Pub Date : 2022-07-11DOI: 10.3389/fsoil.2022.890437
Yushu Xia, K. Mcsweeney, M. Wander
To explore how well large spatial scale digital soil mapping can contribute to efforts to monitor soil organic carbon (SOC) stocks and changes, we reviewed regional and national studies quantifying SOC within lands dominated by agriculture using SCORPAN approaches that rely on soil (S), climate (C), organisms (O), relief (R), parent material (P), age (A), and space (N) covariates representing soil forming factors. After identifying 79 regional (> 10,000 km2) and national studies that attempted to estimate SOC, we evaluated model performances with reference to soil sampling depth, number of predictors, grid-distance, and spatial extent. SCORPAN covariates were then investigated in terms of their frequency of use and data sources. Lastly, we used 67 studies encompassing a variety of spatial scales to determine which covariates most influenced SOC in agricultural lands using a subjective ranking system. Topography (used in 94% of the cases), climate (87%), and organisms (86%) covariates that were the most frequently used SCORPAN predictors, aligned with the factors (precipitation, temperature, elevation, slope, vegetation indices, and land use) currently identified to be most influential for model estimate at the large spatial extent. Models generally succeeded in estimating SOC with fits represented by R2 with a median value of 0.47 but, performance varied widely (R2 between 0.02 and 0.86) among studies. Predictive success declined significantly with increased soil sampling depth (p < 0.001) and spatial extent (p < 0.001) due to increased variability. While studies have extensively drawn on large-scale surveys and remote sensing databases to estimate environmental covariates, the absence of soils data needed to understand the influence of management or temporal change limits our ability to make useful inferences about changes in SOC stocks at this scale. This review suggests digital soil mapping efforts can be improved through greater use of data representing soil type and parent material and consideration of spatio-temporal dynamics of SOC occurring within different depths and land use or management systems.
{"title":"Digital Mapping of Agricultural Soil Organic Carbon Using Soil Forming Factors: A Review of Current Efforts at the Regional and National Scales","authors":"Yushu Xia, K. Mcsweeney, M. Wander","doi":"10.3389/fsoil.2022.890437","DOIUrl":"https://doi.org/10.3389/fsoil.2022.890437","url":null,"abstract":"To explore how well large spatial scale digital soil mapping can contribute to efforts to monitor soil organic carbon (SOC) stocks and changes, we reviewed regional and national studies quantifying SOC within lands dominated by agriculture using SCORPAN approaches that rely on soil (S), climate (C), organisms (O), relief (R), parent material (P), age (A), and space (N) covariates representing soil forming factors. After identifying 79 regional (> 10,000 km2) and national studies that attempted to estimate SOC, we evaluated model performances with reference to soil sampling depth, number of predictors, grid-distance, and spatial extent. SCORPAN covariates were then investigated in terms of their frequency of use and data sources. Lastly, we used 67 studies encompassing a variety of spatial scales to determine which covariates most influenced SOC in agricultural lands using a subjective ranking system. Topography (used in 94% of the cases), climate (87%), and organisms (86%) covariates that were the most frequently used SCORPAN predictors, aligned with the factors (precipitation, temperature, elevation, slope, vegetation indices, and land use) currently identified to be most influential for model estimate at the large spatial extent. Models generally succeeded in estimating SOC with fits represented by R2 with a median value of 0.47 but, performance varied widely (R2 between 0.02 and 0.86) among studies. Predictive success declined significantly with increased soil sampling depth (p < 0.001) and spatial extent (p < 0.001) due to increased variability. While studies have extensively drawn on large-scale surveys and remote sensing databases to estimate environmental covariates, the absence of soils data needed to understand the influence of management or temporal change limits our ability to make useful inferences about changes in SOC stocks at this scale. This review suggests digital soil mapping efforts can be improved through greater use of data representing soil type and parent material and consideration of spatio-temporal dynamics of SOC occurring within different depths and land use or management systems.","PeriodicalId":73107,"journal":{"name":"Frontiers in soil science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47123657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-07DOI: 10.3389/fsoil.2022.934491
Jacques Kilela Mwanasomwe, Serge Langunu, M. Shutcha, G. Colinet
Phytostabilization is a more appropriate way for rehabilitation of metal-polluted environments in the Copperbelt region. A 1.5-hectare tree planting trial had been installed on the tailings dam (TD) with the help of organic matter (OM) mixed to topsoil. Then, 15 years later, this study aimed to evaluate the performance of the tree plantation, in regard to soils and spontaneous vegetation. The Cu and Co concentration was higher in the reclaimed soil compared with the unreclaimed. Acacia auriculiformis, Acacia polyacantha, Albizia lebbeck, Pinus sylvestris, Psidium guajava, Senna siamea, Senna spectabilis, and Syzygium guineense responded well to the criteria of phytostabilization, whereas Leucaena leucocephala was very invasive. Metal concentration was manifold higher in charcoals than in woods (Zn: 3.8–39.8 mg kg−1 in wood versus 272–523 mg kg−1 in charcoal) with no differences between charcoals regardless of the origin. The tree implantation aided with amendments can meet the criteria of phytostabilization through good survival and regeneration in the heavily contaminated TD.
