Grazing-induced spatial variability of soil bulk density and content of moisture, organic carbon and calcium carbonate in a semi-arid rangeland

A woodland–open forest landscape within the Brigalow Belt South bioregion of Queensland, Australia, was surveyed for soil organic carbon, soil bulk density and soil-surface fine-litter carbon. Soil carbon stocks to 30 cm depth across 14 sites, spanning a range of soil and vegetation complexes, ranged from 10.7 to 61.8 t C/ha, with an overall mean of 36.2 t C/ha. Soil carbon stocks to 100 cm depth ranged from 19.4 to 150.5 t C/ha, with an overall mean of 72.9 t C/ha. The standing stock of fine litter ranged from 1.0 to 7.0 t C/ha, with a mean of 2.6 t C/ha, and soil bulk density averaged 1.4 g/cm3 at the soil surface, and 1.6 g/cm3 at 1 m depth. These results contribute to the currently sparse database of soil organic carbon and bulk density measurements in uncultivated soils within Australian open forests and woodlands. The estimates of total soil organic carbon stock calculated to 30 cm depth were further partitioned into resistant plant material (RPM), humus (HUM), and inert organic matter (IOM) pools using diffuse mid-infrared (MIR) analysis. Prediction of the HUM and RPM pools using the RothC soil carbon model agreed well with the MIR measurements, confirming the suitability of RothC for modelling soil organic carbon in these soils. Methods for quantifying soil organic carbon at landscape scales were also explored, and a new regression-based technique for estimating soil carbon stocks from simple field-measured soil attributes has been proposed. The results of this study are discussed with particular reference to the difficulties encountered in the collection of the data, their limitations, and opportunities for the further development of methods for quantifying soil organic carbon at landscape scales.

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Incorporation of globally available datasets into the roving cosmic-ray neutron probe method for estimating field-scale soil water content

Hydrology and Earth System Sciences ◽

10.5194/hess-20-3859-2016 ◽

2016 ◽

Vol 20 (9) ◽

pp. 3859-3872 ◽

Cited By ~ 27

Author(s):

William Alexander Avery ◽

Catherine Finkenbiner ◽

Trenton E. Franz ◽

Tiejun Wang ◽

Anthony L. Nguy-Robertson ◽

...

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Water Content ◽

Bulk Density ◽

Soil Water Content ◽

Cosmic Ray ◽

Soil Bulk Density ◽

Local Soil ◽

Calibration Parameters

Abstract. The need for accurate, real-time, reliable, and multi-scale soil water content (SWC) monitoring is critical for a multitude of scientific disciplines trying to understand and predict the Earth's terrestrial energy, water, and nutrient cycles. One promising technique to help meet this demand is fixed and roving cosmic-ray neutron probes (CRNPs). However, the relationship between observed low-energy neutrons and SWC is affected by local soil and vegetation calibration parameters. This effect may be accounted for by a calibration equation based on local soil type and the amount of vegetation. However, determining the calibration parameters for this equation is labor- and time-intensive, thus limiting the full potential of the roving CRNP in large surveys and long transects, or its use in novel environments. In this work, our objective is to develop and test the accuracy of globally available datasets (clay weight percent, soil bulk density, and soil organic carbon) to support the operability of the roving CRNP. Here, we develop a 1 km product of soil lattice water over the continental United States (CONUS) using a database of in situ calibration samples and globally available soil taxonomy and soil texture data. We then test the accuracy of the global dataset in the CONUS using comparisons from 61 in situ samples of clay percent (RMSE  =  5.45 wt %, R2  =  0.68), soil bulk density (RMSE  =  0.173 g cm−3, R2  =  0.203), and soil organic carbon (RMSE  =  1.47 wt %, R2  =  0.175). Next, we conduct an uncertainty analysis of the global soil calibration parameters using a Monte Carlo error propagation analysis (maximum RMSE ∼  0.035 cm3 cm−3 at a SWC  =  0.40 cm3 cm−3). In terms of vegetation, fast-growing crops (i.e., maize and soybeans), grasslands, and forests contribute to the CRNP signal primarily through the water within their biomass and this signal must be accounted for accurate estimation of SWC. We estimated the biomass water signal by using a vegetation index derived from MODIS imagery as a proxy for standing wet biomass (RMSE  <  1 kg m−2). Lastly, we make recommendations on the design and validation of future roving CRNP experiments.

