scholarly journals Water Table Dynamics Control Carbon Losses from the Destabilization of Soil Organic Matter in a Small, Lowland Agricultural Catchment

Soil Systems ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 2
Author(s):  
Laurent Jeanneau ◽  
Pauline Buysse ◽  
Marie Denis ◽  
Gérard Gruau ◽  
Patrice Petitjean ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Temperature ◽  
Water Table ◽  
Pore Space ◽  
Soil Surface ◽  
Return Time ◽  
Soil Solutions ◽  
Carbon Losses ◽  
The Impact

The biogeochemistry of soil organic matter (SOM) is driven by a combination of stabilization and destabilization mechanisms. Among the various ways in which SOM is lost, soil moisture controls the leaching of dissolved organic and inorganic carbon (DOC and DIC) and CO2 fluxes (FCO2). The aim of this study was to investigate the impact of naturally occurring water table dynamics on the couplings between these three types of C losses. The DIC and DOC concentrations in the soil solutions and the FCO2 values at the soil surface were collected fortnightly over a nine-month period at four sampling points located along two topographic transects characterized by different water table dynamics. The water table depth, soil temperature and water-filled pore space (WFPS) were monitored at each site. Linear and nonlinear regressions were used to explore the couplings between C losses, WFPS and soil temperature. The dynamics of the water table seem to drive DOC solubilization, diffusion, and export mechanisms in addition to microbial processes and the equilibrium between DIC and CO2. The main descriptors of this water table dynamic were the residence time, return time and number of oscillations of the water table. Considering both transects, FCO2 was positively correlated with DOC, which highlights the importance of substrate accessibility for SOM mineralization. This paper emphasizes the importance of the water table dynamic for the coupling between SOM carbon losses.

scholarly journals HUBUNGAN IKLIM MIKRO DAN BAHAN ORGANIK TANAH DENGAN EMISI CO2 DARI PERMUKAAN TANAH DI HUTAN ALAM BABAHALEKA TAMAN NASIONAL LORE LINDU, SULAWESI TENGAHEFFECT OF MICROCLIMATE AND SOIL ORGANIC MATTER ON SOIL ORGANIC MATTER ON SOIL...

Agromet ◽  
2013 ◽  
Vol 25 (1) ◽  
pp. 1
Author(s):  
Ade Irawan ◽  
Tania June
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Respiration ◽  
Soil Temperature ◽  
Co2 Emission ◽  
Canopy Cover ◽  
Soil Surface ◽  
Co2 Gas ◽  
Gas Sampling ◽  
Canopy Opening

<em>Soil respiration and rate of CO2 emission is determined by its temperature and its organic matter. Canopy opening of a pristine forest affect the amount of radiation energy that are able to go down the canopy and determine the microclimate variability at the forest floor and rate of CO2 emission. This resesarch was conducted at  Babahaleka Forest Lore Lindu National Park, Central Sulawesi  and supported under the  cooperation of IPB-STORMA (Stability of Rainforest Margin) project, with an objective to determine the effect of soil temperature as a consequence of different level of canopy opening (and incoming radiation) on CO2 emission from soil respiration process.  Soil CO2 emission was measured through CO2 gas sampling using a closed chamber method and analyzed using  CO2 gas analyzer.  Measurement of soil temperature, air temperature,  relative humidity and soil organic matter were conducted at each CO2 gas sampling sites for further analysis of correlation between them. It was shown that soil temperature and soil surface temperature, soil moisture and air temperature affected soil respiration and CO2 emission from the soil surface.  Average soil surface CO2 fluxes was 299.15 mgCO<sub>2</sub>m<sup>-2</sup>h<sup>-1</sup>, with fluxes from more open canopy cover was higher than that from a closed canopy cover, 329.33-375.77 mgCO<sub>2</sub>m<sup>-2</sup>h<sup>-1</sup> and 209.24-304.18 mgCO<sub>2</sub>m<sup>-2</sup>h<sup>-1</sup> respectively.</em>

scholarly journals Impact of gravels and organic matter on the thermal properties of grassland soils in southern France

