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Cassio Hamilton Abreujunior - One of the best experts on this subject based on the ideXlab platform.
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long term effects of residual sewage sludge application in Tropical Soils under eucalyptus plantations
Journal of Cleaner Production, 2019Co-Authors: Antonio Leite Florentino, Takashi Muraoka, Thiago Assis Rodrigues Nogueira, Gian Franco Capra, Alexandre De Vicente Ferraz, Jose Leonardo De Moraes Goncalves, Veronica Asensio, Carlos Tadeu Dos Santos Dias, Cassio Hamilton AbreujuniorAbstract:Abstract Studies regarding the residual effects of sewage sludge in soil several years after the first and only application are still scarce, especially for Tropical areas under forestry management. In these Soils, the residual effects can represent a neglected phenomenon, since silvicultural management experiences a longer crop rotation cycle compared to most common agricultural cycles. Consequently, under forestry management, sewage sludge applications can represent an event occurring just once over cycles of several years. This study aimed to evaluate the long-term effects of residual sewage sludge application in infertile Tropical Soils under Eucalyptus plantations in terms of both the main chemical features (pH, soil organic matter, N, P, S, K, Ca, Mg, and cation-exchange capacity) and the potentially toxic elements (As, Ba, Cd, Co, Cr, Cu, Mo, Ni, Pb, Se, and Zn) concentrations/behaviors of soil. Residual effects were evaluated in four areas (Sao Paulo State, Brazil) after 10.0, 12.2, 12.4, and 17.2 years from the first and only application, respectively. Differences in terms of treatments were evaluated by analysis of variance; correlations and similarity analyzed by principal component and cluster analysis, respectively. The results showed that soil organic matter, main macronutrients (N and P), and cation-exchange capacity contents were generally higher in sewage sludge-treated Soils while potentially toxic element contents tended to increase at increasing sewage sludge doses. In most of the investigated treatments, the potentially toxic element concentrations were usually below both the soil natural background concentrations and quality reference values. Principal component and cluster analysis revealed that differences among areas were primary due to differences in applied sewage sludge type and amount. The effects of residual sewage sludge application on soil, in terms of both the pros and cons, can be detected even many years after the first and only application. Studies on the long-term effects of sewage sludge should be mandatory for both monitoring the pedoenvironment and for guiding policymakers and producers on the best practices for their reuse and management.
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effects of sewage sludge application on unfertile Tropical Soils evaluated by multiple approaches a field experiment in a commercial eucalyptus plantation
Science of The Total Environment, 2019Co-Authors: Cassio Hamilton Abreujunior, Thiago Assis Rodrigues Nogueira, Maria Julia De Lima Brossi, R T R Monteiro, Paulo Henrique Silveira Cardoso, Thays Da Silva Mandu, Antonio Ganga, Peter Filzmoser, Fernando Carvalho Oliveira, Lucia Pitol FirmeAbstract:Abstract Sewage sludge (SS) reuse in forest plantation as soil fertilizer/amendment has tremendously increased in recent years. However, SS may have high concentrations of potentially toxic elements (PTE), representing a potential risk for soil and the whole ecosystem. This paper was aimed to assess the toxicity of PTE in unfertile Tropical Soils amended with SS in a commercial Eucalyptus plantation, with an integrated multiple approaches combining: i) the use of a battery of bioassays (Daphnia magna, Pseudokcrichirella subcapitata, Lactuca sativa, and Allium cepa); and ii) the evaluation of some PTE (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) and their availability into the pedoenvironment. Differences in total and available PTE between SS doses and time of treatments were evaluated using ANOVA; correlations between PTE and bioassays by a sparse partial robust M-regression (SPRM), while multiple correlations among parameters were performed by principal factor analysis (PFA). Results show that PTE contents in Soils tended to increase with SS application doses. However this cannot be assumed as a general rule since in all the investigated treatments the PTE concentrations were consistently below both soil natural background concentrations and quality reference values. Bioassays showed a generalized low eco- and genotoxicity of SS with an increase in toxicity at increasing SS doses but with a clear decreasing trend as time went by. A. cepa was the most sensitive bioassay followed by P. subcapitata > D. magna > L. sativa. Overall, the results indicate that in realistic open field conditions SS risk may be lower than expected due to dynamic decrease in PTE toxicity with time after application. This study has an important implication that open-field trials should be strongly encouraged for evaluating environmental risk of SS application in forestry.
