Water content, organic carbon and dry bulk density in flooded sediments

2001 ◽  
Vol 25 (1) ◽  
pp. 25-33 ◽  
Author(s):  
Yoram Avnimelech ◽  
Gad Ritvo ◽  
Leon E. Meijer ◽  
Malka Kochba
Keyword(s):  
Organic Carbon ◽  
Water Content ◽  
Bulk Density

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

2016 ◽  
Vol 20 (9) ◽  
pp. 3859-3872 ◽  
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.

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

2016 ◽  
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 (CRNP). 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 standing biomass. 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 using globally available datasets (clay weight percent, soil bulk density, and soil organic carbon) to support the operability of the 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/cm3, 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 RSME ~0.035 cm3/cm3 at a SWC = 0.40 cm3/cm3). In terms of vegetation, fast growing crops (i.e. maize and soybeans) contribute to the CRNP signal primarily through the water within their biomass and this signal must be minimized 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/m2). Lastly, we make recommendations on the design and validation of future roving CRNP experiments.

scholarly journals The use of in situ volumetric water content at field capacity to improve the prediction of soil water retention properties

2008 ◽  
Vol 88 (4) ◽  
pp. 533-541 ◽  
Author(s):  
Hassan Al Majou ◽  
Ary Bruand ◽  
Odile Duval
Keyword(s):  
Organic Carbon ◽  
Carbon Content ◽  
Water Content ◽  
Bulk Density ◽  
Water Retention ◽  
Field Capacity ◽  
Volumetric Water Content ◽  
Organic Carbon Content ◽  
Water Retention Properties

Most pedotransfer functions (PTF) developed over the past three decades to generate water retention characteristics use soil texture, bulk density and organic carbon content as predictors. Despite the high number of PTFs published, most being class- or continuous-PTFs, the accuracy of prediction remains limited. In this study, we compared the performance of different class- and continuous-PTFs developed with a regional database. Results showed that the use of in situ volumetric water content at field capacity as a predictor led to much better estimation of water retention properties compared with using predictors derived from the texture, or the organic carbon content and bulk density. This was true regardless of the complexity of the PTFs developed. Results also showed that the best prediction quality was achieved by using the in situ volumetric water content at field capacity after stratification by texture. Comparison of in situ volumetric water content at field capacity, with the water retained at different matric potentials as measured in the laboratory, showed field capacity to approximate 100 hPa, whatever the soil texture. Finally, the lack accuracy of PTFs that do not use the in situ volumetric water content at field capacity as predictor did not appear due to the test soils being unrepresentative of the soils used to develop the PTFs, but were instead related to poor correlations between the predictors used and the water retention properties. Key words: Pedotransfer functions, root mean square error, mean error of prediction, standard deviation of prediction, texture, bulk density, organic carbon content

scholarly journals Effects of reduced and traditional tillage on soil properties and diversity of diatoms under winter wheat

2018 ◽  
Vol 32 (3) ◽  
pp. 403-409 ◽  
Author(s):  
Jadwiga Stanek-Tarkowska ◽  
Ewa A. Czyż ◽  
Anthony R. Dexter ◽  
Cezary Sławiński
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Winter Wheat ◽  
Soil Properties ◽  
Water Content ◽  
Bulk Density ◽  
Reduced Tillage ◽  
Research Station ◽  
Organic Carbon Content ◽  
Dispersible Clay

Abstract The aim of this study was to quantify soil properties, microbial biodiversity and crop yield under two tillage systems used for winter wheat production in monoculture. The study was conducted in the period 2013-2016, on a long-term field experiment on a silt loam at the Krasne Research Station near Rzeszów, Poland. Traditional tillage involved soil inversion whereas reduced tillage was a non-inversion system. The following soil properties: chemical (soil organic carbon, pH, available P, K, Mg), physical (soil bulk density, water content, stability in water), and biological (the diversity of diatoms) were measured on samples collected throughout the growing season and at harvest. Soil organic carbon content, water content and bulk density in the 0-5 and 5-10 cm layers were greater in reduced tillage than in traditional tillage. Under reduced tillage the amount of readily dispersible clay was reduced giving increased soil stability in water. Soil under reduced tillage had greater diversity of diatoms (139 taxa) than that under traditional tillage (102 taxa). Wheat yields were positively correlated with precipitation, soil water content and soil organic carbon, and negatively correlated with readily dispersible clay.

