Canadian Journal of Soil Science最新文献

{"title":"The story of long-term research sites and soil health in Canadian agriculture","authors":"C. Norris, M. Gorzelak, M. Arcand, D. Bruhjell, C. Carlyle, M. Dyck, B. Ellert, M. Entz, C. Geddes, X. Hao, K. Janovicek, F. Larney, W. May, M. S. Luce, L. V. Van Eerd, Tiequan Zhang, R. Beck, Tony Cowen, D. Liptzin, C. Morgan","doi":"10.1139/cjss-2021-0174","DOIUrl":"https://doi.org/10.1139/cjss-2021-0174","url":null,"abstract":"Abstract Canada's interest in agricultural lands has changed with time from a desire of crop yields at Confederation through to discussions in the Senate on adaptation and resilience in 2018. Long-term research experiments (LTRs) have been present and utilized by federal and university researchers to provide answers throughout. Here we highlight the importance of LTRs by identifying the historical context of LTRs and soil health research in Canada. We then briefly describe the history and key results from select LTRs and illustrate the wealth of information collected from the North American Project to Evaluate Soil Health Measurements cross-country point-in-time soil sampling from these LTRs. We discuss the LTRs, and the knowledge gained from them, with the hope that by showing the distinctive narratives associated with each of these study sites, researchers will be inspired to use them to address their research questions and make sound predictions to facilitate the adaptation of Canadian agroecosystems to climate challenges. Through identifying the value generated by these unique LTRs, we hope that the importance of these sites will inspire not only their continued maintenance but also the next generation of LTRs.","PeriodicalId":9384,"journal":{"name":"Canadian Journal of Soil Science","volume":"103 1","pages":"164 - 190"},"PeriodicalIF":1.7,"publicationDate":"2022-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43759630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improved parent material map disaggregation methods in the Saskatchewan prairies using historical bare soil composite imagery","authors":"Preston Thomas Sorenson, J. Kiss, A. Bedard-Haughn","doi":"10.1139/cjss-2021-0154","DOIUrl":"https://doi.org/10.1139/cjss-2021-0154","url":null,"abstract":"Abstract The major drivers of soil variation in Saskatchewan at scales finer than the existing soil maps are parent material variance, slope position, and salinity. There is therefore a need to generate finer-scale parent material maps as part of updating soil maps in Saskatchewan. As spatially referenced soil point data are lacking in Saskatchewan, predictive soil mapping methods that disaggregate existing soil parent material maps are required. This study focused on investigating important environmental covariates to use in parent material disaggregation, particularly bare soil composite imagery (BSCI). Synthetic point observations were generated using an area-proportional approach based on existing soil survey polygons and a random forest model was trained with those synthetic observations to predict parent material classes. Including BSCI as environmental covariates increased model accuracy from 0.38 to 0.52 and the model Kappa score from 0.19 to 0.35 compared with models where it was not included. Models that included training points from all locations, regardless of whether BSCI was available, and included BSCI as environmental covariates had similar results to the BSCI model with an accuracy of 0.48 and a Kappa value of 0.30. Based on these results, BSCI is an important covariate for parent material disaggregation in the Saskatchewan Prairies. Future work to disaggregate soil classes based on slope position and salinity, and to combine those methods with parent material disaggregation is needed to generate detailed soil maps for the Canadian Prairies.","PeriodicalId":9384,"journal":{"name":"Canadian Journal of Soil Science","volume":"103 1","pages":"47 - 63"},"PeriodicalIF":1.7,"publicationDate":"2022-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46387981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Water and salt transport characteristics in a soil column in the presence of a low-permeable body","authors":"Yi Guo, Quanjiu Wang, Yang Liu, Jihong Zhang, K. Wei","doi":"10.1139/cjss-2022-0061","DOIUrl":"https://doi.org/10.1139/cjss-2022-0061","url":null,"abstract":"Abstract Soil water infiltration is an important factor affecting surface runoff, soil erosion, and soil solute transmission. Increasing soil infiltration reduces runoff and erosion. The presence of low-permeable body in soil can enhance soil infiltration capacity. However, different depths of low-permeable body have unknown effects on water infiltration and salt transfer. In this