Abstract Deep vertical rotary tillage (DVRT) is a novel technique; however, its influence on soil bacterial diversity and community structure remains unclear. Herein, it was hypothesized that this tillage method significantly improves the bacterial diversity and alters the bacterial community structure and therefore it supports enhanced soil ecosystem functions in cultivated land. We investigated the soil bacterial communities and performed molecular ecological network analysis of cultivated land soils under different tillage regimes using high-throughput 16S rRNA gene Illumina sequencing. Soil samples were collected from the experimental field under 2 treatments: DVRT and conventional rotary tillage (CT) in Shizuishan City, Ningxia, China, in a 2-year field experiment. The α-diversity indices showed that DVRT resulted in higher bacterial diversity. In addition, the principal coordinate analysis results revealed a clear separation among the groups of cultivated land soils under the 2 treatment regimes. The key physicochemical factors that significantly influenced bacterial diversity and community structure were pH and total potassium concentration. The network analysis indicated that the bacterial network of DVRT soils consisted of more functionally interrelated bacterial modules than that of soils under CT, and the topological roles of characteristic bacteria and key bacteria were also different. In relation to CT, the relative abundances of organisms belonging to the functional groups of “Xenobiotics biodegradation and metabolism”, “Signal transduction”, and “Metabolism of cofactors and vitamins” were significantly increased in cultivated land soils under DVRT. It was concluded that DVRT treatment could improve bacterial diversity, alter the bacterial network structure, and enhance potential ecosystem functions in soils of cultivated land. Résumé Le labour rotatif vertical en profondeur (LRVP) est une nouvelle technique dont on connaît mal l’incidence sur la diversité et la structure de la microflore tellurique. Les auteurs ont formulé l’hypothèse que cette pratique améliore la diversité des bactéries et modifie la structure de leur population, donc améliore le fonctionnement de l’écosystème dans les terres cultivées. Pour le vérifier, ils ont examiné la microflore du sol et procédé à une analyse moléculaire du réseau écologique dans les terres cultivées selon différents régimes de travail du sol. L’analyse reposait sur la méthode Illumina de séquençage à haut débit des gènes de l’ARNr 16S. Les échantillons de sol venaient d’une parcelle soumise à deux régimes (LRVP et binage rotatif classique ou BR) dans le cadre d’une expérience sur le terrain de deux ans à Shizuishan, dans la régions autonome du Ningxia, en Chine. Les indices alpha de la diversité montrent que le LRVP accroît la diversité de la population bactérienne. En outre, les résultats de l’analyse en coordonnées principales révèlent une nette distinction entre les groupes présents dan
{"title":"Deep vertical rotary tillage increases the diversity of bacterial communities and alters the bacterial network structure in soil planted to corn","authors":"Wanyu Xia, Xiaoyue Ren, Yanyun Chen","doi":"10.1139/cjss-2021-0208","DOIUrl":"https://doi.org/10.1139/cjss-2021-0208","url":null,"abstract":"Abstract Deep vertical rotary tillage (DVRT) is a novel technique; however, its influence on soil bacterial diversity and community structure remains unclear. Herein, it was hypothesized that this tillage method significantly improves the bacterial diversity and alters the bacterial community structure and therefore it supports enhanced soil ecosystem functions in cultivated land. We investigated the soil bacterial communities and performed molecular ecological network analysis of cultivated land soils under different tillage regimes using high-throughput 16S rRNA gene Illumina sequencing. Soil samples were collected from the experimental field under 2 treatments: DVRT and conventional rotary tillage (CT) in Shizuishan City, Ningxia, China, in a 2-year field experiment. The α-diversity indices showed that DVRT resulted in higher bacterial diversity. In addition, the principal coordinate analysis results revealed a clear separation among the groups of cultivated land soils under the 2 treatment regimes. The key physicochemical factors that significantly influenced bacterial diversity and community structure were pH and total potassium concentration. The network analysis indicated that the bacterial network of DVRT soils consisted of more functionally interrelated bacterial modules than that of soils under CT, and the topological roles of characteristic bacteria and key bacteria were also different. In relation to CT, the relative abundances of organisms belonging to the functional groups of “Xenobiotics biodegradation and metabolism”, “Signal transduction”, and “Metabolism of cofactors and vitamins” were significantly increased in cultivated land soils under DVRT. It was concluded that DVRT treatment could improve bacterial diversity, alter the bacterial network structure, and enhance potential ecosystem functions in soils of cultivated land. Résumé Le labour rotatif vertical en profondeur (LRVP) est une nouvelle technique dont on connaît mal l’incidence sur la diversité et la structure de la microflore tellurique. Les auteurs ont formulé l’hypothèse que cette pratique améliore la diversité des bactéries et modifie la structure de leur population, donc améliore le fonctionnement de l’écosystème dans les terres cultivées. Pour le vérifier, ils ont examiné la microflore du sol et procédé à une analyse moléculaire du réseau écologique dans les terres cultivées selon différents régimes de travail du sol. L’analyse reposait sur la méthode Illumina de séquençage à haut débit des gènes de l’ARNr 16S. Les échantillons de sol venaient d’une parcelle soumise à deux régimes (LRVP et binage rotatif classique ou BR) dans le cadre d’une expérience sur le terrain de deux ans à Shizuishan, dans la régions autonome du Ningxia, en Chine. Les indices alpha de la diversité montrent que le LRVP accroît la diversité de la population bactérienne. En outre, les résultats de l’analyse en coordonnées principales révèlent une nette distinction entre les groupes présents dan","PeriodicalId":9384,"journal":{"name":"Canadian Journal of Soil Science","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2022-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42216506","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}
Soufiane Lahbouki, Lahoucine Ech-chatir, S. Er-raki, A. Outzourhit, A. Meddich
