Use of the neutron method in assessing the changes in soil strength of undisturbed and ameliorated transitional red-brown earths during soil drying cycles

Soil Research ◽  
1990 ◽  
Vol 28 (2) ◽  
pp. 167
Author(s):  
NS Jayawardane ◽  
J Blackwell
Keyword(s):  
Bulk Density ◽  
Soil Strength ◽  
Wheat Crop ◽  
Regression Equations ◽  
Experimental Site ◽  
Undisturbed Soil ◽  
Soil Matrix ◽  
Penetrometer Resistance ◽  
Neutron Count ◽  
Neutron Method

The relationships between penetrometer resistance (qp) and volumetric moisture content (�v) measured using the neutron method in an undisturbed transitional red-brown earth and after an~elioration by application of surface gypsum and slotted gypsum were examined. A very highly significant (P < 0.001) negative correlation was obtained between qp and �v in all treatments. The low r2 values of the regressions were attributed to heterogeneity in strength characteristics of the soil matrix, due to presence of cracks and macropores and the associated wetting patterns. The qp at any given e, was significantly reduced in the slots with lower bulk density compared to the undisturbed soil. The differences in qp- �v relationship of the undisturbed part of the soil under different ameliorative practices were attributed to changes in the swelling characteristic, and hence in the bulk density at any given �v of the undisturbed soil, caused by the presence of gypsum and the slots. Regression equations between qp and neutron count rate (n) for the undisturbed soil and for the slots were developed by combining the qp on �v relationships with the neutron meter calibration for �v measurements. The use of these regression equations and measured n values to predict changes in soil strength profiles during a wheat crop drying cycle in an undisturbed and ameliorated transitional red-brown earth was evaluated on another experimental site. There were no significant differences between the predicted and measured qp values in the non-ameliorated soil and the gypsum-slotted soil. Significant differences were observed between the predicted and measured qp values in the surface gypsum applied soil. The study shows the potential for using the neutron method as a convenient in-situ field technique to predict qp profile changes, preferably using qp on n relationships developed at the experimental site.

Use of natural heterogeneity in a small field site to explore the influence of the soil matrix on nitrogen mineralisation and nitrification

Soil Research ◽  
1997 ◽  
Vol 35 (3) ◽  
pp. 579 ◽  
Author(s):  
D. T. Strong ◽  
P. W. G. Sale ◽  
K. R. Helyar
Keyword(s):  
Soil Properties ◽  
Multiple Regression ◽  
Multiple Regression Equation ◽  
Regression Equations ◽  
Small Field ◽  
Undisturbed Soil ◽  
Soil Matrix ◽  
Ph Buffering ◽  
Functional Relationships ◽  
Physical Scale

The influence of soil properties on microbiological processes is often examined by comparing the behaviour of taxonomically disparate soils. One of the limitations of this approach is that the results can be confounded by the unmeasured properties which vary between soils of different type or between soils which have had different climatic and management histories. This study tested the hypothesis that the heterogeneity between 100 small contiguous undisturbed soil cubes (about 1·7 cm3), sampled from the surface of a very small field plot (14 by 14 cm), was sufficiently large to use for the exploration of how soil properties influence biological processes. After incubation of the soil for 35 days, the coefficients of variation for nitrate (NO3), ammonium (NH4), gravimetric water content (θg), bulk density (BD), pH buffering capacity (pHBC), and pH were 28, 39, 27, 10, 13, and 2%, respectively. A multiple regression equation predicting nitrate concentration had an r2 value of 0·89 and significantly included 4 predictor variables, with only pH being non-significant. These analyses confirmed the hypothesis. When the values of measured soil properties of adjoining soil cubes were meaned to estimate values for larger soil volumes, the multiple regression equations for predicting NO3 concentration explained more of the variation (r2 values as high as 0·99). However, information concerning the influence of certain soil properties on N mineralisation and nitrification was lost, with only pHBC and BD remaining significant in the regression model. It was concluded that at a given physical scale of investigation, the structure of the spatial variability may determine whether or not a relationship between 2 variables is observed. Smaller samples are more likely to identify functional relationships which may exist between measured variables at the microscale.

