Fluidized-bed: As an alternative method for rill erodibility modeling

2020 ◽  
Author(s):  
Selen Deviren Saygin ◽  
Fikret Ari ◽  
Cagla Temiz ◽  
Sefika Arslan ◽  
Mehmet Altay Unal ◽  
...  
Keyword(s):  
Soil Properties ◽  
Flow Velocity ◽  
Fluidized Bed ◽  
Soil Types ◽  
Soil Conditions ◽  
Data Sets ◽  
Flume Experiments ◽  
Concentrated Flow ◽  
Erosion Prediction ◽  
Moisture Conditions

<p>Rill erodibility (Kr), which is a measure of the resistance of soil particles against disintegration in a rill under concentrated flow conditions, is a significant characteristic for rill initiation in a field.  The Process-based WEPP (Water Erosion Prediction Project) originally models Kr by linear excess shear stress (τ), and it is mostly obtained from mini-flume experiments at laboratory conditions. Alternatively, a critical value of flow stress (τ<sub>cr</sub>) that points to fragmentation in rills can be modeled by a fluidized bed approach that quantifies the conditions in terms of cohesion (Co) and flow velocity (V<sub>f</sub>) by considering the soil as a cohesive material. In there, the water as a fluid applies pressure on solid particle proportional to flow rate of the fluid (v). But, performed related studies on it were mostly tested for the limited soil types. The objectives of this study were to test these relationships and model the rill characteristic for the heavy textures of different soil types and investigate the role of basic soil properties on rill initiation. Experimental results showed that the stronger regression coefficient (R<sup>2</sup>=0.78) was found between Kr and flow velocity (V<sub>f</sub>) monitored at the fluidization stage than that between Co & τ<sub>cr</sub> at the studied soil conditions. However, correlations between constant and dynamic soil properties and the measured Kr, τ<sub>cr</sub>, Co and V<sub>f</sub> values were also quite remarkable (p<0.01) for next-generation modeling studies in terms of rill dynamics. It is believed that the fluidized-bed approach has a great potential to model Kr and encouragingly it is worth to be tested with wider data-sets under different soil-moisture conditions.</p><p><strong>Keywords:</strong> Rill erodibility, Soil Cohesion, Fluidized bed approach, WEPP</p>

scholarly journals PENGARUH PENGGUNAAN KOLOM PASIR, LAYER PASIR, DAN TERUCUK BAMBU PADA TANAH LEMPUNG JENUH AIR TERHADAP PENURUNAN TANAH LEMPUNG MENGGUNAKAN UJI LABORATORIUM

2020 ◽  
Vol 16 (1) ◽  
pp. 64-73
Author(s):  
Dian Eksana Wibowo ◽  
Satriarda Dirgantara S. ◽  
Ridwan Kurniawan
Keyword(s):  
Moisture Content ◽  
Soil Properties ◽  
Water Content ◽  
Clay Soil ◽  
Soil Types ◽  
Soil Conditions ◽  
High Plasticity ◽  
Consolidation Process ◽  
Water Saturated ◽  
Effective Use