work, we evaluated the effects of low-permeable body with varied depths (control (CK), 0, 0.5, 1, and 1.5 cm) on silty loam soil water and salt movement using 15 soil columns (23 cm internal diameter, 50 cm length). Experimental results showed that low-permeable body increased infiltration rate and wetting front migration rate. Infiltration rate and wetting front propulsion rate decreased with the increase of the burial depth. Compared with the CK, when the depth of wetting front reached 20 cm, the infiltration time of 0, 0.5, 1, and 1.5 cm burial depth treatment was shortened by 72.24%, 56.29%, 44.61%, and 31.01%, respectively. Simultaneously, the existence of low-permeable body led to the increase of soil water content and salt content in the same soil layer, which indicated that the low-permeable body enhanced the soil holding capacity and reduced the salt leakage to the deep soil. Furthermore, the Philip’s model and the algebraic model were used to describe the infiltration process. Fitting results showed that the sorptivity in the Philip’s model increased with burial depth, while the comprehensive shape coefficient in the algebraic model decreased. Therefore, this study provides a reference for the application of low-permeable body in the improving soil infiltration capacity and controlling salt transport. Résumé L’infiltration de l’eau dans le sol est un facteur important qui affecte le ruissellement en surface, l’érosion du sol et le transport des solutés. Quand l’infiltration augmente, le ruissellement et l’érosion s’amenuisent. La présence d’un corps peu perméable dans le sol peut accroître l’infiltration d’eau. Cependant, on ignore quels effets il pourrait avoir sur l’infiltration et le transport des sels selon la profondeur d’enfouissement. Les auteurs ont évalué les effets d’un corps peu perméable situé à diverses profondeurs (témoin (CK), 0, 0,5, 1, 1,5 cm) sur la concentration d’eau dans un loam limoneux et sur le déplacement des sels en recourant à 15 colonnes de sol (23 cm de diamètre interne, 50 cm de longueur). Les résultats de l’expérience montrent que le corps peu perméable augmente le taux d’infiltration et la vitesse de déplacement du front d’humectation. Ces deux paramètres diminuent à mesure que s’accroît la profondeur de l’enfouissement. Comparativement au traitement CK, où le front d’humectation a atteint 20 cm de profondeur, le temps d’infiltration s’est respectivement raccourci de 72,24 %, 56,29 %, 44,61 % et 31,01 % avec une profondeur d’enfouissement de 0, 0,5, 1 et 1,5 cm. Parallèlement, l’existence d’un corps peu perméable a entraîné une ","PeriodicalId":9384,"journal":{"name":"Canadian Journal of Soil Science","volume":"102 1","pages":"991 - 999"},"PeriodicalIF":1.7,"publicationDate":"2022-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47373516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ex situ soil respiration assessment using minimally disturbed microcosms and dried–sieved soils; comparison of methods to assess soil health","authors":"L. Comeau, Kyle MacKinley, Adrian Unc, J. Vallotton","doi":"10.1139/cjss-2021-0143","DOIUrl":"https://doi.org/10.1139/cjss-2021-0143","url":null,"abstract":"Abstract Soil respiration measurements are commonly used as soil health indicators. Several ex situ soil respiration methods exist, but comparative performances between them have rarely been analyzed. Specifically, there is a lack of comparisons between intact microcosms and destructive methods. The objective of this study was to analyze and compare three different ex situ soil respiration methodologies: minimally disturbed microcosms using fresh soil, dried–sieved 24 h burst test, and dried–sieved 10-day incubation. We hypothesized that (i) the respiration rates for the three methods are correlated to each other; (ii) the respiration rates are strongly correlated with soil physico-chemical parameters; (iii) disturbance caused by drying and sieving reduces regression coefficients compared with microcosms; and (iv) drying and sieving soil produces larger respiration rates. Soil was collected in the Province of New Brunswick, Canada. Total carbon and nitrogen (C:N), pH, aggregate stability, total dissolved C and N, NO3 and NH4, texture, and labile C were determined prior to incubations. Our results showed that the three methods had CO2 efflux in similar ranges. However, all the methods had low to no significant correlations between soil physico-chemical parameters and respiration. Total dissolved N had the strongest correlation with CO2 efflux. The results of the microcosm method significantly correlated with the results for 24 h burst test but not with the 10-day incubation method. We conclude that drying and sieving soil prior to performing ex situ soil