Soil moisture thresholds for combustion of organic soils in western Tasmania

2020 ◽  
Vol 29 (7) ◽  
pp. 637 ◽  
Author(s):  
Lynda D. Prior ◽  
Ben J. French ◽  
Kathryn Storey ◽  
Grant J. Williamson ◽  
David M. J. S. Bowman
Keyword(s):  
Soil Moisture ◽  
High Resolution ◽  
Moisture Content ◽  
Organic Soil ◽  
Soil Bulk Density ◽  
Organic Content ◽  
Time Domain Reflectometry ◽  
Weather Data ◽  
Organic Soils ◽  
Vegetation Types

The present study aimed to determine moisture thresholds for combustion of organic soils sampled from various vegetation types at 63 locations in Tasmania, Australia. To observe whether the soil sample sustained smouldering combustion, moisture content was experimentally manipulated and heat was applied. Combustion was primarily determined by moisture content, but was also influenced by soil bulk density and organic content: the gravimetric moisture content corresponding to a 50% probability of burning ranged from 25 to 94% as organic content varied from 34 to 96%. There was no evidence of differences among vegetation types in the relationship between soil combustibility and organic content. Combustion in Tasmanian organic soils occurred with moisture levels similar to those reported elsewhere, despite differences in vegetation and environment. It was also found that a hand-held meter that measured volumetric moisture content using time domain reflectometry could be used to satisfactorily predict organic soil combustion. Finally, combining the data with estimates of volumetric soil moisture based on high-resolution gridded weather data (Bureau of Meteorology Atmospheric high-resolution Regional Reanalysis for Australia, or BARRA), it was demonstrated that most Tasmanian organic soils are likely to be combustible at some time almost every summer (December to February).

Development of calibration algorithms for selected water content reflectometry probes for burned and non-burned organic soils of Alaska

2010 ◽  
Vol 19 (7) ◽  
pp. 961 ◽  
Author(s):  
Laura L. Bourgeau-Chavez ◽  
Gordon C. Garwood ◽  
Kevin Riordan ◽  
Benjamin W. Koziol ◽  
James Slawski
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Water Content ◽  
Soil Profile ◽  
Soil Moisture Content ◽  
Mineral Soil ◽  
Organic Soil ◽  
Organic Content ◽  
Organic Soils ◽  
Probe Type

Water content reflectometry is a method used by many commercial manufacturers of affordable sensors to electronically estimate soil moisture content. Field‐deployable and handheld water content reflectometry probes were used in a variety of organic soil‐profile types in Alaska. These probes were calibrated using 65 organic soil samples harvested from these burned and unburned, primarily moss‐dominated sites in the boreal forest. Probe output was compared with gravimetrically measured volumetric moisture content, to produce calibration algorithms for surface‐down‐inserted handheld probes in specific soil‐profile types, as well as field‐deployable horizontally inserted probes in specific organic soil horizons. General organic algorithms for each probe type were also developed. Calibrations are statistically compared to determine their suitability. The resulting calibrations showed good agreement with in situ validation and varied from the default mineral‐soil‐based calibrations by 20% or more. These results are of particular interest to researchers measuring soil moisture content with water content reflectometry probes in soils with high organic content.

scholarly journals EFFECTS OF HYDROPHILIC POLYMERS AND ORGANIC AMENDMENTS ON ESTABLISHMENT OF KENTUCKY BLUEGRASS.

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 588a-588
Author(s):  
A. James Downer ◽  
Ben Faber ◽  
Richard White
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Water Content ◽  
Soil Moisture Content ◽  
Organic Amendments ◽  
Kentucky Bluegrass ◽  
Soil Bulk Density ◽  
Time Domain Reflectometry ◽  
Peat Moss ◽  
Turf Quality

Three polymers (a polyacrylamide, polyacrylate and a propenoate-propenamide copolymer) and three organic amendments (peat moss, wood shavings, and composted yardwaste) were incorporated at five rates in a sandy soil to 15cm depth. Soil moisture content was determined by time domain reflectometry and gravimetrically. Only the highest polymer rates (2928kg/ha [60#/1000sq.ft.]) produced significant increases in soil moisture content and reductions of soil bulk density. Peat moss and yardwaste increased soil water content while shavings decreased water content. Turf quality scores were not affected by polymers but were initially reduced by yardwaste and shavings.

scholarly journals Field Calibration of TDR to Assess the Soil Moisture of Drained Peatland Surface Layers

Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1842 ◽  
Author(s):  
Tomasz Gnatowski ◽  
Jan Szatyłowicz ◽  
Bogumiła Pawluśkiewicz ◽  
Ryszard Oleszczuk ◽  
Maria Janicka ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Mean Squared Error ◽  
Time Domain Reflectometry ◽  
Calibration Model ◽  
Surface Layers ◽  
Calibration Equation ◽  
North East

The proper monitoring of soil moisture content is important to understand water-related processes in peatland ecosystems. Time domain reflectometry (TDR) is a popular method used for soil moisture content measurements, the applicability of which is still challenging in field studies due to requirements regarding the calibration curve which converts the dielectric constant into the soil moisture content. The main objective of this study was to develop a general calibration equation for the TDR method based on simultaneous field measurements of the dielectric constant and gravimetric water content in the surface layers of degraded peatlands. Data were collected during field campaigns conducted temporarily between the years 2006 and 2016 at the drained peatland Kuwasy located in the north-east area of Poland. Based on the data analysis, a two-slopes linear calibration equation was developed as a general broken-line model (GBLM). A site-specific calibration model (SSM-D) for the TDR method was obtained in the form of a two-slopes equation describing the relationship between the soil moisture content and the dielectric constant and introducing the bioindices as covariates relating to plant species biodiversity and the state of the habitats. The root mean squared error for the GBLM and SSM-D models were equal, respectively, at 0.04 and 0.035 cm3 cm−3.

Impact of density on the hydraulic properties of peat and the time domain reflectometry (TDR) moisture calibration curve

2005 ◽  
Vol 42 (1) ◽  
pp. 279-286 ◽  
Author(s):  
Anushka Shibchurn ◽  
Paul J Van Geel ◽  
Paula L Kennedy
Keyword(s):  
Dielectric Constant ◽  
Soil Moisture ◽  
Water Content ◽  
Time Domain ◽  
Calibration Curve ◽  
Hydraulic Properties ◽  
Time Domain Reflectometry ◽  
Organic Soils ◽  
Dry Density ◽  
Water Contents

The hydraulic properties of a peat used in a commercial peat biofilter were evaluated to determine their relationship with density and to establish a time domain reflectometry (TDR) calibration curve for water content as a function of the measured dielectric constant. The peat studied was a milled Sphagnum peat with a high organic content (99%). The dry densities evaluated in this study ranged from 90 to 180 kg/m3. The saturated hydraulic conductivity (Ks) decreased with an increase in dry density (ρdry) and was found to follow a log-linear relationship (Ks = 0.2462 exp(–0.0438ρdry), correlation coefficient R2 = 0.9789). As expected, the soil moisture curve was impacted by density, with a higher density resulting in higher water contents for a given suction. The data were fit to the van Genuchten relationship. A TDR calibration curve was generated at five different densities. A comparison of the curves indicates that the water content as a function of dielectric constant was not dependent on density because of the significantly larger dielectric constant (Ka) of water compared with those of peat solids and air-filled voids. The TDR calibration curve for the peat evaluated in this study (volumetric water content Θv = 0.2667 ln(Ka) – 0.1405, R2 = 0.9564) predicted higher water contents for a given dielectric constant compared with those from similar calibration curves for peat published in the literature. The data were compared with those from six other studies and indicated that the TDR calibration varied for different organic soils. The density-dependent hydraulic parameters and TDR calibration curve are important parameters needed to study the hydraulics of peat biofilters.Key words: peat, TDR, time domain reflectometry, density, hydraulics, soil moisture.

scholarly journals Semi-Arid Region Soil Moisture Prediction using Multivariate Regression

2019 ◽  
Vol 8 (4) ◽  
pp. 12457-12460
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Properties ◽  
Arid Region ◽  
Soil Moisture Content ◽  
Linear Regression Analysis ◽  
Organic Content ◽  
Dry Density ◽  
Semi Arid Region ◽  
Semi Arid

The Water Scarcity is a prominent feature in Arid and Semi-Arid region. Soil moisture content is significant factor in deciding vegetation growth and also affects the performance of any water harvesting system in place. This paper evaluates the interrelationship of Soil properties with Soil Moisture content. The study covers about 13 soil Samples from Single Watershed. The soil properties covered in the study are Conductivity, pH, Bulk Density, Dry Density, Specific gravity, organic content, void ratio, and Moisture Content. Multiple linear regression analysis was done to determine significance of each soil properties for soil moisture content as individual and as whole. Modelling was done based on soil characteristics to predict Soil Moisture. Principal Component Analysis was performed to identify most significant soil properties responsible for variation of prediction of Soil Moisture content. The Correlation between location topography and Moisture Content was obtained through Cluster Analysis.

