Pub Date : 2020-08-19DOI: 10.4236/ojss.2020.108017
C. Horta, J. Carneiro
The use of digestates or cattle slurries as fertilisers could contribute to the recycling of nutrients and organic matter, thus meeting the goals of the circular economy in agriculture. This work aims at evaluating the fertilising properties of a solid digestate (DG) in comparison with undigested cattle slurry (CS) and mineral fertilisation (MF). The experiment was performed in pots with ryegrass (Lolium multiflorum Lam.) grown in an acidic soil during a 163 days crop cycle. The results showed that throughout the crop cycle neither DG nor CS increased soil organic matter. DG significantly increased (P < 0.001) the sum of the soil exchangeable bases and soil P availability compared with CS or MF. Also, DG significantly increased (P < 0.05) the apparent P recovery of ryegrass (43%) compared with MF (27%). In the first cut, the ryegrass yield was higher in DG and CS than in MF, decreasing in the second and third cuts as a consequence of a decrease in N availability. Nevertheless, the fertilisation with DG or CS could replace the half amount of mineral N fertilisation, without a significant decrease in the ryegrass forage production. In addition, DG enables greater efficiency in the use of P than CS or MF.
{"title":"Assessment of Fertilising Properties of a Solid Digestate in Comparison with Undigested Cattle Slurry Applied to an Acidic Soil","authors":"C. Horta, J. Carneiro","doi":"10.4236/ojss.2020.108017","DOIUrl":"https://doi.org/10.4236/ojss.2020.108017","url":null,"abstract":"The use of digestates or cattle slurries as fertilisers could contribute to the recycling of nutrients and organic matter, thus meeting the goals of the circular economy in agriculture. This work aims at evaluating the fertilising properties of a solid digestate (DG) in comparison with undigested cattle slurry (CS) and mineral fertilisation (MF). The experiment was performed in pots with ryegrass (Lolium multiflorum Lam.) grown in an acidic soil during a 163 days crop cycle. The results showed that throughout the crop cycle neither DG nor CS increased soil organic matter. DG significantly increased (P < 0.001) the sum of the soil exchangeable bases and soil P availability compared with CS or MF. Also, DG significantly increased (P < 0.05) the apparent P recovery of ryegrass (43%) compared with MF (27%). In the first cut, the ryegrass yield was higher in DG and CS than in MF, decreasing in the second and third cuts as a consequence of a decrease in N availability. Nevertheless, the fertilisation with DG or CS could replace the half amount of mineral N fertilisation, without a significant decrease in the ryegrass forage production. In addition, DG enables greater efficiency in the use of P than CS or MF.","PeriodicalId":57369,"journal":{"name":"土壤科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49271471","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 : 2020-07-01DOI: 10.4236/ojss.2020.107016
A. Chatterjee, Alexsandro Felipe de Jesus, Diksha Goyal, S. Sigdel, L. Cihacek, Bhupinder S. Farmaha, S. Jagadamma, L. Sharma, D. Long
Soil temperature controls gaseous nitrogen losses through nitrous oxide (N2O) and ammonia (NH3) fluxes. Eight surface soils from agricultural fields across the United States were incubated at 10°C, 20°C, and 30°C, and N2O and NH3 flux were measured twice a week for 91 and 47 d, respectively. Changes in cumulative N2O and NH3 flux and net N mineralization at three temperatures were fitted to calculate Q10 using the Arrhenius equation. For the majority of soils, Q10 values for the N2O loss ranged between 0.23 and 2.14, except for Blackville, North Carolina (11.4) and Jackson, Tennessee (10.1). For NH3 flux, Q10 values ranged from 0.63 (Frenchville, Maine) to 1.24 (North Bend, Nebraska). Net soil N mineralization-Q10 ranged from 0.96 to 1.00. Distribution of soil organic carbon and total soil N can explain the variability of Q10 for N2O loss. Understanding the Q10 variability of soil N dynamics will help us to predict the N loss.