Residual effects of a slant-legged subsoiler on some soil physical conditions and the root growth of spring barley

1988 ◽  
Vol 110 (3) ◽  
pp. 481-489 ◽  
Author(s):  
N. A. Hipps ◽  
D. R. Hodgson
Keyword(s):  
Root Growth ◽  
Bulk Density ◽  
Spring Barley ◽  
Soil Strength ◽  
Soil Disturbance ◽  
Residual Effects ◽  
Soil Cores ◽  
Undisturbed Soil ◽  
Cone Resistance ◽  
Trade Name

SummarySoil disturbance caused by a slant-legged subsoiler (Trade name, ‘Paraplow’) and the duration of its effect was investigated in an experiment comparing long-term direct drilling with shallow tine cultivation and mouldboard ploughing. The ‘Paraplow’ significantly reduced soil strength, measured by cone resistance, to the depth of cultivation (33–35 cm) for up to 20 months, after which soil recompacted. The ‘Paraplow’ increased the volume of soil with cone resistance < 1·5 MPa by 52% within its working depth, compared with an equivalent depth of undisturbed soil. Contour diagrams of cone resistances clearly illustrate the patterns of soil loosening caused by the ‘Paraplow’.Measurements on soil cores (73 mm diameter × 50 mm) show that the ‘Paraplow’ did not appear to increase significantly the volume of macropores (> 60 μm) in direct-drilled soil, nor did it reduce the bulk density in the top 5 cm as effectively as the mouldboard plough.The root density of spring barley, measured at the beginning and end of tillering, was significantly increased within the horizon disturbed by the ‘Paraplow’ but below the depth of loosening there were no differences. This improvement of root growth probably resulted from an increase in the number of large pores (which could not be measured adequately in the soil cores), as well as the reduced soil strength. Better drainage of the soil loosened with the ‘Paraplow’ suggested that macroporosity was improved. The need to sample large volumes of soil to detect changes in bulk density and macroporosity is stressed.

The Effect of Soil Strength on the Growth of Young Wheat Plants

1987 ◽  
Vol 14 (6) ◽  
pp. 643 ◽  
Author(s):  
J Masle ◽  
JB Passioura
Keyword(s):  
Water Content ◽  
Bulk Density ◽  
Soil Phosphorus ◽  
Soil Strength ◽  
Leaf Expansion ◽  
Wheat Seedlings ◽  
Penetrometer Resistance ◽  
Carbon Supply ◽  
High Soil ◽  
Carbon Demand

Wheat seedlings were grown in soil of various strengths, obtained by changing the bulk density or the water content of the soil. Leaf expansion and transpiration rate were monitored from emergence until the main stem had 5-7 leaves. Leaf area, and shoot and root dry weights, were negatively correlated with soil strength as measured by penetrometer resistance. The growth of roots was less affected than that of shoots. Leaf expansion was reduced before the first leaf was fully expanded. Relative rates of leaf expansion thereafter were consistently lower at high soil strength, although not always significantly. High soil strength also produced substantially smaller stomatal conductances. All effects were the same whether variations of soil strength were brought about by changes in water content or in bulk density. Three possible causes of reduced shoot growth were examined: (1) a limiting supply of nutrients; or (2) of water, because of a restricted root system; or (3) a reduced carbon supply because of a higher carbon demand from the roots, or because of the low stomatal conductance. We conclude that these are all unlikely explanations for the onset of the effects of soil strength, which were independent of soil phosphorus content, of leaf water potential, and of the amount of carbon reserves in the seed. We suggest that growth of the shoot is primarily reduced in response to some hormonal message induced in the roots when they experience high soil strength.