scholarly journals Effect of tillage practices at different levels of soil moisture on some soil properties and maize productivity

2020 ◽  
Vol 5 (01) ◽  
pp. 1-15
Author(s):  
Abdel-Aal M. H.
Keyword(s):  
Soil Moisture ◽  
Hydraulic Conductivity ◽  
Moisture Content ◽  
Soil Properties ◽  
Total Porosity ◽  
Soil Bulk Density ◽  
Conventional Tillage ◽  
No Tillage ◽  
Tillage Practices ◽  
Moisture Contents

A field experiment was carried out during the early summer seasons of 2018, at Agricultural Research Centre (ARC) Giza, Egypt. This study aims to examine the effect of three tillage treatments under three different moisture contents on some soil properties and on maize crop production. The experiments included three moisture contents of (MC1, 27.2 %), (MC2, 15.4 %) and (MC3, 7.2 %); as well as three tillage treatments, no-tillage control (NT), minimum tillage (MT) and conventional tillage (CT). The experimental was laid out in split-split plot design with four replications. The results showed that, there was significant effect of tillage at different moisture levels on soil physical and chemical properties. It was also indicated that the effect of tillage practices was significantly on soil bulk density, total porosity, hydraulic conductivity and moisture constants, where the conventional tillage at soil moisture level 15.4% (MC2) helped in improving soil bulk density, hydraulic conductivity and total porosity. Soil organic C, cations exchange capacity CEC, available N, P and K were improved in the soil surface layer of NT and decreased with depth. Clod mean weight diameter of soil was improved with 15.4-% of soil moisture content regardless of tillage depth and enhanced root proliferation by increasing density roots compared with minimum and no tillage in maize plant. The grain yields of maize were improving more under conventional tillage at moisture content 15.4% compared with other treatments. It was found that plant height and roots value increased by using conventional tillage compared with other tillage treatments.

scholarly journals Is the Time-Domain Reflectometry (TDR) Technique Suitable for Moisture Content Measurement in Low-Porosity Building Materials?

2020 ◽  
Vol 12 (19) ◽  
pp. 7855 ◽  
Author(s):  
Teresa Stingl Freitas ◽  
Ana Sofia Guimarães ◽  
Staf Roels ◽  
Vasco Peixoto de Freitas ◽  
Andrea Cataldo
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Time Domain ◽  
Building Materials ◽  
Construction Materials ◽  
Gravimetric Method ◽  
Time Domain Reflectometry ◽  
Advantages And Disadvantages ◽  
The Time Domain ◽  
Low Porosity

Measuring moisture content in building materials is essential both for professional practice and for research. However, this is a very complex task, especially when long-term minor destructive measurements are desired. The time-domain reflectometry (TDR) technique is commonly used for soil moisture measurements, but its application in construction materials is considered a relatively new method, particularly for low-porosity building materials. The major obstacles to its current use in construction materials are (1) the difficulty of ensuring good contact between the TDR probe and the material, and (2) the lack of appropriate conversion functions between the measured relative permittivity and the moisture content of building materials. This paper intends to contribute to overcoming these difficulties by explaining in detail all the required steps to monitor moisture content in real-scale limestone walls. For that, a device is presented to guarantee the correct installation of the TDR probes on the walls, and a calibration procedure through the gravimetric method is proposed to avoid the use of an unsuitable calibration function developed for soil moisture measurements. In addition, the importance of the individual probe calibration is discussed, as well as TDR advantages and disadvantages for construction materials. The results obtained so far reveal that the TDR technique is suitable to detect moisture content variations in limestone, which is a low-porosity building material.

scholarly journals Machinery-Induced Damage to Soil and Remaining Forest Stands—Case Study from Slovakia

Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1289
Author(s):  
Zuzana Dudáková (Allmanová) ◽  
Michal Allman ◽  
Ján Merganič ◽  
Katarína Merganičová
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Bulk Density ◽  
Soil Moisture Content ◽  
Soil Bulk Density ◽  
Forest Stands ◽  
Forest Operations ◽  
Factorial Anova ◽  
Size Type ◽  
The Impact

