scholarly journals Influence of Saturated Organic Matter on the Accuracy of In-Situ Measurements Recorded with a Nuclear Moisture and Density Gauge

2021 ◽  
Vol 42 (2) ◽  
Author(s):  
Eric R. Labelle ◽  
Dirk Jaeger
Keyword(s):  
Organic Matter ◽  
Soil Moisture ◽  
Moisture Content ◽  
Bulk Density ◽  
Forest Soils ◽  
Mineral Soil ◽  
Soil Bulk Density ◽  
Organic Layer ◽  
Correction Factors ◽  
Non Destructive

The impact of machines on forest soils is regularly assessed and quantified using absolute bulk density, which is most frequently obtained by soil cores. However, to allow for repeated measurements at the exact same locations, non-destructive devices are increasingly being used to determine soil bulk density and moisture content in field studies. An example of such a device is a nuclear moisture and density gauge (NMDG), originally designed as a control measurement for soil bulk density and moisture content in geotechnical applications. Unlike road construction or foundation projects that use mineral soil or gravel, forest soils have complex structures and the presence of organic matter, which can skew moisture and density readings from a NMDG. To gain further knowledge in this respect, we performed controlled tests in a sandbox to quantify the influence of varying amounts of saturated organic matter (3, 5, 10, and 15%) mixed with mineral soil in different layers (0–5, 0–10, 0–20 and 0–40 cm) on the accuracy of soil moisture content obtained by a NMDG and soil theta probe at varying depths. Main results illustrated that the presence of saturated organic matter per se was not problematic but moisture content overestimations and related underestimation of dry bulk density occurred when the tested measurement depth was below the created organic layer. Since forest soils often exhibit higher organic matter contents in the upper horizon, correction factors are suggested to minimize the moisture content variations between NMDG and reference method. With the use of correction factors, NMDG can present a non-destructive, fast, and accurate method of measuring soil moisture and bulk density in forestry applications.

scholarly journals Predicting rut depth induced by an 8-wheeled forwarder in fine-grained boreal forest soils

2020 ◽  
Vol 77 (2) ◽  
Author(s):  
Jori Uusitalo ◽  
Jari Ala-Ilomäki ◽  
Harri Lindeman ◽  
Jenny Toivio ◽  
Matti Siren
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Bulk Density ◽  
Soil Moisture Content ◽  
Mineral Soil ◽  
Coarse Grained ◽  
Forest Operations ◽  
Fine Grained ◽  
Humus Layer ◽  
Cumulative Mass

Abstract Key message Rut depth in fine-grained boreal soils induced by an 8-wheeled forwarder is best predicted with soil moisture content, cumulative mass of machine passes, bulk density and thickness of the humus layer. Context Forest machines are today very heavy and will cause serious damage to soil and prevent future growth if forest operations are carried out at the wrong time of the year. Forest operations performed during the wettest season should therefore be directed at coarse-grained soils that are not as prone to soil damage. Aims The study aimed at investigating the significance of the most important soil characteristics on rutting and developing models that can be utilized in predicting rutting prior to forest operations. Methods A set of wheeling tests on two fine-grained mineral soil stands in Southern Finland were performed. The wheeling experiments were conducted in three different periods of autumn in order to get the largest possible variation in moisture content. The test drives were carried out with an 8-wheeled forwarder. Results Soil moisture content is the most important factor affecting rut depth. Rut depth of an 8-wheeled forwarder in fine-grained boreal soil is best predicted with soil moisture content, cumulative mass of machine passes, bulk density and thickness of the humus layer. Conclusion The results emphasize the importance of moisture content on the risk of rutting in fine-grained mineral soils, especially with high moisture content values when soil saturation reaches 80%. The results indicate that it is of high importance that soil type and soil wetness can be predicted prior to forest operations.

scholarly journals Aspen and white spruce productivity is reduced by organic matter removal and soil compaction

2012 ◽  
Vol 88 (03) ◽  
pp. 306-316 ◽  
Author(s):  
Richard Kabzems
Keyword(s):  
Organic Matter ◽  
Soil Properties ◽  
Bulk Density ◽  
Soil Compaction ◽  
Forest Floor ◽  
Mineral Soil ◽  
White Spruce ◽  
Soil Bulk Density ◽  
Post Treatment ◽  
Organic Matter Removal