{"title":"Effects of 15-Year-Old Plantation on Soil Conditions, Spontaneous Vegetation, and the Trace Metal Content in Wood Products at Kipushi Tailings Dam","authors":"Jacques Kilela Mwanasomwe, Serge Langunu, M. Shutcha, G. Colinet","doi":"10.3389/fsoil.2022.934491","DOIUrl":"https://doi.org/10.3389/fsoil.2022.934491","url":null,"abstract":"Phytostabilization is a more appropriate way for rehabilitation of metal-polluted environments in the Copperbelt region. A 1.5-hectare tree planting trial had been installed on the tailings dam (TD) with the help of organic matter (OM) mixed to topsoil. Then, 15 years later, this study aimed to evaluate the performance of the tree plantation, in regard to soils and spontaneous vegetation. The Cu and Co concentration was higher in the reclaimed soil compared with the unreclaimed. Acacia auriculiformis, Acacia polyacantha, Albizia lebbeck, Pinus sylvestris, Psidium guajava, Senna siamea, Senna spectabilis, and Syzygium guineense responded well to the criteria of phytostabilization, whereas Leucaena leucocephala was very invasive. Metal concentration was manifold higher in charcoals than in woods (Zn: 3.8–39.8 mg kg−1 in wood versus 272–523 mg kg−1 in charcoal) with no differences between charcoals regardless of the origin. The tree implantation aided with amendments can meet the criteria of phytostabilization through good survival and regeneration in the heavily contaminated TD.","PeriodicalId":73107,"journal":{"name":"Frontiers in soil science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44762835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-07DOI: 10.3389/fsoil.2022.901843
F. Rekik, H. van Es
A holistic view on possible determinants of human health within a poor subsistence farming community is important to addressing pressing issues surrounding hidden hunger. This survey study assesses the mineral nutrition of women in rural tribal communities of Jharkhand, India, and its possible connection with the mineral status of the soils and the staple crop rice. Associations were explored with inherent and dynamic life features namely geography; socio-demographics; and agronomic, processing and cooking practices. A total of 43 soil and rice and 35 human hair samples were collected from 43 rice fields and their associated households. All samples were analyzed for micronutrients and toxic elements, which included As, B, Ba, Cd, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Se, Sr, V and Zn. Soil samples were additionally analyzed for biological and physical indicators. Kruskal-Wallis ANOVA tests and regularized regressions methods (ridge and lasso) were performed on qualitative parameters with respect to the soil, rice and hair mineral content. For soil data, associations existed between (i) livestock management and Mo and Cd levels in the soil, and (ii) most soil micronutrients and toxic elements with districts and soil textural groups. For rice, Fe concentrations differed among variety types (traditional> hybrid> improved), Cu between landscape positions (midland > lowland), Mn, Ba and Pb among soil textural classes, and Cr, Ba and Pb among districts. In hair, Cd significantly differed between cooking water sources (well water > other), Mn between rice cooking methods (absorption > boil and drain), and Fe, Cr and Ba between the hair-dyed groups. Linear regressions with quantitative variables such as age, household size, number of years farming, fertilization duration (as proxy for land size ownership) and hair sampling length (cm) showed that only hair Ni and Cr were significantly affected by land size ownership, and that the latter mineral is also affected by hair sampling length. The regularized regressions revealed many interlinkages between soil and humans through the rice crop intermediate, as well as between socio-demographics and human health, albeit complex and indirect. To this end, associations were in many cases uninterpretable, yet, they present insight into the confounding factors and possible challenges in the assessment of soil-to-human mineral interlinkages. Future studies are advised to account for these to pinpoint direct and causational relationships in the soil-to-human pathway.