2015 ◽  
Vol 2 (1) ◽  
pp. 737-765
Author(s):  
J.-C. Calvet ◽  
N. Fritz ◽  
C. Berne ◽  
B. Piguet ◽  
W. Maurel ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Organic Matter ◽  
Soil Moisture ◽  
Soil Organic Matter ◽  
Soil Temperature ◽  
Soil Thermal Conductivity ◽  
Volumetric Fraction ◽  
Southern France ◽  
The Impact ◽  
Conductivity Models

Abstract. Soil moisture is the main driver of temporal changes in values of the soil thermal conductivity. The latter is a key variable in land surface models (LSMs) used in hydrometeorology, for the simulation of the vertical profile of soil temperature in relation to soil moisture. Shortcomings in soil thermal conductivity models tend to limit the impact of improving the simulation of soil moisture in LSMs. Models of the thermal conductivity of soils are affected by uncertainties, especially in the representation of the impact of soil properties such as the volumetric fraction of quartz (q), soil organic matter, and gravels. As soil organic matter and gravels are often neglected in LSMs, the soil thermal conductivity models used in most LSMs represent the mineral fine earth, only. Moreover, there is no map of q and it is often assumed that this quantity is equal to the volumetric fraction of sand. In this study, q values are derived by reverse modelling from the continuous soil moisture and soil temperature sub-hourly observations of the Soil Moisture Observing System – Meteorological Automatic Network Integrated Application (SMOSMANIA) network at 21 grassland sites in southern France, from 2008 to 2015. The soil temperature observations are used to retrieve the soil thermal diffusivity (Dh) at a depth of 0.10 m in unfrozen conditions, solving the thermal diffusion equation. The soil moisture and Dh values are then used together with the measured soil properties to retrieve soil thermal conductivity (λ) values. For ten sites, the obtained λ value at saturation (λsat) cannot be retrieved or is lower than the value corresponding to a null value of q, probably in relation to a high density of grass roots at these sites or to the presence of stones. For the remaining eleven sites, q is negatively correlated with the volumetric fraction of solids other than sand. The impact of neglecting gravels and organic matter on λsat is assessed. It is shown that these factors have a major impact on λsat.

scholarly journals Effect of Digestate and Straw Combined Application on Maintaining Rice Production and Paddy Environment

2021 ◽  
Vol 18 (11) ◽  
pp. 5714
Author(s):  
Xue Hu ◽  
Hongyi Liu ◽  
Chengyu Xu ◽  
Xiaomin Huang ◽  
Min Jiang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Surface Water ◽  
Soil Organic Matter ◽  
Paddy Soil ◽  
Rice Yield ◽  
Soil Surface ◽  
Rice Production ◽  
Straw Decomposition ◽  
Rice Grains ◽  
Combined Application

Few studies have focused on the combined application of digestate and straw and its feasibility in rice production. Therefore, we conducted a two-year field experiment, including six treatments: without nutrients and straw (Control), digestate (D), digestate + fertilizer (DF), digestate + straw (DS), digestate + fertilizer + straw (DFS) and conventional fertilizer + straw (CS), to clarify the responses of rice growth and paddy soil nutrients to different straw and fertilizer combinations. Our results showed that digestate and straw combined application (i.e., treatment DFS) increased rice yield by 2.71 t ha−1 compared with the Control, and digestate combined with straw addition could distribute more nitrogen (N) to rice grains. Our results also showed that the straw decomposition rate at 0 cm depth under DS was 5% to 102% higher than that under CS. Activities of catalase, urease, sucrase and phosphatase at maturity under DS were all higher than that under both Control and CS. In addition, soil organic matter (SOM) and total nitrogen (TN) under DS and DFS were 20~26% and 11~12% higher than that under B and DF respectively, suggesting straw addition could benefit paddy soil quality. Moreover, coupling straw and digestate would contribute to decrease the N content in soil surface water. Overall, our results demonstrated that digestate and straw combined application could maintain rice production and have potential positive paddy environmental effects.

scholarly journals Some Peculiarities of Arable Soil Organic Matter Detection Using Optical Remote Sensing Data

2021 ◽  
Vol 13 (12) ◽  
pp. 2313
Author(s):  
Elena Prudnikova ◽  
Igor Savin
Keyword(s):  
Remote Sensing ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Spectral Reflectance ◽  
Remote Sensing Data ◽  
Soil Surface ◽  
Optical Remote Sensing ◽  
Test Field ◽  
Sensing Data ◽  
Sentinel 2