{"title":"Temperature Sensitivity of Nitrogen Dynamics of Agricultural Soils of the United States","authors":"A. Chatterjee, Alexsandro Felipe de Jesus, Diksha Goyal, S. Sigdel, L. Cihacek, Bhupinder S. Farmaha, S. Jagadamma, L. Sharma, D. Long","doi":"10.4236/ojss.2020.107016","DOIUrl":"https://doi.org/10.4236/ojss.2020.107016","url":null,"abstract":"Soil temperature controls gaseous nitrogen losses through nitrous oxide (N2O) and ammonia (NH3) fluxes. Eight surface soils from agricultural fields across the United States were incubated at 10°C, 20°C, and 30°C, and N2O and NH3 flux were measured twice a week for 91 and 47 d, respectively. Changes in cumulative N2O and NH3 flux and net N mineralization at three temperatures were fitted to calculate Q10 using the Arrhenius equation. For the majority of soils, Q10 values for the N2O loss ranged between 0.23 and 2.14, except for Blackville, North Carolina (11.4) and Jackson, Tennessee (10.1). For NH3 flux, Q10 values ranged from 0.63 (Frenchville, Maine) to 1.24 (North Bend, Nebraska). Net soil N mineralization-Q10 ranged from 0.96 to 1.00. Distribution of soil organic carbon and total soil N can explain the variability of Q10 for N2O loss. Understanding the Q10 variability of soil N dynamics will help us to predict the N loss.","PeriodicalId":57369,"journal":{"name":"土壤科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45211964","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 : 2020-07-01DOI: 10.4236/ojss.2020.107014
G. K. Kome, F. O. Tabi, R. K. Enang, F. Silatsa
Declining yields in oil palm fresh fruit bunch (FFB) have been recorded over the past years in the coastal lowlands of southwest Cameroon and current actual yields are very low (−1•yr−1) compared to the potential yields (25 t FFB ha−1•yr−1). One of the problems limiting optimum oil palm production is lack of detailed pedological information to guide plantation establishment and management. A land suitability evaluation was carried out for some major oil palm producing areas of southwest Cameroon to identify land qualities limiting optimal production. Thirteen sites (9 with sedimentary parent materials and 4 with volcanic parent material) were evaluated using a parametric method. Results indicate that climate was not a major limiting factor for oil palm production in coastal plains of southwest Cameroon. However, soil physical characteristics (mainly clayey texture and poor drainage) and soil fertility constitute limitations to oil palm production. Specifically, limitations in cation exchange capacity (CEC), base saturation (BS), organic carbon (OC) and pH were slight to moderate while K mole fraction was the most severe and the most limiting in all the sites. The fertility limitations were more pronounced in soils derived from sedimentary parent materials where 33% had limitations caused by soil pH and OC compared to none for volcanic soils. In addition, 77.8% of sedimentary soils had limitations caused by CEC compared to 25% for volcanic soils. Considering the overall suitability, soils derived from volcanic parent materials were potentially more suitable for oil palm cultivation ((S3)—50%, (S2)—50%) compared to sedimentary soils ((N)—11%, (S3)—78% and (S2)—11%). Based on the suitability classes of the different soils derived from dissimilar parent materials, appropriate site-specific soil management is needed to improve oil palm yields, especially with emphasis on K fertilization and improved soil water management. Plantation management in coastal plains of South West Cameroon therefore should factor in differences in soil parent material.