{"title":"Soils and Human Health: Connections Between Geo-Environmental, Socio-Demographic, and Lifestyle factors and Nutrition of Tribal Women of Jharkhand, India","authors":"F. Rekik, H. van Es","doi":"10.3389/fsoil.2022.901843","DOIUrl":"https://doi.org/10.3389/fsoil.2022.901843","url":null,"abstract":"A holistic view on possible determinants of human health within a poor subsistence farming community is important to addressing pressing issues surrounding hidden hunger. This survey study assesses the mineral nutrition of women in rural tribal communities of Jharkhand, India, and its possible connection with the mineral status of the soils and the staple crop rice. Associations were explored with inherent and dynamic life features namely geography; socio-demographics; and agronomic, processing and cooking practices. A total of 43 soil and rice and 35 human hair samples were collected from 43 rice fields and their associated households. All samples were analyzed for micronutrients and toxic elements, which included As, B, Ba, Cd, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Se, Sr, V and Zn. Soil samples were additionally analyzed for biological and physical indicators. Kruskal-Wallis ANOVA tests and regularized regressions methods (ridge and lasso) were performed on qualitative parameters with respect to the soil, rice and hair mineral content. For soil data, associations existed between (i) livestock management and Mo and Cd levels in the soil, and (ii) most soil micronutrients and toxic elements with districts and soil textural groups. For rice, Fe concentrations differed among variety types (traditional> hybrid> improved), Cu between landscape positions (midland > lowland), Mn, Ba and Pb among soil textural classes, and Cr, Ba and Pb among districts. In hair, Cd significantly differed between cooking water sources (well water > other), Mn between rice cooking methods (absorption > boil and drain), and Fe, Cr and Ba between the hair-dyed groups. Linear regressions with quantitative variables such as age, household size, number of years farming, fertilization duration (as proxy for land size ownership) and hair sampling length (cm) showed that only hair Ni and Cr were significantly affected by land size ownership, and that the latter mineral is also affected by hair sampling length. The regularized regressions revealed many interlinkages between soil and humans through the rice crop intermediate, as well as between socio-demographics and human health, albeit complex and indirect. To this end, associations were in many cases uninterpretable, yet, they present insight into the confounding factors and possible challenges in the assessment of soil-to-human mineral interlinkages. Future studies are advised to account for these to pinpoint direct and causational relationships in the soil-to-human pathway.","PeriodicalId":73107,"journal":{"name":"Frontiers in soil science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43866575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-01DOI: 10.3389/fsoil.2022.801227
Jiakai Gao, Ling Liu, Z. Shi, J. Lv
The application of biochar in conjunction with fertilizer in agricultural production is one of the most promising types of management to improve soil quality. However, the effects on the soil microbial community and methane (CH4) emissions from the interactive mechanisms of biochar combined with fertilizer are unclear. In this study, soil column trial was conducted to monitor the surface water nitrogen, dissolved organic carbon (DOC) and CH4 emission dynamics during the process of leaching. Additionally, bacterial and archaeal communities of the soil (0-10 cm) amended with biochar derived from different pyrolysis temperatures (300°C, 500°C, and 700°C) were also analyzed. High-throughput sequencing revealed that the soil archaeal and bacterial community diversities increased under the biochar amendments. The CH4 emission flux of all the treatments in the whole leaching period ranged from 0.0001 to 2.04 μg m-2 h-1, and the DOC ranged from 1.86 to 24.4 mg L-1. Our results showed that biochar amendments significantly increase the soil pH, total nitrogen (TN), and DOC contents, while inhibiting the loss of NO 3 − N during leaching. In addition, biochar addition increased the paddy soil CH4 emissions, which ascribed to the increasing ratio of the abundances of methanogens to methanotrophs. Consequently, the higher CH4 emissions were probably caused by the stimulation of methanogenic archaea under the biochar amendments. Thus, the results obtained in this study can be applied to guide the application of biochar on greenhouse gas emissions in paddy soil.
{"title":"Biochar Amendments Facilitate Methane Production by Regulating the Abundances of Methanogens and Methanotrophs in Flooded Paddy Soil","authors":"Jiakai Gao, Ling Liu, Z. Shi, J. Lv","doi":"10.3389/fsoil.2022.801227","DOIUrl":"https://doi.org/10.3389/fsoil.2022.801227","url":null,"abstract":"The application of biochar in conjunction with fertilizer in agricultural production is one of the most promising types of management to improve soil quality. However, the effects on the soil microbial community and methane (CH4) emissions from the interactive mechanisms of biochar combined with fertilizer are unclear. In this study, soil column trial was conducted to monitor the surface water nitrogen, dissolved organic carbon (DOC) and CH4 emission dynamics during the process of leaching. Additionally, bacterial and archaeal communities of the soil (0-10 cm) amended with biochar derived from different pyrolysis temperatures (300°C, 500°C, and 700°C) were also analyzed. High-throughput sequencing revealed that the soil archaeal and bacterial community diversities increased under the biochar amendments. The CH4 emission flux of all the treatments in the whole leaching period ranged from 0.0001 to 2.04 μg m-2 h-1, and the DOC ranged from 1.86 to 24.4 mg L-1. Our results showed that biochar amendments significantly increase the soil pH, total nitrogen (TN), and DOC contents, while inhibiting the loss of NO 3 − N during leaching. In addition, biochar addition increased the paddy soil CH4 emissions, which ascribed to the increasing ratio of the abundances of methanogens to methanotrophs. Consequently, the higher CH4 emissions were probably caused by the stimulation of methanogenic archaea under the biochar amendments. Thus, the results obtained in this study can be applied to guide the application of biochar on greenhouse gas emissions in paddy soil.","PeriodicalId":73107,"journal":{"name":"Frontiers in soil science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45001084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-30DOI: 10.3389/fsoil.2022.818862
