scholarly journals Nicodrilus nocturnus and Allolobophora icterica drill compacted soils but do not decrease their bulk density – A laboratory experiment using two contrasted soils at two different compaction levels

Geoderma ◽  
2021 ◽  
Vol 402 ◽  
pp. 115164
Author(s):  
Ophélie Sauzet ◽  
Roxane Kohler-Milleret ◽  
François Füllemann ◽  
Yvan Capowiez ◽  
Pascal Boivin
2015 ◽  
Vol 29 (1) ◽  
pp. 101-106 ◽  
Author(s):  
A.A. Abd El-Halim ◽  
Arunsiri Kumlung

Abstract Until now sandy soils can be considered as one roup having common hydrophysical problems. Therefore, a laboratory experiment was conducted to evaluate the influence of bagasse as an amendment to improve hydrophysical properties of sandy soil, through the determination of bulk density, aggregatesize distribution, total porosity, hydraulic conductivity, pore-space structure and water retention. To fulfil this objective, sandy soils were amended with bagasse at the rate of 0, 0.5, 1, 2, 3 and 4% on the dry weight basis. The study results demonstrated that the addition of bagasse to sandy soils in between 3 to 4% on the dry weight basis led to a significant decrease in bulk density, hydraulic conductivity, and rapid-drainable pores, and increase in the total porosity, water-holding pores, fine capillary pores, water retained at field capacity, wilting point, and soil available water as compared with the control treatment


1992 ◽  
Vol 9 (4) ◽  
pp. 138-141 ◽  
Author(s):  
Thomas W. Reisinger ◽  
Phillip E. Pope ◽  
Sheldon C. Hammond

Abstract Recovery of soils compacted from conventional ground-based logging operations was assessed on six upland oak-hickory timber sales in south central Indiana. Two areas were selectively harvested in each of the years 1984, 1986, and 1988. Mean bulk density of undisturbed forest soils ranged from 0.93 to 1.02 mg/m3 for the silt loam soils found on all six study areas. Even though soil disturbance averaged 18% of the total sale area immediately after harvesting, the visible amount of soil disturbance decreased to 2.0 and 2.5% for the areas sampled 2 and 4 years after logging, respectively. Compacted soils on secondary skid trails (i.e., 1.08 mg/m3) recovered to preharvest bulk density in 2 to 4 years, but primary skid trails and landings with higher bulk density values (i.e., 1.19 to 1.28 and 1.35 mg/m3) will require somewhat longer than 4 years to recover. North. J. Appl. For. 9(4):138-141.


2007 ◽  
Vol 33 (2) ◽  
pp. 140-146
Author(s):  
Angela Rivenshield ◽  
Nina Bassuk

Samples of compacted sandy loam and clay loam soil were amended with organic matter: sphagnum peat or food waste compost. Amendments were incorporated into the soil samples at 0%, 10%, 33%, 50%, and 75% on a volume-to-volume basis. Changes in bulk density and macroporosity resulting from amendation were measured. In every permutation but one, macroporosity increased and bulk density decreased to below root-restricting thresholds. These results held true for the half of the samples that were manually recompacted. Differences between the amendments were not significant. Amendation with sufficient amounts of sphagnum peat or food waste compost alleviates compaction, creating an environment more conducive for root growth.


2006 ◽  
Author(s):  
Daren S. Protolipac ◽  
Lisa Finkelstein ◽  
John Kulas

TAPPI Journal ◽  
2015 ◽  
Vol 14 (6) ◽  
pp. 395-402
Author(s):  
FLÁVIO MARCELO CORREIA ◽  
JOSÉ VICENTE HALLAK D’ANGELO ◽  
SUELI APARECIDA MINGOTI

Alkali charge is one of the most relevant variables in the continuous kraft cooking process. The white liquor mass flow rate can be determined by analyzing the chip bulk density fed to the process. At the mills, the total time for this analysis usually is greater than the residence time in the digester. This can lead to an increasing error in the mass of white liquor added relative to the specified alkali charge. This paper proposes a new approach using the Box-Jenkins methodology to develop a dynamic model for predicting chip bulk density. Industrial data were gathered on 1948 observations over a period of 12 months from a Kamyr continuous digester at a bleached eucalyptus kraft pulp mill in Brazil. Autoregressive integrated moving average (ARIMA) models were evaluated according to different statistical decision criteria, leading to the choice of ARIMA (2,0,2) as the best forecasting model, which was validated against a new dataset gathered during 2 months of operations. A combination of predictors has shown more accurate results compared to those obtained by laboratory analysis, allowing a reduction of around 25% of the chip bulk density error to the alkali addition amount.


Author(s):  
Jing Li ◽  
Shankar Mahalingam ◽  
David R. Weise
Keyword(s):  

Author(s):  
E.B. Solovyeva ◽  
◽  
Yu.M. Inshakov ◽  

General approaches to the analysis of the Gibbs phenomenon for discontinuous periodic signals approximated by the truncated Fourier series are considered. Methods for smoothing the truncated Fourier series and improving its convergence are discussed. The software means for modeling is a universal measuring complex LabVIEW, which possesses a convenient environment for analyzing electrical signals, on the basis of this complex a laboratory experiment is carried out. The advantages of the measuring LabVIEW complex and its capabilities for in-depth study of discontinuous periodic signals are noted.


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