Spatial Variability of Sodium Adsorption Ratio and Sodicity in Salt-Affected Soils of Northeast Thailand

2014 ◽  
Vol 931-932 ◽  
pp. 709-715 ◽  
Author(s):  
Porntip Phontusang ◽  
Roengsak Katawatin ◽  
Krirk Pannangpetch ◽  
Sununtha Kingpaiboon ◽  
Rattana Lerdsuwansri
Keyword(s):  
Spatial Variability ◽  
Spatial Correlation ◽  
Sodium Adsorption Ratio ◽  
Descriptive Statistics ◽  
Sodic Soils ◽  
Soil Sodicity ◽  
Class 1 ◽  
Salt Affected Soils ◽  
Study Sites ◽  
Very High

Information on spatial variability of Sodium Adsorption Ratio (SAR) is useful for implementation of appropriate control measures for the salt-affected soils. The major objective of this study was to use geostatistics to describe the spatial variability of (i) the SAR and consequently (ii) the soil sodicity, in areas of different classes of salt-affected soils. Attention was on areas of very severely salt-affected soils (class 1), severely salt-affected soils (class 2), and moderately salt-affected soils (class 3). For each class, 2 study sites were chosen, totally 6 sites were taken into consideration. In each site, 100 soil samples were collected at 0-30 cm depth according to the stratified systematic unaligned sampling method in the dry season of 2012, and analyzed for the SAR in the laboratory. Descriptive statistics and Geostatistics were applied to describe the variability and spatial variability of SAR and soil sodicity, respectively. The result revealed very high variability of SAR. Descriptive statistics showed the CV values of ≥ 35% for every site of every class. When using semivariogram to describe the spatial correlation of SAR, it was found that in 3 study sites, the semivariogram models fitted well with the corresponding semivariogram samples indicating spatial correlation of SAR in the areas. In these cases, the Ordinary Kriging was applied to generate soil sodicity map. The relatively short range values especially for class 1 indicated very high variation of SAR. However, for the other 3 study sites, the linear models were fitted indicating no spatial correlation. Consequently, Trend Surface Analysis was applied instead. According to the soil sodicity maps generated in this study, the areas of class 1 were entirely occupied by strongly sodic soils. For classes 2 and 3, the soils in all study sites belonging to these classes included normal and slightly sodic soils of different proportions. Furthermore, inconsistency of the spatial variability patterns of SAR was found even in areas within the same class of salt-affected soils. As a result, prior to the intensive management of this problem soil in a particular area, investigation on the spatial variability pattern should be performed

scholarly journals Characterization and Formation of Salt affected Soils in Eastern Rajasthan Upland

Agropedology ◽  
2019 ◽  
Vol 26 (2) ◽  
Author(s):  
S.S. Sharma ◽  
◽  
R.P. Sharma ◽  
R.S. Singh ◽  
S. K. Singh ◽  
...  
Keyword(s):  
Underground Water ◽  
Sodium Adsorption Ratio ◽  
Soil Reaction ◽  
Sodic Soils ◽  
Mean Values ◽  
Physico Chemical ◽  
Increasing Trend ◽  
Problematic Soils ◽  
The Mean ◽  
Salt Affected Soils