Isaac J. Madsen, J. Parks, M. Friesen, R. E. Clark
Intercropping is an ancient agricultural management practice quickly re-gaining interest in mechanized agricultural systems. Mechanized management practices have led to a decreased biodiversity at the macro- and micro-fauna levels. These agricultural practices have also resulted in the degradation of soil and long-term inefficiencies in land, water, and nutrients. The inland Pacific Northwest (iPNW) of the United States of America is a wheat-dominated cropping system. The integration of winter and spring legumes and oilseeds has improved the biodiversity and nutrient-use efficiency of the cropping systems. This article examines the feasibility of pea-canola (peaola) intercropping in dryland production systems of the iPNW. In two site years, small plot peaola trials were established near Davenport, WA. Overall, the land equivalence ratio (LER) of peaola was found to be 1.46, showing an increase in efficiency of the system. Increasing the N fertilizer application rates did not affect peaola yield, indicating that peaola has low demand for N inputs. The effects of peaola on insects and bacterial diversity were examined on replicated large scale strip trials. Peaola was found to have significantly greater numbers of beneficial insects than the monoculture controls. There were no significant differences between the diversity of the soil bacterial communities found in peaola vs. pea and canola monocultures. However, we found that the strict core soil bacterial microbiome of peaola was larger than the monocultures and included core members from both the canola and pea soil microbiomes. In conclusion, the widespread adoption of peaola would likely increase the biodiversity and increase the land use efficiency of dryland production systems in the iPNW.
{"title":"Increasing Biodiversity and Land-Use Efficiency Through Pea (Pisum aestivum)-Canola (Brassica napus) Intercropping (Peaola)","authors":"Isaac J. Madsen, J. Parks, M. Friesen, R. E. Clark","doi":"10.3389/fsoil.2022.818862","DOIUrl":"https://doi.org/10.3389/fsoil.2022.818862","url":null,"abstract":"Intercropping is an ancient agricultural management practice quickly re-gaining interest in mechanized agricultural systems. Mechanized management practices have led to a decreased biodiversity at the macro- and micro-fauna levels. These agricultural practices have also resulted in the degradation of soil and long-term inefficiencies in land, water, and nutrients. The inland Pacific Northwest (iPNW) of the United States of America is a wheat-dominated cropping system. The integration of winter and spring legumes and oilseeds has improved the biodiversity and nutrient-use efficiency of the cropping systems. This article examines the feasibility of pea-canola (peaola) intercropping in dryland production systems of the iPNW. In two site years, small plot peaola trials were established near Davenport, WA. Overall, the land equivalence ratio (LER) of peaola was found to be 1.46, showing an increase in efficiency of the system. Increasing the N fertilizer application rates did not affect peaola yield, indicating that peaola has low demand for N inputs. The effects of peaola on insects and bacterial diversity were examined on replicated large scale strip trials. Peaola was found to have significantly greater numbers of beneficial insects than the monoculture controls. There were no significant differences between the diversity of the soil bacterial communities found in peaola vs. pea and canola monocultures. However, we found that the strict core soil bacterial microbiome of peaola was larger than the monocultures and included core members from both the canola and pea soil microbiomes. In conclusion, the widespread adoption of peaola would likely increase the biodiversity and increase the land use efficiency of dryland production systems in the iPNW.","PeriodicalId":73107,"journal":{"name":"Frontiers in soil science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45219468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-30DOI: 10.3389/fsoil.2022.905664
Shefaza Esmail, M. Oelbermann
African countries are urbanizing at a rapid rate. Research on urban agriculture may be key to ensuring urban food and soil security. This study aimed to evaluate pathways for integrated soil fertility management using a mixed methods approach to consider both social perspectives and soil quality in the city of Mwanza, Tanzania. The social component of urban agriculture was explored using semi-structured interviews with urban farmers (n=34), through judgement and snowball sampling. Qualitative analyses showed that urban farmers range in age and gender, as well as in experiences and cultivation practices, though all use hand tools. Farmers reported reliance on rainy seasons for cultivating. However, farmers also raised concerns about a changing climate and unpredictability of rain, which impacts crop productivity. Most interviewed farmers (82%) would like to improve their soils, and many use manure as an amendment stating that animal manure is the best way to improve soil. Additionally, most urban farmers (62%) have not tried any form of food waste compost but responded positively to try it if they had access and were taught how to use it. For the second aspect of this study a field trial was conducted to evaluate and compare the effects of organic and inorganic amendments on soil quality and crop productivity over the short-term. The results from the field trial determined that organic amendments (poultry manure and food waste compost) improved soil water holding capacity by 14 to 19% and enhanced microbial biomass 1.7 to 4 times compared to treatments with inorganic nitrogen fertilizer. Crop productivity with organic amendments was comparable to that in treatments with nitrogen fertilizer. We conclude that urban agriculture is an integral aspect of Mwanza City, and the application of organic amendments improves urban soil quality compared to the application of inorganic fertilizer, which has implications for urban soil security, land use planning, and food sovereignty in developing countries.
