Pub Date : 2020-03-03DOI: 10.4236/ojss.2020.103006
Colin T. Tobin, Shikha Singh, Sandeep Kumar, Tong Wang, P. Sexton
Integrated crop-livestock system (ICLS) is an alternative that can help in intensifying food production while benefiting the environment. However, the assessments of the impacts of ICLS on the soil and economic benefits relative to specific environments in South Dakota are still lacking. This study was to assess the effects of ICLS on soil health and economic benefits under a corn (Zea mays L.)-soybean (Glycine max L.)-rye (Secale cereale L.) rotation in South Dakota. Cover crops blends were planted after the rye crop, and grazing treatments (with and without) were applied after the cover crops establishment in 2015-2016. Data from this study indicate that most soil properties are not negatively impacted by grazing. However, the grazing increased soil bulk density (BD) and decreased soil organic carbon (SOC) and soil water retention (SWR) compared with the ungrazing. The effect of grazing on corn yield was not significant. The cover crops did not impact the pH, electrical conductivity (EC), total nitrogen (TN), β-glucosidase, acid hydrolysis carbon fraction, microbial biomass carbon, and SWR, but impacted the SOC, hot/cold water carbon fraction, BD, infiltration rate (qs) in some phases and depths. The effects of different cover crop blends on corn yield were not as strong. The economic analysis showed that implementing ICLS increased the profit of the farm by $17.23 ac−1 in the first year and $43.61 ac−1 in the second year. These findings indicate that ICLS practices with proper management benefit soil health and producer income.
作物-牲畜综合系统(ICLS)是一种替代方案，可以帮助加强粮食生产，同时有益于环境。然而，在南达科他州，ICLS对土壤的影响和相对于特定环境的经济效益的评估仍然缺乏。本研究旨在评价玉米(Zea mays L.)-大豆(Glycine max L.)-黑麦(Secale谷类L.)轮作下ICLS对土壤健康和经济效益的影响。2015-2016年在黑麦作物种植后进行复盖作物混播，复盖作物建立后进行放牧处理(复盖和不复盖)。本研究的数据表明，放牧对大多数土壤性质没有负面影响。与未放牧相比，放牧增加了土壤容重(BD)，降低了土壤有机碳(SOC)和土壤保水(SWR)。放牧对玉米产量的影响不显著。覆盖作物对土壤pH、电导率(EC)、总氮(TN)、β-葡萄糖苷酶、酸水解碳组分、微生物生物量碳和SWR无显著影响，但对土壤有机碳(SOC)、冷热水碳组分、BD、部分相深度的入渗速率(qs)有显著影响。不同覆盖作物混作对玉米产量的影响不明显。经济分析表明，实施ICLS第一年使农场的利润增加了17.23美元，第二年增加了43.61美元。这些结果表明，管理得当的ICLS做法有利于土壤健康和生产者收入。
{"title":"Demonstrating Short-Term Impacts of Grazing and Cover Crops on Soil Health and Economic Benefits in an Integrated Crop-Livestock System in South Dakota","authors":"Colin T. Tobin, Shikha Singh, Sandeep Kumar, Tong Wang, P. Sexton","doi":"10.4236/ojss.2020.103006","DOIUrl":"https://doi.org/10.4236/ojss.2020.103006","url":null,"abstract":"Integrated crop-livestock system (ICLS) is an alternative that can help in intensifying food production while benefiting the environment. However, the assessments of the impacts of ICLS on the soil and economic benefits relative to specific environments in South Dakota are still lacking. This study was to assess the effects of ICLS on soil health and economic benefits under a corn (Zea mays L.)-soybean (Glycine max L.)-rye (Secale cereale L.) rotation in South Dakota. Cover crops blends were planted after the rye crop, and grazing treatments (with and without) were applied after the cover crops establishment in 2015-2016. Data from this study indicate that most soil properties are not negatively impacted by grazing. However, the grazing increased soil bulk density (BD) and decreased soil organic carbon (SOC) and soil water retention (SWR) compared with the ungrazing. The effect of grazing on corn yield was not significant. The cover crops did not impact the pH, electrical conductivity (EC), total nitrogen (TN), β-glucosidase, acid hydrolysis carbon fraction, microbial biomass carbon, and SWR, but impacted the SOC, hot/cold water carbon fraction, BD, infiltration rate (qs) in some phases and depths. The effects of different cover crop blends on corn yield were not as strong. The economic analysis showed that implementing ICLS increased the profit of the farm by $17.23 ac−1 in the first year and $43.61 ac−1 in the second year. These findings indicate that ICLS practices with proper management benefit soil health and producer income.","PeriodicalId":57369,"journal":{"name":"土壤科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46169164","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 : 2020-02-28DOI: 10.4236/ojss.2020.102004
S. Diatta, Laure Tall, Y. Ndour, M. Sembéne, K. Assigbétsé