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fertilization using sewage sludge in unfertile Tropical Soils increased wood production in eucalyptus plantations
Journal of Environmental Management, 2017Co-Authors: Cassio Hamilton Abreujunior, Lucia Pitol Firme, Carlos Alberto Baca Maldonado, Sebastiao Pires De Moraes Neto, Marcelo Correa Alves, Takashi Muraoka, Antonio Enedi Boaretto, Jose Luis Gava, Thiago Assis Rodrigues Nogueira, Gian Franco CapraAbstract:Abstract Fertilization of Eucalyptus plantations using sewage sludge on unfertile Tropical Soils represents an alternative to using mineral N and P fertilizers. A 44-month field experiment was conducted to study the effects of increasing application of sludge, and its interactions with mineral N and P fertilizers, on wood volume. Four rates of sludge (0, 8, 15 and 23 Mg ha −1 , dry base), N (0, 47, 95 and 142 kg ha −1 ) and P (0, 28, 56 and 84 kg ha −1 of P 2 O 5 ) were combined in a 4 × 4 × 4 factorial scheme in a totally randomized block design. Response surface and age-shift modeling was used to establish an initial recommendation for mineral fertilization of the Eucalyptus plantations treated with sludge and to analyze the implications of increased growth on the duration of the forest cycle in a Tropical climate. The results showed that from 8 to 44 months after planting, the sludge application (with or without N and P) yielded a statistically larger wood volume ( P i ) application of sludge based on N criterion reduced the need for N and P fertilizers by 100%; and ii ) an increase in wood volume by 7% could be achieved, compared to NPK fertilizers only, if 2/3 of the recommended P was applied. The cultivation time to produce 150 m 3 ha −1 of wood volume was 45 months for the control and was reduced by two, three, four, or five months, respectively, through application of recommended P, sludge dose, sludge plus one third of P, and sludge plus two thirds of P. On the whole, sewage sludge could represent an excellent unconventional N and P fertilizer source for wood production on unfertile Tropical Soils.
Gian Franco Capra - One of the best experts on this subject based on the ideXlab platform.
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long term effects of residual sewage sludge application in Tropical Soils under eucalyptus plantations
Journal of Cleaner Production, 2019Co-Authors: Antonio Leite Florentino, Takashi Muraoka, Thiago Assis Rodrigues Nogueira, Gian Franco Capra, Alexandre De Vicente Ferraz, Jose Leonardo De Moraes Goncalves, Veronica Asensio, Carlos Tadeu Dos Santos Dias, Cassio Hamilton AbreujuniorAbstract:Abstract Studies regarding the residual effects of sewage sludge in soil several years after the first and only application are still scarce, especially for Tropical areas under forestry management. In these Soils, the residual effects can represent a neglected phenomenon, since silvicultural management experiences a longer crop rotation cycle compared to most common agricultural cycles. Consequently, under forestry management, sewage sludge applications can represent an event occurring just once over cycles of several years. This study aimed to evaluate the long-term effects of residual sewage sludge application in infertile Tropical Soils under Eucalyptus plantations in terms of both the main chemical features (pH, soil organic matter, N, P, S, K, Ca, Mg, and cation-exchange capacity) and the potentially toxic elements (As, Ba, Cd, Co, Cr, Cu, Mo, Ni, Pb, Se, and Zn) concentrations/behaviors of soil. Residual effects were evaluated in four areas (Sao Paulo State, Brazil) after 10.0, 12.2, 12.4, and 17.2 years from the first and only application, respectively. Differences in terms of treatments were evaluated by analysis of variance; correlations and similarity analyzed by principal component and cluster analysis, respectively. The results showed that soil organic matter, main macronutrients (N and P), and cation-exchange capacity contents were generally higher in sewage sludge-treated Soils while potentially toxic element contents tended to increase at increasing sewage sludge doses. In most of the investigated treatments, the potentially toxic element concentrations were usually below both the soil natural background concentrations and quality reference values. Principal component and cluster analysis revealed that differences among areas were primary due to differences in applied sewage sludge type and amount. The effects of residual sewage sludge application on soil, in terms of both the pros and cons, can be detected even many years after the first and only application. Studies on the long-term effects of sewage sludge should be mandatory for both monitoring the pedoenvironment and for guiding policymakers and producers on the best practices for their reuse and management.