heterotrophic respiration measurements using the 24 h burst tests can produce cautiously reliable results. Despite the disturbance, results from the 24 h burst tests are comparable with the results of the microcosm method.","PeriodicalId":9384,"journal":{"name":"Canadian Journal of Soil Science","volume":"103 1","pages":"143 - 151"},"PeriodicalIF":1.7,"publicationDate":"2022-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42403947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The impacts of rock pulverization on soil quality and functional soil nematode and respiration properties of boreal lands converted from forest to agricultural use","authors":"E. Young, J. Vallotton, A. J. Kedir, Ayodeji O. Medaiyese, C. Goyer, L. Comeau, Adrian Unc","doi":"10.1139/cjss-2022-0007","DOIUrl":"https://doi.org/10.1139/cjss-2022-0007","url":null,"abstract":"Abstract Rock pulverization is recommended when converting boreal forests to agricultural land use to facilitate tillage operations. Resulting rock dust incorporation might alter physical, chemical, and biological properties of soils. We assessed soil nematode trophic group abundances and indices, basal and burst respiration, and phosphorus extractability after land use conversion (LUC) and recent pulverization (<1 year) on three soil types in eastern Newfoundland, Canada. Nine treatments representing varied pulverization statuses (managed pulverized, managed unpulverized, natural) were nested in soil type (Podzol, Luvisol, and Organic). Conversion to agriculture impacted soil quality more than the recent rock pulverization. Nonetheless, nematode indices (fungivore/bacterivore, fungivore/fungivore+bacterivore, fungivore + bacterivore/herbivore) suggested no significant functional differences with either LUC or pulverization. Soil organic matter (SOM) and pH were substantial direct and indirect drivers of nematode community composition and soil respiration, mainly by altering availability of aluminium and iron. The functional parameters diverged between Organic and mineral soils. For all soils, most respiration parameters were significantly related to SOM, pH, available iron and aluminium. For nematodes, significant relationships were identified in the Organic soil: bacterivores and fungivores abundances were inversely related to SOM, and bacterivore abundance was positively related to pH. While for the mineral soils, citric acid extracted more phosphorus than the Mehlich-3 or water methods, Mehlich-3 was most effective for the Organic soil. Pulverization did not affect phosphorus extractability. The distinct relationships between soil quality properties and functional parameters between mineral and Organic soils are of interest for further investigations into the concepts of soil quality and soil health. Résumé Quand on souhaite adapter la forêt boréale à l’agriculture, on préconise de pulvériser le roc pour faciliter les labours. L’incorporation de la poussière rocheuse au sol peut cependant en altérer les propriétés physiques, chimiques et biologiques. Les auteurs ont évalué l’abondance des groupes trophiques de nématodes dans le sol et leurs indices, ainsi que le taux de respiration de base, l’explosion oxydative et l’extractabilité du phosphore après conversion de la vocation des terres (CVT) et pulvérisation récente du roc (moins d’un an) pour trois types de sol de l’est de Terre-Neuve, au Canada. Ils ont combiné différents degrés de pulvérisation (gestion de la pierre pulvérisée, gestion de la pierre non pulvérisée, état naturel) et types de sols (podzols, luvisols et sols organiques) en neuf traitements. La conversion en terre agricole a plus d’impact sur la qualité du sol que la pulvérisation récente du roc. Malgré cela, les indices des nématodes (fongivore/bactérivore, fongivore/fongivore+bactérivore, fongivore+bactérivore/herbivore) lai","PeriodicalId":9384,"journal":{"name":"Canadian Journal of Soil Science","volume":"102 1","pages":"977 - 990"},"PeriodicalIF":1.7,"publicationDate":"2022-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46803071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Twenty-four years of contrasting cropping systems on a brown chernozem in Southern Alberta: crop yields, soil carbon, and subsoil salinity","authors":"E. Bremer, D. Pauly, R. McKenzie, B. Ellert, H. Janzen","doi":"10.1139/cjss-2021-0181","DOIUrl":"https://doi.org/10.1139/cjss-2021-0181","url":null,"abstract":"Abstract Cropping systems with perennial forages and reduced fallow frequency generally increase soil organic carbon and thus subsequent soil health and crop yield. We evaluated the impact of prior cropping systems on subsequent yields and soil properties in a semiarid region by using crop yields as a bioassay of soil health