scholarly journals Effects of species-dominated patches on soil organic carbon and total nitrogen storage in a degraded grassland in China

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6897 ◽  
Author(s):  
Yujuan Zhang ◽  
Shiming Tang ◽  
Shu Xie ◽  
Kesi Liu ◽  
Jinsheng Li ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Total Nitrogen ◽  
Microbial Biomass Nitrogen ◽  
Soil C ◽  
Artemisia Frigida ◽  
C Stocks ◽  
Soil C And N ◽  
C And N

Background Patchy vegetation is a very common phenomenon due to long-term overgrazing in degraded steppe grasslands, which results in substantial uncertainty associated with soil carbon (C) and nitrogen (N) dynamics because of changes in the amount of litter accumulation and nutrition input into soil. Methods We investigated soil C and N stocks beneath three types of monodominant species patches according to community dominance. Stipa krylovii patches, Artemisia frigida patches, and Potentilla acaulis patches represent better to worse vegetation conditions in a grassland in northern China. Results The results revealed that the soil C stock (0–40 cm) changed significantly, from 84.7 to 95.7 Mg ha−1, and that the soil organic carbon content (0–10 cm) and microbial biomass carbon (0–10 and 10–20 cm) varied remarkably among the different monodominant species communities (P < 0.05). However, soil total nitrogen and microbial biomass nitrogen showed no significant differences among different plant patches in the top 0–20 cm of topsoil. The soil C stocks under the P. acaulis and S. krylovii patches were greater than that under the A. frigida patch. Our study implies that accurate estimates of soil C and N storage in degenerated grassland require integrated analyses of the concurrent effects of differences in plant community composition.

scholarly journals Effects of litter and root manipulations on soil carbon and nitrogen in a Schrenk’s spruce (Picea schrenkiana) forest

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0247725
Author(s):  
Haiqiang Zhu ◽  
Lu Gong ◽  
Zhaolong Ding ◽  
Yuefeng Li
Keyword(s):  
Enzyme Activity ◽  
Microbial Biomass ◽  
Organic Carbon ◽  
Soil Carbon ◽  
Abiotic Factors ◽  
Soil C ◽  
Plant Detritus ◽  
Soil C And N ◽  
C And N ◽  
Root Exclusion

Plant detritus represents the major source of soil carbon (C) and nitrogen (N), and changes in its quantity can influence below-ground biogeochemical processes in forests. However, we lack a mechanistic understanding of how above- and belowground detrital inputs affect soil C and N in mountain forests in an arid land. Here, we explored the effects of litter and root manipulations (control (CK), doubled litter input (DL), removal of litter (NL), root exclusion (NR), and a combination of litter removal and root exclusion (NI)) on soil C and N concentrations, enzyme activity and microbial biomass during a 2-year field experiment. We found that DL had no significant effect on soil total organic carbon (SOC) and total nitrogen (TN) but significantly increased soil dissolved organic carbon (DOC), microbial biomass C, N and inorganic N as well as soil cellulase, phosphatase and peroxidase activities. Conversely, NL and NR reduced soil C and N concentrations and enzyme activities. We also found an increase in the biomass of soil bacteria, fungi and actinomycetes in the DL treatment, while NL reduced the biomass of gram-positive bacteria, gram-negative bacteria and fungi by 5.15%, 17.50% and 14.17%, respectively. The NR decreased the biomass of these three taxonomic groups by 8.97%, 22.11% and 21.36%, respectively. Correlation analysis showed that soil biotic factors (enzyme activity and microbial biomass) and abiotic factors (soil moisture content) significantly controlled the change in soil C and N concentrations (P < 0.01). In brief, we found that the short-term input of plant detritus could markedly affect the concentrations and biological characteristics of the C and N fractions in soil. The removal experiment indicated that the contribution of roots to soil nutrients is greater than that of the litter.

scholarly journals Alteration of carbon, nitrogen, and phosphorus stoichiometry and their related enzymes as affected by increased soil coarseness

2016 ◽  
Author(s):  
Ruzhen Wang ◽  
Linyou Lü ◽  
Courtney A. Creamer ◽  
Heyong Liu ◽  
Xue Feng ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Total Nitrogen ◽  
Enzyme Activities ◽  
Microbial Biomass Carbon ◽  
Soil Parameters ◽  
Available Phosphorus ◽  
Carbon And Nitrogen ◽  
Acid Phosphomonoesterase