Soils of the Bhilwara district are affected with different degree and extent of soluble salts. These soils are distributed in hot semi-arid agro-ecological sub region of Rajasthan. It is located between 25o 01' to 25o 58' N latitude and 74o 01' to 75o28' E longitude at an elevation between 380 and 500 meters above the mean sea level. The physico-chemical analysis of soils revealed the dominant cations such as sodium followed by calcium. Exchangeable sodium percentage was ranged 23.1 to 54.6, 17 to 38.5 and 7.1 to 20.0 in saline, sodic and saline-sodic soils, respectively. The Sodium Adsorption Ratio varied from 2.5 to 16.8, 3.2 to 9.4 and 3.8 to 12.6 in these problematic soils, respectively. Soil reaction was ranged from 7.6 to 8.4, 8.5 to 9.3 and 8.5 to 8.8 whereas electrical conductivity of saturation extract varied from 14.4 to 25.2, 1.0 to 5.6 and 2.4 to 13.6 dSm-1 in saline, sodic and saline-sodic soils, respectively. Area under saline and saline-sodic soils was moderately-well to well drained whereas sodic soils were imperfectly drained. Accumulation of calcium carbonate showed increasing trend with depth of profile in all three soils. Mean values of adjusted sodium adsorption ratio of irrigation water was 43.55, 41.88 and 36.74 for saline, saline-sodic and sodic soils. Use of low quality underground water for irrigation, aggravated the process of formation of the salt affected soils in eastern Rajasthan Uplands.

scholarly journals Field-scale Spatial Variability of Electrical Conductivity of the Inland, Salt-affected Soils of Northeast Thailand

2017 ◽  
Vol 15 (5) ◽  
pp. 341-355 ◽  
Author(s):  
Porntip PHONTUSANG ◽  
Roengsak KATAWATIN ◽  
Krirk PANNANGPETCH ◽  
Rattana LERDSUWANSRI ◽  
Sununtha KINGPAIBOON ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Spatial Variability ◽  
Effective Range ◽  
Small Scale ◽  
Model Parameters ◽  
Northeast Thailand ◽  
Field Scale ◽  
Salt Affected Soil ◽  
Class 1 ◽  
Salt Affected Soils

Salt-affected soil maps for Northeast Thailand focus on the percentage of salt crusts. Investigation was done to find the field-scale spatial variability of the electrical conductivity of saturation extract (ECe) in salt-affected areas (percentage salt crusts: very severely = class 1; severely = class 2, and moderately = class 3). Two study sites were selected for each class (n = 6). Soil samples (n = 100) were collected at each site using stratified, systematic, unaligned sampling, and analyzed for ECe. Variations in ECe were assessed using basic statistics and geostatistics. At the field-scale, in every class, the best-fit semivariogram model generated was satisfactory (R2 > 0.8). Interpretation from the relevant model parameters (i.e., nugget, sill, and effective range), together with the interpolated (kriged) maps, demonstrated that the characteristics of spatial variability of soil ECe were inconsistent, even between different sites of the same salt-affected soil class. In general, various degrees of small-scale variation were observed, very high variation of ECe was common, spatial dependence was strong to moderate, while the spatial distribution pattern was in distinctive patches. The size of patches depended on the effective range at each site. This study also revealed that the class 1 areas were entirely, very strongly saline (ECes range, 56.70 and 433.00 dS·m-1), whereas the areas of class 3 were non-saline to moderately saline (range, 0.11 - 5.26 dS·m-1). Class 2 areas were much more complex; the soils varied from non-saline to very strongly saline (range, 0.16 - 49.00 dS·m-1). Information on the nature and characteristics in the spatial variability of soil ECe is useful for developing strategies for management of salt-affected soils in precision agriculture in this region.

scholarly journals Environmental Performances and Biological Toxicity of Snowpack Water

2019 ◽  
Vol 9 (1) ◽  
pp. 4967-4971
Keyword(s):  
Reference Class ◽  
Biological Toxicity ◽  
Snow Covered Area ◽  
Covered Area ◽  
Sampling Points ◽  
Class 1 ◽  
High Concentrations ◽  
Medium Toxicity ◽  
Very High ◽  
Snow Samples