following the termination of a 24-year crop rotation study in the Brown soil zone in Alberta. During 24 growing seasons from 1992 to 2015, the study included three fallow-containing rotations, two annual crop rotations that were cropped continuously, and perennial grass hay, each with two to six fertilizer treatments. During the bioassay period from 2016 through 2020, all plots in the study were uniformly cropped. Compared to unfertilized fallow wheat, soil organic C in the fall of 2015 was 54% higher after 24 years of fertilized grass and up to 14% higher following annual crops in rotations without fallow. The most notable impact of the previous cropping system on yield during the bioassay years was low yield following perennial grass in 2016 and 2018. Soil electrical conductivity measurements showed that subsoil salinity was elevated following perennial grass, demonstrating the importance of subsoil characteristics for healthy soils. Crop yields in the fifth year of the crop bioassay were 10%–20% greater due to reduced fallow frequency or increased crop diversity. The long-term impact of the cropping system on crop yield in this study depended on drought intensity due to counteracting changes in soil organic matter and subsoil salinity.","PeriodicalId":9384,"journal":{"name":"Canadian Journal of Soil Science","volume":"103 1","pages":"134 - 142"},"PeriodicalIF":1.7,"publicationDate":"2022-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49138916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Predictive soil mapping in the Boreal Plains of Northern Alberta by using multi-temporal remote sensing data and terrain derivatives","authors":"P. Sorenson, J. Kiss, Anna Serdetchnaia, J. Iqbal, A. Bedard-Haughn","doi":"10.1139/cjss-2022-0028","DOIUrl":"https://doi.org/10.1139/cjss-2022-0028","url":null,"abstract":"Abstract As Canada's vast Boreal Plains are extensively managed, predictive soil mapping could be used as an effective tool to generate high-resolution soil information for the region to inform sustainable resource management. This study aimed to investigate the use of multi-temporal remote sensing data and terrain derivatives to map soil types in the region. A method of constraining subgroup and great-group soil-type predictions based on the predictions at higher-order levels (great-group and order, respectively) was tested. Sentinel time series median values obtained by using Google Earth Engine were tested in combination with first- and second-order digital elevation model derivatives for use as predictor variables in the predictive models. A recursive feature selection process was implemented to reduce the number of predictor variables used in model training. Soil classes were predicted at the order, great-group, and subgroup levels and two approaches were tested. In the first approach, models were unconstrained based on previous predictions. In the second approach, models were constrained to predict only soil great-group classes that occur within the predicted soil order for a given location and similarly predict only soil subgroup classes that occur within the predicted soil great group for a given location. Determined through independent validation testing, the most probable predicted soil maps had overall accuracies ranging from 42% to 68% and kappa scores ranging from 0.33 to 0.48. Overall, the constrained models had the best performance of the approaches tested. Résumé Les vastes plaines boréales du Canada étant largement aménagées, une carte prédictive des sols constituerait un bon moyen pour obtenir des données à haute résolution sur les sols régionaux et ainsi faciliter la gestion des ressources durables. Les auteurs ont examiné comment des données de télédétection multitemporelles et les dérivées du terrain pourraient servir à cartographier la nature des sols locaux. Dans cette optique, ils ont testé une méthode qui contraint les prévisions du sous-groupe et du grand groupe de sols d’après les prévisions effectuées à un ordre plus élevé (ceux du grand groupe et de l’ordre, respectivement). La valeur médiane des séries chronologiques sentinelles obtenues avec le moteur Google Earth a été testée en combinaison avec les dérivées de modèles numériques des hauteurs du premier et du deuxième ordre, employées comme variables explicatives dans le modèle prédictif. Pour réduire le nombre de variables explicatives servant à former le modèle, les auteurs ont recouru à un processus récursif de sélection des propriétés du sol. Les classes de sol ont été prédites aux niveaux de l’ordre, du grand groupe et du sous-groupe, et deux approches ont été vérifiées. Dans la première, les auteurs n’ont pas contraint le modèle selon les prévisions antérieures; dans la seconde, le modèle a été