Abstract. Soil coarseness decreases ecosystem productivity, ecosystem carbon and nitrogen stocks, and soil nutrient contents in sandy grasslands. To gain insight into changes in soil carbon and nitrogen pools, microbial biomass, and enzyme activities in response to soil coarseness, a field experiment of sand addition was conducted to coarsen soil with different intensities: 0 % sand addition, 10 %, 30 %, 50 %, and 70 %. Soil organic carbon and total nitrogen decreased with the intensification of soil coarseness across three depths (0–10 cm, 10–20 cm, and 20–40 cm) by up to 43.9 % and 53.7 %, respectively. At 0–10 cm, soil microbial biomass carbon (MBC) and nitrogen (MBN) declined with soil coarseness by up to 44.1 % and 51.9 %, respectively, while microbial biomass phosphorus (MBP) increased by as much as 73.9 %. Soil coarseness significantly decreased the activities of β-glucosidase, N-acetyl-glucosaminidase, and acid phosphomonoesterase by 20.2 %–57.5 %, 24.5 %–53.0 %, and 22.2 %–88.7 %, respectively. Soil coarseness enhanced microbial C and N limitation relative to P, indicated by the ratios of β-glucosidase and N-acetyl-glucosaminidase to acid phosphomonoesterase (and MBC:MBP and MBN:MBP ratios). As compared to laboratory measurement, values of soil parameters from theoretical sand dilution was significantly lower for soil organic carbon, total nitrogen, dissolved organic carbon, total dissolved nitrogen, available phosphorus, MBC, MBN, and MBP. Phosphorus immobilization in microbial biomass might aggravate plant P limitation in nutrient-poor grassland ecosystems as affected by soil coarseness. We conclude that microbial C:N:P and enzyme activities might be good indicators for nutrient limitation of microorganisms and plants.

A review of sampling designs for the measurement of soil organic carbon in Australian grazing lands

2010 ◽  
Vol 32 (2) ◽  
pp. 227 ◽  
Author(s):  
D. E. Allen ◽  
M. J. Pringle ◽  
K. L. Page ◽  
R. C. Dalal
Keyword(s):  
Microbial Biomass ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Plant Growth ◽  
Temporal Change ◽  
Organic C ◽  
Soil C ◽  
Efficient Sampling ◽  
Soc Stock ◽  
Grazing Lands

The accurate measurement of the soil organic carbon (SOC) stock in Australian grazing lands is important due to the major role that SOC plays in soil productivity and the potential influence of soil C cycling on Australia’s greenhouse gas emissions. However, the current sampling methodologies for SOC stock are varied and potentially conflicting. It was the objective of this paper to review the nature of, and reasons for, SOC variability; the sampling methodologies commonly used; and to identify knowledge gaps for SOC measurement in grazing lands. Soil C consists of a range of biological materials, in various SOC pools such as dissolved organic C, micro- and meso-fauna (microbial biomass), fungal hyphae and fresh plant residues in or on the soil (particulate organic C, light-fraction C), the products of decomposition (humus, slow pool C) and complexed organic C, and char and phytoliths (inert, passive or resistant C); and soil inorganic C (carbonates and bicarbonates). Microbial biomass and particulate or light-fraction organic C are most sensitive to management or land-use change; resistant organic C and soil carbonates are least sensitive. The SOC present at any location is influenced by a series of complex interactions between plant growth, climate, soil type or parent material, topography and site management. Because of this, SOC stock and SOC pools are highly variable on both spatial and temporal scales. This creates a challenge for efficient sampling. Sampling methods are predominantly based on design-based (classical) statistical techniques, crucial to which is a randomised sampling pattern that negates bias. Alternatively a model-based (geostatistical) analysis can be used, which does not require randomisation. Each approach is equally valid to characterise SOC in the rangelands. However, given that SOC reporting in the rangelands will almost certainly rely on average values for some aggregated scale (such as a paddock or property), we contend that the design-based approach might be preferred. We also challenge soil surveyors and their sponsors to realise that: (i) paired sites are the most efficient way of detecting a temporal change in SOC stock, but destructive sampling and cumulative measurement errors decrease our ability to detect change; (ii) due to (i), an efficient sampling scheme to estimate baseline status is not likely to be an efficient sampling scheme to estimate temporal change; (iii) samples should be collected as widely as possible within the area of interest; (iv) replicate of laboratory analyses is a critical step in being able to characterise temporal change. Sampling requirements for SOC stock in Australian grazing lands are yet to be explicitly quantified and an examination of a range of these ecosystems is required in order to assess the sampling densities and techniques necessary to detect specified changes in SOC stock and SOC pools. An examination of techniques that can help reduce sampling requirements (such as measurement of the SOC fractions that are most sensitive to management changes and/or measurement at specific times of the year – preferably before rapid plant growth – to decrease temporal variability), and new technologies for in situ SOC measurement is also required.