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Comparison of different models for predicting soil bulk density. Case study – Slovakian agricultural soils

International Agrophysics ◽

10.1515/intag-2016-0079 ◽

2017 ◽

Vol 31 (4) ◽

pp. 491-498 ◽

Cited By ~ 2

Author(s):

Jarmila Makovníková ◽

Miloš Širáň ◽

Beata Houšková ◽

Boris Pálka ◽

Arwyn Jones

Keyword(s):

Organic Carbon ◽

Bulk Density ◽

Monitoring System ◽

Soil Bulk Density ◽

Pedotransfer Functions ◽

Research Centre ◽

Organic Carbon Content ◽

Joint Research ◽

Data Set ◽

Sustainable Resources

Abstract Soil bulk density is one of the main direct indicators of soil health, and is an important aspect of models for determining agroecosystem services potential. By way of applying multi-regression methods, we have created a distributed prediction of soil bulk density used subsequently for topsoil carbon stock estimation. The soil data used for this study were from the Slovakian partial monitoring system-soil database. In our work, two models of soil bulk density in an equilibrium state, with different combinations of input parameters (soil particle size distribution and soil organic carbon content in %), have been created, and subsequently validated using a data set from 15 principal sampling sites of Slovakian partial monitoring system-soil, that were different from those used to generate the bulk density equations. We have made a comparison of measured bulk density data and data calculated by the pedotransfer equations against soil bulk density calculated according to equations recommended by Joint Research Centre Sustainable Resources for Europe. The differences between measured soil bulk density and the model values vary from −0.144 to 0.135 g cm−3 in the verification data set. Furthermore, all models based on pedotransfer functions give moderately lower values. The soil bulk density model was then applied to generate a first approximation of soil bulk density map for Slovakia using texture information from 17 523 sampling sites, and was subsequently utilised for topsoil organic carbon estimation.

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Physical Soil Quality of Semi - Arid Savanna as Influenced by Acacia senegalensis in Desert Research Experimental Plot Yobe State University Damaturu, Northern Nigeria

International Journal of Plant & Soil Science ◽

10.9734/ijpss/2021/v33i530432 ◽

2021 ◽

pp. 7-17

Author(s):

Hamza Haruna ◽

Galal H.G. Hussein ◽

Mohammed B

Keyword(s):