ABSTRAKPenelitian ini bertujuan untuk mengetahui klasifikasi jenis tanah, properti tanah pengujian dan pengaruh penggunaan metode penambahan variasi tanah lempung jenuh air dengan menggunakan pasir dan cerucuk bambu, terhadap penurunan tanah lempung, kadar air, dan analisis T90. Penelitian eksperimen dengan menggunakan model boks baja, berukuran 100 cm x 100 cm x 40 cm sebagai media penempatan tanah lempung. Hasil penelitian ini yaitu: (1) Jenis tanah termasuk CH (Clay High Plasticity) menurut klasifikasi USCS dan kelompok 4-7-6(40) menurut klasifikasi AASTHO. (2) Properti tanah adalah G=2,63, LL=74,71%, PL=29,76%, IP=44,95%, SL=19,06%, C=0,75 kg/cm2, OMC=39,2%. (3)  Penambahan TPV sangat efektif memperkecil penurunan. Pada pemberian tekanan 0,0125 kg/cm2, 0,025 kg/cm2, 0,05 kg/cm2, dan 0,01 kg/cm2 memperkecil penurunan, berturut-turut: 75,93%; 56,32%; 59,44% dan 42,32%. Pada kedalaman -10 cm penggunaan TPH paling efektif mengurangi kadar air tanah lempung  yaitu sebesar 53,30%, berarti mengurangi kadar air sebesar 3,62% dari kondisi tanah asli (TTD). Pada kedalaman 20 cm, penggunaan TCB paling efektif mengurangi kadar air sebesar 3,55% dari kadar air tanah lempung asli (TTD). Penggunaan CTPVH pada beban 0,1 kg/cm2 paling efektif dalam proses konsolidasi yaitu sebesar 94,10% dari tanah asli (TTD) dimana mempunyai nilai sebesar nilai t90 untuk CTPVH yaitu sebesar 15,21 menit. Kata Kunci: air, perkuatan, tanah lempung, T90  ABSTRACT This study aims to determine the classification of soil types, soil properties tested and the effect of using the method of adding variations in the water-saturated clay, using sand and bamboo piles, to clay settlement, moisture content, and T90 analysis. The experimental study used a steel box model, measuring 100 cm x 100 cm x 40 cm as a medium for clay placement. The results of this study are: (1) Soil types including CH (Clay High Plasticity) according to USCS classification and groups 4-7-6 (40) according to AASTHO classification. (2) Soil properties is G=2,63, LL=74,71%, PL=29,76%, IP=44,95%, SL=19,06%, C=0,75 kg/cm2, OMC=39,2%. (3) Addition of TPV is very effective in reducing the settlement. At a pressure of 0,0125 kg/cm2, 0,025 kg/cm2, 0,05 kg/cm2, and 0.01 kg/cm2 minimizing the settlement,  respectively: 75,93%; 56,32%; 59,44% and 42,32%. At depths of -10 cm the most effective use of TPH reduces clay soil moisture content by 53,30%, which means reducing water content by 3,62% from the original soil conditions (TTD). At a depth of 20 cm, using TCB is most effective at reducing water content by 3,55% from the original clay soil content (TTD). The use of CTPVH at a load of 0,1 kg/cm2 is most effective in the consolidation process which is 94.10% of the original soil (TTD) which has a value of T90 for CTPVH which is 15,21 minutes. Keywors: water, strainthening, clay, T90

scholarly journals Biochar Improves Maize Growth but Has a Limited Effect on Soil Properties: Evidence from a Three-Year Field Experiment

2021 ◽  
Vol 13 (7) ◽  
pp. 3617
Author(s):  
Agnieszka Medyńska-Juraszek ◽  
Agnieszka Latawiec ◽  
Jolanta Królczyk ◽  
Adam Bogacz ◽  
Dorota Kawałko ◽  
...  
Keyword(s):  
Low Temperature ◽  
Field Experiment ◽  
Soil Properties ◽  
High Efficiency ◽  
Crop Yields ◽  
Temperate Climate ◽  
Soil Conditions ◽  
Maize Growth ◽  
Chemical Soil ◽  
Physical And Chemical

Biochar application is reported as a method for improving physical and chemical soil properties, with a still questionable impact on the crop yields and quality. Plant productivity can be affected by biochar properties and soil conditions. High efficiency of biochar application was reported many times for plant cultivation in tropical and arid climates; however, the knowledge of how the biochar affects soils in temperate climate zones exhibiting different properties is still limited. Therefore, a three-year-long field experiment was conducted on a loamy Haplic Luvisol, a common arable soil in Central Europe, to extend the laboratory-scale experiments on biochar effectiveness. A low-temperature pinewood biochar was applied at the rate of 50 t h−1, and maize was selected as a tested crop. Biochar application did not significantly impact the chemical soil properties and fertility of tested soil. However, biochar improved soil physical properties and water retention, reducing plant water stress during hot dry summers, and thus resulting in better maize growth and higher yields. Limited influence of the low-temperature biochar on soil properties suggests the crucial importance of biochar-production technology and biochar properties on the effectiveness and validity of its application in agriculture.