The soils of the semi-arid Sudano-Sahelian region of West Africa have been identified as being highly vulnerable to soil degradation with impacts on their capacity to provide goods and services in which soil microorganisms participate. Unfortunately, soil microbial diversity from this semi-arid region with high rainfall variability remains largely unexplored. The aim of the present study was to characterize the diversity and composition of the soil bacterial communities and to identify factors involved in their spatial distribution along an environmental gradient in Senegal. Samples were collected from non-anthropogenic sites across four pedoclimatic zones. Bacterial communities were characterized using next-generation sequencing and soil physico-chemical parameters were determined. Our results showed that Firmicutes, Actinobacteria, Proteobacteria, Chloroflexi, Gemmatimonadetes, Acidobacteria, and Verrucomicrobia phyla were predominant in the soils of the region. Bacterial α-diversity was stable along the environmental gradient whereas β-diversity highlighted significant changes in the composition of the soil bacterial community. Changes were driven by shifts in the relative abundance of OTUs belonging mainly to the genus Bacillus, Conexibacter, Kaistobacter, Solirubrobacter, Ktedonobacter, Sphingomonas, Microvirga, Rubrobacter and Pelobacter. Soil properties like pH, soil moisture and clay content were the environmental parameters identified as drivers of the composition of the bacterial communities in the semi-arid Sudano-Sahelian region of Senegal (West Africa).
{"title":"Composition and Diversity of Soil Bacterial Communities along an Environmental Gradient in the Sudano-Sahelian Region of Senegal","authors":"S. Diatta, Laure Tall, Y. Ndour, M. Sembéne, K. Assigbétsé","doi":"10.4236/ojss.2020.102004","DOIUrl":"https://doi.org/10.4236/ojss.2020.102004","url":null,"abstract":"The soils of the semi-arid Sudano-Sahelian region of West Africa have been identified as being highly vulnerable to soil degradation with impacts on their capacity to provide goods and services in which soil microorganisms participate. Unfortunately, soil microbial diversity from this semi-arid region with high rainfall variability remains largely unexplored. The aim of the present study was to characterize the diversity and composition of the soil bacterial communities and to identify factors involved in their spatial distribution along an environmental gradient in Senegal. Samples were collected from non-anthropogenic sites across four pedoclimatic zones. Bacterial communities were characterized using next-generation sequencing and soil physico-chemical parameters were determined. Our results showed that Firmicutes, Actinobacteria, Proteobacteria, Chloroflexi, Gemmatimonadetes, Acidobacteria, and Verrucomicrobia phyla were predominant in the soils of the region. Bacterial α-diversity was stable along the environmental gradient whereas β-diversity highlighted significant changes in the composition of the soil bacterial community. Changes were driven by shifts in the relative abundance of OTUs belonging mainly to the genus Bacillus, Conexibacter, Kaistobacter, Solirubrobacter, Ktedonobacter, Sphingomonas, Microvirga, Rubrobacter and Pelobacter. Soil properties like pH, soil moisture and clay content were the environmental parameters identified as drivers of the composition of the bacterial communities in the semi-arid Sudano-Sahelian region of Senegal (West Africa).","PeriodicalId":57369,"journal":{"name":"土壤科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47129209","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 : 2020-02-21DOI: 10.4236/ojss.2020.102003
A. Thomas, Antwi Eric Ofosu, Amankwah Emmanuel, Ankamah Johnson De-Graft, A. Ayine, A. Asare, Antwi Alexander
Infiltration is an important component of the hydrological cycle. It provides soil moisture in the vadose zone to support plant growth. This study was conducted to compare the validity of four infiltration models with measured values from the double ring infiltrometer. The parameters of the four models compared were estimated using the linear regression analysis. The C.C was used to show the performance of the predictability of the models. The RMSE, MAE and MBE were employed to check the anomalies between the predicted and the observed values. The results showed that, average values of the C.C ranged from 0.9294 - 0.9852. The average values of the RMSE were 4.0033, −17.489, 11.2400 and 49.8448; MAE were 3.1341, 15.9802, 10.6525, and 61.4736; and MBE were 0.0786, 9.5755, 0.0007 and 47.0204 for Philip, Horton, Green Ampt and Kostiakov respectively for the wetland soils. Statistical results also from the Fisher’s multiple comparison test show that the mean