{"title":"Investigating Farmer Perspectives and Compost Application for Soil Management in Urban Agriculture in Mwanza, Tanzania","authors":"Shefaza Esmail, M. Oelbermann","doi":"10.3389/fsoil.2022.905664","DOIUrl":"https://doi.org/10.3389/fsoil.2022.905664","url":null,"abstract":"African countries are urbanizing at a rapid rate. Research on urban agriculture may be key to ensuring urban food and soil security. This study aimed to evaluate pathways for integrated soil fertility management using a mixed methods approach to consider both social perspectives and soil quality in the city of Mwanza, Tanzania. The social component of urban agriculture was explored using semi-structured interviews with urban farmers (n=34), through judgement and snowball sampling. Qualitative analyses showed that urban farmers range in age and gender, as well as in experiences and cultivation practices, though all use hand tools. Farmers reported reliance on rainy seasons for cultivating. However, farmers also raised concerns about a changing climate and unpredictability of rain, which impacts crop productivity. Most interviewed farmers (82%) would like to improve their soils, and many use manure as an amendment stating that animal manure is the best way to improve soil. Additionally, most urban farmers (62%) have not tried any form of food waste compost but responded positively to try it if they had access and were taught how to use it. For the second aspect of this study a field trial was conducted to evaluate and compare the effects of organic and inorganic amendments on soil quality and crop productivity over the short-term. The results from the field trial determined that organic amendments (poultry manure and food waste compost) improved soil water holding capacity by 14 to 19% and enhanced microbial biomass 1.7 to 4 times compared to treatments with inorganic nitrogen fertilizer. Crop productivity with organic amendments was comparable to that in treatments with nitrogen fertilizer. We conclude that urban agriculture is an integral aspect of Mwanza City, and the application of organic amendments improves urban soil quality compared to the application of inorganic fertilizer, which has implications for urban soil security, land use planning, and food sovereignty in developing countries.","PeriodicalId":73107,"journal":{"name":"Frontiers in soil science","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41317341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-29DOI: 10.3389/fsoil.2022.814554
Yvonne Uwituze, J. Nyiraneza, T. Fraser, Jacynthe Dessureaut-Rompré, N. Ziadi, J. Lafond
Extracellular soil enzymes play a key role in soil organic matter decomposition and nutrient cycling. However, it is not fully understood how these enzymes respond to different land use. Long-term research studies were used to evaluate how diversified management practices affect extracellular enzymes driving C cycling [phenol oxidases (PO), peroxidases (PP), α-glucosidase (AG), β-glucosidase (BG), cellobiohydrolase (CB), β-1,-4-Nacetylglucosaminidase (NAG)], N cycling [leucine aminopeptidase (LAP)], and P cycling [phosphomonoesterase (PME)]. The soil pH, contents of total organic C, total N, mehlich-3 P, soil respiration and soil nitrogen supply capacity were also measured. Different land use included tillage frequency, tillage regimes, mineral N fertilization, crop rotations and liquid dairy manure. Compared to medium or high tillage frequency, low tillage frequency increased total organic C and total N and soil respiration as well as NAG and PME activities, whereas it decreased soil nitrogen supply, mehlich-3 P, and soil pH, as well as PO, PP, AG, BG, CB, and LAP activities. Non till was associated with lower PP and PO activities than moldboard plow. Nitrogen fertilization decreased soil pH and PO activity but increased PME activity. Barley (Hordeum vulgare) in rotation with forage increased total organic C, total N, soil nitrogen supply and soil respiration by 31, 21, 44, and 33%, respectively, in comparison with barley in monoculture. The application of liquid dairy manure increased soil pH, total N and soil nitrogen supply and soil enzyme activities (AG, BG, NAG) in comparison to the mineral N fertilizer. When principal component analysis was performed, soil pH, PO, PP, CB, LAP, and PME were grouped in the first component, which explained the highest variance. This is the core group controlling the C, N, and P cycling. The activities of C, N, and P acquiring enzymes, soil nitrogen supply and soil respiration were related to changes in soil total C and N, and extractable P contents across a broad range of management practices. Increased PO and PP activities reflect total C decline.