SOIL MORPHOLOGY AND SOIL PHYSICAL PROPERTIES. II. MECHANICAL IMPEDANCE AND MOISTURE RETENTION AND MOVEMENT

1973 ◽  
Vol 53 (1) ◽  
pp. 9-19 ◽  
Author(s):  
K. W. AYRES ◽  
R. G. BUTTON ◽  
E. DE JONG
Keyword(s):  
Hydraulic Conductivity ◽  
Bulk Density ◽  
Soil Structure ◽  
Pore Space ◽  
Mechanical Impedance ◽  
The Other ◽  
Regression Equations ◽  
Soil Morphology ◽  
Moisture Retention ◽  
Undisturbed Soil

The relations among soil structure, soil mechanical impedance, and moisture retention and movement were investigated on undisturbed soil cores from soil horizons exhibiting six distinct kinds of soil structure (prismatic, columnar, blocky, granular, platy, massive) over a broad range of soil texture. Mechanical impedance was characterized by measurements of bulk density and soil strength. Moisture retention and movement were characterized by measurements of [Formula: see text]-atm moisture content and saturated hydraulic conductivity. The columnar structures from Solonetzic soils were singled out as having a higher mechanical impedance and lower hydraulic conductivity than the other structures, most of which were sampled from Chernozemic soils. Total porosity (P) and bulk density (Db) were highly correlated; however, the regression coefficient for P vs. Db for columnar structures was significantly higher than that found for the other five structural types. Regression equations predicted that the hydraulic conductivity of platy structures could be zero for samples having as much as 15% air-filled pore space at [Formula: see text]-atm suction as compared with 6–8% for the other structures.

scholarly journals Effect of Different Extrusion Processing Parameters on Physical Properties of Soy White Flakes and High Protein Distillers Dried Grains-Based Extruded Aquafeeds

2014 ◽  
Vol 3 (6) ◽  
pp. 107 ◽  
Author(s):  
Sushil K. Singh ◽  
K. Muthukumarappan
Keyword(s):  
Physical Properties ◽  
Water Absorption ◽  
Bulk Density ◽  
Water Solubility ◽  
Expansion Ratio ◽  
High Protein ◽  
Regression Equations ◽  
Process Variables ◽  
Distillers Dried Grains ◽  
Durability Index

<p>Nutritionally balanced ingredient blends for catla (<em>Catla catla</em>), belonging to the family Cyprinidae, were extruded using single screw extruder. The extrusion was carried out at five levels of soy white flakes content (21%, 29%, 40%, 52%, and 59% db), five levels of moisture content (15, 19, 25, 31, and 35% db) and five levels of barrel temperature (100, 110, 125, 140, and 150 ºC) using three different die nozzles (having L/D ratios 3.33, 5.83, and 7.25). Blends with net protein content of 32.5% contains soy white flakes, along with high protein distillers dried grains (HP-DDG), corn flour, corn gluten meal, fish meal, vitamin, and mineral mix. A central composite rotatable design (CCRD) and  response surface methodology (RSM) was used to investigate the significance of independent and interaction effects of the extrusion process variables on the extrudates physical properties namely pellet durability index, bulk density, water absorption and solubility indices and expansion ratio. Quadratic polynomial regression equations were developed to correlate the product responses and process variables as well as to obtain the response surfaces plots. The independent variables had significant (<em>P </em>&lt; 0.05) effects on physical properties of extrudates: (i) higher soy white flakes content increased the pellet durability index and water absorption index, but decreased the water solubility index, (ii) higher temperature decreased pellet durability index, bulk density and water solubility index, (iii) increased L/D ratio from 3.33 to 7.25 increased the pellet durability index, expansion ratio but decreased the bulk density of the extrudates.</p>

Profile Soil Property Estimation Using a VIS-NIR-EC-Force Probe

2017 ◽  
Vol 60 (3) ◽  
pp. 683-692 ◽  
Author(s):  
Yongjin Cho ◽  
Kenneth A. Sudduth ◽  
Scott T. Drummond
Keyword(s):  
Soil Properties ◽  
Water Content ◽  
Bulk Density ◽  
Soil Property ◽  
Soil Strength ◽  
Reflectance Spectra ◽  
Land Resource ◽  
Strength Data ◽  
Soil Sensors ◽  
Combining Data