infiltration rate estimated from the Green Ampt’s, Philip’s and Horton’s model was not significantly different (p > 0.05) from the observed. The results indicated that the Kostiakov’s model had the highest deviations as it overestimated the measured data in all the plots. Comparison of the statistical parameters C.C, RMSE, MAE, and MBE for the four models indicates that the Philip’s model agreed well with the measured data and therefore, performed better than the Green Ampt’s, Horton’s and Kostiakov’s models respectively in that order for Besease wetland soils. Estimation of infiltration rate by the Philip’s model is important in the design of irrigation schemes and scheduling. Therefore, in the absence of measured infiltration data, the Philip’s model could be used to produce infiltration information for inland valley bottom soils that exhibit similar characteristic as Besease wetland soils.
{"title":"Comparison and Estimation of Four Infiltration Models","authors":"A. Thomas, Antwi Eric Ofosu, Amankwah Emmanuel, Ankamah Johnson De-Graft, A. Ayine, A. Asare, Antwi Alexander","doi":"10.4236/ojss.2020.102003","DOIUrl":"https://doi.org/10.4236/ojss.2020.102003","url":null,"abstract":"Infiltration is an important component of the hydrological cycle. It provides soil moisture in the vadose zone to support plant growth. This study was conducted to compare the validity of four infiltration models with measured values from the double ring infiltrometer. The parameters of the four models compared were estimated using the linear regression analysis. The C.C was used to show the performance of the predictability of the models. The RMSE, MAE and MBE were employed to check the anomalies between the predicted and the observed values. The results showed that, average values of the C.C ranged from 0.9294 - 0.9852. The average values of the RMSE were 4.0033, −17.489, 11.2400 and 49.8448; MAE were 3.1341, 15.9802, 10.6525, and 61.4736; and MBE were 0.0786, 9.5755, 0.0007 and 47.0204 for Philip, Horton, Green Ampt and Kostiakov respectively for the wetland soils. Statistical results also from the Fisher’s multiple comparison test show that the mean infiltration rate estimated from the Green Ampt’s, Philip’s and Horton’s model was not significantly different (p > 0.05) from the observed. The results indicated that the Kostiakov’s model had the highest deviations as it overestimated the measured data in all the plots. Comparison of the statistical parameters C.C, RMSE, MAE, and MBE for the four models indicates that the Philip’s model agreed well with the measured data and therefore, performed better than the Green Ampt’s, Horton’s and Kostiakov’s models respectively in that order for Besease wetland soils. Estimation of infiltration rate by the Philip’s model is important in the design of irrigation schemes and scheduling. Therefore, in the absence of measured infiltration data, the Philip’s model could be used to produce infiltration information for inland valley bottom soils that exhibit similar characteristic as Besease wetland soils.","PeriodicalId":57369,"journal":{"name":"土壤科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70632385","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 : 2020-01-20DOI: 10.4236/ojss.2020.101002
Kenneth Ray Olson, David R. Speidel
One only needs to study the soil and geologic history and location of the ancient Mississippi and Ohio Rivers to understand why Len Small levee if patched will continue to fail. Much of Dogtooth Bend located in Alexander County, Illinois was originally in the ancient Ohio River valley (Figure 1) alluvial sediments north and east of the confluence with the ancient Mississippi River. The ancient Ohio River valley soils underlain by alluvial sediments and have been easily eroded by the re-aligning modern Mississippi River which now travels through the bedrock controlled Thebes Gap (Figure 2) and into the Ancient Ohio river valley. The primary objectives of this paper are: 1) to explain why Len Small levee, Alexander County, Illinois, US will continue to breach during major flooding events if repaired and 2) to develop a new combined raised causeway and levee system which will provide a Mississippi River floodwater bypass, be sustainable, encourage and fund a land use change, restore the degraded highway road beds, protect remaining Dogtooth Bend farmsteads and farmland that have not yet been degraded by past flooding events and provide floodwater storage during major flooding events at the confluence of the Mississippi and Ohio Rivers.