{"title":"Land Suitability Evaluation for Oil Palm (Elaeis guineensis Jacq.) in Coastal Plains of Southwest Cameroon","authors":"G. K. Kome, F. O. Tabi, R. K. Enang, F. Silatsa","doi":"10.4236/ojss.2020.107014","DOIUrl":"https://doi.org/10.4236/ojss.2020.107014","url":null,"abstract":"Declining yields in oil palm fresh fruit bunch (FFB) have been recorded over the past years in the coastal lowlands of southwest Cameroon and current actual yields are very low (−1•yr−1) compared to the potential yields (25 t FFB ha−1•yr−1). One of the problems limiting optimum oil palm production is lack of detailed pedological information to guide plantation establishment and management. A land suitability evaluation was carried out for some major oil palm producing areas of southwest Cameroon to identify land qualities limiting optimal production. Thirteen sites (9 with sedimentary parent materials and 4 with volcanic parent material) were evaluated using a parametric method. Results indicate that climate was not a major limiting factor for oil palm production in coastal plains of southwest Cameroon. However, soil physical characteristics (mainly clayey texture and poor drainage) and soil fertility constitute limitations to oil palm production. Specifically, limitations in cation exchange capacity (CEC), base saturation (BS), organic carbon (OC) and pH were slight to moderate while K mole fraction was the most severe and the most limiting in all the sites. The fertility limitations were more pronounced in soils derived from sedimentary parent materials where 33% had limitations caused by soil pH and OC compared to none for volcanic soils. In addition, 77.8% of sedimentary soils had limitations caused by CEC compared to 25% for volcanic soils. Considering the overall suitability, soils derived from volcanic parent materials were potentially more suitable for oil palm cultivation ((S3)—50%, (S2)—50%) compared to sedimentary soils ((N)—11%, (S3)—78% and (S2)—11%). Based on the suitability classes of the different soils derived from dissimilar parent materials, appropriate site-specific soil management is needed to improve oil palm yields, especially with emphasis on K fertilization and improved soil water management. Plantation management in coastal plains of South West Cameroon therefore should factor in differences in soil parent material.","PeriodicalId":57369,"journal":{"name":"土壤科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42647871","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 : 2020-07-01DOI: 10.4236/ojss.2020.107015
R. Lascano, G. Leiker, T. Goebel, S. Mauget, D. C. Gitz
Crop production in the Texas High Plains is shifting from irrigated to dryland due to the increase of the depth to the water table from the Ogallala aquifer in regions where the saturated thickness of 9 m, the minimum to sustain irrigation, has been reached. Our objective was to use the mechanistic model ENWATBAL to evaluate the daily and annual water balance for three scenarios of rainfall in this region, a dry (189 mm), an average (449 mm) and a wet (669 mm) year. These three scenarios were applied to two major soil series of this region, Pullman and Amarillo. In all simulations, we used hourly input weather data for a location near Lubbock, Texas and used measured soil hydraulic properties to simulate the water balance for each soil series and the three rainfall scenarios. Results showed that in years with average and wet rain, storage of rainfall occurred in the Pullman but not in in the Amarillo soil series. However, storage of water could be enhanced by combining furrow dikes with minimum tillage along with crop covers that provide a surface residue. The implications of our results for dryland crop production in the semiarid climate of the THP suggest that for years with average and wetter rainfall soils in the Pullman series could store water that would be available for crop use. However, this was not the case for the Amarillo soil series and these soils represent a higher risk for dryland crop production.
{"title":"Water Balance of Two Major Soil Types of the Texas High Plains: Implications for Dryland Crop Production","authors":"R. Lascano, G. Leiker, T. Goebel, S. Mauget, D. C. Gitz","doi":"10.4236/ojss.2020.107015","DOIUrl":"https://doi.org/10.4236/ojss.2020.107015","url":null,"abstract":"Crop production in the Texas High Plains is shifting from irrigated to dryland due to the increase of the depth to the water table from the Ogallala aquifer in regions where the saturated thickness of 9 m, the minimum to sustain irrigation, has been reached. Our objective was to use the mechanistic model ENWATBAL to evaluate the daily and annual water balance for three scenarios of rainfall in this region, a dry (189 mm), an average (449 mm) and a wet (669 mm) year. These three scenarios were applied to two major soil series of this region, Pullman and Amarillo. In all simulations, we used hourly input weather data for a location near Lubbock, Texas and used measured soil hydraulic properties to simulate the water balance for each soil series and the three rainfall scenarios. Results showed that in years with average and wet rain, storage of rainfall occurred in the Pullman but not in in the Amarillo soil series. However, storage of water could be enhanced by combining furrow dikes with minimum tillage along with crop covers that provide a surface residue. The implications of our results for dryland crop production in the semiarid climate of the THP suggest that for years with average and wetter rainfall soils in the Pullman series could store water that would be available for crop use. However, this was not the case for the Amarillo soil series and these soils represent a higher risk for dryland crop production.","PeriodicalId":57369,"journal":{"name":"土壤科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47993563","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 : 2020-06-05DOI: 10.4236/ojss.2020.106011
Konan Kouakou Marius, K. N’guessan, Kouassi Kouadio Ignace, K. Kevin, K. Kouassi, Z. Arsène, Dogbo Dénézon Odette
Looking of finding an alternative to the use of chemical fertilizers to increase yields of cassava (Manihot esculenta), trials were carried out in the Lamto zone in central Cote d’Ivoire. Thus, the effects of compost and ash from cocoa shell and NPK were tested on the agronomic parameters of cassava. The trial was conducted for two years with four varieties of cassava: Yace, Alleda agba, Six mois and Bonoua, grown on elementary plots treated with one of these fertilizers. The experimental design was complete randomized blocks with three replicates. Analysis of the results showed that the Six mois variety gave the longest stems (131, 67 cm) with the cocoa shell compost. The Bonoua variety, on the other hand, gave the largest diameter of the stem base (21.56 mm), a higher number of leaves (77.30) and a large wingspan (136.89 cm) with cocoa shell compost. The leaves developed by the plants of this variety were wider (19.30 cm) and longer (17.96 cm) with cocoa shell compost. Also, this Bonoua variety treated with shell compost yielded a high number of tuberized roots (5.11), high average weight per plant (5.83 kg/plant) and higher yield (58.29 t/ha). This compost of cocoa shell has also allowed a better conservation of the cultivated soils quality.