This work analyzes the state of snowpack in Nizhny Novgorod on the basis of certain chemical performances and integral biological toxicity. Snow samples were obtained in February 2018 along major highways of Nizhny Novgorod. A snow-covered area in Dubrava forestry was selected as reference. The studies demonstrated that the snowpack was characterized by very high concentrations of chlorides and sulfides: in sampling points of the Lower City, the content of chlorides and sulfates varied in the ranges of 24.67–62.36 mg/l and 30.16–62.09 mg/l, respectively, and in sampling points of the Upper City, this variability was 416.82–988.45 mg/l and 280.11–879.22 mg/l, respectively. The content of lead in snowpack in both the Lower City and the Upper City was approximately the same (0.0053 and 0.0048 mg/l). The minimum content of pollutants in snow samples from reference site was characterized by toxicity (10%, V = 6.0%) which was estimated as allowable (toxicity class 1). Snowpack water from the Lower City was characterized generally by medium toxicity (class 2), and sampled in the Upper City – by acute toxicity (59%, V = 26.5%), with regard to the reference (class 3).

scholarly journals EFFECTS OF SPATIAL VARIABILITY OF SOIL CHEMICAL PARAMETERS ON TIFTON 85 GRASS YIELD1

2020 ◽  
Vol 33 (1) ◽  
pp. 236-245
Author(s):  
EUDOCIO RAFAEL OTAVIO DA SILVA ◽  
MURILO MACHADO DE BARROS ◽  
MARCOS GERVASIO PEREIRA ◽  
JOÃO HENRIQUE GAIA GOMES ◽  
STEPHANY DA COSTA SOARES
Keyword(s):  
Decision Making ◽  
Spatial Variability ◽  
Dry Matter ◽  
Irregular Sampling ◽  
Descriptive Statistics ◽  
Dry Matter Yield ◽  
Chemical Parameters ◽  
Tropical Pastures ◽  
Chemical Attributes ◽  
Soil Chemical Parameters

ABSTRACT Studies on spatial variability of soil attributes of tropical pastures gather information that can assist in decision making about managements of these soils. The objective of the present study was to evaluate the spatial variability of soil chemical attributes and their effects on grass yield of Tifton 85. The experiment was carried out in an area of 3.91 ha at the Feno Rio Farm of the Federal Rural University of Rio de Janeiro, Seropédica, RJ, Brazil. Soils of the 0-0.20 and 0.20-0.40 m layers were sampled considering an irregular sampling mesh, making a total of 50 georeferenced points. The parameters evaluated were: the soil chemical attributes pH, Al+3, Ca+2, Mg+2, Na+, K+, P, H+Al, and total organic carbon (TOC); and the Tifton 85 dry matter yield (DMY). The results of these parameters were subjected to descriptive statistics, linear correlation, and geostatistics, and maps were developed for the analyses. Regions with grass yields different from the general mean were found in the area, which presented mean grass yield of 2248 kg ha-1. The soil chemical parameters Na+, Ca+2, TOC, and H+Al were significantly correlated with DMY, confirming that they are important and affect the Tifton 85 grass yield. The mapping of the Tifton 85 cycle is important for understanding the variability of DMY. The investigation of areas with different productive potentials should be followed by development of maps of soil chemical attributes to correlate and understand the ratios that may be involved with these variations.

scholarly journals Localized basal area affects soil respiration temperature sensitivity in a coastal deciduous forest

2020 ◽  
Vol 17 (3) ◽  
pp. 771-780 ◽  
Author(s):  
Stephanie C. Pennington ◽  
Nate G. McDowell ◽  
J. Patrick Megonigal ◽  
James C. Stegen ◽  
Ben Bond-Lamberty
Keyword(s):  
Soil Moisture ◽  
Soil Respiration ◽  
Spatial Variability ◽  
Temperature Sensitivity ◽  
Large Scale ◽  
Deciduous Forest ◽  
Basal Area ◽  
Soil Surface ◽  
Study Sites ◽  
Positive Effect