The paper deals with the damage of the remaining stand and soil caused by harvesting using three ground-based forest operations methods (harvester-forwarder/cable skidder/animal-tractor). It compares the impact of the most common harvesting technologies applied in Slovakia and in Central Europe and thus contributes with valuable information to the knowledge on the suitability of their application in forests stands dominated by broadleaved tree species. Harvesting was performed in five forest stands located at the University Forest Enterprise of Technical University in Zvolen in central Slovakia from August to October 2019. Damage to remaining trees was assessed from the point of its size, type, and position of damage along stem. We expected lower damage of remaining trees in stands where harvesters were used because of the applied cut-to-length short wood system and fully mechanized harvesting system. In addition, we examined soil bulk density and soil moisture content in ruts, space between ruts, and in undisturbed stand to reveal the impact of harvesting machinery on soil. We expected greater soil bulk densities and lower soil moisture content in these stands due to the greatest weight of harvesters and in ruts created by machinery compared with undisturbed stand soil. The highest percentage of damaged remaining trees equal to 20.47% and 23.36% was recorded for harvester forest operations, followed by skidder (19.44%) and animal forest operations with 19.86% and 14.47%. Factorial ANOVA confirmed significant higher soil compaction in stands where harvesters were used (higer bulk density) than in stands where skidding was performed with the skidder and animal power. Higher soil moisture content was recorded in ruts created by harvesters and the skidder. The lowest soil moisture content was in undisturbed stands irrespective of the applied forest operation method.

scholarly journals Sensitivity of PR2 Capacitance Soil Moisture Meter for Irrigation Scheduling

2021 ◽  
Vol 1 (3) ◽  
pp. 1-5
Author(s):  
Olotu Y.* ◽  
◽  
Omoakhalen A.I. ◽  
Ososomi A.S. ◽  
Gbalaja Mayowa ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Organic Soil ◽  
Integrated Water Resources Management ◽  
Irrigation Scheduling ◽  
Computer Algorithms ◽  
Resources Management ◽  
Moisture Content Measurement ◽  
Complex Computer

Accurate soil moisture content measurement is essential for designing a robust irrigation scheduling and integrated water resources management (I.W.R.M.). Capacitance-based sensors have widely been used to monitor soil moisture at different measuring depths coupled with continuous and instantaneous outputs. This study's objective was to evaluate the PR2 capacitance moisture meter's performance on mineral and organic soil water content. The outputs of PR2 in m3 /m3 and vol.% were compared with gravimetrically measured soil moisture. The R.M.S.E. measurement at Site A at the first and second replicates increased from 0.49% to 0.67%. In contrast, the r2 value of 0.99 was obtained for the two replications when comparing the soil moisture content observed from gravimetric measurement and the automated outputs from the PR2 Probe soil monitor. The R.M.S.E. values were 0.48%, and 1.32% were estimated for the first and second replications at Site B. The result indicates that the PR2 Profile Probe could be a reliable alternative to other time-consuming, complex computer algorithms for accurate point measurement of soil moisture.

Effect of weather on maize yields and the efficiency of fertilization

2005 ◽  
Vol 53 (1) ◽  
pp. 31-39 ◽  
Author(s):  
L. Huzsvay ◽  
J. Nagy
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Regression Line ◽  
Soil Layer ◽  
Nutrient Utilization ◽  
Weather Data ◽  
Water Supplies ◽  
Daily Weather Data ◽  
Maize Yields

The yield of maize is primarily influenced by sunlight, temperature, available plant nutrients and water supply. Since plants take up water through their roots, the most decisive factor is not precipitation but the quantity of water available in the soil. In this study, a simple, easy-to-reproduce, capacitive model was elaborated to determine the available moisture content for maize. During the calculations, based on the balance method, the available moisture content in the top 110 cm soil layer was determined, taking daily weather data into account. The examinations were carried out on a medium heavy chernozem soil with lime deposits, in a multifactorial experiment at the Látókép Experimental Station of the Center of Agricultural Sciences, Debrecen University, between 1990 and 2004. Annual yield fluctuation is primarily determined by the soil moisture content in the month of July and the water supplies in May, according to regression analysis. The maize yields in the past 15 years could be calculated with an accuracy of 570 kg/ha, an error limit of below 10% and an r value of 0.805, using a regression line and the data of monthly moisture supplies. However, the yields of fertilized plots can only be estimated with an accuracy of 1 t/ha on average. Fertilizer utilization is influenced by the moisture content of the soil, so it makes sense to include this in the analysis instead of the other environmental factors. Water is required for nutrient utilization. In years with poor or medium water supplies, moderate fertilizer rates are more effective, compared to higher rates in years with better water supplies. Efficient fertilization in maize production can only be achieved by harmonizing soil moisture content and the applied fertilizer rate.

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