A model for soil moisture content prediction based on the change in ultrasonic velocity and bulk density of tillage soil under alternating drying and wetting conditions

Measurement ◽  
2021 ◽  
pp. 110504
Author(s):  
Limin Pan ◽  
Yingyi Chen ◽  
Yan Xu ◽  
Jun Li ◽  
Huazhong Lu
Author(s):  
Y. A. Unguwanrimi ◽  
A. M. Sada ◽  
G. N. Ugama ◽  
H. S. Garuba ◽  
A. Ugoani

Draft requirements of two animal – drawn (IAR) weeders operating on loam soil were determined in the study. The implements include a straddle row weeder and an emcot attached rotary weeder evaluated under the same soil conditions, using a pair of white Fulani breed of oxen. The animal draft requirement was first estimated from the animal ergonomics measurements. Using area of 0.054 hectare as experimental plot for each implement the draft requirement of each implement was investigated after taking soil samples for soil moisture content and bulk density determinations. The implements tested showed variation in their average draft requirement. The straddle row weeder had the highest value of 338.15 N respectively while the emcot attached rotary weeder had the lowest value of 188.12 N with 47.03%, respectively. The average soil moisture contents and bulk density were 13.0% and 1.46%/cm3, respectively.


2020 ◽  
Vol 77 (2) ◽  
Author(s):  
Jori Uusitalo ◽  
Jari Ala-Ilomäki ◽  
Harri Lindeman ◽  
Jenny Toivio ◽  
Matti Siren

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.


2015 ◽  
Vol 24 (3) ◽  
pp. e038 ◽  
Author(s):  
Michal Allman ◽  
Martin Jankovský ◽  
Valéria Messingerová ◽  
Zuzana Allmanová ◽  
Michal Ferenčík

<p><em>Aim of study: </em>The primary objective of this paper was to compare the effects of different types of forestry machine chassis on the compaction of the top layers of soil and to define the soil moisture content level, at which machine traffic results in maximum compaction.</p><p><em>Area of study:</em> Measurements were conducted in eight forest stands located in Slovakia and the Czech Republic. The soil types in the stands subjected to the study were luvisols, stagnosols, cambisols, and rendzinas.</p><p><em>Material and Methods:</em> The measurements were focused on tracked and wheeled (equipped with low pressure tyres) cut-to-length machines, and skidders equipped with wide and standard tyres. The bulk density of soil was determined from soil samples extracted from the ruts, the centre of the skid trail, and the undisturbed stand. To determine soil moisture content, at which the soil is the most susceptible to compaction, the Proctor standard test was employed.</p><p><em>Main results:</em> The moisture content for maximal compaction fluctuated from 12% to 34.06%. Wheeled machines compacted the soil to 1.24 – 1.36 g.cm<sup>-3</sup> (30.3 – 35.4 % compaction) in dried state. Bulk density of soil in stands where tracked machine operated was lower, ranging from 1.02 to 1.06 g.cm<sup>-3</sup> (25.3 % compaction).</p><p><em>Research highlights:</em> All wheeled machines caused the same amount of soil compaction in the ruts, despite differences in tyres, machine weight, etc. Maximum compaction caused by forestry machines occurred at minimal moisture contents, easily achievable in European climatic conditions.  </p><p><strong>Keywords:</strong> soil compaction; bulk density; soil moisture content limits; cut-to-length machines; skidders.</p>


Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1289
Author(s):  
Zuzana Dudáková (Allmanová) ◽  
Michal Allman ◽  
Ján Merganič ◽  
Katarína Merganičová

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.


2020 ◽  
Vol 12 (19) ◽  
pp. 8238
Author(s):  
Jibing Xiong ◽  
Runhua Yu ◽  
Ejazul Islam ◽  
Fuhai Zhu ◽  
Jianfeng Zha ◽  
...  

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.


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