Abstract The prickly pear (Opuntia ficus-indica) is an essential economic and ecological medicinal plant in arid and semi-arid areas, especially in Morocco, where water scarcity affects its survival and growth. Evidence suggests that subsurface water retention technology (SWRT) may enhance crops’ drought resistance. A field experiment was conducted to explore SWRT application effects on cactus cladodes’ growth and physiological and biochemical performance under drought conditions. Two water regimes were applied (rainfed conditions; irrigated with 4 L of water twice a week) with two treatments (without SWRT; with SWRT). The results showed that cactus cladodes’ growth and physiological and biochemical parameters cultivated for 8 months were negatively affected by drought. Drought-exposed cactus cladodes under SWRT application showed an increase in surface area and cladode stomatal densities by 65% and 29%, respectively, compared with no SWRT. This technology reduced drought-induced oxidative stress by mitigating malondialdehyde and hydrogen peroxide excess by 22% and 17%, respectively. Moreover, lower levels of enzymatic and nonenzymatic antioxidant activities were concluded, and soil organic matter and assimilable phosphorus contents were enhanced. In conclusion, our findings highlighted SWRT’s positive impacts on the tested parameters, thus presenting it as a promising technology for cactus growth and development improvement under water deficiency. Résumé La figue de barbarie (Opuntia ficus-indica) est une plante médicinale indispensable à l’économie et à l’écologie des régions arides et semi-arides, surtout au Maroc, où le manque d’eau en affecte la survie et la croissance. Apparemment, les techniques de rétention souterraine de l’eau (TRSE) pourraient rendre cette culture plus résistante à la sécheresse. Les auteurs ont procédé à une expérience sur le terrain afin de préciser les effets de telles techniques sur la croissance des cladodes du cactus, ainsi que sur leur performance physiologique et biochimique en période de sécheresse. Dans cette optique, ils ont combiné deux régimes hydriques (culture sèche, irrigation avec quatre litres d’eau deux fois par semaine) à deux traitements (TRSE ou pas). Les résultats de l’expérience indiquent que la sécheresse a une incidence négative sur la croissance ainsi que sur les paramètres physiologiques et biochimiques des cladodes après huit mois de culture. Les cladodes exposés au régime sec avec TRSE présentaient une plus grande surface (65 %) et des stomates plus denses (29 %) que ceux des cactus cultivés sans TRSE. La rétention souterraine d’eau réduit le stress oxydatif causé par la sécheresse en diminuant respectivement l’excédent de malonaldéhyde et de peroxyde d’hydrogène de 22 % et de 17 %. Les auteurs ont aussi relevé une baisse de l’activité des antioxydants, enzymatiques ou pas, parallèlement à une hausse de la quantité de matière organique et de phosphore assimilable présents dans le sol. Ils e
{"title":"Improving drought tolerance of Opuntia ficus-indica under field using subsurface water retention technology: changes in physiological and biochemical parameters","authors":"Soufiane Lahbouki, Lahoucine Ech-chatir, S. Er-raki, A. Outzourhit, A. Meddich","doi":"10.1139/cjss-2022-0022","DOIUrl":"https://doi.org/10.1139/cjss-2022-0022","url":null,"abstract":"Abstract The prickly pear (Opuntia ficus-indica) is an essential economic and ecological medicinal plant in arid and semi-arid areas, especially in Morocco, where water scarcity affects its survival and growth. Evidence suggests that subsurface water retention technology (SWRT) may enhance crops’ drought resistance. A field experiment was conducted to explore SWRT application effects on cactus cladodes’ growth and physiological and biochemical performance under drought conditions. Two water regimes were applied (rainfed conditions; irrigated with 4 L of water twice a week) with two treatments (without SWRT; with SWRT). The results showed that cactus cladodes’ growth and physiological and biochemical parameters cultivated for 8 months were negatively affected by drought. Drought-exposed cactus cladodes under SWRT application showed an increase in surface area and cladode stomatal densities by 65% and 29%, respectively, compared with no SWRT. This technology reduced drought-induced oxidative stress by mitigating malondialdehyde and hydrogen peroxide excess by 22% and 17%, respectively. Moreover, lower levels of enzymatic and nonenzymatic antioxidant activities were concluded, and soil organic matter and assimilable phosphorus contents were enhanced. In conclusion, our findings highlighted SWRT’s positive impacts on the tested parameters, thus presenting it as a promising technology for cactus growth and development improvement under water deficiency. Résumé La figue de barbarie (Opuntia ficus-indica) est une plante médicinale indispensable à l’économie et à l’écologie des régions arides et semi-arides, surtout au Maroc, où le manque d’eau en affecte la survie et la croissance. Apparemment, les techniques de rétention souterraine de l’eau (TRSE) pourraient rendre cette culture plus résistante à la sécheresse. Les auteurs ont procédé à une expérience sur le terrain afin de préciser les effets de telles techniques sur la croissance des cladodes du cactus, ainsi que sur leur performance physiologique et biochimique en période de sécheresse. Dans cette optique, ils ont combiné deux régimes hydriques (culture sèche, irrigation avec quatre litres d’eau deux fois par semaine) à deux traitements (TRSE ou pas). Les résultats de l’expérience indiquent que la sécheresse a une incidence négative sur la croissance ainsi que sur les paramètres physiologiques et biochimiques des cladodes après huit mois de culture. Les cladodes exposés au régime sec avec TRSE présentaient une plus grande surface (65 %) et des stomates plus denses (29 %) que ceux des cactus cultivés sans TRSE. La rétention souterraine d’eau réduit le stress oxydatif causé par la sécheresse en diminuant respectivement l’excédent de malonaldéhyde et de peroxyde d’hydrogène de 22 % et de 17 %. Les auteurs ont aussi relevé une baisse de l’activité des antioxydants, enzymatiques ou pas, parallèlement à une hausse de la quantité de matière organique et de phosphore assimilable présents dans le sol. Ils e","PeriodicalId":9384,"journal":{"name":"Canadian Journal of Soil Science","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2022-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49480242","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}