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fertilization using sewage sludge in unfertile Tropical Soils increased wood production in eucalyptus plantations
Journal of Environmental Management, 2017Co-Authors: Cassio Hamilton Abreujunior, Lucia Pitol Firme, Carlos Alberto Baca Maldonado, Sebastiao Pires De Moraes Neto, Marcelo Correa Alves, Takashi Muraoka, Antonio Enedi Boaretto, Jose Luis Gava, Thiago Assis Rodrigues Nogueira, Gian Franco CapraAbstract:Abstract Fertilization of Eucalyptus plantations using sewage sludge on unfertile Tropical Soils represents an alternative to using mineral N and P fertilizers. A 44-month field experiment was conducted to study the effects of increasing application of sludge, and its interactions with mineral N and P fertilizers, on wood volume. Four rates of sludge (0, 8, 15 and 23 Mg ha −1 , dry base), N (0, 47, 95 and 142 kg ha −1 ) and P (0, 28, 56 and 84 kg ha −1 of P 2 O 5 ) were combined in a 4 × 4 × 4 factorial scheme in a totally randomized block design. Response surface and age-shift modeling was used to establish an initial recommendation for mineral fertilization of the Eucalyptus plantations treated with sludge and to analyze the implications of increased growth on the duration of the forest cycle in a Tropical climate. The results showed that from 8 to 44 months after planting, the sludge application (with or without N and P) yielded a statistically larger wood volume ( P i ) application of sludge based on N criterion reduced the need for N and P fertilizers by 100%; and ii ) an increase in wood volume by 7% could be achieved, compared to NPK fertilizers only, if 2/3 of the recommended P was applied. The cultivation time to produce 150 m 3 ha −1 of wood volume was 45 months for the control and was reduced by two, three, four, or five months, respectively, through application of recommended P, sludge dose, sludge plus one third of P, and sludge plus two thirds of P. On the whole, sewage sludge could represent an excellent unconventional N and P fertilizer source for wood production on unfertile Tropical Soils.
Luis Reynaldo Ferracciu Alleoni - One of the best experts on this subject based on the ideXlab platform.