scholarly journals Bacillus amyloliquefaciens FH-1 significantly affects cucumber seedlings and the rhizosphere bacterial community but not soil

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jingjing Wang ◽  
Song Xu ◽  
Rong Yang ◽  
Wei Zhao ◽  
Dan Zhu ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Soil Properties ◽  
Bacillus Amyloliquefaciens ◽  
Soil Conditions ◽  
Plant Growth Promoting Bacteria ◽  
Linear Discriminant ◽  
Cucumber Seedlings ◽  
Ecological Roles ◽  
Plant Growth Promoting ◽  
Rhizosphere Bacterial Community

AbstractPlant growth-promoting bacteria (PGPB) inoculants have been applied worldwide. However, the ecological roles of PGPB under different soil conditions are still not well understood. The present study aimed to explore the ecological roles of Bacillus amyloliquefaciens FH-1 (FH) on cucumber seedlings, rhizosphere soil properties, and the bacterial community in pot experiments. The results showed that FH had significant effects on cucumber seedlings and the rhizosphere bacterial community but not on soil properties. The FH promoted cucumber seedlings growth, reduced the rhizosphere bacterial diversity, increased Proteobacteria, and decreased Acidobacteria. Linear discriminant analysis (LDA) effect size (LEfSe) revealed that FH enriched two taxa (GKS2_174 and Nannocystaceae) and inhibited 18 taxa (mainly Acidobacteria, Actinobacteria, BRC1, Chloroflexi, Plantctomycetes, and Verrucomicrobia). Co-occurrence network analysis demonstrated that FH increased bacteria-bacteria interactions and that Bacillus (genus of FH) had few interactions with the enriched and inhibited taxa. This might indicate that FH does not directly affect the enriched and inhibited taxa. Correlation analysis results displayed that cucumber seedlings’ weight and height/length (except root length) were significantly correlated with the 18 inhibited taxa and the enriched taxa Nannocystaceae. It was speculated that FH might promote cucumber seedling growth by indirectly enriching Nannocystaceae and inhibiting some taxa from Acidobacteria, Actinobacteria, BRC1, Chloroflexi, Plantctomycetes, and Verrucomicrobia.

scholarly journals Effects of glyphosate-based herbicides and their active ingredients on earthworms, water infiltration and glyphosate leaching are influenced by soil properties

2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Johann G. Zaller ◽  
Maureen Weber ◽  
Michael Maderthaner ◽  
Edith Gruber ◽  
Eszter Takács ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Properties ◽  
Weed Control ◽  
Amaranthus Retroflexus ◽  
Water Infiltration ◽  
Soil Conditions ◽  
Soil Functions ◽  
Active Ingredients ◽  
Hand Weeding ◽  
Earthworm Activity