Abstract Drainage refers to the frequency and duration of periods of saturation, and how quickly excess water is removed from the soil profile. It is one of the central concepts used to differentiate soil series within the Canadian System of Soil Classification (CSSC). Currently, seven drainage classes are recognized in the CSSC: very rapid, rapid, well, moderately well, imperfect, poor, and very poor. In redoximorphic soils (imperfect, poor, and very poor drainage classes), drainage is typically differentiated based on morphological features (i.e., the presence of gleying and mottles). Non-redoximorphic soils (very rapid, rapid, and well-drained classes) do not display such morphological features but are differentiated based on available water holding capacity (AWHC) as inferred from soil texture and particle size. Moderately well-drained soils are intermediate, in some cases defined by the presence of redoximorphic characteristics, but in other cases inferred based on texture. In effect, drainage in materials without redoximorphic features is estimated based on AWHC as related to texture class, which should include sand subfractions. Values for AWHC were calculated using a published pedotransfer function for combinations of sand, silt, and clay-sized particles, including various combinations of very fine to very coarse sand separates as input. Calculated values were compared with currently assigned drainage classes and several inconsistencies were identified. Revisions are proposed to textural assessment of soil drainage for non-redoximorphic soils. Résumé Le drainage exprime la fréquence et la durée des périodes de saturation d’eau, ainsi que la rapidité avec laquelle l’eau en excédent se retire du sol. Il s’agit d’un des principes fondamentaux employés pour différencier les séries de sols dans le Système canadien de classification des sols (SCCS). Pour l’instant, le SCCS répertorie sept classes de drainage : très rapide, rapide, bon, modérément bon, imparfait, pauvre et très pauvre. Chez les sols rédoximorphiques (drainage imparfait, pauvre ou très pauvre), on différencie habituellement le drainage d’après les paramètres morphologiques (p. ex., présence de gleyification et de marbrures). Comme ils ne présentent pas de caractères morphologiques de ce genre, on différencie les sols non rédoximorphiques (drainage très rapide, rapide ou bon) d’après leur capacité à retenir l’eau (CRE) disponible grâce à leur texture et à leur granulométrie. Les sols modérément bien drainés se situent entre les deux et sont définis parfois par l’existence de certains paramètres rédoximorphiques, parfois par leur texture. Le drainage des matériaux sans propriétés rédoximorphiques est estimé d’après la CRE et le type de texture, qui devrait inclure les sous-fractions sableuses. Les auteurs ont calculé la CRE de mélanges de sable, de limon et d’argile avec une fonction de pédotransfert publiée, notamment celle de fractions sableuses aux particules allant de très fine
{"title":"A proposed framework for assigning soil drainage classes to non-redoximorphic soils in the Canadian System of Soil Classification","authors":"D. Saurette, C. J. Warren, R. Heck","doi":"10.1139/cjss-2022-0024","DOIUrl":"https://doi.org/10.1139/cjss-2022-0024","url":null,"abstract":"Abstract Drainage refers to the frequency and duration of periods of saturation, and how quickly excess water is removed from the soil profile. It is one of the central concepts used to differentiate soil series within the Canadian System of Soil Classification (CSSC). Currently, seven drainage classes are recognized in the CSSC: very rapid, rapid, well, moderately well, imperfect, poor, and very poor. In redoximorphic soils (imperfect, poor, and very poor drainage classes), drainage is typically differentiated based on morphological features (i.e., the presence of gleying and mottles). Non-redoximorphic soils (very rapid, rapid, and well-drained classes) do not display such morphological features but are differentiated based on available water holding capacity (AWHC) as inferred from soil texture and particle size. Moderately well-drained soils are intermediate, in some cases defined by the presence of redoximorphic characteristics, but in other cases inferred based on texture. In effect, drainage in materials without redoximorphic features is estimated based on AWHC as related to texture class, which should include sand subfractions. Values for AWHC were calculated using a published pedotransfer function for combinations of sand, silt, and clay-sized particles, including various combinations of very fine to very coarse sand separates as input. Calculated values were compared with currently assigned drainage classes and several inconsistencies were identified. Revisions are proposed to textural assessment of soil drainage for non-redoximorphic soils. Résumé Le drainage exprime la fréquence et la durée des périodes de saturation d’eau, ainsi que la rapidité avec laquelle l’eau en excédent se retire du sol. Il s’agit d’un des principes fondamentaux employés pour différencier les séries de sols dans le Système canadien de classification des sols (SCCS). Pour l’instant, le SCCS répertorie sept classes de drainage : très rapide, rapide, bon, modérément bon, imparfait, pauvre et très pauvre. Chez les sols rédoximorphiques (drainage imparfait, pauvre ou très pauvre), on différencie habituellement le drainage d’après les paramètres morphologiques (p. ex., présence de gleyification et de marbrures). Comme ils ne présentent pas de caractères morphologiques de ce genre, on différencie les sols non rédoximorphiques (drainage très rapide, rapide ou bon) d’après leur capacité à retenir l’eau (CRE) disponible grâce à leur texture et à leur granulométrie. Les sols modérément bien drainés se situent entre les deux et sont définis parfois par l’existence de certains paramètres rédoximorphiques, parfois par leur texture. Le drainage des matériaux sans propriétés rédoximorphiques est estimé d’après la CRE et le type de texture, qui devrait inclure les sous-fractions sableuses. Les auteurs ont calculé la CRE de mélanges de sable, de limon et d’argile avec une fonction de pédotransfert publiée, notamment celle de fractions sableuses aux particules allant de très fine","PeriodicalId":9384,"journal":{"name":"Canadian Journal of Soil Science","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2022-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45799958","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}
Chantel J. Chizen, M. Krzic, T. A. Black, R. Jassal, S. Smukler
Abstract Soil nitrous oxide (N2O) emissions and potato yield were evaluated under 0, 90, and 120 kg N ha−1 fertilizer rates and two planting dates, at productive and degraded fields in the Fraser Valley delta. During the growing season, N2O emissions were comparable among N fertilizer rates. Following November rainfall, N2O emissions increased by three times with 120 kg N ha−1. In the degraded field, yield did not respond to the increasing N fertilizer rates. These findings suggest that lower N fertilizer rates, especially in fields with degraded soils, can lower N2O emissions from British Columbia potato production. Résumé Les auteurs ont évalué les émissions de protoxyde d’azote (N2O) du sol et le rendement de la pomme de terre après l’application de 0, de 90 ou de 120 kg d’engrais N par hectare et deux dates de repiquage, dans des champs en production ou dégradés du delta de la vallée du Fraser. Pendant la période végétative, ils ont relevé des dégagements similaires de N2O pour tous les taux d’application de l’engrais. Après une précipitation en novembre, les émissions de N2O ont triplé avec le traitement de 120 kg de N par hectare. Le rendement du champ dégradé a mal réagi à la hausse des applications d’engrais. Ces résultats laissent croire que l’application d’une moins grande quantité d’engrais N, surtout sur les sols dégradés, pourrait réduire les dégagements de N2O résultant de la culture de la pomme de terre en Colombie-Britannique. [Traduction par la Rédaction]