contraint afin de ne prédire que les classes du grand groupe dans","PeriodicalId":9384,"journal":{"name":"Canadian Journal of Soil Science","volume":"102 1","pages":"852 - 866"},"PeriodicalIF":1.7,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47505785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Better recognition of limnic materials at the great group and subgroup levels of the Organic Order of the Canadian System of Soil Classification","authors":"D. Saurette, Raphaël Deragon","doi":"10.1139/cjss-2022-0030","DOIUrl":"https://doi.org/10.1139/cjss-2022-0030","url":null,"abstract":"Abstract In the Canadian System of Soil Classification (CSSC), soils of the Organic order are classified at the great group level primarily based on the dominant organic material in the middle tier. The system recognizes four types of organic horizons: fibric (Of), mesic (Om), humic (Oh), and coprogenous earth (Oco), of which only the latter is not recognized at the great group level of the Organic order. Furthermore, at the subgroup level, Limnic subgroups cannot have terric or hydric layers. This is problematic in soils where the middle tier is dominated by limnic materials, and those which have dominantly limnic materials and have a terric layer. We describe 29 soil profiles in Ontario and Quebec, which are either poorly captured in the CSSC or that cannot be classified into the Organic order based on their diagnostic criteria. Based on an analysis of soil survey information in five provinces across Canada, we estimate 32057 ha of organic soils which potentially contain limnic deposits. In key vegetable-producing areas of Quebec, large organic deposits in agricultural production are subject to peat subsidence and erosion, resulting in shallower depths to underlying coprogenous earth, which is not a suitable medium for crop production. This can potentially have negative effects on crops when mixed with humic materials in the plow layer. Due to these taxonomic and agronomic considerations, we propose the addition of a new great group, Limnisol, and suggest further integration of limnic materials at the subgroup level for the Humisol, Mesisol, and Fibrisol great groups.","PeriodicalId":9384,"journal":{"name":"Canadian Journal of Soil Science","volume":"103 1","pages":"1 - 20"},"PeriodicalIF":1.7,"publicationDate":"2022-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45722085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Beware of scaling artefacts and implicit model characteristics when fitting soil water release and moisture capacity data","authors":"W. D. Reynolds, C. Drury","doi":"10.1139/cjss-2022-0003","DOIUrl":"https://doi.org/10.1139/cjss-2022-0003","url":null,"abstract":"Abstract The primary objectives of this study were to: (i) elucidate the impacts of nonlinear scale transformations on the shapes and parameter values of soil water release and moisture capacity curves; and (ii) demonstrate how implicit characteristics of some established soil water release and moisture capacity models can impact model-data fits and estimates of model parameters. Nonlinear scale transformations of the tension head (h) axis (e.g., log10h, h1/2) were found to distort release and capacity curve shapes, create fictitious curve inflections and modes, and occasionally erase visual evidence of actual inflections and modes. The popular van Genuchten–Mualem and Assouline–Grant models were shown to always generate a release curve inflection and a capacity curve mode, even when inflections and modes did not exist in the data, and this in turn caused poor model-data fits in the critical near-saturated region. The van Genuchten model with four independently fitted parameters and the Dexter–Weibull model could accurately fit data sets with no inflection or mode, but this resulted in a physically unrealistic zero-angle intersection between the release curve and the water content axis. It was concluded that nonlinear h axis transforms should not be used when determining inflections, modes, pore size distributions, soil structure parameters, or soil quality indexes from soil water release and moisture capacity data-sets. It was also recommended that more flexible release curve models should be developed that do not assume the existence of inflections and modes, and also produce physically realistic angles of intersection between the water content axis and the fitted model. Résumé Les principaux objectifs de cette étude étaient les suivants : i) élucider l’impact de la conversion non linéaire des échelles sur la forme et la valeur des paramètres des courbes de la pression capillaire et de la rétention d’eau du sol, et ii) montrer comment les particularités implicites de certains modèles de la pression capillaire