Optical remote sensing only provides information about the very thin surface layer of soil. Rainfall splash alters soil surface properties and its spectral reflectance. We analyzed the impact of rainfall on the success of soil organic matter (SOM) content (% by mass) detection and mapping based on optical remote sensing data. The subject of the study was the arable soils of a test field located in the Tula region (Russia), their spectral reflectance, and Sentinel-2 data. Our research demonstrated that rainfall negatively affects the accuracy of SOM predictions based on Sentinel-2 data. Depending on the average precipitation per day, the R2cv of models varied from 0.67 to 0.72, RMSEcv from 0.64 to 1.1% and RPIQ from 1.4 to 2.3. The incorporation of information on the soil surface state in the model resulted in an increase in accuracy of SOM content detection based on Sentinel-2 data: the R2cv of the models increased up to 0.78 to 0.84, the RMSEcv decreased to 0.61 to 0.71%, and the RPIQ increased to 2.1 to 2.4. Further studies are necessary to identify how the SOM content and composition of the soil surface change under the influence of rainfall for other soils, and to determine the relationships between rainfall-induced SOM changes and soil surface spectral reflectance.

Accumulation patterns of soil organic matter in forests as a legacy of historical charcoal burning

2021 ◽  
Author(s):  
Anna Schneider ◽  
Alexander Bonhage ◽  
Florian Hirsch ◽  
Alexandra Raab ◽  
Thomas Raab
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Large Scale ◽  
Soil Surface ◽  
Landscape Scale ◽  
Legacy Effects ◽  
Charcoal Production ◽  
Study Region ◽  
Land Use Legacies

&lt;p&gt;Human land use and occupation often lead to a high heterogeneity of soil stratigraphy and properties in landscapes within small, clearly delimited areas. Legacy effects of past land use also are also abundant in recent forest areas. Although such land use legacies can occur on considerable fractions of the soil surface, they are hardly considered in soil mapping and inventories. The heterogenous spatial distribution of land use legacy soils challenges the quantification of their impacts on the landscape scale. Relict charcoal hearths (RCH) are a widespread example for the long-lasting effect of historical land use on soil landscapes in forests of many European countries and also northeastern USA. Soils on RCH clearly differ from surrounding forest soils in their stratigraphy and properties, and are most prominently characterized by a technogenic substrate layer with high contents of charcoal. The properties of RCH soils have recently been studied for several regions, but their relevance on the landscape scale has hardly been quantified.&lt;/p&gt;&lt;p&gt;We analyse and discuss the distribution and ecological relevance of land use legacy soils across scales for RCH in the state of Brandenburg, Germany, with a focus on soil organic matter (SOM) stocks. Our analysis is based on a large-scale mapping of RCH from digital elevation models (DEM), combined with modelled SOM stocks in RCH soils.&amp;#160;The distribution of RCH soils in the study region shows heterogeneity at different scales. The large-scale variation is related to the concentration of charcoal production to specific forest areas and the small-scale accumulation pattern is related to the irregular distribution of single RCH within the charcoal production fields. Considerable fractions of the surface area are covered by RCH soils in the major charcoal production areas within the study region. The results also show that RCH can significantly contribute to the soil organic matter stocks of forests, even for areas where they cover only a small fraction of the soil surface. The study highlights that considering land use legacy effects can be relevant for the results of soil mapping and inventories; and that prospecting and mapping land use legacies from DEM can contribute to improving such approaches.&lt;/p&gt;

scholarly journals Differences in soil organic matter and humus of sandy soil after application of biochar substrates and combination of biochar substrates with mineral fertilizers

2020 ◽  
Vol 23 (3) ◽  
pp. 117-124
Author(s):  
Dušan Šrank ◽  
Vladimír Šimanský
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Carbon Content ◽  
Humic Substances ◽  
Sandy Soil ◽  
The Other ◽  
Mineral Fertilizers ◽  
Other Hand ◽  
Sheep Manure ◽  
The Impact