在弗雷泽河谷三角洲高产田和退化田，研究了0、90和120 kg N ha - 1施肥量和2个种植日期下的土壤氧化亚氮排放和马铃薯产量。在生长季节，氮肥施用量之间的N2O排放量具有可比性。11月降雨后，N2O排放量增加了3倍，N ha−1为120 kg。在退化田，产量不随施氮量的增加而变化。这些发现表明，较低的氮肥施用量，特别是在土壤退化的田地，可以降低不列颠哥伦比亚省马铃薯生产中的N2O排放。rsamuest est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est est。在所有与之类似的情况下，所有与之相关的情况都是如此。在11月的一次降水中，平均每公顷120公斤氮肥的产量增加了三倍。所有的数据都显示，所有的数据都显示，所有的数据都显示，所有的数据都显示，所有的数据都显示。在哥伦比亚-不列颠的土地文化和土地资源咨询师的指导下，在哥伦比亚-不列颠的土地文化和土地资源咨询师的指导下，在哥伦比亚-不列颠的土地资源咨询师的指导下，在哥伦比亚-不列颠的土地资源咨询师的指导下，在哥伦比亚-不列颠的土地资源咨询师的指导下，在哥伦比亚-不列颠的土地资源咨询师的指导下，在哥伦比亚-不列颠的土地资源咨询师的指导下，取得了成功。[反贿赂]
{"title":"Nitrous oxide emissions from productive and degraded potato fields in the Fraser Valley delta of British Columbia","authors":"Chantel J. Chizen, M. Krzic, T. A. Black, R. Jassal, S. Smukler","doi":"10.1139/cjss-2022-0032","DOIUrl":"https://doi.org/10.1139/cjss-2022-0032","url":null,"abstract":"Abstract Soil nitrous oxide (N2O) emissions and potato yield were evaluated under 0, 90, and 120 kg N ha−1 fertilizer rates and two planting dates, at productive and degraded fields in the Fraser Valley delta. During the growing season, N2O emissions were comparable among N fertilizer rates. Following November rainfall, N2O emissions increased by three times with 120 kg N ha−1. In the degraded field, yield did not respond to the increasing N fertilizer rates. These findings suggest that lower N fertilizer rates, especially in fields with degraded soils, can lower N2O emissions from British Columbia potato production. Résumé Les auteurs ont évalué les émissions de protoxyde d’azote (N2O) du sol et le rendement de la pomme de terre après l’application de 0, de 90 ou de 120 kg d’engrais N par hectare et deux dates de repiquage, dans des champs en production ou dégradés du delta de la vallée du Fraser. Pendant la période végétative, ils ont relevé des dégagements similaires de N2O pour tous les taux d’application de l’engrais. Après une précipitation en novembre, les émissions de N2O ont triplé avec le traitement de 120 kg de N par hectare. Le rendement du champ dégradé a mal réagi à la hausse des applications d’engrais. Ces résultats laissent croire que l’application d’une moins grande quantité d’engrais N, surtout sur les sols dégradés, pourrait réduire les dégagements de N2O résultant de la culture de la pomme de terre en Colombie-Britannique. [Traduction par la Rédaction]","PeriodicalId":9384,"journal":{"name":"Canadian Journal of Soil Science","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2022-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41455049","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}
Abstract Soil texture, or the relative proportions of sand, silt, and clay, is a key soil attribute that influences many important physical, chemical, and biological properties of soils. Digital soil mapping is increasingly used to predict soil texture; however, few comparisons have been made between direct prediction of a texture class, and the indirect prediction of texture class by first predicting sand, silt, and clay content, and subsequently converting the predictions to a texture class. We predicted soil texture class for the 5–15 and 30–60 cm depth intervals of the Ottawa soil survey project using direct and indirect approaches which yielded a similar overall accuracy (28–36%) and kappa (0.19–0.27). The predicted soil maps had a similar spatial distribution of soil texture classes. We then used the Euclidean distance between the texture classes to adjust the model performance metrics, revealing the indirect approach provided the better soil texture class prediction. When comparing the predictions, the 5–15 and 30–60 cm maps were in perfect agreement for 53% and 42% of the study area, respectively, and in both cases texture class predictions were within one texture class for over 87% of the map area. For many studies, including legacy soil surveys, texture class information is available, and particle size distribution data are generally lacking. This study confirms that direct prediction of soil texture class performs almost equally with indirect prediction. Résumé La texture du sol, c’est-à-dire les proportions relatives de sable, de limon et d’argile, est une caractéristique capitale qui influe sur de nombreuses propriétés physiques, chimiques et biologiques du sol. On recourt de plus en plus à la cartographie numérique des sols pour en prévoir la texture. Cependant, on a rarement comparé la méthode de prévision directe à la méthode indirecte qui prévoit, en un premier temps, les proportions de sable, de limon et d’argile, puis convertit le résultat en classe de texture. Les auteurs ont prévu la classe de texture des sols d’Ottawa échantillonnés à une profondeur de 5–15 cm et de 30–60 cm par les deux approches et ont obtenu des résultats similaires pour l’exactitude générale (28–36 %) et l’indice kappa (0,19–0,27). Les cartes du sol illustraient une distribution spatiale semblable pour les classes de texture. Ensuite, les auteurs ont utilisé la distance euclidienne entre les classes de texture pour ajuster les mesures de la performance du modèle et ont constaté que l’approche indirecte donne les meilleures prévisions. Quand on compare celles-ci, les cartes pour les intervalles de profondeur de 5–15 cm et de 30–60 cm s’accordent à la perfection avec 53 % et 42 % des sols examinés, respectivement. Dans les deux cas, la classe de texture prévue se situe à moins d’une classe de distance pour au-delà de 87 % de la surface couverte par la carte. Si la classe de texture est souvent connue, même pour les levés les plus anciens, les données sur l