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degree of phosphate saturation in highly weathered Tropical Soils
Agricultural Water Management, 2018Co-Authors: Murilo De Campos, Joao Arthur Antonangelo, Sjoerd E A T M Van Der Zee, Luis Reynaldo Ferracciu AlleoniAbstract:The degree of phosphate saturation (DPS) is an indicator for P-saturation, which is of assistance to the prediction of P losses and potential eutrophication of surface water. The scaling factor (α) estimates the adsorption capacity of the soil and is used to calculate the DPS. In Soils from temperate regions, the value of α = 0.5 is widely used. However, using just a single value for α may fail to estimate the adsorption capacity correctly for all Soils. In this study, the aims were (i) to calculate the scaling factor α and the DPS of highly weathered Tropical Soils with different chemical, physical and mineralogical properties in order to predict P losses; and (ii) to identify which soil properties are related to P adsorption. The scaling factor α and the DPS were calculated at 1, 3, 7, 21, 42 and 84 days (d), the highest one in recognition of the long-term kinetics of sorption. The values of α increased as the contact period increased. Lower DPS values were obtained in Soils with high P adsorption capacity whereas the highest DPS values were obtained in Soils with a lower adsorption capacity. Out of ten Oxisols studied, six of them had an α higher than 1. Contents of clay, organic carbon (C) and poorly crystalline (Alox) and crystalline (“free”) Al oxides were the properties that best correlated with P adsorption. For the Oxisols, the clay content, poorly crystalline together with crystalline Fe and Al oxides represented the main components related to P adsorption. The highest DPS (31%) was found in Typic Udorthent. The content of poorly crystalline oxides was not suitable for the scaling factor α for most Oxisols, and only the Typic Udorthent exceeded the critical threshold of 23%, and is thus more susceptible to loss of P.
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cadmium sorption and extractability in Tropical Soils with variable charge
Environmental Monitoring and Assessment, 2018Co-Authors: Marina Colzato, Luis Reynaldo Ferracciu Alleoni, Marcos Yassuo KamogawaAbstract:The availability of cadmium (Cd) for plants and its impact in the environment depends on Cd sorption in soil colloids. The study of Cd sorption in soil and its fractionation is an interesting tool for the evaluation of Cd affinity with soil pools. The objective with this study was to evaluate Cd sorption and desorption in Tropical Soils with variable charge (three Oxisols), in a Mollisol and in two Entisols with diverse physical, chemical, and mineralogical attributes. We used a thermodynamic approach to evaluate Cd sorption and performed a chemical fractionation of Cd in the six Soils. Data from Cd sorption fit the Langmuir model (r > 0.94), and the sorption capacity ranged from 0.33 to 11.5 mmol kg-1. The Gibbs standard free energy was positively correlated to Cd sorption capacity (r = 0.74, except for the Quartzipsamments), and it was more favorable in Soils with great sorption capacity. Distribution of Cd among fractions was not affected (t test, α = 0.05) by initial concentration, and there was a predominance of Cd extractable in 0.1 mol L-1 CaCl2.
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phosphorus sorption index in humid Tropical Soils
Soil & Tillage Research, 2016Co-Authors: Murilo Rodrigues De Campos, Joao Arthur Antonangelo, Luis Reynaldo Ferracciu AlleoniAbstract:Abstract The dynamics of phosphorus (P) in Soils is strongly influenced by organic and inorganic solid phases, biological activity and environmental factors. Highly weathered Soils naturally contain low levels of P available to plants and have high adsorption capacity. The maximum adsorption capacity of P ( S max ) has been widely used to evaluate the adsorption capacity of soil P. The P sorption index (PSI) is also used for evaluating the P adsorption capacity of soil from a single concentration of P and is an effective alternative in the estimation of maximum adsorption. We obtained the maximum capacity of P adsorption ( S max ) and the P sorption index (PSI) of 29 Brazilian Soils with different chemical, physical and mineralogical attributes. The use of the PSI to estimate the adsorption of P in a long-term experiment was also evaluated. For S max , rates of 10, 25, 50, 100, 200 and 260 mg L −1 of P in 24 h of contact were used. For the PSI, Soils were divided into groups because of the variation in their capacity to adsorb P, and each group received an optimal P rate: 200, 500, 1000, 1500 or 3000 mg L −1 of P. The periods of reaction assessed were 1, 3, 7, 21, 42, and 84 d. S max was affected by amounts of clay, Fe and Al oxides and organic carbon (OC), which ranged from 61.7 (Typic Haploxeralf) to 5459.5 mg kg −1 (Mollic Fluvaquent). In the PSI, the average percentage of P adsorbed at the end of the contact period (84 d) ranged from 23% to 49% of P that was mixed initially and was, on average, four times higher than their values after 1 d of contact. Oxisols, Alfisols and Gleysols had the highest values of PSI. On the other hand, Ultisols and Entisols had the lowest ones. The PSI behaved similarly to the S max , and the highest values were found in Soils with high contents of clay, C, crystalline and poorly crystallized Fe and Al oxides. Furthermore, the PSI was higher in the 84th day, highlighting the influence of the period of contact on P adsorption.