{"title":"Carbon, Nitrogen, Phosphorus, and Extracellular Soil Enzyme Responses to Different Land Use","authors":"Yvonne Uwituze, J. Nyiraneza, T. Fraser, Jacynthe Dessureaut-Rompré, N. Ziadi, J. Lafond","doi":"10.3389/fsoil.2022.814554","DOIUrl":"https://doi.org/10.3389/fsoil.2022.814554","url":null,"abstract":"Extracellular soil enzymes play a key role in soil organic matter decomposition and nutrient cycling. However, it is not fully understood how these enzymes respond to different land use. Long-term research studies were used to evaluate how diversified management practices affect extracellular enzymes driving C cycling [phenol oxidases (PO), peroxidases (PP), α-glucosidase (AG), β-glucosidase (BG), cellobiohydrolase (CB), β-1,-4-Nacetylglucosaminidase (NAG)], N cycling [leucine aminopeptidase (LAP)], and P cycling [phosphomonoesterase (PME)]. The soil pH, contents of total organic C, total N, mehlich-3 P, soil respiration and soil nitrogen supply capacity were also measured. Different land use included tillage frequency, tillage regimes, mineral N fertilization, crop rotations and liquid dairy manure. Compared to medium or high tillage frequency, low tillage frequency increased total organic C and total N and soil respiration as well as NAG and PME activities, whereas it decreased soil nitrogen supply, mehlich-3 P, and soil pH, as well as PO, PP, AG, BG, CB, and LAP activities. Non till was associated with lower PP and PO activities than moldboard plow. Nitrogen fertilization decreased soil pH and PO activity but increased PME activity. Barley (Hordeum vulgare) in rotation with forage increased total organic C, total N, soil nitrogen supply and soil respiration by 31, 21, 44, and 33%, respectively, in comparison with barley in monoculture. The application of liquid dairy manure increased soil pH, total N and soil nitrogen supply and soil enzyme activities (AG, BG, NAG) in comparison to the mineral N fertilizer. When principal component analysis was performed, soil pH, PO, PP, CB, LAP, and PME were grouped in the first component, which explained the highest variance. This is the core group controlling the C, N, and P cycling. The activities of C, N, and P acquiring enzymes, soil nitrogen supply and soil respiration were related to changes in soil total C and N, and extractable P contents across a broad range of management practices. Increased PO and PP activities reflect total C decline.","PeriodicalId":73107,"journal":{"name":"Frontiers in soil science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47374613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-29DOI: 10.3389/fsoil.2022.898618
Jean-Pascal Matteau, P. Célicourt, Elnaz Shahriarina, Philipe Letellier, Thiago Gumiere, S. Gumiere
Soil disturbance resulting from tuber crop harvesting is a major threat to soil health. The depth of soil intervention is a critical factor that further strengthens the effects of such disturbance and makes harvest one of the most harmful cropping operations. In the case of potato, soil moisture is a determining factor for root and stolon development, hence, a deeper soil intervention may be required at harvest. While potato ranks as the fourth most cultivated crop worldwide, the impact of soil moisture on potato tuber vertical and horizontal distribution has received very little attention. The objective of this study was to evaluate the effects of four soil matric potential thresholds (SMPTs; –10, –20, –30, and –45 kPa) on the spatial (vertical and horizontal) distribution of potato tubers grown in plastic containers filled with sandy soil using an X-ray computed tomography scanner. The results of the experiments conducted in a greenhouse environment suggest that the horizontal distribution of the tubers did not differ significantly across the irrigation treatments. However, a linear relationship between SMPT, and therefore irrigation threshold, and potato tuber depth was observed. In addition, the deepest tuber position was observed under the –10 kPa SMPT, while the tubers were closer to the soil surface under the –45 kPa SMPT, which could lead to a greater preponderance of tuber diseases such as late blight or greening. Thus, potato irrigation events implementing a SMPT between –20 and –30 kPa could reduce the harvest depth, hence, decreasing the negative impacts of soil disturbance on soil structural stability and soil organic carbon degradation while mitigating the impacts of disease as well as reducing fuel costs, greenhouse gas emissions, soil loss and erosion.