{"title":"Comparing direct and indirect approaches to predicting soil texture class","authors":"D. Saurette","doi":"10.1139/cjss-2022-0040","DOIUrl":"https://doi.org/10.1139/cjss-2022-0040","url":null,"abstract":"Abstract Soil texture, or the relative proportions of sand, silt, and clay, is a key soil attribute that influences many important physical, chemical, and biological properties of soils. Digital soil mapping is increasingly used to predict soil texture; however, few comparisons have been made between direct prediction of a texture class, and the indirect prediction of texture class by first predicting sand, silt, and clay content, and subsequently converting the predictions to a texture class. We predicted soil texture class for the 5–15 and 30–60 cm depth intervals of the Ottawa soil survey project using direct and indirect approaches which yielded a similar overall accuracy (28–36%) and kappa (0.19–0.27). The predicted soil maps had a similar spatial distribution of soil texture classes. We then used the Euclidean distance between the texture classes to adjust the model performance metrics, revealing the indirect approach provided the better soil texture class prediction. When comparing the predictions, the 5–15 and 30–60 cm maps were in perfect agreement for 53% and 42% of the study area, respectively, and in both cases texture class predictions were within one texture class for over 87% of the map area. For many studies, including legacy soil surveys, texture class information is available, and particle size distribution data are generally lacking. This study confirms that direct prediction of soil texture class performs almost equally with indirect prediction. Résumé La texture du sol, c’est-à-dire les proportions relatives de sable, de limon et d’argile, est une caractéristique capitale qui influe sur de nombreuses propriétés physiques, chimiques et biologiques du sol. On recourt de plus en plus à la cartographie numérique des sols pour en prévoir la texture. Cependant, on a rarement comparé la méthode de prévision directe à la méthode indirecte qui prévoit, en un premier temps, les proportions de sable, de limon et d’argile, puis convertit le résultat en classe de texture. Les auteurs ont prévu la classe de texture des sols d’Ottawa échantillonnés à une profondeur de 5–15 cm et de 30–60 cm par les deux approches et ont obtenu des résultats similaires pour l’exactitude générale (28–36 %) et l’indice kappa (0,19–0,27). Les cartes du sol illustraient une distribution spatiale semblable pour les classes de texture. Ensuite, les auteurs ont utilisé la distance euclidienne entre les classes de texture pour ajuster les mesures de la performance du modèle et ont constaté que l’approche indirecte donne les meilleures prévisions. Quand on compare celles-ci, les cartes pour les intervalles de profondeur de 5–15 cm et de 30–60 cm s’accordent à la perfection avec 53 % et 42 % des sols examinés, respectivement. Dans les deux cas, la classe de texture prévue se situe à moins d’une classe de distance pour au-delà de 87 % de la surface couverte par la carte. Si la classe de texture est souvent connue, même pour les levés les plus anciens, les données sur l","PeriodicalId":9384,"journal":{"name":"Canadian Journal of Soil Science","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2022-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41358171","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}
Aduan L. Silva, R. C. Araújo, V. Melo, Cássio S. Sergio, C. Schaefer
Abstract Knowledge on magnetic phases and properties of magnetic minerals has wide applications in soils and in agriculture, by the possibility, and perspectives in application of rock magnetic methods in soil science and agriculture; however, their role in highly weathered soils is still unclear. We characterized the mineralogy of soils from Brazilian northern Amazonia, with emphasis on magnetic soils. Samples with varying weathering degrees were collected from four different localities, and their magnetic phases (MPs) were separated and subjected to the following analysis: X-ray fluorescence (XRF), X-ray diffractometry (XRD), and measurements of field and temperature magnetization. The chemical composition by XRF analyses revealed the predominance of Fe, Si, Ti, and Mn. The XRD analysis, using the Rietveld method, revealed the presence of hematite, goethite, maghemite, and magnetite as magnetic phases: The highest concentration of MPs was detected in an Fe-rich Typic Eutrudept (54% magnetite). Magnetization measurements of the magnetic phases showed the presence of magnetite, associated with hematite and goethite, with magnetization values and transition temperature characteristics of these minerals. The magnetization varied according to soil type, indicating different weathering processes. Soil magnetism varied as a function of parent igneous rocks, in the following order: diabase > basalt > granite. The results indicate that parent material and mineral weathering influence soil magnetism in a tropical climate. Résumé Connaître les phases magnétiques (PM) et les propriétés des minéraux magnétiques aurait de vastes applications en pédologie et en agriculture, car on pourrait appliquer les méthodes associées au magnétisme des pierres à ces deux sciences. Néanmoins, le rôle de tels minéraux dans les sols très altérés manque de clarté. Les auteurs ont caractérisé la minéralogie des sols du nord de l’Amazonie, au Brésil, en se concentrant sur les sols magnétiques. Dans cette optique, ils ont prélevé des échantillons altérés à divers degrés à quatre endroits, puis ils en ont séparé les PM qu’ils ont analysées avec les techniques suivantes : fluorescence aux rayons X (XRF), diffractométrie aux rayons X (XRD) et détermination du magnétisme en fonction du terrain et de la température. L’analyse de la composition chimique par XRF révèle la prédominance des éléments Fe, Si, Ti et Mn. L’analyse par XRD selon la méthode de Rietveld révèle que les phases magnétiques découlent de la présence d’hématite, de goethite, de maghémite et de magnétite. La concentration la plus élevée de PM a été relevée dans un eutrudept typique riche en fer (54 % de magnétite). Après quantification, la magnétisation des phases magnétiques indique la présence de magnétite associée à de l’hématite et à de la goethite, le magnétisme et les températures de transition étant caractéristiques à ces minéraux. La magnétisation varie avec la nature du sol, signe que des mécanismes d’altérat
{"title":"Magnetic phases of soils developed from igneous rocks in a climate gradient transept, Brazilian northern Amazonia","authors":"Aduan L. Silva, R. C. Araújo, V. Melo, Cássio S. Sergio, C. Schaefer","doi":"10.1139/cjss-2021-0171","DOIUrl":"https://doi.org/10.1139/cjss-2021-0171","url":null,"abstract":"Abstract Knowledge on magnetic phases and properties of magnetic minerals has wide applications in soils and in agriculture, by the possibility, and perspectives in application of rock magnetic methods in soil science and agriculture; however, their role in highly weathered soils is still unclear. We characterized the mineralogy of soils from Brazilian northern Amazonia, with emphasis on magnetic soils. Samples with varying weathering degrees were collected from four different localities, and their magnetic phases (MPs) were separated and subjected to the following analysis: X-ray fluorescence (XRF), X-ray diffractometry (XRD), and measurements of field and temperature magnetization. The chemical composition by XRF analyses revealed the predominance of Fe, Si, Ti, and Mn. The XRD analysis, using the Rietveld method, revealed