Land Use ◽

Organic Carbon ◽

Bulk Density ◽

Soil Quality ◽

Minimum Data Set ◽

Organic Carbon Content ◽

Data Set ◽

Minimum Data ◽

Lower Bulk Density ◽

Semi Arid

Soil is a living and dynamic natural reservoir and source of plant nutrients that play numerous key roles in terrestrial ecosystems. This study investigated the impact of three adjacent land use systems (Acacia senegalensis plantation (ACP), pilostigma raticulatum plantation (PRP) and Ground nut field (GNF) on selected soil physical quality indicators in a Northern Nigeria semi- arid Savanna. Minimum data set for assessing soil quality (Prime quality agricultural land) in this study include bulk density, organic carbon content, total nitrogen, carbon stock, available phosphorus and pH values obtained from DRMCC research field. Mean values of the data set were arranged and scored to obtain totals among the minimum data set (MDS). Soil quality is considered a key element for evaluating the sustainability of land management practices. Data generated were analyzed using ANOVA and significant means were determined using Duncan multiple range test (DMRT). ACP had significantly higher organic carbon content (9.37 gkg-1) and lower bulk density (2.16 gkg-1) than pilostigma and GNF respectively. The lower bulk density (ρb) and high organic carbon in ACP might be due to high leaf shading by acacia while the lower bulk density in ground nut field aided by trampling induced compaction resulted in its high relative field capacity (RFC), permanent wilting point (PWP) and micro-p ore spaces (PMIC) tillage in ground nut field created loose soil in the plough layer (<20 cm) which turn out to its low bulk density (ρb). Acacia plantation contained highest total nitrogen value (1.23 gkg-1); perhaps resulting Acacia leaf litter is known to have a high decomposition rate. Pilostigma plantation contained (1.22 gkg-1) nitrogen, while the least nitrogen content was obtained under ground nut field. On scoring the land use types and depth against the minimum data set, the least total was that under acacia plantation, followed by pilostigma plantation then ground nut field. Therefore, soils under acacia plantation were ranked best quality (SQ1) for cultivation purposes at 0-10 cm, followed by pilostigma land use type that were ranked SQ2. Ground nut field soils were ranked least (SQ6) in quality for use in crop production at depth of 10-20 cm.

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Stocks and changes in organic carbon in Danish agricultural soils – role of bulk density and stone fractions

10.5194/egusphere-egu21-16073 ◽

2021 ◽

Author(s):

Laura Sofie Harbo ◽

Jørgen Eivind Olesen ◽

Zhi Liang ◽

Lars Elsgaard

Keyword(s):

Organic Carbon ◽

Bulk Density ◽

Management Practices ◽

Agricultural Soils ◽

Soil Bulk Density ◽

Agricultural Management ◽

Specific Information ◽

High Productivity ◽

Soc Estimation ◽

Sampling Campaign

Soil organic carbon (SOC) is essential for soil fertility and further represents a global carbon stock with potential to control atmospheric CO2 concentrations. Due to intense agricultural management, SOC is decreasing in many parts of the world, meaning that the soils act as CO2 sources rather than CO2 sinks, which they could have the capacity to be. Therefore, it is important to identify pertinent agricultural management practices that allow for high productivity, but at the same time allow for carbon sequestration and increase in SOC.In order to document changes in SOC, it is necessary to monitor SOC over decadal time scales, since changes occur slowly and are small as compared with existing stocks. The SOC content in Danish agricultural soils has been monitored at approx. 10-yr intervals (1986, 1997, 2009) since the first systematic national observations in 1986, where soils were sampled from a national 7 km x 7 km grid.In 2018, a new sampling campaign was conducted from the national 7 km x 7 km grid and soils were analysed for SOC to 1 m depth. The procedures applied in 2018 allowed for more precise relocation of the sampling points from 2009 as compared to precision obtained during the period from 1986-2009. Further, measurements in 2018 included assessment of soil bulk density and stone content in the upper 0-50 cm, which was not measured previously. Thus, one of the aims of the study was to evaluate how more precise point-specific information on bulk density and stone fractions affected the calculated SOC stocks across different soil types and management practices.The point-specific bulk density measured in 2018 were on average lower than the bulk densities used previously, which were retrieved from a database of texture-based soil classes. The volumetric stone fraction in the upper 0-50 cm was found to be <5% for roughly 90% of the soils, whereas <3% of the soils had stone fractions of >10%. On average, the inclusion of point-specific bulk density and stone fractions lead to approx. 5% lower SOC estimation, with equal approximmately contribution from the two variables.

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Predicting Spatial Variability of Soil Bulk Density in Gravel-Mulched Fields

Journal of Hydrologic Engineering ◽

10.1061/(asce)he.1943-5584.0001667 ◽

2018 ◽

Vol 23 (6) ◽

pp. 04018022 ◽

Cited By ~ 2

Author(s):

Wenju Zhao ◽

Zhen Cui ◽

Yanwei Fan ◽

Qiangzhong Cao

Keyword(s):

Spatial Variability ◽

Bulk Density ◽

Soil Bulk Density

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Soil Aggregation, Organic Carbon Concentration, and Soil Bulk Density As Affected by Cover Crop Species in a No-Tillage System