{"title":"Comparative Effects of Organic Cocoa Shell-Based and Inorganic NPK Fertilization on the Growth and Yield of Four Cassava Varieties","authors":"Konan Kouakou Marius, K. N’guessan, Kouassi Kouadio Ignace, K. Kevin, K. Kouassi, Z. Arsène, Dogbo Dénézon Odette","doi":"10.4236/ojss.2020.106011","DOIUrl":"https://doi.org/10.4236/ojss.2020.106011","url":null,"abstract":"Looking of finding an \u0000alternative to the use of chemical fertilizers to increase yields of cassava (Manihot \u0000esculenta), trials were carried out in the Lamto zone in central Cote \u0000d’Ivoire. Thus, the effects of compost and ash from cocoa shell and NPK were \u0000tested on the agronomic parameters of cassava. The trial was conducted for two \u0000years with four varieties of cassava: Yace, Alleda agba, Six mois and Bonoua, \u0000grown on elementary plots treated with one of these fertilizers. The \u0000experimental design was complete randomized blocks with three replicates. \u0000Analysis of the results showed that the Six mois variety gave the \u0000longest stems (131, 67 cm) with the cocoa shell compost. The Bonoua variety, on the \u0000other hand, gave the largest diameter of the stem base (21.56 mm), a higher \u0000number of leaves (77.30) and a large wingspan (136.89 cm) with cocoa shell compost. The leaves \u0000developed by the plants of this variety were wider (19.30 cm) and longer (17.96 \u0000cm) with cocoa shell compost. Also, this Bonoua variety treated with \u0000shell compost yielded a high number of tuberized roots (5.11), high average \u0000weight per plant (5.83 kg/plant) and higher yield (58.29 t/ha). This compost of \u0000cocoa shell has also allowed a better conservation of the cultivated soils \u0000quality.","PeriodicalId":57369,"journal":{"name":"土壤科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43896808","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 : 2020-06-05DOI: 10.4236/ojss.2020.106012
J. D. Jabro, W. B. Stevens, W. Iversen
Soil bulk density and moisture content are dynamic properties that vary with changes in soil and field conditions and have many agricultural, hydrological and environmental implications. The main objective of this study was to compare between a soil core sampling method (core) and the CPN MC-3 EliteTM nuclear gauge method (radiation) for measuring bulk density (ρB) and volumetric moisture content (θv) in a clay loam soil. Soil ρB and θv measurements were determined using the core and radiation methods at 0 - 10 and 10 - 20 cm soil depths. The mean values of soil ρB obtained using the core method (1.454, 1.492 g·cm−3) were greater than those obtained using the radiation method (1.343, 1.476 g·cm−3) at the 0 - 10 and 10 - 20 cm depths, respectively. Mean ρB and θv values averaged across both depths (referred to as the 0 - 20 cm depth) measured by the core method were 4.47% and 22.74% greater, respectively, than those obtained by the radiation method. The coefficients of variation (CV) of soil ρB values measured by the core method were lower than the CV values of those measured by the radiation method at both depths; however, the CV’s of ρB values for both methods were larger at the 0 - 10 cm depth than those measured at the 10 - 20 cm depth. Similarly, the CV values of soil θv values measured by the core method were lower than the CV values of those measured by the radiation method at both depths. There were significant differences between two methods in terms of ρB and θv, with the core method generating greater values than the radiation method at the 0 - 20 cm depth. These discrepancies between the two methods could have resulted from soil compaction and soil disturbance caused by the core and radiation techniques, respectively, as well as by other sources of error. Nevertheless, the core sampling method is considered the most common one for measuring ρB for many agricultural, hydrological and environmental studies in most soils.