{"title":"Relationship Between Irrigation Thresholds and Potato Tuber Depth in Sandy Soil","authors":"Jean-Pascal Matteau, P. Célicourt, Elnaz Shahriarina, Philipe Letellier, Thiago Gumiere, S. Gumiere","doi":"10.3389/fsoil.2022.898618","DOIUrl":"https://doi.org/10.3389/fsoil.2022.898618","url":null,"abstract":"Soil disturbance resulting from tuber crop harvesting is a major threat to soil health. The depth of soil intervention is a critical factor that further strengthens the effects of such disturbance and makes harvest one of the most harmful cropping operations. In the case of potato, soil moisture is a determining factor for root and stolon development, hence, a deeper soil intervention may be required at harvest. While potato ranks as the fourth most cultivated crop worldwide, the impact of soil moisture on potato tuber vertical and horizontal distribution has received very little attention. The objective of this study was to evaluate the effects of four soil matric potential thresholds (SMPTs; –10, –20, –30, and –45 kPa) on the spatial (vertical and horizontal) distribution of potato tubers grown in plastic containers filled with sandy soil using an X-ray computed tomography scanner. The results of the experiments conducted in a greenhouse environment suggest that the horizontal distribution of the tubers did not differ significantly across the irrigation treatments. However, a linear relationship between SMPT, and therefore irrigation threshold, and potato tuber depth was observed. In addition, the deepest tuber position was observed under the –10 kPa SMPT, while the tubers were closer to the soil surface under the –45 kPa SMPT, which could lead to a greater preponderance of tuber diseases such as late blight or greening. Thus, potato irrigation events implementing a SMPT between –20 and –30 kPa could reduce the harvest depth, hence, decreasing the negative impacts of soil disturbance on soil structural stability and soil organic carbon degradation while mitigating the impacts of disease as well as reducing fuel costs, greenhouse gas emissions, soil loss and erosion.","PeriodicalId":73107,"journal":{"name":"Frontiers in soil science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43831226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shrub encroachment is a common phenomenon in grasslands all over the world. However, little is known about the consequences of shrub encroachment on soil microbial community structure in different layers. We investigated the effects of three common shrub encroachment (Potentilla fruticosa, Spiraea alpina, and Caragana microphylla) on grassland soil bacterial communities at the surface and deep layers in Qinghai–Tibetan Plateau. 16S rRNA gene sequencing was used to investigate the bacterial communities, and Fourier translation infrared spectroscopy (FTIR) was conducted to assess the soil organic carbon (SOC) chemical composition in surface and deep layers of shrub-encroached alpine grassland. Shrub encroachment has significantly increased SOC degradation in deep layer. After shrub invasion, the bacterial alpha-diversity in the surface and deep soil was higher than in grassland soil (except for the surface layer of C. microphylla). Factors driving bacterial community changes in soil surface and deep layer were different. Among the soil properties that were measured, SOC content was the primary factor that altered soil bacterial community composition in surface soil, while SOC chemical composition (aromatic and polysaccharides) was the main driver in the deep layer. A total of 39 and 42 biomarkers were found by linear discriminant analysis (LDA) effect size (LEfSe) in the surface and deep soil layer among the four sampling groups, respectively. Phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) showed that the most abundant predicted functional genes belonged to categories of metabolism (52.83%) in the primary metabolic pathway. Redundancy analysis (RDA) results also showed that the key factors affecting bacterial metabolic function appear to be SOC, pH, and aromatics, which are largely consistent with those affecting community composition. We suggest that shrub encroachment affect the structure, diversity, and predicted functions of bacterial communities, thus affecting the C cycle in this region.
{"title":"Effect of Shrub Encroachment on Alpine Grass Soil Microbial Community Assembly","authors":"Zhuoma Dengzeng, Wenming Ma, Changting Wang, Sihong Tang, Dong Zhang","doi":"10.3389/fsoil.2022.829575","DOIUrl":"https://doi.org/10.3389/fsoil.2022.829575","url":null,"abstract":"Shrub encroachment is a common phenomenon in grasslands all over the world. However, little is known about the consequences of shrub encroachment on soil microbial community structure in different layers. We investigated the effects of three common shrub encroachment (Potentilla fruticosa, Spiraea alpina, and Caragana microphylla) on grassland soil bacterial communities at the surface and deep layers in Qinghai–Tibetan Plateau. 16S rRNA gene sequencing was used to investigate the bacterial communities, and Fourier translation infrared spectroscopy (FTIR) was conducted to assess the soil organic carbon (SOC) chemical composition in surface and deep layers of shrub-encroached alpine grassland. Shrub encroachment has significantly increased SOC degradation in deep layer. After shrub invasion, the bacterial alpha-diversity in the surface and deep soil was higher than in grassland soil (except for the surface layer of C. microphylla). Factors driving bacterial community changes in soil surface and deep layer were different. Among the soil properties that were measured, SOC content was the primary factor that altered soil bacterial community composition in surface soil, while SOC chemical composition (aromatic and polysaccharides) was the main driver in the deep layer. A total of 39 and 42 biomarkers were found by linear discriminant analysis (LDA) effect size (LEfSe) in the surface and deep soil layer among the four sampling groups, respectively. Phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) showed that the most abundant predicted functional genes belonged to categories of metabolism (52.83%) in the primary metabolic pathway. Redundancy analysis (RDA) results also showed that the key factors affecting bacterial metabolic function appear to be SOC, pH, and aromatics, which are largely consistent with those affecting community composition. We suggest that shrub encroachment affect the structure, diversity, and predicted functions of bacterial communities, thus affecting the C cycle in this region.","PeriodicalId":73107,"journal":{"name":"Frontiers in soil science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49095441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-23DOI: 10.3389/fsoil.2022.903544