{"title":"Why Does the Repaired Len Small Levee, Alexander County, Illinois, US Continue to Breach during Major Flooding Events?","authors":"Kenneth Ray Olson, David R. Speidel","doi":"10.4236/ojss.2020.101002","DOIUrl":"https://doi.org/10.4236/ojss.2020.101002","url":null,"abstract":"One only needs to study the soil and geologic history and location of the ancient Mississippi and Ohio Rivers to understand why Len Small levee if patched will continue to fail. Much of Dogtooth Bend located in Alexander County, Illinois was originally in the ancient Ohio River valley (Figure 1) alluvial sediments north and east of the confluence with the ancient Mississippi River. The ancient Ohio River valley soils underlain by alluvial sediments and have been easily eroded by the re-aligning modern Mississippi River which now travels through the bedrock controlled Thebes Gap (Figure 2) and into the Ancient Ohio river valley. The primary objectives of this paper are: 1) to explain why Len Small levee, Alexander County, Illinois, US will continue to breach during major flooding events if repaired and 2) to develop a new combined raised causeway and levee system which will provide a Mississippi River floodwater bypass, be sustainable, encourage and fund a land use change, restore the degraded highway road beds, protect remaining Dogtooth Bend farmsteads and farmland that have not yet been degraded by past flooding events and provide floodwater storage during major flooding events at the confluence of the Mississippi and Ohio Rivers.","PeriodicalId":57369,"journal":{"name":"土壤科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47847694","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 : 2020-01-20DOI: 10.4236/ojss.2020.101001
Firmin N Anago, D. G. Dieudonné, A. C. Emile, Oussou C. T. Brice, A. L. Guillaume
Inorganic fertilizers are alternative ways of providing the necessary nutrients to rice crop and increase its productivity. In order to identify the factors determining inorganic fertilizer technology adoption and rainfed rice yield, a survey was carried out among 763 farmers in 11 municipalities in four agriculture development centers (ADC) of Benin. Composite soil samples were collected from 227 farmer fields and analyzed at the laboratory. Rainfed rice yields were determined in these different fields. Data collected was analyzed with R version 3.5.1 software. Results show that inorganic fertilizer technology adoption depends significantly on age, educational status, household size, contribution of rice to household income and organic fertilizer use (0.004 kg•ha−1 with a mean of 74.68 kg•ha−1. The quantities of inorganic fertilizer applied differ more importantly from one farmer to another and range from 4.58% to 90.5% with a mean of 27.15% of the level recommended by research. However, nitrogen, phosphorous, potassium, organic carbon, pH water, and exchanging capacity cation determine the rainfed rice yield. The policies that aim at promoting inorganic fertilizer among rainfed rice farmers must take into account these factors.