{"title":"Comparing Two Methods for Measuring Soil Bulk Density and Moisture Content","authors":"J. D. Jabro, W. B. Stevens, W. Iversen","doi":"10.4236/ojss.2020.106012","DOIUrl":"https://doi.org/10.4236/ojss.2020.106012","url":null,"abstract":"Soil bulk density and moisture content are dynamic properties that vary with changes in soil and field conditions and have many agricultural, hydrological and environmental implications. The main objective of this study was to compare between a soil core sampling method (core) and the CPN MC-3 EliteTM nuclear gauge method (radiation) for measuring bulk density (ρB) and volumetric moisture content (θv) in a clay loam soil. Soil ρB and θv measurements were determined using the core and radiation methods at 0 - 10 and 10 - 20 cm soil depths. The mean values of soil ρB obtained using the core method (1.454, 1.492 g·cm−3) were greater than those obtained using the radiation method (1.343, 1.476 g·cm−3) at the 0 - 10 and 10 - 20 cm depths, respectively. Mean ρB and θv values averaged across both depths (referred to as the 0 - 20 cm depth) measured by the core method were 4.47% and 22.74% greater, respectively, than those obtained by the radiation method. The coefficients of variation (CV) of soil ρB values measured by the core method were lower than the CV values of those measured by the radiation method at both depths; however, the CV’s of ρB values for both methods were larger at the 0 - 10 cm depth than those measured at the 10 - 20 cm depth. Similarly, the CV values of soil θv values measured by the core method were lower than the CV values of those measured by the radiation method at both depths. There were significant differences between two methods in terms of ρB and θv, with the core method generating greater values than the radiation method at the 0 - 20 cm depth. These discrepancies between the two methods could have resulted from soil compaction and soil disturbance caused by the core and radiation techniques, respectively, as well as by other sources of error. Nevertheless, the core sampling method is considered the most common one for measuring ρB for many agricultural, hydrological and environmental studies in most soils.","PeriodicalId":57369,"journal":{"name":"土壤科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42134100","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 : 2020-05-18DOI: 10.4236/ojss.2020.105010
Kenneth Ray Olson, David R. Speidel
For more than 2500 years, soil tunnels have been used in warfare and smuggling. Initially tunnels were utilized to attack fortresses that were underlain by unconsolidated (non-bedrock) soil materials. Later tunnels provided housing and served as smuggling corridors. The medieval warfare undermining technique involved digging soil tunnels with wooden or beam props to hold up the soil ceilings. Then flammable material, such as hay or straw, was put in the tunnel and set on fire. The fire burnt the support beams which collapsed the soil tunnel ceilings and undermined the overlying perimeter wall. Later gunpowder and dynamite replaced fire when attempting to collapse a tunnel, fortress or perimeter defense. Modern warfare soil tunnels were the pathways used to move troops, weapons and supplies to the other side of a border or wall for surprise attacks. Most of the soil tunnels were placed in easy-to-dig unconsolidated soil materials that had a low water table and were not subject to flooding. Eventually, machinery was used to drill through bedrock permitting deeper and longer tunnels for troop movement or smuggling. However, when drilling through bedrock under international borders, the process creates both noise and vibrations which were often detected by the enemy. Once discovered the tunnels were often collapsed by blowing up the tunnel, injection of gas, filling with water or wastewater, or inserting barriers. A series of case studies will be examined with the goal of determining soil and site criteria required to permit successful tunneling. The most restrictive soil and geologic conditions will be identified as well as potential mitigation methods used to overcome the site restrictions will be documented. Countries with warfare or smuggling issues along their borders, such as Israel and United States, need to identify the sections of the border most likely to be undermined by soil tunnels. In the case of Israel their entire border is susceptible as a result of the favorable arid climate, soils and geology. The US border with Mexico can become vulnerable wherever a new wall is created. Without a wall there is usually no need for soil tunnels. The US Department of Homeland Security and border patrol will need to monitor the noise and vibrations, just like the Israel does, to identify future soil tunnel locations. Eventually most of 3200 km border will have a wall that will become the target of more soil tunnels for smuggling goods and people from Mexico into the United States.