scholarly journals Comparing microbial and chemical approaches for modelling soil organic carbon decomposition using the DecoChem v1.0 and DecoBio v1.0 models

2014 ◽  
Vol 7 (1) ◽  
pp. 33-72 ◽  
Author(s):  
G. Xenakis ◽  
M. Williams
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Microbial Activity ◽  
Biological Model ◽  
Chemical Model ◽  
Soil C ◽  
Model Soil ◽  
Carbon Decomposition ◽  
C Stocks ◽  
Soil Organic Carbon Decomposition

Abstract. Soil organic matter is a vast store of carbon, with a critical role in the global carbon cycle. Despite its importance the dynamics of soil organic carbon decomposition, under the impact of climate change or changing litter inputs, are poorly understood. Current biogeochemical models usually lack microbial processes and thus miss an important feedback when considering the fate of carbon. Here we use a series of modelling experiments to evaluate two different model structures, one with a standard first order kinetic representation of soil decomposition (DecoChem v1.0, hearafter chemical model) and one with control of soil decomposition through microbial activity (DecoBio v1.0, hereafter biological model). We tested two hypotheses. First, that increased litter inputs and glucose addition prime microbial activity and reduce soil carbon stocks in the biological model, but increase C stocks in the chemical model. Experiments provided some support for this hypothesis, with soil C stocks increasing in the chemical model in response to litter increases. In the biological model, responses to changed litter quantity were more rapid, but with the residence time of soil C altering such that soil C stocks were buffered. However, in the biological model there was a strong response to increased glucose additions (i.e., changes in litter quality), with significant losses to soil C stocks over time, driven by priming. Secondly, we hypothesised that warming will stimulate decomposition in the chemical model, and loss of C, but in the biological model soil C will be less sensitive to warming, due to complex microbial feedbacks. The experiments supported this hypothesis, with the chemical model soil C residence times and steady state C stocks adjusting strongly with temperature changes, extending over decades. On the other hand, the biological model showed a rapid response to temperature that subsided after a few years, with total soil C stocks largely unchanged. The microbial model shows qualitative agreement with experimental warming studies, that found transient increases in soil respiration that decline within a few years. In conclusion, the biological model is largely buffered against bulk changes in litter inputs and climate, unlike the chemical model, while the biological model displays a strong priming response to additions of labile litter. Our result have therefore highlighted significantly different sensitivities between chemical and biological modelling approaches for soil decomposition.

scholarly journals Indicators of peat soil degradation in the Biebrza valley, Poland

2019 ◽  
Vol 30 (2) ◽  
pp. 41-51
Author(s):  
Jadwiga Sienkiewicz ◽  
Grażyna Porębska ◽  
Apolonia Ostrowska ◽  
Dariusz Gozdowski
Keyword(s):  
Organic Carbon ◽  
Soil Degradation ◽  
Peat Soil ◽  
Peat Soils ◽  
Soil C ◽  
Peat Deposits ◽  
External Sources ◽  
Soil C And N ◽  
C And N ◽  
Linear Regressions

Abstract Peat mineralisation leads to net loss of CO2 to the atmosphere, as well as to release of other elements from the decomposed soil organic matter (SOM) to groundwater. This results in the degradation of peat soils and the ecosystems they support. Here we evaluated the practical indicatory suitability of the existing and proposed new indices for the assessment of peat soil degradation in the Biebrza river valley encompassing, unique on European scale, peatland ecosystems. We studied relationships between soil organic carbon (SOC) and total nitrogen (Ntot), dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) in a series of degraded peat soils in the Biebrza valley. Samples were taken from soils developed on peat deposits that varied in thickness and the degree of peat decomposition, from undegraded to highly mineralised peats. The relationships between changes in the SOC content and changes in the values of the remaining variables (SOM, Ntot, DOC, DON, C/N ratio), were statistically tested. Linear and non-linear regressions were used to establish the relationships amongst the variables examined. The losses of soil C and N occur independently and differ between stages of peat soil mineralisation. From our study, it results that the peat mineralisation intensity may be estimated based on the loss of SOC. We found that 1% loss of SOC corresponded to 1.028% loss of SOM, regardless of the degree of peat soil mineralisation, whereas SOM solubility, measured by the content of DOC, varied based on the intensity of peat soil mineralisation. The content of DOC decreased with the decrease in the SOC content, whereas the DOC/ SOC ratio increased depending on the intensity of peat decomposition. The C/N ratio is not a reliable indicator of peat mineralisation, because its values are driven not only by the nitrogen natively present in peat soils but also by nitrogen from external sources. The contents of SOC and Ntot did not decrease uniformly during peat decomposition because C and N show various mobility in the processes of SOM mineralisation. We found that the DOC/SOC ratio was most indicative of peat soil mineralisation intensity. © IOŚ-PIB

scholarly journals Integration of biochar and chemical fertilizer to enhance quality of soil and wheat crop (Triticum aestivum L.)