Abstract. Combining data collected in-field from multiple soil sensors has the potential to improve the efficiency and accuracy of soil property estimates. Optical diffuse reflectance spectroscopy (DRS) has been used to estimate many important soil properties, such as soil carbon, water content, and texture. Other common soil sensors include penetrometers that measure soil strength and apparent electrical conductivity (ECa) sensors. Previous field research has related these sensor measurements to soil properties such as bulk density, water content, and texture. A commercial instrument that can simultaneously collect reflectance spectra, ECa, and soil strength data is now available. The objective of this research was to relate laboratory-measured soil properties, including bulk density (BD), total organic carbon (TOC), water content (WC), and texture fractions to sensor data from this instrument. At four field sites in mid-Missouri, profile sensor measurements were obtained to 0.9 m depth, followed by collection of soil cores at each site for laboratory measurements. Using only DRS data, BD, TOC, and WC were not well-estimated (R2 = 0.32, 0.67, and 0.40, respectively). Adding ECa and soil strength data provided only a slight improvement in WC estimation (R2 = 0.47) and little to no improvement in BD and TOC estimation. When data were analyzed separately by major land resource area (MLRA), fusion of data from all sensors improved soil texture fraction estimates. The largest improvement compared to reflectance alone was for MLRA 115B, where estimation errors for the various soil properties were reduced by approximately 14% to 26%. This study showed promise for in-field sensor measurement of some soil properties. Additional field data collection and model development are needed for those soil properties for which a combination of data from multiple sensors is required. Keywords: NIR spectroscopy, Precision agriculture, Reflectance spectra, Soil properties, Soil sensing.

scholarly journals INTERVALO HÍDRICO ÓTIMO PARA AVALIAÇÃO DE SISTEMAS DE PRODUÇÃO E RENDIMENTO DO FEIJÃO

Irriga ◽  
2017 ◽  
Vol 22 (2) ◽  
pp. 383-399 ◽  
Author(s):  
Laura Fernanda Simões Da Silva ◽  
Mara De Andrade Marinho ◽  
Raquel Stucchi Boschi ◽  
Edson Eiji Matsura
Keyword(s):  
Bulk Density ◽  
Lower Limit ◽  
Management Systems ◽  
Conventional System ◽  
Undisturbed Soil ◽  
Important Indicator ◽  
Physical Quality ◽  
Soil Physical Quality ◽  
Wide Range ◽  
Bean Yield