the presence of hematite, goethite, maghemite, and magnetite as magnetic phases: The highest concentration of MPs was detected in an Fe-rich Typic Eutrudept (54% magnetite). Magnetization measurements of the magnetic phases showed the presence of magnetite, associated with hematite and goethite, with magnetization values and transition temperature characteristics of these minerals. The magnetization varied according to soil type, indicating different weathering processes. Soil magnetism varied as a function of parent igneous rocks, in the following order: diabase > basalt > granite. The results indicate that parent material and mineral weathering influence soil magnetism in a tropical climate. Résumé Connaître les phases magnétiques (PM) et les propriétés des minéraux magnétiques aurait de vastes applications en pédologie et en agriculture, car on pourrait appliquer les méthodes associées au magnétisme des pierres à ces deux sciences. Néanmoins, le rôle de tels minéraux dans les sols très altérés manque de clarté. Les auteurs ont caractérisé la minéralogie des sols du nord de l’Amazonie, au Brésil, en se concentrant sur les sols magnétiques. Dans cette optique, ils ont prélevé des échantillons altérés à divers degrés à quatre endroits, puis ils en ont séparé les PM qu’ils ont analysées avec les techniques suivantes : fluorescence aux rayons X (XRF), diffractométrie aux rayons X (XRD) et détermination du magnétisme en fonction du terrain et de la température. L’analyse de la composition chimique par XRF révèle la prédominance des éléments Fe, Si, Ti et Mn. L’analyse par XRD selon la méthode de Rietveld révèle que les phases magnétiques découlent de la présence d’hématite, de goethite, de maghémite et de magnétite. La concentration la plus élevée de PM a été relevée dans un eutrudept typique riche en fer (54 % de magnétite). Après quantification, la magnétisation des phases magnétiques indique la présence de magnétite associée à de l’hématite et à de la goethite, le magnétisme et les températures de transition étant caractéristiques à ces minéraux. La magnétisation varie avec la nature du sol, signe que des mécanismes d’altérat","PeriodicalId":9384,"journal":{"name":"Canadian Journal of Soil Science","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2022-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43234951","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}
Abstract Healthy soils are fundamental to building prosperous and resilient farms and to efforts to reduce greenhouse gas emissions and enhance overall environmental impacts from agriculture. Understanding the adoption of beneficial management practices (BMPs) that promote soil health is necessary for these benefits to be obtained. Drawing from a survey of Ontario farmers (n = 247) with 60% being crop producers and 22% livestock farmers, we explore the variation in adoption for six soil health BMPs: cover crops, crop rotations, no-till, soil testing, conservation buffers, and organic amendments. Soil testing had the highest rate of adoption, while conservation buffers had the least. The majority of farmers (73%) implemented four or more BMPs as the use of practices such as a rotation with winter wheat, cover cropping, and no-till tend to be positively correlated. Adopters of the BMPs tend to operate larger farms both in the area operated and farm cash receipts than non-adopters. Improving soil health was the most widely selected motivation for adoption across all six BMPs. The most effective interventions to enhance adoption among non-adopters include financial incentives, easily accessible information and advice, and farmer-to-farmer learning. Our results suggest that farmers that adopt BMPs do so primarily to enhance soil health rather than solely for economic considerations. Encouraging use among non-adopters may require monitoring and promoting the benefits of soil health. The results should aid in the development of strategic frameworks that facilitate innovations in policy to enhance soil health. Résumé Des fermes prospères et résilientes ont besoin de sols vigoureux, sans lesquels on ne pourra d’ailleurs pas réduire les émissions de gaz à effet de serre ni atténuer les répercussions générales de l’agriculture sur l’environnement. Pour que de tels avantages se concrétisent, il faut comprendre l’adoption des bonnes pratiques de gestion (BPGs) qui confèrent au sol sa vitalité. Partant d’un sondage auprès des agriculteurs ontariens (n = 247), pour 60 % spécialisés dans les productions végétales et pour 22 % dans les productions animales, les auteurs ont examiné dans quelle mesure variait l’adoption de six BPGs associées à la vitalité du sol : cultures-abris, assolements, non-travail du sol, analyse du sol, bandes de préservation et amendements organiques. L’analyse du sol est la pratique la mieux acceptée, alors que les bandes de préservation se situent à l’opposé du spectre. La plupart des agriculteurs (73 %) appliquent quatre BPGs ou davantage et les pratiques comme l’assolement avec le blé d’hiver, les cultures-abris ainsi que le non-travail du sol présentent une corrélation positive. Ceux qui épousent les BPGs ont tendance à exploiter de plus grandes fermes que ceux qui ne les ont pas adoptées, tant au niveau de la superficie qu’à celui des recettes en espèces. Rendre le sol plus fertile est sans doute la raison principale qui motive l’ado
{"title":"Adoption of beneficial management practices to improve soil health","authors":"Ananka Shah, A. Weersink, R. Vyn","doi":"10.1139/cjss-2021-0187","DOIUrl":"https://doi.org/10.1139/cjss-2021-0187","url":null,"abstract":"Abstract Healthy soils are fundamental to building prosperous and resilient farms and to efforts to reduce greenhouse gas emissions and enhance overall environmental impacts from agriculture. Understanding the adoption of beneficial management practices (BMPs) that promote soil health is necessary for these benefits to be obtained. Drawing from a survey of Ontario farmers (n = 247) with 60% being crop producers and 22% livestock farmers, we explore the variation in adoption for six soil health BMPs: cover crops, crop rotations, no-till, soil testing, conservation buffers, and organic amendments. Soil testing had the highest rate of adoption, while conservation buffers had the least. The majority of farmers (73%) implemented four or more BMPs as the use of practices such as a rotation with winter wheat, cover cropping, and no-till tend to be positively correlated. Adopters of the BMPs tend to operate larger farms both in the area operated and farm cash receipts than non-adopters. Improving soil health was the most widely selected motivation for adoption across all six BMPs. The most effective interventions to enhance adoption among non-adopters include financial incentives, easily accessible information and advice, and farmer-to-farmer learning. Our results