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heavy metal sequential extraction methods a modification for Tropical Soils
Chemosphere, 2006Co-Authors: Maria L Silveira, Luis Reynaldo Ferracciu Alleoni, G A Oconnor, Andrew C ChangAbstract:Abstract Sequential extractions of metals can be useful to study metal distributions in various soil fractions. Although several sequential extraction procedures have been suggested in the literature, most were developed for temperate Soils and may not be suitable for Tropical Soils with high contents of Mn and Fe oxides. The objective of this study was to develop a sequential fractionation procedure for Cu and Zn in Tropical Soils. Extractions were performed on surface (0–20 cm) samples of ten representative Soils of Sao Paulo State, Brazil. Chemically reactive Mn forms were satisfactorily assessed by the new modified procedure. Amorphous and crystalline Fe oxides were more selectively extracted in a new two-step extraction. Soil-born Zn and Cu were primarily associated with recalcitrant soil fractions. The proposed procedure provided more detailed information on metal distribution in Tropical Soils and better characterization of the various components of the soil matrix. The new procedure is expected to be an important tool for predicting the potential effects of environmental changes and land application of metals on the redistribution of chemical forms of metals in Tropical Soils.
Thiago Assis Rodrigues Nogueira - One of the best experts on this subject based on the ideXlab platform.
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long term effects of residual sewage sludge application in Tropical Soils under eucalyptus plantations
Journal of Cleaner Production, 2019Co-Authors: Antonio Leite Florentino, Takashi Muraoka, Thiago Assis Rodrigues Nogueira, Gian Franco Capra, Alexandre De Vicente Ferraz, Jose Leonardo De Moraes Goncalves, Veronica Asensio, Carlos Tadeu Dos Santos Dias, Cassio Hamilton AbreujuniorAbstract:Abstract Studies regarding the residual effects of sewage sludge in soil several years after the first and only application are still scarce, especially for Tropical areas under forestry management. In these Soils, the residual effects can represent a neglected phenomenon, since silvicultural management experiences a longer crop rotation cycle compared to most common agricultural cycles. Consequently, under forestry management, sewage sludge applications can represent an event occurring just once over cycles of several years. This study aimed to evaluate the long-term effects of residual sewage sludge application in infertile Tropical Soils under Eucalyptus plantations in terms of both the main chemical features (pH, soil organic matter, N, P, S, K, Ca, Mg, and cation-exchange capacity) and the potentially toxic elements (As, Ba, Cd, Co, Cr, Cu, Mo, Ni, Pb, Se, and Zn) concentrations/behaviors of soil. Residual effects were evaluated in four areas (Sao Paulo State, Brazil) after 10.0, 12.2, 12.4, and 17.2 years from the first and only application, respectively. Differences in terms of treatments were evaluated by analysis of variance; correlations and similarity analyzed by principal component and cluster analysis, respectively. The results showed that soil organic matter, main macronutrients (N and P), and cation-exchange capacity contents were generally higher in sewage sludge-treated Soils while potentially toxic element contents tended to increase at increasing sewage sludge doses. In most of the investigated treatments, the potentially toxic element concentrations were usually below both the soil natural background concentrations and quality reference values. Principal component and cluster analysis revealed that differences among areas were primary due to differences in applied sewage sludge type and amount. The effects of residual sewage sludge application on soil, in terms of both the pros and cons, can be detected even many years after the first and only application. Studies on the long-term effects of sewage sludge should be mandatory for both monitoring the pedoenvironment and for guiding policymakers and producers on the best practices for their reuse and management.