Measurement of Soil Bulk Density and Water Content with Time Domain Reflectometry: Algorithm Implementation and Method Analysis

2021 ◽  
pp. 126389
Author(s):  
Marco Bittelli ◽  
Fausto Tomei ◽  
Anbazhagan P. ◽  
Raghuveer Rao Pallapati ◽  
Puskar Mahajan ◽  
...  
Keyword(s):  
Water Content ◽  
Bulk Density ◽  
Time Domain ◽  
Soil Bulk Density ◽  
Time Domain Reflectometry ◽  
Algorithm Implementation ◽  
Method Analysis

scholarly journals Characterizing Soil Physical Properties for Soil Moisture Monitoring with the North Carolina Environment and Climate Observing Network

2012 ◽  
Vol 29 (7) ◽  
pp. 933-943 ◽  
Author(s):  
Weinan Pan ◽  
R. P. Boyles ◽  
J. G. White ◽  
J. L. Heitman
Keyword(s):  
North Carolina ◽  
Soil Moisture ◽  
Physical Properties ◽  
Soil Properties ◽  
Water Content ◽  
Bulk Density ◽  
Soil Physical Properties ◽  
The North ◽  
Wide Range ◽  
Soil Moisture Monitoring

Abstract Soil moisture has important implications for meteorology, climatology, hydrology, and agriculture. This has led to growing interest in development of in situ soil moisture monitoring networks. Measurement interpretation is severely limited without soil property data. In North Carolina, soil moisture has been monitored since 1999 as a routine parameter in the statewide Environment and Climate Observing Network (ECONet), but with little soils information available for ECONet sites. The objective of this paper is to provide soils data for ECONet development. The authors studied soil physical properties at 27 ECONet sites and generated a database with 13 soil physical parameters, including sand, silt, and clay contents; bulk density; total porosity; saturated hydraulic conductivity; air-dried water content; and water retention at six pressures. Soil properties were highly variable among individual ECONet sites [coefficients of variation (CVs) ranging from 12% to 80%]. This wide range of properties suggests very different behavior among sites with respect to soil moisture. A principal component analysis indicated parameter groupings associated primarily with soil texture, bulk density, and air-dried water content accounted for 80% of the total variance in the dataset. These results suggested that a few specific soil properties could be measured to provide an understanding of differences in sites with respect to major soil properties. The authors also illustrate how the measured soil properties have been used to develop new soil moisture products and data screening for the North Carolina ECONet. The methods, analysis, and results presented here have applications to North Carolina and for other regions with heterogeneous soils where soil moisture monitoring is valuable.

Profile Soil Property Estimation Using a VIS-NIR-EC-Force Probe

2017 ◽  
Vol 60 (3) ◽  
pp. 683-692 ◽  
Author(s):  
Yongjin Cho ◽  
Kenneth A. Sudduth ◽  
Scott T. Drummond
Keyword(s):  
Soil Properties ◽  
Water Content ◽  
Bulk Density ◽  
Soil Property ◽  
Soil Strength ◽  
Reflectance Spectra ◽  
Land Resource ◽  
Strength Data ◽  
Soil Sensors ◽  
Combining Data

Abstract. Combining data collected in-field from multiple soil sensors has the potential to improve the efficiency and accuracy of soil property estimates. Optical diffuse reflectance spectroscopy (DRS) has been used to estimate many important soil properties, such as soil carbon, water content, and texture. Other common soil sensors include penetrometers that measure soil strength and apparent electrical conductivity (ECa) sensors. Previous field research has related these sensor measurements to soil properties such as bulk density, water content, and texture. A commercial instrument that can simultaneously collect reflectance spectra, ECa, and soil strength data is now available. The objective of this research was to relate laboratory-measured soil properties, including bulk density (BD), total organic carbon (TOC), water content (WC), and texture fractions to sensor data from this instrument. At four field sites in mid-Missouri, profile sensor measurements were obtained to 0.9 m depth, followed by collection of soil cores at each site for laboratory measurements. Using only DRS data, BD, TOC, and WC were not well-estimated (R2 = 0.32, 0.67, and 0.40, respectively). Adding ECa and soil strength data provided only a slight improvement in WC estimation (R2 = 0.47) and little to no improvement in BD and TOC estimation. When data were analyzed separately by major land resource area (MLRA), fusion of data from all sensors improved soil texture fraction estimates. The largest improvement compared to reflectance alone was for MLRA 115B, where estimation errors for the various soil properties were reduced by approximately 14% to 26%. This study showed promise for in-field sensor measurement of some soil properties. Additional field data collection and model development are needed for those soil properties for which a combination of data from multiple sensors is required. Keywords: NIR spectroscopy, Precision agriculture, Reflectance spectra, Soil properties, Soil sensing.

scholarly journals Agro-forestry Systems as a Means to Achieve Carbon Co-benefits in Nepal

2016 ◽  
Vol 13 (1) ◽  
pp. 59-68
Author(s):  
Roshan M. Bajracharya ◽  
Him Lal Shrestha ◽  
Ramesh Shakya ◽  
Bishal K. Sitaula
Keyword(s):  
Organic Carbon ◽  
Soil Properties ◽  
Soil Carbon ◽  
Bulk Density ◽  
Agricultural Land ◽  
Carbon Stocks ◽  
Community Forests ◽  
C Stocks ◽  
Soil Carbon Stocks ◽  
Agro Forestry