Declines in forest productivity have been linked to losses of organic matter and soil porosity. To assess how removal of organic matter and soil compaction affect short-term ecosystem dynamics, pre-treatment and year 1, 5 and 10 post-treatment soil properties and post-treatment plant community responses were examined in a boreal trembling aspen (Populus tremuloidesMichx.)-dominated ecosystem in northeastern British Columbia. The experiment used a completely randomized design with three levels of organic matter removal (tree stems only; stems and slash; stems, slash and forest floor) and three levels of soil compaction (none, intermediate [2-cm impression], heavy [5-cm impression]). Removal of the forest floor initially stimulated aspen regeneration and significantly reduced height growth of aspen (198 cm compared to 472–480 cm) as well as white spruce (Picea glauca [Moench] Voss) height (82 cm compared to 154–156 cm). The compaction treatments had no effect on aspen regeneration density. At Year 10, heights of both aspen and white spruce were negatively correlated with upper mineral soil bulk density and were lowest on forest floor + whole tree removal treatments. Recovery of soil properties was occurring in the 0 cm to 2 cm layer of mineral soil. Bulk density values for the 0 cm to 10 cm depth remained above 86% of the maximum bulk density for the site, a soil condition where reduced tree growth can be expected.

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 Carbon, nitrogen, and phosphorus stoichiometry of organic matter in Swedish forest soils and its relationship with climate, tree species, and soil texture

2021 ◽  
Author(s):  
Marie Spohn ◽  
Johan Stendahl
Keyword(s):  
Organic Matter ◽  
Boreal Forest ◽  
Forest Soils ◽  
Soil Texture ◽  
Tree Species ◽  
Mineral Soil ◽  
Stand Age ◽  
Organic Layer ◽  
Mean Annual Temperature ◽  
P Concentration

Abstract. While the carbon (C) content of temperate and boreal forest soils is relatively well studied, much less is known about the ratios of C, nitrogen (N), and phosphorus (P) of the soil organic matter, and the abiotic and biotic factors that shape them. Therefore, the aim of this study was to explore carbon, nitrogen, and organic phosphorus (OP) contents and element ratios in temperate and boreal forest soils and their relationships with climate, dominant tree species, and soil texture. For this purpose, we studied 309 forest soils with a stand age >60 years located all over Sweden between 56° N and 68° N. The soils are a representative subsample of Swedish forest soils with a stand age >60 years that were sampled for the Swedish Forest Soil Inventory. We found that the N stock of the organic layer increased by a factor of 7.5 from −2 °C to 7.5 °C mean annual temperature (MAT), it increased almost twice as much as the organic layer stock along the MAT gradient. The increase in the N stock went along with an increase in the N : P ratio of the organic layer by a factor of 2.1 from −2 °C to 7.5 °C MAT (R2 = 0.36, p < 0.001). Forests dominated by pine had higher C : N ratios in the litter layer and mineral soil down to a depth of 65 cm than forests dominated by other tree species. Further, also the C : P ratio was increased in the pine-dominated forests compared to forests dominated by other tree species in the organic layer, but the C : OP ratio in the mineral soil was not elevated in pine forests. C, N and OP contents in the mineral soil were higher in fine-textured soils than in coarse-textured soils by a factor of 2.3, 3.5, and 4.6, respectively. Thus, the effect of texture was stronger on OP than on N and C, likely because OP adsorbs very rigidly to mineral surfaces. Further, we found, that the P and K concentrations of the organic layer were inversely related with the organic layer stock. The C and N concentrations of the mineral soil were best predicted by the combination of MAT, texture, and tree species, whereas the OP concentration was best predicted by the combination of MAT, texture and the P concentration of the parent material in the mineral soil. In the organic layer, the P concentration was best predicted by the organic layer stock. Taken together, the results show that the N : P ratio of the organic layer was most strongly related to MAT. Further, the C : N ratio was most strongly related to dominant tree species, even in the mineral subsoil. In contrast, the C : P ratio was only affected by dominant tree species in the organic layer, but the C : OP ratio in the mineral soil was hardly affected by tree species due to the strong effect of soil texture on the OP concentration.