INTERVALO HÍDRICO ÓTIMO PARA AVALIAÇÃO DE SISTEMAS DE PRODUÇÃO E RENDIMENTO DO FEIJÃO Laura Fernanda Simões da Silva1; Mara de Andrade Marinho2; Raquel Stucchi Boschi3 E Edson Eiji Matsura2  ¹Programa de Pós-Graduação em Agroecologia e Desenvolvimento Rural / CCA / UFSCar Rodovia Anhanguera, km 174 – SP-330 - Araras - SP - Brasil - CEP: 13600-970, email: [email protected] ²Faculdade de Engenharia Agrícola, Universidade Estadual de Campinas, Avenida Candido Rondon, n 501, Barão Geraldo, Campinas – SP, Brasil - CEP 13083-875, email: [email protected]; [email protected]³Secretaria de Gestão Ambiental e Sustentabilidade/ UFSCar Rod. Washington Luis, km 235 - São Carlos - SP - Brasil - CEP:13565-905, email: [email protected]  1 RESUMO O objetivo deste trabalho foi compreender o efeito de dois sistemas de produção agrícola, com e sem irrigação, sobre atributos físicos do solo e sobre o rendimento do feijão, utilizando o conceito de intervalo hídrico ótimo (IHO). A pesquisa foi conduzida em parcelas experimentais situadas na região de Campinas, cultivadas com feijão sob Sistema Plantio Direto (SPD) e Sistema Convencional com Grade (SC). Para determinação do IHO, os atributos densidade do solo (Ds), curva de retenção de água (CRA), curva de resistência do solo à penetração (RP) e porosidade de aeração foram determinados para camada do solo 0-0,20 m, a partir de amostras indeformadas extraídas de diferentes locais, de modo a representar uma faixa ampla de variação da densidade do solo. O monitoramento da qualidade do solo e do desempenho dos sistemas de produção foi efetuado com base em dados de: Ds, umidade volumétrica e produtividade da cultura de feijão, irrigado e não irrigado para uma safra agrícola de inverno. Os limites do IHO foram definidos pelo q-0,01MPa (limite superior) e pelo q-1,5MPa (limite inferior), para os valores de Ds até 1,2 kg dm-3. A partir deste valor de Ds, o limite inferior passa a ser definido pelo qRP. O período de dias em que o solo permaneceu fora das condições ideais de umidade estabelecidas pelo IHO foi suficiente para afetar diferencialmente a produtividade do feijoeiro nos tratamentos não irrigados, com vantagem para o SPD. O IHO representa um importante indicador na avaliação da qualidade estrutural do solo submetido a diferentes sistemas de manejo. Ainda, o IHO pode ser utilizado no monitoramento da qualidade física do solo associado a uma maior ou menor frequência de ocorrência da umidade do solo fora dos limites estabelecido pelo mesmo. Palavras-chave: manejo de irrigação, densidade do solo, sistema plantio direto, sistema convencional, qualidade física.  Silva, L. F. S.; Marinho, M. A.; Boschi, R. S.; Matsura, E. E.LEAST LIMITING WATER RANGE TO ASSESS BEAN MANAGEMENT SYSTEMS AND YIELD   2 ABSTRACT The objective of this study was to understand the effect of two management systems, with and without irrigation, on soil physical properties and bean yield, using the concept of least limiting water range (LLWR). The study was conducted in experimental plots located in Campinas, planted with beans under no tillage system (NTS) and conventional system (SC). To determine the LLWR, bulk density (BD), water retention curve (WRC), soil resistance to penetration curve (SRPC) and macroporosity were determined for the layer 0-0.20 m, from undisturbed soil samples extracted from different locations to represent a wide range of bulk density. Monitoring of soil quality and performance of production systems was made based on the following data: BD, water content and productivity of bean crops, irrigated and non-irrigated, for a harvest of winter. The θ-0,01MPa determined the upper limit of the LLWR and θ-1,5MPa the lower limit to BD equal to 1.2 kg dm-3 from which the lower limit is set by SRPC. The period of days that the soil remained outside the ideal conditions of moisture established by the LLWR was enough to differentially affect bean yield in non-irrigated treatments, with better results for NTS. The LLWR is an important indicator for assessing the soil structural quality under different management systems. Additionally, the LLWR can be used to monitor the soil physical quality associated with a higher or lower frequency of occurrence of soil moisture outside the limits set by LLWR. Keywords: irrigation management, bulk density, direct drilling system, conventional system, soil physical quality.

Studies on the water retention in arable sandy soil amended with fine size-fractionated sunflower husk biochar 

2021 ◽  
Author(s):  
Łukasz Gluba ◽  
Anna Rafalska-Przysucha ◽  
Kamil Szewczak ◽  
Mateusz Łukowski ◽  
Radosław Szlązak ◽  
...  
Keyword(s):  
Particle Size ◽  
Bulk Density ◽  
Size Distribution ◽  
Sandy Soil ◽  
Water Retention ◽  
Reference Level ◽  
Satellite Monitoring ◽  
Soil Matrix ◽  
Size Fractions ◽  
Biochar Amendment