Land management regimes and forest types play an important role in the productivity and accumulation of terrestrial carbon pools. While it is commonly accepted that forests enhance carbon sequestration and conventional agriculture causes carbon depletion, the effects of agro-forestry are not well documented. This study investigated the carbon stocks in biomass and soil, along with the selected soil properties in agro-forestry plots compared to community forests (CF) and upland farms in Chitwan, Gorkha and Rasuwa districts of Central Nepal during the year 2012-2013. We determined the total above ground biomass carbon, soil organic carbon (SOC) stocks and soil properties (bulk density, organic carbon per cent, pH, total nitrogen (TN), available phosphorus (P), exchangeable potassium (K), and cation exchange capacity (CEC)) on samples taken from four replicates of 500 m2 plots each in community forests, agro-forestry systems and agricultural land. The soil was sampled in two increments at 0-15 cm and 15-30 cm depths and intact cores removed for bulk density and SOC determination, while loose samples were separately collected for the laboratory analysis of other soil properties. The mean SOC percent and corresponding soil carbon stocks to 30 cm depth were generally highest in CF (3.71 and 3.69 per cent, and 74.98 and 76.24 t ha-1, respectively), followed by leasehold forest (LHF) (2.26 and 1.13 per cent and 40.72 and 21.34 t ha-1, respectively) and least in the agricultural land (3.05 and 1.09 per cent, and 63.54 and 19.42 t ha-1, respectively). This trend was not, however, observed in Chitwan, where agriculture (AG) had the highest SOC content (1.98 per cent) and soil carbon stocks (42.5 t ha-1), followed by CF (1.8 per cent and 41.2 t ha-1) and leasehold forests (1.56 per cent and 35.3 t ha-1) although the differences were not statistically significant. Other soil properties were not significantly different among land use types with the exceptions of pH, total N, available P and CEC in the Chitwan plots. Typically, SOC and soil carbon stocks (to 30cm depth) were positively correlated with each other and with TN and CEC. The AGB-C was expectantly highest in Rasuwa district CF (ranging from 107.3 to 260.3 t ha-1) due to dense growth and cool climate, followed by Gorkha (3.1 to 118.4 t ha-1), and least in Chitwan (17.6 to 95.2 t ha-1). The highest C stocks for agro-forestry systems in both above ground and soil were observed in Rasuwa, followed by Chitwan district. Besides forests, agro-forestry systems also hold good potential to store and accumulate carbon, hence they have scope for contributing to climate change mitigation and adaptation with co-benefits.Journal of Forest and Livelihood 13(1) May, 2015, page: 56-68

scholarly journals Tahanan Penetrasi Tanah Terhadap Penekanan Plat Dengan Sudut Penekanan dan Ukuran Plat yang Berbeda di Sawah

2018 ◽  
Vol 1 (2) ◽  
pp. 238-243
Author(s):  
Taufik Rizaldi ◽  
Sumono Sumono
Keyword(s):  
Water Content ◽  
Bulk Density ◽  
Rice Field ◽  
Compressive Force ◽  
Field Measurements ◽  
Penetration Resistance ◽  
Paddy Fields ◽  
Soil Penetration Resistance ◽  
Plate Size ◽  
Measuring Plate

Penelitian dilakukan di Desa Lubuk Bayas Kecapamatan Perbaungan Kabupaten Serdang Bedagai pada lahan sawah bertekstur lempung berpasir dengan kadar air 49.17% dan dry bulk density 1.26 g/cm3. Tahanan penetrasi tanah ditentukan melalui pengukuran tahanan penetrasi plat dengan menggunakan penetrometer secara langsung di sawah. Pengukuran dilakukan dengan ukuran plat 5x5 cm2, 5x10 cm2, 5x15 cm2 dan 5x20 cm2. Sudut penekanan 90o, 75o, 60o, 45o, 30o dan kedalaman penekanan 4 cm, 8 cm, 12 cm, 16 cm dan 20 cm. Dari hasil pengukuran diperoleh bahwa semakin besar ukuran plat maka gaya penekanan semakin besar namun tahanan penetrasi tanah semakin kecil. Sedangkan semakin dalam plat masuk ke tanah maka tahanan penetrasi tanah semakin besar. Semakin besar sudut penekanan tahanan penetrasi tanah semakin besar. Untuk ukuran plat, sudut tekan dan kedalaman penekanan plat yang sama pada kedalaman lumpur yang berbeda akan menghasilkan gaya penekanan dan tahanan penetrasi tanah yang berbeda. The study was conducted in Lubuk Bayas Village, Perbaungan Subdistrict, Serdang Bedagai District, in paddy fields with sandy clay texture with a water content of 49.17% and dry bulk density of 1.26 g / cm3. Soil penetration resistance iwas determined by measuring plate penetration resistance using a penetrometer directly in the rice field. Measurements were made with a plate size of 5x5 cm2, 5x10 cm2, 5x15 cm2 and 5x20 cm2. The angle of emphasis was 90o, 75o, 60o, 45o, 30o and the depth of emphasis was 4 cm, 8 cm, 12 cm, 16 cm and 20 cm. Results showed that the larger the plate size found, the greater the compressive force, but the penetration resistance of the soil got smaller. Whereas the deeper the plate entered the ground, the greater the penetration resistance of the soil occurred. The greater the angle of suppression the greater the penetration penetration of the soil. For the plate size, the pressure angle and depth of the same plate compression at different mud depths will result in a different force of suppression and soil penetration resistance.

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