Abstract Background Glyphosate-based herbicides (GBHs) are among the most often used pesticides. The hundreds of GBHs used worldwide consist of the active ingredient (AI) glyphosate in form of different salts, possibly other AIs, and various mostly undisclosed co-formulants. Pesticide risk assessments are commonly performed using single AIs or GBHs at standard soil conditions without vegetation. In a greenhouse experiment, we established a weed population with common amaranth (Amaranthus retroflexus) to examine the effects of three GBHs (Roundup LB Plus, Roundup PowerFlex, Touchdown Quattro) and their corresponding AIs (salts of glyphosate isopropylammonium, potassium, diammonium) on the activity and physiological biomarkers (glutathione S-transferase, GST; acetylcholine esterase, AChE) of an ecologically relevant earthworm species (Lumbricus terrestris). GBHs and AIs were applied at recommended doses; hand weeding served as control. Experiments were established with two soil types differing in organic matter content (SOM; 3.0% vs. 4.1%) and other properties. Results Earthworm activity (casting and movement activity) decreased after application of glyphosate formulations or active ingredients compared to hand weeding. We found no consistent pattern that formulations had either higher or lower effects on earthworm activity than their active ingredients; rather, differences were substance-specific. Earthworm activity was little affected by soil organic matter levels. Biomarkers remained unaffected by weed control types; GST but not AChE was decreased under high SOM. Water infiltration after a simulated heavy rainfall was interactively affected by weed control types and SOM. Leachate amount was higher after application of formulations than active ingredients and was higher under low SOM. Glyphosate concentrations in soil and leachate were strongly affected by application of formulations or active ingredients and varied with SOM (significant weed control type x SOM interaction). Conclusions We found that both commercial formulations and pure active ingredients can influence earthworms with consequences on important soil functions. Glyphosate products showed increased, reduced or similar effects than pure glyphosate on particular soil functions; soil properties can substantially alter this. Especially at lower SOM, heavy rainfalls could lead to more glyphosate leaching into water bodies. A full disclosure of co-formulants would be necessary to further decipher their specific contributions to these inconsistent effects.

scholarly journals Interactive coupling of regional atmosphere with biosphere in the new generation regional climate system model REMO-iMOVE

2014 ◽  
Vol 7 (3) ◽  
pp. 1093-1114 ◽  
Author(s):  
C. Wilhelm ◽  
D. Rechid ◽  
D. Jacob
Keyword(s):  
Land Surface ◽  
Regional Climate ◽  
Regional Model ◽  
Horizontal Resolution ◽  
Soil Conditions ◽  
Data Sets ◽  
Vegetation Phenology ◽  
Land Surface Scheme ◽  
New Model ◽  
Surface Scheme

Abstract. The main objective of this study is the coupling of the regional climate model REMO with a new land surface scheme including dynamic vegetation phenology, and the evaluation of the new model version called REMO with interactive MOsaic-based VEgetation: REMO-iMOVE. First, we focus on the documentation of the technical aspects of the new model constituents and the coupling mechanism. The representation of vegetation in iMOVE is based on plant functional types (PFTs). Their geographical distribution is prescribed to the model which can be derived from different land surface data sets. Here, the PFT distribution is derived from the GLOBCOVER 2000 data set which is available on 1 km × 1 km horizontal resolution. Plant physiological processes like photosynthesis, respiration and transpiration are incorporated into the model. The vegetation modules are fully coupled to atmosphere and soil. In this way, plant physiological activity is directly driven by atmospheric and soil conditions at the model time step (two minutes to some seconds). In turn, the vegetation processes and properties influence the exchange of substances, energy and momentum between land and atmosphere. With the new coupled regional model system, dynamic feedbacks between vegetation, soil and atmosphere are represented at regional to local scale. In the evaluation part, we compare simulation results of REMO-iMOVE and of the reference version REMO2009 to multiple observation data sets of temperature, precipitation, latent heat flux, leaf area index and net primary production, in order to investigate the sensitivity of the regional model to the new land surface scheme and to evaluate the performance of both model versions. Simulations for the regional model domain Europe on a horizontal resolution of 0.44° had been carried out for the time period 1995–2005, forced with ECMWF ERA-Interim reanalyses data as lateral boundary conditions. REMO-iMOVE is able to simulate the European climate with the same quality as the parent model REMO2009. Differences in near-surface climate parameters can be restricted to some regions and are mainly related to the new representation of vegetation phenology. The seasonal and interannual variations in growth and senescence of vegetation are captured by the model. The net primary productivity lies in the range of observed values for most European regions. This study reveals the need for implementing vertical soil water dynamics in order to differentiate the access of plants to water due to different rooting depths. This gets especially important if the model will be used in dynamic vegetation studies.

scholarly journals Using Multivariate Geostatistics to Assess Patterns of Spatial Dependence of Apparent Soil Electrical Conductivity and Selected Soil Properties