Abstract. Soil respiration (Rs), the flow of CO2 from the soil surface to the atmosphere, is one of the largest carbon fluxes in the terrestrial biosphere. The spatial variability of Rs is both large and poorly understood, limiting our ability to robustly scale it in space. One factor in Rs spatial variability is the autotrophic contribution from plant roots, but it is uncertain how the presence of plants affects the magnitude and temperature sensitivity of Rs. This study used 1 year of Rs measurements to examine the effect of localized basal area on Rs in the growing and dormant seasons, as well as during moisture-limited times, in a temperate, coastal, deciduous forest in eastern Maryland, USA. In a linear mixed-effects model, tree basal area within a 5 m radius (BA5) exerted a significant positive effect on the temperature sensitivity of soil respiration. Soil moisture was the dominant control on Rs during the dry portions of the year, while soil moisture, temperature, and BA5 all exerted significant effects on Rs in wetter periods. Our results suggest that autotrophic respiration is more sensitive to temperature than heterotrophic respiration at these sites, although we did not measure these source fluxes directly, and that soil respiration is highly moisture sensitive, even in a record-rainfall year. The Rs flux magnitudes (0.46–15.0 µmol m−2 s−1) and variability (coefficient of variability 10 %–23 % across plots) observed in this study were comparable to values observed in similar forests. Six Rs observations would be required in order to estimate the mean across all study sites to within 50 %, and 518 would be required in order to estimate it to within 5 %, with 95 % confidence. A better understanding of the spatial interactions between plants and microbes, as well as the strength and speed of above- and belowground coupling, is necessary to link these processes with large-scale soil-to-atmosphere C fluxes.

scholarly journals Logging Residue Volumes and Characteristics following Integrated Roundwood and Energy-Wood Whole-Tree Harvesting in Central Maine

2011 ◽  
Vol 28 (2) ◽  
pp. 66-71 ◽  
Author(s):  
Julia I. Briedis ◽  
Jeremy S. Wilson ◽  
Jeffrey G. Benjamin ◽  
Robert G. Wagner
Keyword(s):  
Limited Information ◽  
Ecological Processes ◽  
Energy Wood ◽  
Partial Harvesting ◽  
Class 1 ◽  
Logging Residue ◽  
Downed Wood ◽  
Study Sites ◽  
Whole Tree Harvesting ◽  
Whole Tree

Abstract Integrated roundwood and energy-wood whole-tree, partial harvesting has become common in Maine over the past decade, yet there is limited information about the volume and characteristics of logging residues left behind on such harvest sites. To better inform forest managers about the downed woody material remaining after whole-tree partial harvesting, we measured downed wood volume and characteristics on 12 harvested sites in central Maine using line intersect sampling. All sites were harvested using mechanical systems (feller-bunchers and grapple skidders) within a year prior to sampling. The mean volume of downed wood across all sites was 726 ± 57 ft3/ac (±SE), 47% of which was residue generated by the harvest. The variability of residue volumes was higher within sites (coefficients of variation between 36 and 69%) than between sites (coefficient of variation, 27%). Coarse woody material between 3 and 6 in. in diameter at the large end dominated the postharvest debris, while logs greater than 10 in. in diameter were scarce. The majority of harvest-generated downed wood was in decay class 1, whereas preharvest debris consisted of mostly decay classes 2, 3, and 4. The volumes of downed wood remaining on the study sites were within the range of volumes found on other managed sites of similar forest types. However, further research is necessary to assess whether these amounts and characteristics are adequate for long-term maintenance of ecological processes.

scholarly journals Reclamation of Saline–Sodic Soils with Combined Amendments: Impact on Quinoa Performance and Biological Soil Quality

2018 ◽  
Vol 10 (9) ◽  
pp. 3083 ◽  
Author(s):  
María Alcívar ◽  
Andrés Zurita-Silva ◽  
Marco Sandoval ◽  
Cristina Muñoz ◽  
Mauricio Schoebitz
Keyword(s):  
Root Biomass ◽  
Soil Microbial Biomass ◽  
Seed Quality ◽  
Combined Treatment ◽  
Sodium Adsorption Ratio ◽  
Arid Zones ◽  
Exchangeable Sodium ◽  
Sodic Soils ◽  
Soil Microbial ◽  
The Individual

