legumes as live soil mulches and their effects on C, N and P of the microbial biomass

2003 ◽  
Vol 60 (1) ◽  
pp. 139-147 ◽  
Author(s):  
Gustavo Pereira Duda ◽  
José Guilherme Marinho Guerra ◽  
Marcela Teixeira Monteiro ◽  
Helvécio De-Polli ◽  
Marcelo Grandi Teixeira
Keyword(s):  
Microbial Biomass ◽  
Soil Depth ◽  
Vegetation Management ◽  
Pueraria Phaseoloides ◽  
Organic C ◽  
Arachis Pintoi ◽  
Factorial Combination ◽  
C And N ◽  
Microbial C ◽  
Macroptilium Atropurpureum

The use of living mulch with legumes is increasing but the impact of this management technique on the soil microbial pool is not well known. In this work, the effect of different live mulches was evaluated in relation to the C, N and P pools of the microbial biomass, in a Typic Alfisol of Seropédica, RJ, Brazil. The field experiment was divided in two parts: the first, consisted of treatments set in a 2 x 2 x 4 factorial combination of the following factors: live mulch species (Arachis pintoi and Macroptilium atropurpureum), vegetation management after cutting (leaving residue as a mulch or residue remotion from the plots) and four soil depths. The second part had treatments set in a 4 x 2 x 2 factorial combination of the following factors: absence of live mulch, A. pintoi, Pueraria phaseoloides, and M. atropurpureum, P levels (0 and 88 kg ha-1) and vegetation management after cutting. Variation of microbial C was not observed in relation to soil depth. However, the amount of microbial P and N, water soluble C, available C, and mineralizable C decreased with soil depth. Among the tested legumes, Arachis pintoi promoted an increase of microbial C and available C content of the soil, when compared to the other legume species (Pueraria phaseoloides and Macroptilium atropurpureum). Keeping the shoot as a mulch promoted an increase on soil content of microbial C and N, total organic C and N, and organic C fractions, indicating the importance of this practice to improve soil fertility.

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

Microbial biomass and activity in the humus layer following burning: short-term effects of two different fires

1993 ◽  
Vol 23 (7) ◽  
pp. 1275-1285 ◽  
Author(s):  
Janna Pietikäinen ◽  
Hannu Fritze
Keyword(s):  
Microbial Community ◽  
Microbial Biomass ◽  
Soil Respiration ◽  
Mass Loss ◽  
Forest Fire ◽  
Prescribed Burning ◽  
Microbial Biomass C ◽  
Soil Microbial ◽  
Fungal Hyphae ◽  
C And N

During a 3-year study, soil microbial biomass C and N, length of the fungal hyphae, soil respiration, and the percent mass loss of needle litter were recorded in coniferous forest soil humus layers following a prescribed burning (PB) treatment or a forest fire simulation (FF) treatment (five plots per treatment). Unburned humus from adjacent plots served as controls (PC and FC, respectively). Prescribed burning was more intensive than the forest fire, and this was reflected in all the measurements taken. The amounts of microbial biomass C and N, length of fungal hyphae, and soil respiration in the PB area did not recover to their controls levels, whereas unchanged microbial biomass N and recovery of the length of the fungal hyphae to control levels were observed in the FF area. The mean microbial C/N ratio was approximately 7 in all the areas, which reflected the C/N ratio of the soil microbial community. Deviation from this mean value, as observed during the first three samplings from the PB area (3, 18, and 35 days after fire treatment), suggested a change in the composition of the microbial community. Of the two treated areas, the decrease in soil respiration (laboratory measurements) was much more pronounced in the PB area. However, when the humus samples from both areas were adjusted to 60% water holding capacity, no differences in respiration capacity were observed. The drier humus, due to higher soil temperatures, of the PB area is a likely explanation for the low soil respiration. Lower soil respiration was not reflected in lower litter decomposition rates of the PB area, since there was a significantly higher needle litter mass loss during the first year in the PB area followed by a decline to the control level during the second year. Consistently higher mass losses were recorded in the FC area than in the FF area.

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