2016 ◽  
Author(s):  
Usman Khalid Chaudhry ◽  
Salman Shahzad ◽  
Muhammad Nadir Naqqash ◽  
Abdul Saboor ◽  
Sana Yaqoob ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Microbial Biomass ◽  
Soil Amendments ◽  
Block Design ◽  
Combined Treatment ◽  
Wheat Crop ◽  
Microbial Biomass Nitrogen ◽  
Soil Microbial

A wide variety of soil amendments like manures, compost, humic acid and bio-sorbents have been used to make nutrients available to crops as well as to protect them from toxic elements. Among soil amendments, biochar has been known to improve soil crumping, soil nutrients’ availability to plants and ultimately the yield of crops. A field experiment was conducted by using biochar prepared from Dalbergia sissoo Roxb. wood by brick batch process. Two doses of biochar were applied to soil 0 and 12 t ha-1. Fertilizer rates used in the experiments were 25% recommended doses of fertilizers (RDF), 50% RDF, 75% RDF and 100% RDF alone & with biochar applied under two factorial randomized complete block design in natural field conditions (RDF of NPK fertilizer is 120-60-60 kg ha-1) . Soil physico-chemical properties viz., bulk density, particle density, porosity, pH, electrical conductivity, organic matter, soil organic carbon, total nitrogen, available phosphorus, available potassium, soil organic carbon, soil microbial biomass carbon and soil microbial biomass nitrogen were measured from the soil samples collected from 0-30 cm depth. All these parameters varied significantly among the treatments. A combined treatment of biochar and 50% of the recommended dose of NPK was most effective for soil conditioning. Agronomic parameters were also measured by standard methods. Due to chelation of heavy metal ions and availability of nutrients to the soil, yield of the crop may significantly increase due to cumulative treatment of fertilizer and biochar but upto a certain limit.

scholarly journals Alteration of soil carbon and nitrogen pools and enzyme activities as affected by increased soil coarseness

2017 ◽  
Vol 14 (8) ◽  
pp. 2155-2166 ◽  
Author(s):  
Ruzhen Wang ◽  
Linyou Lü ◽  
Courtney A. Creamer ◽  
Feike A. Dijkstra ◽  
Heyong Liu ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Enzyme Activities ◽  
Organic C ◽  
Soil C ◽  
N Limitation ◽  
Soil C And N ◽  
C And N ◽  
Microbial C ◽  
Sandy Grasslands ◽  
Acid Phosphomonoesterase

Abstract. Soil coarseness decreases ecosystem productivity, ecosystem carbon (C) and nitrogen (N) stocks, and soil nutrient contents in sandy grasslands subjected to desertification. To gain insight into changes in soil C and N pools, microbial biomass, and enzyme activities in response to soil coarseness, a field experiment was conducted by mixing native soil with river sand in different mass proportions: 0, 10, 30, 50, and 70 % sand addition. Four years after establishing plots and 2 years after transplanting, soil organic C and total N concentrations decreased with increased soil coarseness down to 32.2 and 53.7 % of concentrations in control plots, respectively. Soil microbial biomass C (MBC) and N (MBN) declined with soil coarseness down to 44.1 and 51.9 %, respectively, while microbial biomass phosphorus (MBP) increased by as much as 73.9 %. Soil coarseness significantly decreased the enzyme activities of β-glucosidase, N-acetyl-glucosaminidase, and acid phosphomonoesterase by 20.2–57.5 %, 24.5–53.0 %, and 22.2–88.7 %, used for C, N and P cycling, respectively. However, observed values of soil organic C, dissolved organic C, total dissolved N, available P, MBC, MBN, and MBP were often significantly higher than would be predicted from dilution effects caused by the sand addition. Soil coarseness enhanced microbial C and N limitation relative to P, as indicated by the ratios of β-glucosidase and N-acetyl-glucosaminidase to acid phosphomonoesterase (and MBC : MBP and MBN : MBP ratios). Enhanced microbial recycling of P might alleviate plant P limitation in nutrient-poor grassland ecosystems that are affected by soil coarseness. Soil coarseness is a critical parameter affecting soil C and N storage and increases in soil coarseness can enhance microbial C and N limitation relative to P, potentially posing a threat to plant productivity in sandy grasslands suffering from desertification.