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effects of sewage sludge application on unfertile Tropical Soils evaluated by multiple approaches a field experiment in a commercial eucalyptus plantation
Science of The Total Environment, 2019Co-Authors: Cassio Hamilton Abreujunior, Thiago Assis Rodrigues Nogueira, Maria Julia De Lima Brossi, R T R Monteiro, Paulo Henrique Silveira Cardoso, Thays Da Silva Mandu, Antonio Ganga, Peter Filzmoser, Fernando Carvalho Oliveira, Lucia Pitol FirmeAbstract:Abstract Sewage sludge (SS) reuse in forest plantation as soil fertilizer/amendment has tremendously increased in recent years. However, SS may have high concentrations of potentially toxic elements (PTE), representing a potential risk for soil and the whole ecosystem. This paper was aimed to assess the toxicity of PTE in unfertile Tropical Soils amended with SS in a commercial Eucalyptus plantation, with an integrated multiple approaches combining: i) the use of a battery of bioassays (Daphnia magna, Pseudokcrichirella subcapitata, Lactuca sativa, and Allium cepa); and ii) the evaluation of some PTE (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) and their availability into the pedoenvironment. Differences in total and available PTE between SS doses and time of treatments were evaluated using ANOVA; correlations between PTE and bioassays by a sparse partial robust M-regression (SPRM), while multiple correlations among parameters were performed by principal factor analysis (PFA). Results show that PTE contents in Soils tended to increase with SS application doses. However this cannot be assumed as a general rule since in all the investigated treatments the PTE concentrations were consistently below both soil natural background concentrations and quality reference values. Bioassays showed a generalized low eco- and genotoxicity of SS with an increase in toxicity at increasing SS doses but with a clear decreasing trend as time went by. A. cepa was the most sensitive bioassay followed by P. subcapitata > D. magna > L. sativa. Overall, the results indicate that in realistic open field conditions SS risk may be lower than expected due to dynamic decrease in PTE toxicity with time after application. This study has an important implication that open-field trials should be strongly encouraged for evaluating environmental risk of SS application in forestry.
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fertilization using sewage sludge in unfertile Tropical Soils increased wood production in eucalyptus plantations
Journal of Environmental Management, 2017Co-Authors: Cassio Hamilton Abreujunior, Lucia Pitol Firme, Carlos Alberto Baca Maldonado, Sebastiao Pires De Moraes Neto, Marcelo Correa Alves, Takashi Muraoka, Antonio Enedi Boaretto, Jose Luis Gava, Thiago Assis Rodrigues Nogueira, Gian Franco CapraAbstract:Abstract Fertilization of Eucalyptus plantations using sewage sludge on unfertile Tropical Soils represents an alternative to using mineral N and P fertilizers. A 44-month field experiment was conducted to study the effects of increasing application of sludge, and its interactions with mineral N and P fertilizers, on wood volume. Four rates of sludge (0, 8, 15 and 23 Mg ha −1 , dry base), N (0, 47, 95 and 142 kg ha −1 ) and P (0, 28, 56 and 84 kg ha −1 of P 2 O 5 ) were combined in a 4 × 4 × 4 factorial scheme in a totally randomized block design. Response surface and age-shift modeling was used to establish an initial recommendation for mineral fertilization of the Eucalyptus plantations treated with sludge and to analyze the implications of increased growth on the duration of the forest cycle in a Tropical climate. The results showed that from 8 to 44 months after planting, the sludge application (with or without N and P) yielded a statistically larger wood volume ( P i ) application of sludge based on N criterion reduced the need for N and P fertilizers by 100%; and ii ) an increase in wood volume by 7% could be achieved, compared to NPK fertilizers only, if 2/3 of the recommended P was applied. The cultivation time to produce 150 m 3 ha −1 of wood volume was 45 months for the control and was reduced by two, three, four, or five months, respectively, through application of recommended P, sludge dose, sludge plus one third of P, and sludge plus two thirds of P. On the whole, sewage sludge could represent an excellent unconventional N and P fertilizer source for wood production on unfertile Tropical Soils.