The effort to achieve the sustainable farming system in arable soil led to the intensive search for a new solution but an inspiration can also be found in the application of traditional methods of soil fertility improvement as it is shown in numerous examples in history. Recently many scientific teams have focused their attention on the evaluation of biochar effects on soil properties and crop yields. Since there are a lot of knowledge gaps, especially in explanations how biochar can affect soil organic matter (SOM) and humus substances, we aimed this study at the solution of these questions. Therefore, the objective of the experiment was to evaluate the impact of two biochar substrates (B1 – biochar blended with sheep manure, and B2 – biochar blended with sheep manure and the residue from the biogas station) at two rates (10 and 20 t ha-1) applied alone or in combination with mineral fertilizers (Urea was applied in 2018, at rate 100 kg ha-1, and Urea at rate 100 kg ha-1 + AMOFOS NP 12-52 at 100 kg ha-1 were applied in 2019) on the quantity and quality of SOM and humus of sandy soil (Arenosol, Dolná Streda, Slovakia). The results showed that application of the biochar substrates together with mineral fertilizers (MF) had more pronounced effect on the organic matter mineralization in the sandy soil which resulted in low accumulation of soil organic carbon (Corg) and labile carbon compared to biochar substrates treatments without MF. The share of humic substances in Corg significantly decreased by 16, 50, 16 and 24% in B1 at 10 t ha-1, B1 at 20 t ha-1, B2 at 10 t ha-1 and B2 at 20 t ha-1 treatments, respectively, compared to the control. A similar tendency was observed for biochar substrates treatments + MF, compared to MF control. The carbon content of humic substances (CHS) was equal to 4.40 – 5.80 g kg-1 and the biochar substrates had statistically significant influence on CHS content. On average, there was a smaller decrease of CHS in B1 at rate 10 t ha-1 than at rate 20 t ha-1 and no effect of B2 compared to control. The carbon content of fulvic acid (CFA) was 9% higher in B1 at 10 t ha-1, and 20 t ha-1, 47% higher in B2 at 10 t ha-1 and 17% higher in B2 at 20 t ha-1 compared to control. As a result of biochar substrates + MF application, the reduction in CFA was observed. The results showed a decrease of CHA : CFA ratio with association to biochar substrates alone application compared to control on one hand, and a wider of CHA : CFA ratio in biochar substrates + MF treatments in comparison to MF control on the other hand. Humus stability was increased in biochar substrates alone treatments compared to control, on the other hand, compared to MF control, the application of biochar substrates + MF resulted in a lower humus stability.

scholarly journals CO2-C losses and carbon quality of selected Maritime Antarctic soils

2012 ◽  
Vol 25 (1) ◽  
pp. 11-18 ◽  
Author(s):  
Juliana Vanir De Souza Carvalho ◽  
Eduardo De Sá Mendonça ◽  
Newton La Scala ◽  
César Reis ◽  
Efrain Lázaro Reis ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Temperature ◽  
Soil Carbon ◽  
Humic Substances ◽  
Microbial Activity ◽  
Chemical Characteristics ◽  
Maritime Antarctic ◽  
Antarctic Soils ◽  
Humification Degree

AbstractPolar Regions are the most important soil carbon reservoirs on Earth. Monitoring soil carbon storage in a changing global climate context may indicate possible effects of climate change on terrestrial environments. In this regard, we need to understand the dynamics of soil organic matter in relation to its chemical characteristics. We evaluated the influence of chemical characteristics of humic substances on the process of soil organic matter mineralization in selected Maritime Antarctic soils. A laboratory assay was carried out with soils from five locations from King George Island. We determined the contents of total organic carbon, oxidizable carbon fractions of soil organic matter, and humic substances. Two in situ field experiments were carried out during two summers, in order to evaluate the CO2-C emissions in relation to soil temperature variations. The overall low amounts of soil organic matter in Maritime Antarctic soils have a low humification degree and reduced microbial activity. CO2-C emissions showed significant exponential relationship with temperature, suggesting a sharp increase in CO2-C emissions with a warming scenario, and Q10 values (the percentage increase in emission for a 10°C increase in soil temperature) were higher than values reported from elsewhere. The sensitivity of the CO2-C emission in relation to temperature was significantly correlated with the humification degree of soil organic matter and microbial activity for Antarctic soils.