{"title":"Inorganic Fertilizer Adoption, Use Intensity and Rainfed Rice Yield in Benin","authors":"Firmin N Anago, D. G. Dieudonné, A. C. Emile, Oussou C. T. Brice, A. L. Guillaume","doi":"10.4236/ojss.2020.101001","DOIUrl":"https://doi.org/10.4236/ojss.2020.101001","url":null,"abstract":"Inorganic fertilizers are alternative ways of providing the necessary nutrients to rice crop and increase its productivity. In order to identify the factors determining inorganic fertilizer technology adoption and rainfed rice yield, a survey was carried out among 763 farmers in 11 municipalities in four agriculture development centers (ADC) of Benin. Composite soil samples were collected from 227 farmer fields and analyzed at the laboratory. Rainfed rice yields were determined in these different fields. Data collected was analyzed with R version 3.5.1 software. Results show that inorganic fertilizer technology adoption depends significantly on age, educational status, household size, contribution of rice to household income and organic fertilizer use (0.004 kg•ha−1 with a mean of 74.68 kg•ha−1. The quantities of inorganic fertilizer applied differ more importantly from one farmer to another and range from 4.58% to 90.5% with a mean of 27.15% of the level recommended by research. However, nitrogen, phosphorous, potassium, organic carbon, pH water, and exchanging capacity cation determine the rainfed rice yield. The policies that aim at promoting inorganic fertilizer among rainfed rice farmers must take into account these factors.","PeriodicalId":57369,"journal":{"name":"土壤科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46564707","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 : 2020-01-01DOI: 10.4236/ojss.2020.105009
A. K. Alphonse, Ballo Koffi Célestin, Kouassi Kouakou Joselin, Y. Albert
Degradation of the physical quality of the soil is a common problem encountered in agrosystems, particularly in the case of open field cropping systems in the northern areas of Cote d’Ivoire. Thus, the structural stability of the soil, which is a good indicator of the sensitivity to threshing and to water erosion in relation to the accumulation of organic matter, was evaluated in two types of soil (Ferralsol and Cambisol) in cashew orchards, in two villages (Mahana and Sanankoro) producing cashew nuts, located the Department of Touba in the North West of Cote d’Ivoire. The objective of this study is to develop new technical routes that are better suited to further promote the sequestration of organic carbon in the soil. Soil samples were taken from open soil profiles at the two chosen sites to allow laboratory analyzes. The results indicate that the surface horizon of Cambisol (site 1) is more stable (Is = 0.78) than that of Ferralsol (site 2; Is = 1.08) with nevertheless relatively small thicknesses of horizons. The median horizons and those of depth, indicate a mediocre stability (Is vary from 1.03 to 1.62). In terms of the quantity of organic carbon, the estimated values vary from 1.96 to 4.53 t⋅ha−1 for Cambisol (site 1) and from 1.44 to 3.46 t⋅ha−1 for Ferralsol (site 2). These values remain relatively low especially at the level of the median horizons and those located in depths. Statistical tests have shown a very highly significant and negative association between the structural stability of soils and the amount of organic carbon in the different horizons. The relationship implies that organic carbon plays an important role in the structural stability of soil horizons under cashew tree orchards.
{"title":"Structural Stability and Accumulation of Organic Matter in Some Soils under Cashew Tree Orchards in the Department of Touba in North-West Côte d’Ivoire","authors":"A. K. Alphonse, Ballo Koffi Célestin, Kouassi Kouakou Joselin, Y. Albert","doi":"10.4236/ojss.2020.105009","DOIUrl":"https://doi.org/10.4236/ojss.2020.105009","url":null,"abstract":"Degradation of the physical quality of the soil is a common problem encountered in agrosystems, particularly in the case of open field cropping systems in the northern areas of Cote d’Ivoire. Thus, the structural stability of the soil, which is a good indicator of the sensitivity to threshing and to water erosion in relation to the accumulation of organic matter, was evaluated in two types of soil (Ferralsol and Cambisol) in cashew orchards, in two villages (Mahana and Sanankoro) producing cashew nuts, located the Department of Touba in the North West of Cote d’Ivoire. The objective of this study is to develop new technical routes that are better suited to further promote the sequestration of organic carbon in the soil. Soil samples were taken from open soil profiles at the two chosen sites to allow laboratory analyzes. The results indicate that the surface horizon of Cambisol (site 1) is more stable (Is = 0.78) than that of Ferralsol (site 2; Is = 1.08) with nevertheless relatively small thicknesses of horizons. The median horizons and those of depth, indicate a mediocre stability (Is vary from 1.03 to 1.62). In terms of the quantity of organic carbon, the estimated values vary from 1.96 to 4.53 t⋅ha−1 for Cambisol (site 1) and from 1.44 to 3.46 t⋅ha−1 for Ferralsol (site 2). These values remain relatively low especially at the level of the median horizons and those located in depths. Statistical tests have shown a very highly significant and negative association between the structural stability of soils and the amount of organic carbon in the different horizons. The relationship implies that organic carbon plays an important role in the structural stability of soil horizons under cashew tree orchards.","PeriodicalId":57369,"journal":{"name":"土壤科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70632500","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 : 2020-01-01DOI: 10.4236/ojss.2020.109022