scholarly journals Simulation of the long-term carbon and nitrogen dynamics in Dutch forest soils under Scots pine

1998 ◽  
Vol 2 (4) ◽  
pp. 439-449 ◽  
Author(s):  
B.-J. Groenenberg ◽  
W. de Vries ◽  
H. Kros
Keyword(s):  
Organic Matter ◽  
Scots Pine ◽  
Forest Soils ◽  
Mineral Soil ◽  
Root Turnover ◽  
Organic Layer ◽  
Transformation Rate ◽  
Organic Layers ◽  
Pine Stands ◽  
Scots Pine Stands

Abstract. Dynamics of C and N in forest soils in the Nutrient Cycling and Soil Acidification Model (NUCSAM) are described by the transformation and decomposition of three organic matter compartments, litter, fermented material and humic material. These three compartments are allocated to the morphological distinguishable L, F and H horizons of the organic layer. Changes in the pools of these organic compartments are described with first order equations for decomposition and transformation. Rate constants for decomposition and transformation were derived by calibrating the model to measured organic matter pools in organic layers of a chrono-sequence of five first succession Scots pine stands between 15 and 120 years old. Simulated pools of organic matter in the organic layers were in agreement with measured pools in the five pine stands, except for the first thirty years of the H-horizon. During this period, an increase in organic matter in the H horizon was simulated while no H horizons were observed in the field. The simulated total pool of organic matter in the organic layer agreed well with values from a field inventory in 20 other Scots pine stands, but the simulated distribution over the three horizons differed from the field measurements which varied among sites. For the Scots pine stands the model was able to simulate the organic matter accumulation in the top 40-cm of the mineral soil; derived almost completely from fine root turnover. The accumulated pool of nitrogen in the organic layer was in agreement with measured pools for the oldest Scots pine stand but was too high for the younger stands. Especially, the accumulation of N in the F-horizon was too fast, presumably due to an overestimated retention of nitrogen.

scholarly journals Data Grouping Method for the Purpose of Forecasting the Mechanical Strength of Plastic Soils

Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 578
Author(s):  
Dariusz Błażejczak ◽  
Jan Jurga ◽  
Jarosław Pytka
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Bulk Density ◽  
Field Measurements ◽  
Penetration Resistance ◽  
Soil Bulk Density ◽  
Regression Equations ◽  
Soil Penetration Resistance ◽  
Small Set ◽  
Data Grouping

The aim of this work was to develop a method of data grouping (DGM) that enables the selection of regression equations for forecasting soil penetration resistance based on an easily available and small set of input data: soil moisture content, soil bulk density and the grain size distribution of the soil. Models for forecasting the penetration resistance were created by selecting regression equations for specific intervals of granulometric variability of soil fractions. A field measurements campaign was conducted and soil samples were taken from the subsoil on 43 profiles, at depths of 25–30, 35–40, 45–50 and 55–60 cm. It was found that the dry bulk density is much less useful for predicting the penetration resistance of plastic soils than soil moisture. The study also showed that it is possible to forecast the soil penetration resistance on the basis of the gravimetric moisture content and the soil specific surface.

scholarly journals Effect of Biochar on Soil Temperature under High Soil Surface Temperature in Coal Mined Arid and Semiarid Regions

2020 ◽  
Vol 12 (19) ◽  
pp. 8238
Author(s):  
Jibing Xiong ◽  
Runhua Yu ◽  
Ejazul Islam ◽  
Fuhai Zhu ◽  
Jianfeng Zha ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Surface Temperature ◽  
Soil Temperature ◽  
Bulk Density ◽  
Soil Moisture Content ◽  
Soil Surface ◽  
Soil Bulk Density ◽  
High Soil ◽  
Soil Surface Temperature