Rate of recycling of sulfur from urine, feces and litter applied to the soil surface

Soil Research ◽  
1994 ◽  
Vol 32 (3) ◽  
pp. 543 ◽  
Author(s):  
GJ Blair ◽  
AR Till ◽  
C Boswell
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Surface ◽  
Plant Litter ◽  
Test Plant ◽  
Soil P ◽  
S Uptake ◽  
Organic Matter Pool ◽  
Preferential Uptake ◽  
Soil Organic Matter Pool

The recycling of S from plant litter, dung and urine is an important process for supplying S for pastures. A pot experiment was conducted where 35S-labelled litter (25% white clover/38% ryegrass/21% weed) and S-35-labelled urine and faeces collected from sheep fed the same herbage as was used as litter was surface applied to pots and the fate of the applied S was followed for 100 days with ryegrass as the test plant. In camp soil, 45% of the S applied in urine was taken up by ryegrass plants within 12 days of application. In non-camp soil, the uptake of urine-S was about 20% over the same period. Cumulative uptake of 35S from urine in camp soil was subsequently restricted, with a maximum of 60% eventually measured in plants after 100 days. Mean rates of release of S (0-37 days) from litter and faeces was respectively 16.2 and 4.5 mg g-1 day-1. The calculated half-times from S in the two materials were respectively 43 and 154 days under controlled environmental conditions with adequate moisture. Litter S followed organic matter (OM) decomposition, but faecal S release was initially more rapid than faecal OM decomposition. There was little S release from faeces after day 25. Rather, S was immobilized in faeces during the 25-100 day period. The decomposition of litter and faeces was divided into an initial rapid process during which soluble S and more labile S was released, followed by a slower process involving the release of S from tissues more resistant to mineralization. The uptake of 35S from labelled materials was initially more rapid than would be expected for total S released from the added litter and faeces and the 35Suptake effect was short-lived relative to the continued effect of added material on total S uptake. The preferential uptake of 35S from the surface-applied material appears to be due to limited root development at the early stages of the experiment. Movement of 35S into the soil organic matter pool was very rapid; 58.4% of urine S was in the soil organic matter fraction in the non-camp soil by day 6. The amount of applied S in the organic matter equilibrated at about day 75. The accumulation of applied S from the materials added was greater than that recorded in previously reported studies for inorganic sulfate (e.g. about 50%). Soil P and S status had little effect on rates of release of S. from the applied materials, however, the effect of the camp and non-camp soil on total S recycling was markedly different as a result of the different amounts of plant growth and thus S uptake in the two soils. The decomposition of litter indicated peak rates of S release at two specific times over the 100 days and indicated successional changes in micro-organism activity. With faeces, the experiment was not continued for sufficiently long to show micro-organism effects.

scholarly journals Evaluation of Noah-MP Land-Model Uncertainties over Sparsely Vegetated Sites on the Tibet Plateau

Atmosphere ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 458
Author(s):  
Guo Zhang ◽  
Fei Chen ◽  
Yueli Chen ◽  
Jianduo Li ◽  
Xindong Peng
Keyword(s):  
Heat Flux ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Tibetan Plateau ◽  
Sensible Heat Flux ◽  
Limiting Factors ◽  
Tibet Plateau ◽  
The Tibetan Plateau ◽  
Annual Total ◽  
The Impact

The water budget and energy exchange over the Tibetan Plateau (TP) region play an important role on the Asian monsoon. However, it is not well presented in the current land surface models (LSMs). In this study, uncertainties in the Noah with multiparameterization (Noah-MP) LSM are assessed through physics ensemble simulations in three sparsely vegetated sites located in the central TP. The impact of soil organic matter on energy flux and water cycles, along with the influence of uncertainties in precipitation are explored using observations at those sites during the third Tibetan Plateau Experiment from 1August2014 to31July2015. The greatest uncertainties are in the subprocesses of the canopy resistance, soil moisture limiting factors for evaporation, runoff (RNF) and ground water, and surface-layer parameterization. These uncertain subprocesses do not change across the different precipitation datasets. More precipitation can increase the annual total net radiation (Rn), latent heat flux (LH) and RNF, but decrease sensible heat flux (SH). Soil organic matter enlarges the annual total LH by ~26% but lessens the annual total Rn, SH, and RNF by ~7%, 7%, and 39%, respectively. Its effect on the LH and RNF at the Nagqu site, which has a sand soil texture type, is greater than that at the other two sites with sandy loam. This study highlights the importance of precipitation uncertainties and the effect of soil organic matter on the Noah-MP land-model simulations. It provides a guidance to improve the Noah-MP LSM further and hence the land-atmosphere interactions simulated by weather and climate models over the TP region.

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