Kenneth Ray Olson, J. M. Lang
The physical, chemical and biological attributes of the Yukon River and tributary basins impact soil erosion, sediment transport and sediment delivery. The glacier, snow and permafrost melting, runoff, erosion, transport, deposition and storage of gravelly, sandy, silty and clayey sediments determine the habitat distribution and water quality within the river channels and floodplains. The ecological functioning, with food and nutrient delivery, migratory cues, breeding, habitats, and riparian and floodplain ecological cycles are all dependent on the transported sediment at specific times of the year. Annual temperatures have been rising since the 1840s which could contribute to higher runoff water flows and greater sedimentation. The primary objective was to document the sedimentation in the Yukon watershed with little soil erosion as a result of agriculture or urban development. The causes of the soil erosion and sedimentation were permafrost, alpine glacial melting, drilling for gas and oil, road construction, gold mining, cold war military sites, pipeline construction, forest fires and steep slopes.
{"title":"Sediment Delivery by the Yukon River to the Yukon Flats, Yukon Delta and the Bering Sea","authors":"Kenneth Ray Olson, J. M. Lang","doi":"10.4236/ojss.2020.109022","DOIUrl":"https://doi.org/10.4236/ojss.2020.109022","url":null,"abstract":"The physical, chemical and biological attributes of the Yukon River and tributary basins impact soil erosion, sediment transport and sediment delivery. The glacier, snow and permafrost melting, runoff, erosion, transport, deposition and storage of gravelly, sandy, silty and clayey sediments determine the habitat distribution and water quality within the river channels and floodplains. The ecological functioning, with food and nutrient delivery, migratory cues, breeding, habitats, and riparian and floodplain ecological cycles are all dependent on the transported sediment at specific times of the year. Annual temperatures have been rising since the 1840s which could contribute to higher runoff water flows and greater sedimentation. The primary objective was to document the sedimentation in the Yukon watershed with little soil erosion as a result of agriculture or urban development. The causes of the soil erosion and sedimentation were permafrost, alpine glacial melting, drilling for gas and oil, road construction, gold mining, cold war military sites, pipeline construction, forest fires and steep slopes.","PeriodicalId":57369,"journal":{"name":"土壤科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70633042","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 : 2020-01-01DOI: 10.4236/ojss.2020.109021
Formeluh Abraham Toh, L. M. Ndam, T. E. Angwafo, Ngosong Christopher
Soil organic carbon (SOC) mineralization was carried out on soil samples collected from two depths: 0 - 20 cm and 20 - 40 cm for all land use (LU) types (grasslands, croplands, natural forest/fallow lands, cocoa/palm plantations, and settlement/agro-forests). Microbiological analyses were carried out by measuring microbial activity in 40 g of dried soil samples wetted to 60% water holding capacity and incubated at 27 °C. Carbon dioxide (CO2) emission was measured for 10 weeks using a CO2 trap. Descriptive and graphical analyses of CO2 respiration were done using CO2 emission data. Models were developed to describe CO2 respiration and the first order kinetic model provided best fit to C-mineralization. Potentially mineralizable carbon (Co) and C-mineralization rate were higher in grasslands than other LU types, indicating a higher rate of microbial activity and carbon cycling. Metabolic quotient was higher in forest/fallow lands and reflects greater stress of the microbial community and a high requirement of maintenance energy. Grasslands enhanced more SOC accumulation and decomposition, suggesting a better carbon sink than other land use and management systems (LUMS). Microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) varied across LU patterns with maximum values in grasslands and minimum values in natural forest/fallow lands insinuating better soil quality for grasslands. MBC and SOC positively correlated with Co and C-mineralization, which intimates that C-mineralization is influenced by availability of MBC and SOC. Metabolic quotient (qCO2) negatively correlated with microbial quotient (MBC:SOC), depicting that higher values of qCO2 signify difficulties in using organic substrates during microbial activity as a result of low MBC:SOC. Changes in LUMS affected the mineralization kinetics of SOC in the study area.