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Glécio Machado Siqueira ◽  
Jorge Dafonte Dafonte ◽  
Montserrat Valcárcel Armesto ◽  
Ênio Farias França e Silva
Keyword(s):  
Electrical Conductivity ◽  
Soil Properties ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Clay Content ◽  
Data Sets ◽  
Soil Electrical Conductivity ◽  
Multivariate Geostatistics ◽  
Northwestern Spain

The apparent soil electrical conductivity (ECa) was continuously recorded in three successive dates using electromagnetic induction in horizontal (ECa-H) and vertical (ECa-V) dipole modes at a 6 ha plot located in Northwestern Spain. One of the ECadata sets was used to devise an optimized sampling scheme consisting of 40 points. Soil was sampled at the 0.0–0.3 m depth, in these 40 points, and analyzed for sand, silt, and clay content; gravimetric water content; and electrical conductivity of saturated soil paste. Coefficients of correlation between ECaand gravimetric soil water content (0.685 for ECa-V and 0.649 for ECa-H) were higher than those between ECaand clay content (ranging from 0.197 to 0.495, when different ECarecording dates were taken into account). Ordinary and universal kriging have been used to assess the patterns of spatial variability of the ECadata sets recorded at successive dates and the analyzed soil properties. Ordinary and universal cokriging methods have improved the estimation of gravimetric soil water content using the data of ECaas secondary variable with respect to the use of ordinary kriging.

Opener, packer wheel and packing force effects on crop emergence and yield of direct seeded wheat, canola and field peas

2003 ◽  
Vol 83 (1) ◽  
pp. 129-139 ◽  
Author(s):  
A. M. Johnston ◽  
G. P. Lafond ◽  
W. E. May ◽  
G. L. Hnatowich ◽  
G. E. Hultgreen
Keyword(s):  
Grain Yield ◽  
Environmental Conditions ◽  
Direct Seeding ◽  
Soil Conditions ◽  
High Soil Moisture ◽  
Pea Seedlings ◽  
Field Peas ◽  
Furrow Opener ◽  
Direct Seeded ◽  
Moisture Conditions

An understanding of the effects of different opener designs and on-row packing force would help producers in their selection of appropriate direct seeding implement options for their soil conditions. A field trial was conducted at three locations (Indian Head, Sylvania and Watrous) in Saskatchewan from 1997 to 1999 to evaluate the effect of opener-packer design (spoon-steel V packer; spoon-flat rubber packer; paired row-steel V packer; paired row-flat rubber packer; sweep-pneumatic tire) in combination with a range of on-row packing forces [0, 333, 549, 746, and 1000 Newton (N) per press wheel] on crop emergence and grain yield with direct seeding. The differences observed between opener-packer combinations in this study varied by less than 10% for grain yield, and were almost always associated with the opener design and not the packer type. Despite the variable results, there was a tendency for higher pea and wheat emergence with the sweep + tire compared with other opener types at those locations that tended to be drier in the spring. Also, grain yield tended to be greater for the sweep + tire in 1999 at Indian Head, when the heavy-textured soil at this site had high soil moisture conditions at seeding. The responses to packing force varied with different years and among the crops. Generally, 333 N per press wheel provided adequate emergence and grain yield across the environmental conditions encountered in this study, regardless of the opener-packer combination. In 1997, 5% more pea seedlings emerged with some amount of packing compared with no packing. Relative to the check, some packing resulted in wheat grain yield that was 13% greater at three of the location-by-year combinations, and wheat emergence that was 9% greater in 1998. However, with canola excessive packing force (i.e., the two highest vs. lower packing forces) resulted in 11 fewer seedlings m-2 in 1999. A packing pressure of 333 N per press wheel provided adequate emergence and grain yield across varied environmental conditions, with higher packing force only negatively influencing emergence in canola, and not yield. Key words: Furrow opener, packing force, emergence, direct seeding, zero till

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