scholarly journals Soil properties under different land use systems of Mizoram, North East India

2019 ◽  
Vol 11 (1) ◽  
pp. 121-125 ◽  
Author(s):  
Chowlani Manpoong ◽  
S.K. Tripathi
Keyword(s):  
Land Use ◽  
Soil Moisture ◽  
Microbial Biomass ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Total Nitrogen ◽  
Soil Microbial Biomass ◽  
Microbial Biomass Carbon ◽  
Biomass Carbon ◽  
Soil Microbial

Changes in land use and improper soil management have led to severe land degradation around the globe through the modification in soil physicochemical and biological processes. This study aimed to assess the soil properties of different land use system types. Soil samples (0-15 cm depth) were collected from five land uses; Rubber Plantation (RP), Oil Palm Plantation (OPP), Bamboo Forest (BF), Fallow Land (FL) and Natural Forest (NF) and analyzed for bulk density, soil texture, soil pH, soil moisture, soil carbon, total nitrogen, ammonium, nitrate, soil microbial biomass carbon, soil respiration. Soil pH was lower than 4.9 in all the sites indicating that the surface soil was highly acidic. Soil organic carbon (SOC) and total nitrogen (TN) values ranged from 2.02% to 2.81% and 0.22% to 0.3% respectively. Soil organic carbon (SOC), total nitrogen (TN) and soil microbial biomass (SMBC) were highly affected by soil moisture. NH4+-N and NO3--N ranged from 5.6 mg kg-1 to 10.2 mg kg-1 and 1.15 mg kg-1 to 2.81 mg kg-1 respectively. NF soils showed the maximum soil microbial biomass carbon (SMBC) whereas the minimum was observed in BF with values ranging from 340 mg kg-1 to 345 mg kg-1. Basal respiration was highest in RP (375 mg CO2 m-2 hr-1) and lowest in BF (224 mg CO2 m-2 hr-1). The findings demonstrated significant effect (p<0.05) of land use change on soil nutrient status and organic matter. Findings also indicated that land use change deteriorated native soil physicochemical and biological properties, but that land restoration practices through longer fallow period (>10 years) likely are successful in promoting the recovery of some soil characteristics.

scholarly journals Integration of biochar and chemical fertilizer to enhance quality of soil and wheat crop (Triticum aestivum L.)

2016 ◽  
Author(s):  
Usman Khalid Chaudhry ◽  
Salman Shahzad ◽  
Muhammad Nadir Naqqash ◽  
Abdul Saboor ◽  
Sana Yaqoob ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Microbial Biomass ◽  
Soil Amendments ◽  
Block Design ◽  
Combined Treatment ◽  
Wheat Crop ◽  
Microbial Biomass Nitrogen ◽  
Soil Microbial

A wide variety of soil amendments like manures, compost, humic acid and bio-sorbents have been used to make nutrients available to crops as well as to protect them from toxic elements. Among soil amendments, biochar has been known to improve soil crumping, soil nutrients’ availability to plants and ultimately the yield of crops. A field experiment was conducted by using biochar prepared from Dalbergia sissoo Roxb. wood by brick batch process. Two doses of biochar were applied to soil 0 and 12 t ha-1. Fertilizer rates used in the experiments were 25% recommended doses of fertilizers (RDF), 50% RDF, 75% RDF and 100% RDF alone & with biochar applied under two factorial randomized complete block design in natural field conditions (RDF of NPK fertilizer is 120-60-60 kg ha-1) . Soil physico-chemical properties viz., bulk density, particle density, porosity, pH, electrical conductivity, organic matter, soil organic carbon, total nitrogen, available phosphorus, available potassium, soil organic carbon, soil microbial biomass carbon and soil microbial biomass nitrogen were measured from the soil samples collected from 0-30 cm depth. All these parameters varied significantly among the treatments. A combined treatment of biochar and 50% of the recommended dose of NPK was most effective for soil conditioning. Agronomic parameters were also measured by standard methods. Due to chelation of heavy metal ions and availability of nutrients to the soil, yield of the crop may significantly increase due to cumulative treatment of fertilizer and biochar but upto a certain limit.

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