{"title":"Effect of Land Use Management Patterns on Mineralization Kinetics of Soil Organic Carbon in Mount Bambouto Caldera Area of Cameroon","authors":"Formeluh Abraham Toh, L. M. Ndam, T. E. Angwafo, Ngosong Christopher","doi":"10.4236/ojss.2020.109021","DOIUrl":"https://doi.org/10.4236/ojss.2020.109021","url":null,"abstract":"Soil organic carbon (SOC) mineralization was carried out on soil samples collected from two depths: 0 - 20 cm and 20 - 40 cm for all land use (LU) types (grasslands, croplands, natural forest/fallow lands, cocoa/palm plantations, and settlement/agro-forests). Microbiological analyses were carried out by measuring microbial activity in 40 g of dried soil samples wetted to 60% water holding capacity and incubated at 27 °C. Carbon dioxide (CO2) emission was measured for 10 weeks using a CO2 trap. Descriptive and graphical analyses of CO2 respiration were done using CO2 emission data. Models were developed to describe CO2 respiration and the first order kinetic model provided best fit to C-mineralization. Potentially mineralizable carbon (Co) and C-mineralization rate were higher in grasslands than other LU types, indicating a higher rate of microbial activity and carbon cycling. Metabolic quotient was higher in forest/fallow lands and reflects greater stress of the microbial community and a high requirement of maintenance energy. Grasslands enhanced more SOC accumulation and decomposition, suggesting a better carbon sink than other land use and management systems (LUMS). Microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) varied across LU patterns with maximum values in grasslands and minimum values in natural forest/fallow lands insinuating better soil quality for grasslands. MBC and SOC positively correlated with Co and C-mineralization, which intimates that C-mineralization is influenced by availability of MBC and SOC. Metabolic quotient (qCO2) negatively correlated with microbial quotient (MBC:SOC), depicting that higher values of qCO2 signify difficulties in using organic substrates during microbial activity as a result of low MBC:SOC. Changes in LUMS affected the mineralization kinetics of SOC in the study area.","PeriodicalId":57369,"journal":{"name":"土壤科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70632917","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 : 2020-01-01DOI: 10.4236/ojss.2020.109023
Eman F. A. Awad-Allah, M. Attia, A. Mahdy
Soil salinity is one of the major yield-limiting factors for crop production in many agricultural regions all over the world. Besides following efficient management practices at the field scale to reduce accumulation of salts in the effective root-zone, the effective use of treatments to alleviate the effects of salinity stress and improve crop salt tolerance is a promising solution to ensure crop production in such adverse conditions. A field experiment was carried out to investigate the effect of foliar spray with plant-based biostimulant (i.e. with and/or without 3% yeast extract), three levels of proline (0, 25, and 50 mM), and combined with potassium fertilizers, as potassium sulfate, 48% K2O (0, 50, and 100 kg/fed.) on growth promotion, chemical composition of garlic leaves, bulb quality parameters as well as yield and its components of garlic plant grown under moderate saline soil. Results revealed that the interaction between foliar spray with yeast extract at 3% and proline at 50 mM combined with proper K level at 100 kg/fed., was the best interaction treatment for increasing vegetative growth parameters, i.e. plant height, number of leaves per plant, and mineral contents (N, P, K, S, Ca and Mg in leaves), and proline content of garlic leaves after 135 days from planting time, total yield/fed., and garlic yield quality parameters at harvesting time. In conclusion, the detrimental effects of salinity stress can be alleviated by stress tolerance-inducing compounds, such as yeast extract and proline with proper application rate of K fertilization during the growing season of garlic crop.