High soil surface temperature and loosened soil are major limiting factors of plant productivity in arid and semi-arid coal mining areas of China. Moreover, the extensive and illegitimate burning of crop residues is causing environmental pollution; whereas, these residues could be converted to biochar to benefit soil quality. In this study, the effect of wheat straw biochar (WSB) at rates of 0% (control, CK), 1% (low, LB), 2% (medium, MB) and 4% (high, HB) on soil temperature at different depths (5, 10, 15, and 20 cm) and moisture levels (10 and 20%) was investigated under high soil surface temperature of 50 °C and air humidity of 40%. Our data suggested that soil bulk density was inversely, and soil moisture was directly corelated with soil thermal parameters. Moreover, the increasing rate of WSB addition linearly decreased the soil thermal properties. The maximum decrease in soil bulk density at both moisture levels (10% and 20%) was measured in HB treatment compared to respective CKs. The highest decrease in soil thermal conductivity (59.8% and 24.7%) was found under HB treatment in comparison to respective controls (CK10% and CK20% moisture). The soil volumetric heat capacity was also strongly corelated with soil moisture content (r = 0.91). The WSB treatments displayed differential responses to soil temperature. Under 10% soil moisture, temperature of LB, MB and HB treatments was higher as compared to CK at 5–20 cm depth, and MB treated soil had the smallest increase in temperature. At the 15-cm depth, the MB treatment decreased the temperature by 0.93 °C as compared to the CK20%. Therefore, the effect of WSB on soil temperature was influenced by soil moisture content, soil depth and WSB application rates. It suggested that MB treatment could be a useful farming practice for mitigating soil temperature fluctuation.

Production of surface casts by the earthworm Eisenia rosea

1974 ◽  
Vol 52 (5) ◽  
pp. 659-659 ◽  
Author(s):  
A. J. Thomson ◽  
D. M. Davies
Keyword(s):  
Organic Matter ◽  
Soil Moisture ◽  
Bulk Density ◽  
Soil Bulk Density ◽  
Fine Silt ◽  
First Time

Eisenia rosea was shown to produce surface casts for the first time. The number increased with soil bulk density, organic matter, and fine silt particles. Soil moisture had little effect.

scholarly journals Influence of soil physical factors on productivity of herbaceous forage species in Kivaa and Ntugi rangelands in Eastern Kenya

2020 ◽  
Vol 1 (1) ◽  
pp. 17-24
Author(s):  
E. Karugia ◽  
F. Kariuki ◽  
J. Mwaniki
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Bulk Density ◽  
Soil Texture ◽  
Soil Bulk Density ◽  
Cyperus Rotundus ◽  
Grass Species ◽  
Physical Factors ◽  
Forage Species ◽  
Experimental Plots

Rangelands are extensive tracts of land with natural vegetation which is the main forage resource for domestic and wild ungulates. This study investigated the influence of soil texture, bulk density, and moisture content on the production of herbaceous forage species biomass in Kivaa and Ntugi rangelands in Eastern Kenya. Stratified random sampling was used where one out of four blocks of the target rangelands was picked and three belt transects established. Along the belt transects, ten experimental plots of 5 metres by 5 metres were established at intervals of 5 metres. Key forage species were identified using a structured questionnaire administered to key informants. Soil samples were collected from the experimental plots and analyzed for soil texture, bulk density and moisture content. Forage samples were collected and dry matter weight determined. The data collected were analyzed using both descriptive and inferential statistics especially tabulation and regression respectively. The study identified the most valuable forage species namely, Dichanthium annulatum, Themeda triandra, Cenchrus ciliaris, Rhynchelytrum repens, Digitaria abyssinica, Chloris roxburghiana and Cyperus rotundus. Soils in Ntugi ranged from clay loam to sandy clay while those from Kivaa ranged from silty loam to sandy loam. There was higher moisture content in soils in Ntugi than soils in Kivaa (t = 7.71, P ≤ 0.05). Soil moisture content had significant influence on herbage production in both Kivaa (R= 0.968, P ≤ 0.05) and Ntugi (R = 0.962, P ≤ 0.05). Soil bulk density significantly influenced forage grass species herbage production in Ntugi in 2014 (R= 0.513, P ≤ 0.05) and in 2016 ((R = 0.632, P ≤ 0.05). This study concluded that soil texture, bulk density and moisture content significantly influenced herbaceous forage production in the two rangelands. The study recommends use of rotational grazing systems combined with proper stocking rates to maintain moderate soil bulk density and good levels of soil moisture for the herbaceous forage species to continue producing adequate biomass while maintaining residual foliage for continued primary production.

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