et de la rétention d’eau du sol peuvent modifier l’ajustement modèle-données ainsi que l’estimation des paramètres du modèle. Les auteurs ont constaté qu’en convertissant non linéairement l’échelle de l’axe de la pression interstitielle (h) (à savoir, log10h, h1/2), on fausse la forme des deux courbes, on crée une inflexion et un mode fictifs de la courbe et, parfois, on efface les preuves visuelles d’une inflexion et d’un mode véritables. Les auteurs montrent que les populaires modèles de van Genuchten–Mualem et d’Assouline–Grant confèrent toujours une inflexion à la courbe de la pression capillaire et un mode à celle de la rétention d’eau, même si les données en sont privées, ce qui entraîne un piètre ajustement modèle-données dans la zone critique, proche du point de saturation. Le modèle de van Genuchten à quatre paramètres ajustés indépendamment et celui de Dexter-Weibull pourraient bien s’ajuster aux jeux de données sans inflexion ni","PeriodicalId":9384,"journal":{"name":"Canadian Journal of Soil Science","volume":"102 1","pages":"899 - 918"},"PeriodicalIF":1.7,"publicationDate":"2022-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45077589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of increasing soil pH to near-neutral using lime on phosphorus saturation index and water-extractable phosphorus","authors":"S. Nyamaizi, A. Messiga, J. Cornelis, S. Smukler","doi":"10.1139/cjss-2021-0197","DOIUrl":"https://doi.org/10.1139/cjss-2021-0197","url":null,"abstract":"Abstract We studied the effects of liming to increase soil pH from acidic to near-neutral on the degree of phosphorus saturation (DPS), the P saturation index (PSI), Mehlich-3 P (PM3), and water-extractable P (Pw). Soils collected from a long-term highbush blueberry experiment were incubated at 22.5 °C for 93 days after CaCO3 amendment to increase pH values from 4.1, 4.8, and 5.5 to 6 and from 5.8 to 6.5. Liming decreased PM3 by 8%, 6%, 10%, and 11% with increasing initial soil pH. The PM3 concentrations of all the studied soils belonged to the very high class with critical DPS > 25%, which are associated with increased environmental risk of P loss with runoff. For soils with initial pH values of 5.8, Pw was 3.65 mg kg–1, in line with critical DPS > 25%, but decreased to 2.74 mg kg–1 with CaCO3 addition. In contrast, soils with initial pH < 5.5 had lower Pw concentrations and CaCO3 did not significantly decrease Pw at the end of the incubation averaging 1.02, 1.11, and 1.43 mg kg–1 for initial pH 4.1, 4.8, and 5.5, respectively. The low Pw concentrations of soils with initial pH < 5.5 were in line with low PSI (5.2%–6.1%), but did not reflect DPS values > 25%. It is possible that high exchangeable aluminum (Al) (AlM3 > 2500 mg kg–1) enhanced the fixation of phosphate ions from the soil solution, thus reducing Pw. Our results suggest that using PM3 as a sole indicator of environmental risk likely underestimates potential P losses compared with Pw. Résumé Les auteurs ont étudié les effets du chaulage utilisé pour neutraliser le pH d’un sol acide i) sur le taux de saturation du P (TSP), l’indice de saturation du P (ISP), la teneur en P selon la technique Mehlich-3 (PM3) et la teneur du P extractible à l’eau P (Pw). Des échantillons de sol venant d’une expérience de longue haleine sur le bleuet en corymbe ont été incubés pendant 93 jours à 22,5 °C après avoir été amendés avec du CaCO3 de façon à augmenter le pH de 4,1, 4,8 ou 5,5 à 6 et de 5,8 à 6,5. Le chaulage diminue la concentration de PM3 de 8, 6, 10 et 11 %, selon le pH du sol de plus en plus élevé. Dans tous les sols examinés, la concentration de PM3 se retrouve dans la classe la plus élevée, avec un TSP supérieur à 25 %, associé à un risque plus grand de lixiviation par le ruissellement. Pour les sols dont le pH initial était de 5,8, la concentration de Pw s’établissait à 3,65 mg par kg, ce qui est cohérent avec un TSP critique de plus de 25%, mais l’addition de CaCO3 ramène la concentration à 2,74 mg par kg. En revanche, les sols au pH inférieur à 5,5 au départ se caractérisaient par une concentration inférieure de Pw qui n’avait pas été affectée de manière significative par le CaCO3 à la fin de la période d’incubation (concentration moyenne de 1,02, 1,11 et 1,43 mg par kg pour un pH initial de 4,1, 4,8 ou 5,5, respectivement). La faible concentration de Pw observée dans les sols dont le pH initial était inférieur à 5,5 est cohérente avec le faible ISP (de 5,2 à 6,1 %), mais pas avec un TSP ","PeriodicalId":9384,"journal":{"name":"Canadian Journal of Soil Science","volume":"102 1","pages":"929 - 945"},"PeriodicalIF":1.7,"publicationDate":"2022-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42446655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}