{"title":"Salinity Stress Alleviation by Foliar Bio-Stimulant, Proline and Potassium Nutrition Promotes Growth and Yield Quality of Garlic Plant","authors":"Eman F. A. Awad-Allah, M. Attia, A. Mahdy","doi":"10.4236/ojss.2020.109023","DOIUrl":"https://doi.org/10.4236/ojss.2020.109023","url":null,"abstract":"Soil salinity is one of the major yield-limiting factors for crop production in many agricultural regions all over the world. Besides following efficient management practices at the field scale to reduce accumulation of salts in the effective root-zone, the effective use of treatments to alleviate the effects of salinity stress and improve crop salt tolerance is a promising solution to ensure crop production in such adverse conditions. A field experiment was carried out to investigate the effect of foliar spray with plant-based biostimulant (i.e. with and/or without 3% yeast extract), three levels of proline (0, 25, and 50 mM), and combined with potassium fertilizers, as potassium sulfate, 48% K2O (0, 50, and 100 kg/fed.) on growth promotion, chemical composition of garlic leaves, bulb quality parameters as well as yield and its components of garlic plant grown under moderate saline soil. Results revealed that the interaction between foliar spray with yeast extract at 3% and proline at 50 mM combined with proper K level at 100 kg/fed., was the best interaction treatment for increasing vegetative growth parameters, i.e. plant height, number of leaves per plant, and mineral contents (N, P, K, S, Ca and Mg in leaves), and proline content of garlic leaves after 135 days from planting time, total yield/fed., and garlic yield quality parameters at harvesting time. In conclusion, the detrimental effects of salinity stress can be alleviated by stress tolerance-inducing compounds, such as yeast extract and proline with proper application rate of K fertilization during the growing season of garlic crop.","PeriodicalId":57369,"journal":{"name":"土壤科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70633089","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 : 2020-01-01DOI: 10.4236/ojss.2020.106013
Carson Wright, Jessique Ghezzi-Haeft
Over-application of fertilizer to cropland adversely affects both environmental and agricultural ecosystems. This study examined whether planting a legume-based winter cover crop mix offsets fertilizer application via natural nitrogen inputs. The influence of the cover crop mixture on available nutrients was also assessed. Hairy vetch (Vicia villosa) and winter triticale (×triticosecale) cover crops were planted in fall and terminated in May. Soil fertility data was collected before and after planting the winter cover crop to determine the effect on fixing nitrogen and soil phosphorus, potassium and organic matter levels. Increases of soil ammonium were observed in plots with cover crop treatments. A triticale-hairy vetch cover crop mix was successful at scavenging P for future crops and appears to hold promise for long-term soil fertility benefits.
{"title":"Hairy Vetch and Triticale Cover Crops for N Management in Soils","authors":"Carson Wright, Jessique Ghezzi-Haeft","doi":"10.4236/ojss.2020.106013","DOIUrl":"https://doi.org/10.4236/ojss.2020.106013","url":null,"abstract":"Over-application of fertilizer to cropland adversely affects both environmental and agricultural ecosystems. This study examined whether planting a legume-based winter cover crop mix offsets fertilizer application via natural nitrogen inputs. The influence of the cover crop mixture on available nutrients was also assessed. Hairy vetch (Vicia villosa) and winter triticale (×triticosecale) cover crops were planted in fall and terminated in May. Soil fertility data was collected before and after planting the winter cover crop to determine the effect on fixing nitrogen and soil phosphorus, potassium and organic matter levels. Increases of soil ammonium were observed in plots with cover crop treatments. A triticale-hairy vetch cover crop mix was successful at scavenging P for future crops and appears to hold promise for long-term soil fertility benefits.","PeriodicalId":57369,"journal":{"name":"土壤科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70633243","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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