&lt;p&gt;Biochar application has been reported for improving the physical, chemical, and hydrological properties of soil. However, biochar can be produced from different feedstocks and at different conditions having a direct impact on its properties. Furthermore, the overall effect of improvement depends on the type of soil. That makes biochar amendment difficult to optimize and creates the need for extensive studies of this issue for its better understanding. In these studies, we show that water holding capacity (by means of Available Water Content - AWC) can be significantly improved in arable sandy soil using fine-sized biochar particles.&lt;/p&gt;&lt;p&gt;For our studies, we have used sunflower husk biochar (pyrolyzed at 650&lt;sup&gt;o&lt;/sup&gt;C). Biochar samples were characterized using an elemental analyzer for C, H, N content studies, mercury porosimeter for porosity and specific pore volumes, and vibratory shaker with a stack of sieves for particle size distribution. The examined biochar was sieved in order to obtain four diameter size fractions: &lt;50 &amp;#181;m, 50&amp;#8211;100 &amp;#181;m, 100&amp;#8211;250 &amp;#181;m and &lt;2000 &amp;#181;m and mixed with arable sandy soil for 0.95, 2.24, 4.76 and 9.52 wt.%. The unamended soil sample served as a reference. At first, we have measured the bulk density of the air-dried samples. After then the pressure plate method was used to determine the water retention curves. The results were fitted using the van Genuchten equation. Finally, the AWC for all the measured samples was calculated from a difference between soil water contents for pF=2.2 and pF=4.2.&amp;#160; &lt;/p&gt;&lt;p&gt;The bulk density studies have shown a nonlinear behavior as a function of dose for all fractions of the biochar. The clearest effect is observed for fractions below 100 &amp;#181;m for which the density vs dose characteristics of the samples revealed a maximum for 0.95 wt.% and a decreasing trend for higher biochar contents. The AWC studies shown that the particle size fractions of biochar below 100 &amp;#181;m in diameter cause also the most significant improvement in the water retention, almost doubling the reference level (0.078 m&lt;sup&gt;3 &lt;/sup&gt;m&lt;sup&gt;-3&lt;/sup&gt;) to approximately 0.155 m&lt;sup&gt;3 &lt;/sup&gt;m&lt;sup&gt;-3&lt;/sup&gt; after biochar amendment. The results are explained by the filling of the free volume in the sandy soil matrix by small biochar particles. That leads to a shift of the pore size distribution to smaller radiuses, which in consequence promotes an increase in AWC.&amp;#160;&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;The research was conducted under the project&amp;#160; &quot;Water in soil&amp;#160; -&amp;#160; satellite monitoring and improving the retention using biochar&quot; No. BIOSTRATEG3/345940/7/NCBR/2017 which was financed by the Polish National Centre for Research and Development in the framework of &amp;#8220;Environment, agriculture and forestry&quot; -BIOSTRATEG strategic R&amp;D programme.&lt;/p&gt;

Properties of Dan Kwian, Sukhothai and Ratchaburi Pottery Clays Fired at 700 and 900 °C

2014 ◽  
Vol 608 ◽  
pp. 47-61
Author(s):  
Nonglak Meethong ◽  
Wanwisa Pattanasiriwisawa ◽  
Weenawan Somphon ◽  
Waraporn Tanthanuch ◽  
Sutham Srilomsak
Keyword(s):  
Specific Gravity ◽  
Comparative Study ◽  
Water Absorption ◽  
Bulk Density ◽  
Firing Temperature ◽  
Reflectance Spectra ◽  
Modulus Of Rupture ◽  
Regression Equations ◽  
Statistical Software

Dan Kwian, Sukhothai and Ratchaburi pottery clays are economically important pottery clays. They are well known in the Thai ceramic society for making Dan Kwian pottery, Sawankhalok pottery and Dragon jars, respectively. There have been several studies of these pottery clays. However, few of them used statistics to analyze their results. This work is a comparative study of the compositions and properties of these three pottery clays using statistical software to analyze the results. Results show that the major components of these pottery clays are SiO2 and Al2O3. The Modulus of Rupture (MOR) of each pottery clay fired at 700°C are not significantly different. Sukhothai pottery clay fired at 900°C has a higher MOR and bulk density while its porosity, water absorption and apparent specific gravity are less than those of the Dan Kwian and Ratchaburi pottery clays fired at the same temperature. Additionally, the current study developed regression equations for estimating the properties of all pottery clays under study. Finally, it was found that the L*, a*, b* and reflectance spectra of all pottery clays increased when firing temperature was increased from 700 to 900°C.

Sign in / Sign up

Export Citation Format

Share Document