Ulises Marconato, R. J. Fernández, G. Posse
Estimations of Net Ecosystem Exchange (NEE) are crucial to assess the carbon sequestration/carbon source capacity of agricultural systems. Although several global models have been built to describe carbon flux patterns based on flux tower data, South American ecosystems (and croplands in particular) are underrepresented in the databases used to calibrate these models, leading to large uncertainties in regional and global NEE estimation. Despite the fact that almost half of the land surface is used worldwide for agricultural activities, these models still do not include variables related to cropland management. Using enhanced vegetation index (EVI) derived from MODIS imagery (250 m) and monthly CO2 exchange from a 9-year record of an eddy covariance (EC) flux tower in a crop field in the Inland Pampas region, we developed regression models to predict monthly NEE. We tested whether including a term for crop identity/land cover as a categorical variable (maize, soybean, wheat, and fallow) could improve model capability in capturing monthly NEE dynamics. NEE measured at the flux tower site was scaled to croplands across the Inland Pampa using crop-type maps, from which annual NEE maps were generated for the 2018–2019, 2019–2020, and 2020–2021 agricultural campaigns. The model based solely on EVI showed to be a good predictor of monthly NEE for the study region (r2 = 0.78), but model adjustment was improved by including a term for crop identity (r2 = 0.83). A second set of maps was generated taking into account carbon exports during harvest to estimate Net Biome Productivity (NBP) at the county level. Crops across the region as a whole acted as a carbon sink during the three studied campaigns, although with highly heterogeneous spatial and temporal patterns. Between 60% and 80% of the carbon sequestered was exported during harvest, a large decrease from the carbon sequestration capacity estimated using just NEE, which further decreased if fossil carbon emissions from agricultural supplies are taken into account. Estimates presented in this study are a first step towards upscaling carbon fluxes at the regional scale in a South American cropland area, and could help to improve regional to global estimations of carbon fluxes and refine national greenhouse gas (GHG) inventories.
{"title":"Cropland Net Ecosystem Exchange Estimation for the Inland Pampas (Argentina) Using EVI, Land Cover Maps, and Eddy Covariance Fluxes","authors":"Ulises Marconato, R. J. Fernández, G. Posse","doi":"10.3389/fsoil.2022.903544","DOIUrl":"https://doi.org/10.3389/fsoil.2022.903544","url":null,"abstract":"Estimations of Net Ecosystem Exchange (NEE) are crucial to assess the carbon sequestration/carbon source capacity of agricultural systems. Although several global models have been built to describe carbon flux patterns based on flux tower data, South American ecosystems (and croplands in particular) are underrepresented in the databases used to calibrate these models, leading to large uncertainties in regional and global NEE estimation. Despite the fact that almost half of the land surface is used worldwide for agricultural activities, these models still do not include variables related to cropland management. Using enhanced vegetation index (EVI) derived from MODIS imagery (250 m) and monthly CO2 exchange from a 9-year record of an eddy covariance (EC) flux tower in a crop field in the Inland Pampas region, we developed regression models to predict monthly NEE. We tested whether including a term for crop identity/land cover as a categorical variable (maize, soybean, wheat, and fallow) could improve model capability in capturing monthly NEE dynamics. NEE measured at the flux tower site was scaled to croplands across the Inland Pampa using crop-type maps, from which annual NEE maps were generated for the 2018–2019, 2019–2020, and 2020–2021 agricultural campaigns. The model based solely on EVI showed to be a good predictor of monthly NEE for the study region (r2 = 0.78), but model adjustment was improved by including a term for crop identity (r2 = 0.83). A second set of maps was generated taking into account carbon exports during harvest to estimate Net Biome Productivity (NBP) at the county level. Crops across the region as a whole acted as a carbon sink during the three studied campaigns, although with highly heterogeneous spatial and temporal patterns. Between 60% and 80% of the carbon sequestered was exported during harvest, a large decrease from the carbon sequestration capacity estimated using just NEE, which further decreased if fossil carbon emissions from agricultural supplies are taken into account. Estimates presented in this study are a first step towards upscaling carbon fluxes at the regional scale in a South American cropland area, and could help to improve regional to global estimations of carbon fluxes and refine national greenhouse gas (GHG) inventories.","PeriodicalId":73107,"journal":{"name":"Frontiers in soil science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43961110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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