The objective of this study was to evaluate the individual and synergic effects of the application of Biochar (B), Humic Substances (HS), and Gypsum (G) on the soil properties of a saline–sodic soil, and plant growth and seed quality (polyphenols, protein and yield) of quinoa. Treatments included (B) 22 t ha−1, (HS) 5 kg ha−1, and (G) 47.7 t ha−1. Two quinoa genotypes from Arid Zones (AZ-51 and AZ-103) were selected and established in eight treatments. The B + HS + G combined treatment resulted in increases in root biomass of 206% and 176% in AZ-51 and AZ-103, respectively. Furthermore, electrical conductivity (ECe), sodium adsorption ratio (SAR), and exchangeable sodium percentage (ESP) decreased significantly in all treated soils. When compared to the control, ESP decreased 11-fold in the G treatment, and 9–13-fold in the B + G; B + HS; and B + HS + G treatments. Similarly, soil microbial biomass increased 112% and 322% in the B + HS + G treatment in AZ-51 and AZ-103 genotypes, respectively. Therefore, it can be concluded that the application of combined amendments (B + HS + G) represents an alternative for reclaiming degraded soils, including saline–sodic soils.

scholarly journals SELECTION OF SUMBA ONGOLE (SO) CATTLE BASED ON BREEDING VALUE AND PERFORMANCE TEST

2016 ◽  
Vol 41 (4) ◽  
pp. 175 ◽  
Author(s):  
S. Said ◽  
P. P. Agung ◽  
W. P. B. Putra ◽  
S. Anwar ◽  
A. S. Wulandari ◽  
...  
Keyword(s):  
Performance Test ◽  
Descriptive Statistics ◽  
Breeding Value ◽  
Body Measurements ◽  
Final Weight ◽  
Class 1 ◽  
Increase Productivity ◽  
And Performance ◽  
Selection Of ◽  
Analyze Data

Selection of livestock was purposed to increase productivity. A performance test was conducted using 25 males and 25 females of Sumba Ongole (SO) cattle. The performance test were conducted in three periods (2014, 2015 and 2016) for about 535 days. Descriptive statistics ws used to analyze data of body weight. Cattle with age between 300 to 600 days were used for evaluation. Result showed that heritability value of yearling weight (YW365) was 0.77+0.68 as a high category. The highest breeding value of YW365 were 66.05 kg (male) and 41.89 kg (female). The average of corrected final weight (CFW) weight were 172.55+34.22 kg (male) and 159.80+37.73 kg (female). The performance test in this study obtained six A class (1 bull and 5 cows) based on the standard minimum of body measurements for SO cattle.

Sky-Cover Correlation within a Sky Dome

1991 ◽  
Vol 30 (7) ◽  
pp. 1037-1039 ◽  
Author(s):  
James H. Willand ◽  
Julia Steeves
Keyword(s):  
Spatial Correlation ◽  
Cloud Cover ◽  
Correlation Structure ◽  
National Weather Service ◽  
Structural Pattern ◽  
The Earth ◽  
Spatial Correlation Structure ◽  
Sky Conditions ◽  
Very High ◽  
Weather Service

Abstract A new utility for the use of whole-sky photographs has been developed through an effort to discern the structural pattern of correlations of cloud cover within an observer's sky dome. The photographs were taken from the National Weather Service observing site at Columbia, Missouri, and were originally assembled for the purpose of estimating probabilities of cloud-free lines of sight from the earth through the atmosphere. The procedure for determining the spatial correlation structure of sky cover within the sky dome starts with the defining and tabulating of a dichotomous sky-cover condition over small sectors of the sky dome, and then calculating the correlation associated with the tabulated sky conditions in each sector. This note shows that correlation of sky-cover conditions over a sky dome are very high, and that they are less degrading in the winter than in the summer. The results of this study can be applied to the estimation of cloud-free lines of sight to multiple satellites.

Sign in / Sign up

Export Citation Format

Share Document