suggest that farmers that adopt BMPs do so primarily to enhance soil health rather than solely for economic considerations. Encouraging use among non-adopters may require monitoring and promoting the benefits of soil health. The results should aid in the development of strategic frameworks that facilitate innovations in policy to enhance soil health. Résumé Des fermes prospères et résilientes ont besoin de sols vigoureux, sans lesquels on ne pourra d’ailleurs pas réduire les émissions de gaz à effet de serre ni atténuer les répercussions générales de l’agriculture sur l’environnement. Pour que de tels avantages se concrétisent, il faut comprendre l’adoption des bonnes pratiques de gestion (BPGs) qui confèrent au sol sa vitalité. Partant d’un sondage auprès des agriculteurs ontariens (n = 247), pour 60 % spécialisés dans les productions végétales et pour 22 % dans les productions animales, les auteurs ont examiné dans quelle mesure variait l’adoption de six BPGs associées à la vitalité du sol : cultures-abris, assolements, non-travail du sol, analyse du sol, bandes de préservation et amendements organiques. L’analyse du sol est la pratique la mieux acceptée, alors que les bandes de préservation se situent à l’opposé du spectre. La plupart des agriculteurs (73 %) appliquent quatre BPGs ou davantage et les pratiques comme l’assolement avec le blé d’hiver, les cultures-abris ainsi que le non-travail du sol présentent une corrélation positive. Ceux qui épousent les BPGs ont tendance à exploiter de plus grandes fermes que ceux qui ne les ont pas adoptées, tant au niveau de la superficie qu’à celui des recettes en espèces. Rendre le sol plus fertile est sans doute la raison principale qui motive l’ado","PeriodicalId":9384,"journal":{"name":"Canadian Journal of Soil Science","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2022-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41587982","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}
Abstract Sound micronutrient management requires an understanding of nutrient interactions and transformation processes in soil–plant systems which can regulate bioavailability and plant uptake. A series of studies were conducted under controlled environment and field conditions to evaluate wheat response to Cu and Zn fertilization on P-deficient soils from western Canada. The grain and straw yields of wheat were reduced in two (Waskada and Tisdale) of three soils used in the controlled environment study, while yield was not affected at the Echo field site in 2016 when both Cu and Zn sulfate fertilizer were applied at 5 kg·ha–1 rates. Zinc concentration in soil and plant tissues was increased to apparent toxic levels with fertilizer addition in Waskada soils. An imbalance in tissue P:Zn concentration related to micronutrient fertilization was observed in Waskada and Tisdale soils. The availability of Cu and Zn in post-harvest soils was increased with increasing rate of these fertilizers' addition. Chemical and spectroscopic speciation using sequential extraction and X-ray absorption near edge structure, respectively, revealed that Cu and Zn were mostly speciated as carbonate phases, and complexation of these elements with carbonate and phyllosilicate minerals is likely the process controlling bioavailability in the soils.
{"title":"Antagonistic effect of copper and zinc in fertilization of spring wheat under low soil phosphorus conditions","authors":"N. Rahman, D. Peak, J. Schoenau","doi":"10.1139/cjss-2021-0189","DOIUrl":"https://doi.org/10.1139/cjss-2021-0189","url":null,"abstract":"Abstract Sound micronutrient management requires an understanding of nutrient interactions and transformation processes in soil–plant systems which can regulate bioavailability and plant uptake. A series of studies were conducted under controlled environment and field conditions to evaluate wheat response to Cu and Zn fertilization on P-deficient soils from western Canada. The grain and straw yields of wheat were reduced in two (Waskada and Tisdale) of three soils used in the controlled environment study, while yield was not affected at the Echo field site in 2016 when both Cu and Zn sulfate fertilizer were applied at 5 kg·ha–1 rates. Zinc concentration in soil and plant tissues was increased to apparent toxic levels with fertilizer addition in Waskada soils. An imbalance in tissue P:Zn concentration related to micronutrient fertilization was observed in Waskada and Tisdale soils. The availability of Cu and Zn in post-harvest soils was increased with increasing rate of these fertilizers' addition. Chemical and spectroscopic speciation using sequential extraction and X-ray absorption near edge structure, respectively, revealed that Cu and Zn were mostly speciated as carbonate phases, and complexation of these elements with carbonate and phyllosilicate minerals is likely the process controlling bioavailability in the soils.","PeriodicalId":9384,"journal":{"name":"Canadian Journal of Soil Science","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2022-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49432046","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}
Abstract The amounts and arrangements of polysaccharides (cellulose and hemicellulose), proteins, phenolic lignin, and pectin that make up plant tissue, in part, determine its decay rate. Lignin-rich and/or nitrogen-poor tissue has been described as biochemically recalcitrant causing a slow decay rate. Although a controversial mechanism for organic matter storage in soils with mineral particles, biochemical recalcitrance is still poorly understood in organic peat soil (Histosols). To investigate the role of Sphagnum in formation of peat soil, we characterize biochemical components for 10 species and examine persistence of the components in soil to 150 cm depth in three peatland ecosystems. We hypothesize that species from hummock microforms have more biochemical structural components and cohesion than species from hollows. Relative proportions of biochemical components changed markedly between plant material and the top 10 cm of peat soil, suggesting that decomposition occurred at the peat soil surface, but thereafter relative proportions of biochemical components did not vary significantly to 150 cm deep. A few differences in biochemical components that distinguished hummock species from hollow species persisted to the deepest depth sampled. Although persistence of the lignin-like component was expected, persistence of soluble and ionically bound pectin compounds was surprising as these biopolymers are thought to be readily decomposable. Our findings indicate that structural components of Sphagnum, specifically polysaccharides and pectin in addition to oft-cited phenolic lignin-like components, persist in peat soil and should not be overlooked in trying to understand carbon dynamics in Sphagnum-dominated ecosystems.