Revista Brasileira de Ciência do Solo ◽

10.1590/01000683rbcs20140388 ◽

2015 ◽

Vol 39 (3) ◽

pp. 871-879 ◽

Cited By ~ 14

Author(s):

Adriano Stephan Nascente ◽

Yuncong Li ◽

Carlos Alexandre Costa Crusciol

Keyword(s):

Organic Carbon ◽

Bulk Density ◽

Cover Crops ◽

Cover Crop ◽

Soil Bulk Density ◽

Soil Aggregation ◽

Soil Tillage ◽

Panicum Maximum ◽

No Tillage ◽

Tillage System

Soil aggregation and the distribution of total organic carbon (TOC) may be affected by soil tillage and cover crops. The objective of this study was to determine the effects of crop rotation with cover crops on soil aggregation, TOC concentration in the soil aggregate fractions, and soil bulk density under a no-tillage system (NTS) and conventional tillage system (CTS, one plowing and two disking). This was a three-year study with cover crop/rice/cover crop/rice rotations in the Brazilian Cerrado. A randomized block experimental design with six treatments and three replications was used. The cover crops (treatments) were: fallow, Panicum maximum, Brachiaria ruziziensis, Brachiaria brizantha, and millet (Pennisetum glaucum). An additional treatment, fallow plus CTS, was included as a control. Soil samples were collected at the depths of 0.00-0.05 m, 0.05-0.10 m, and 0.10-0.20 m after the second rice harvest. The treatments under the NTS led to greater stability in the soil aggregates (ranging from 86.33 to 95.37 %) than fallow plus CTS (ranging from 74.62 to 85.94 %). Fallow plus CTS showed the highest number of aggregates smaller than 2 mm. The cover crops affected soil bulk density differently, and the millet treatment in the NTS had the lowest values. The cover crops without incorporation provided the greatest accumulation of TOC in the soil surface layers. The TOC concentration was positively correlated with the aggregate stability index in all layers and negatively correlated with bulk density in the 0.00-0.10 m layer.

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Gamma-ray attenuation method as an efficient tool to investigate soil bulk density spatial variability

Annals of Nuclear Energy ◽

10.1016/j.anucene.2009.08.016 ◽

2009 ◽

Vol 36 (11-12) ◽

pp. 1734-1739 ◽

Cited By ~ 22

Author(s):

L.F. Pires ◽

J.A. Rosa ◽

A.B. Pereira ◽

R.C.J. Arthur ◽

O.O.S. Bacchi

Keyword(s):

Spatial Variability ◽

Bulk Density ◽

Gamma Ray ◽

Soil Bulk Density ◽

Efficient Tool ◽

Gamma Ray Attenuation

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Dynamics of Soil Microbial Properties of Substrate in Vegetation Restoration of Rock Slope

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.347-353.237 ◽

2011 ◽

Vol 347-353 ◽

pp. 237-240

Author(s):

Zhen Ru Wu ◽

Guo Mei Jia ◽

Li Na Cao ◽

Fang Qing Chen

Keyword(s):

Soil Moisture ◽

Microbial Biomass ◽

Organic Carbon ◽

Bulk Density ◽

Total Nitrogen ◽

Rock Slope ◽

Soil Bulk Density ◽

Vegetation Restoration ◽

Microbial Properties ◽

Soil Microbial

Soil microbial properties have been proved to be powerful indicators of soil quality. This study analyzed the changes in soil moisture content, soil bulk density and porosity, soil organic carbon, total nitrogen, and microbial biomass of Substrate in vegetation restoration of Rock Slope. The results showed that soil moisture, soil porosity, organic carbon (OC), total nitrogen (TN) and microbial biomass carbon (MBC), microbial biomass nitrogen (MBN) and C/N increased significantly, and soil bulk density decreased gradually compared with bare rock Slope. Therefore, the results suggested that the vegetation restoration of Rock Slope could improve soil quality.

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