S E Obalum - One of the best experts on this subject based on the ideXlab platform.
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measured versus estimated total porosity along structure stability gradients of coarse textured Tropical Soils with low activity clay
Environmental Earth Sciences, 2014Co-Authors: S E Obalum, M E ObiAbstract:Soil total porosity is, rather than measured by water desorption method, more often estimated from bulk density (BD) and assumed particle density. Measured and estimated total porosities of even kaolinitic Tropical Soils (which have low tendency to expand upon wetting) usually differ by an extent that depends on soil structural stability, but such differences are scarcely documented. Seventy samples of coarse-textured Soils under different fallow- and cultivation-management systems in the southeastern region of Nigeria were analyzed for texture, mean-weight diameter (MWD) of aggregates, BD and organic matter (OM) concentration. Soil total porosities measured by water desorption method were compared with those estimated from BDs (with particle density fixed at 2.70 g cm−3), after grouping the Soils by structural stability, assessed by OM/(silt + clay) for 50 of the samples from fallowed plots (BD > 1.48 g cm−3) and MWD for the rest from cultivated plots (BD < 1.48 g cm−3). The fallowed plots showed a wider stability range than the cultivated plots. Irrespective of land use, structural stability tended to increase with decreasing soil BD. Measured total porosities were consistently higher than their estimated counterparts, with the differences closing up with increasing soil structural stability up till a mean BD of 1.41 ± 0.05 g cm−3 (corresponding to MWD of 2.66 ± 0.12 mm), beyond which the trend reversed. These results suggest that, as the soil structural stability increases, soil particle density decreases while entrapped air and transitory drainage of saturated samples at weighing increase. Estimating total porosity with a fixed particle density of 2.70 g cm−3 appears suitable only in highly stable Soils, with BD of ≤1.40 ± 0.08 g cm−3 and/or MWD of ≥2.92 ± 0.05 mm [corresponding to OM/(silt + clay) of ≥16.38 ± 0.28 %].
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moisture characteristics and their point pedotransfer functions for coarse textured Tropical Soils differing in structural degradation status
Hydrological Processes, 2013Co-Authors: S E Obalum, M E ObiAbstract:The effect of soil structure on hydraulic pedotransfer functions (PTFs) in Tropical Soils with similar mineralogy and texture has not been well documented. Structurally contrasting Soils from representative locations in southeastern Nigeria were analyzed for moisture retention at 0, 6, 10, 33, 100, 300 and 1500 kPa among other properties. They were grouped by depth (topSoils or subSoils) and also by their structural degradation status into low- and high-stability Soils, corresponding to organic matter (OM):[silt + clay] of 7.5%, respectively. Soil depth and structural stability influenced the soil moisture characteristic curves. The data were fitted to three Tropical point PTFs, but none of them proved appropriate for predicting moisture retention in the Soils. We therefore derived new ones using multiple linear stepwise regressions before and after the dataset grouping and compared their performances by means of cross-validation. Moisture retention in the Soils (sand content, 73.2–93.8%) could not be calibrated from texture and OM concentration alone, until when bulk density, total porosity and microporosity were included among the regressors. Microporosity's role was particularly outstanding at all matric potentials but the 1500 kPa. The ensuing PTFs represent a good fit for the soil moisture retention data. The two grouping strategies resulted in lower SE of the estimates in some cases, but this did not enhance the performances of the concerned PTFs. At the 1500 kPa, however, the PTF incorporating all datasets performed better than separate PTFs for topSoils/subSoils but worse than the one for high-stability Soils. Information on soil structure can therefore benefit PTF derivation for kaolinite-dominated, coarse-textured Tropical Soils at all the matric potentials considered. Copyright © 2012 John Wiley & Sons, Ltd.