{"title":"Biochemical components of Sphagnum and persistence in peat soil","authors":"Gwendolyn T. Pipes, J. Yavitt","doi":"10.1139/cjss-2021-0137","DOIUrl":"https://doi.org/10.1139/cjss-2021-0137","url":null,"abstract":"Abstract The amounts and arrangements of polysaccharides (cellulose and hemicellulose), proteins, phenolic lignin, and pectin that make up plant tissue, in part, determine its decay rate. Lignin-rich and/or nitrogen-poor tissue has been described as biochemically recalcitrant causing a slow decay rate. Although a controversial mechanism for organic matter storage in soils with mineral particles, biochemical recalcitrance is still poorly understood in organic peat soil (Histosols). To investigate the role of Sphagnum in formation of peat soil, we characterize biochemical components for 10 species and examine persistence of the components in soil to 150 cm depth in three peatland ecosystems. We hypothesize that species from hummock microforms have more biochemical structural components and cohesion than species from hollows. Relative proportions of biochemical components changed markedly between plant material and the top 10 cm of peat soil, suggesting that decomposition occurred at the peat soil surface, but thereafter relative proportions of biochemical components did not vary significantly to 150 cm deep. A few differences in biochemical components that distinguished hummock species from hollow species persisted to the deepest depth sampled. Although persistence of the lignin-like component was expected, persistence of soluble and ionically bound pectin compounds was surprising as these biopolymers are thought to be readily decomposable. Our findings indicate that structural components of Sphagnum, specifically polysaccharides and pectin in addition to oft-cited phenolic lignin-like components, persist in peat soil and should not be overlooked in trying to understand carbon dynamics in Sphagnum-dominated ecosystems.","PeriodicalId":9384,"journal":{"name":"Canadian Journal of Soil Science","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2022-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46133304","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}
Abstract In the first edition (1974) of Canadian System of Soil Classification (CSSC), the taxonomic criteria for LFH organic horizons allowed application to any soil and land use developed under imperfectly to well-drained conditions. However, in the third edition (1998) of CSSC, the narrower taxonomic criteria for LFH horizons restricted application to only forest soils. A limited survey was conducted of some soil scientists across Canada to ask them if they had observed LFH horizons in nonforest soils. Distinct LFH horizons were observed across Canada under agriculture such as in no-till fields, tame and native pastures, and in reclaimed soils. They have also been observed in urban areas such as golf courses and grass-recreation fields. LFH horizons could also potentially develop under other nonforest land uses across Canada. Since no-till and native and tame pastures are most dominant in the prairies, the potential for LFH horizons is greatest in this region than elsewhere. However, they may occur anywhere in Canada where accumulation exceeds decomposition of organic material and they contain more than 17% organic carbon by weight or 30% organic matter. Therefore, we propose that the taxonomic criteria for applying LFH horizons be revised and broadened to include nonforest soils and be applicable to any soil order (where relevant) within Canada, and be at the discretion of the field pedologist. It is critical to identify and monitor LFH horizons over time because they are important for soil health, climate change, greenhouse gases, carbon sequestration, nutrient cycling, soil erosion, and hydrology.
{"title":"Proposed revision to Canadian System of Soil Classification: broaden taxonomic criteria for applying LFH horizons to include nonforest soils","authors":"J. Miller, D. Chanasyk, R. L. McNeil","doi":"10.1139/cjss-2021-0152","DOIUrl":"https://doi.org/10.1139/cjss-2021-0152","url":null,"abstract":"Abstract In the first edition (1974) of Canadian System of Soil Classification (CSSC), the taxonomic criteria for LFH organic horizons allowed application to any soil and land use developed under imperfectly to well-drained conditions. However, in the third edition (1998) of CSSC, the narrower taxonomic criteria for LFH horizons restricted application to only forest soils. A limited survey was conducted of some soil scientists across Canada to ask them if they had observed LFH horizons in nonforest soils. Distinct LFH horizons were observed across Canada under agriculture such as in no-till fields, tame and native pastures, and in reclaimed soils. They have also been observed in urban areas such as golf courses and grass-recreation fields. LFH horizons could also potentially develop under other nonforest land uses across Canada. Since no-till and native and tame pastures are most dominant in the prairies, the potential for LFH horizons is greatest in this region than elsewhere. However, they may occur anywhere in Canada where accumulation exceeds decomposition of organic material and they contain more than 17% organic carbon by weight or 30% organic matter. Therefore, we propose that the taxonomic criteria for applying LFH horizons be revised and broadened to include nonforest soils and be applicable to any soil order (where relevant) within Canada, and be at the discretion of the field pedologist. It is critical to identify and monitor LFH horizons over time because they are important for soil health, climate change, greenhouse gases, carbon sequestration, nutrient cycling, soil erosion, and hydrology.","PeriodicalId":9384,"journal":{"name":"Canadian Journal of Soil Science","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2022-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47643149","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}
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