{"title":"Review and Analysis: Successful Use of Soil Tunnels in Medieval and Modern Warfare and Smuggling","authors":"Kenneth Ray Olson, David R. Speidel","doi":"10.4236/ojss.2020.105010","DOIUrl":"https://doi.org/10.4236/ojss.2020.105010","url":null,"abstract":"For more than 2500 years, soil tunnels have been used in warfare and smuggling. Initially tunnels were utilized to attack fortresses that were underlain by unconsolidated (non-bedrock) soil materials. Later tunnels provided housing and served as smuggling corridors. The medieval warfare undermining technique involved digging soil tunnels with wooden or beam props to hold up the soil ceilings. Then flammable material, such as hay or straw, was put in the tunnel and set on fire. The fire burnt the support beams which collapsed the soil tunnel ceilings and undermined the overlying perimeter wall. Later gunpowder and dynamite replaced fire when attempting to collapse a tunnel, fortress or perimeter defense. Modern warfare soil tunnels were the pathways used to move troops, weapons and supplies to the other side of a border or wall for surprise attacks. Most of the soil tunnels were placed in easy-to-dig unconsolidated soil materials that had a low water table and were not subject to flooding. Eventually, machinery was used to drill through bedrock permitting deeper and longer tunnels for troop movement or smuggling. However, when drilling through bedrock under international borders, the process creates both noise and vibrations which were often detected by the enemy. Once discovered the tunnels were often collapsed by blowing up the tunnel, injection of gas, filling with water or wastewater, or inserting barriers. A series of case studies will be examined with the goal of determining soil and site criteria required to permit successful tunneling. The most restrictive soil and geologic conditions will be identified as well as potential mitigation methods used to overcome the site restrictions will be documented. Countries with warfare or smuggling issues along their borders, such as Israel and United States, need to identify the sections of the border most likely to be undermined by soil tunnels. In the case of Israel their entire border is susceptible as a result of the favorable arid climate, soils and geology. The US border with Mexico can become vulnerable wherever a new wall is created. Without a wall there is usually no need for soil tunnels. The US Department of Homeland Security and border patrol will need to monitor the noise and vibrations, just like the Israel does, to identify future soil tunnel locations. Eventually most of 3200 km border will have a wall that will become the target of more soil tunnels for smuggling goods and people from Mexico into the United States.","PeriodicalId":57369,"journal":{"name":"土壤科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47662118","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}
Water erosion remains the major problem in many countries, especially those with an extension in the arid and semi-arid area and those marked by a long dry season. The intensification of land degradation which is a result of the strong erosive dynamics on a global scale has stimulated the initiative of multidisciplinary researchers investigate the issue of water erosion from its various facets [1] [2]. The goal is to preserve water and soil, two resources threatened. Multiple attempts were made to diagnose and implement empirical and experimental methods for quantitative estimation of soil loss caused by diffuse erosion. Indeed, the Eastern slope of the high mountains of Asir (Saudi Arabia), formerly worn and cut by the depression of rivers and undeniable branching of the river system, deserves to be studied in detail given the release of a huge erosive potential that is responsible for soil losses that are increasing gradually and continuously. The purpose of this paper was to validate the suitability of agricultural terraces in terms of soil preservation, using the results of the soil loss application as an indicator of the state of function of these latter. Many studies have addressed the agricultural terraces, however, only a few of them have focused on the relationship between erosion and agricultural terraces through an experimental approach. Previous work has concentrated mainly on their socio-economic impact; whilst the knowledge of their environmental impact remained scarce. In terms of the climate change context, soil erosion is becoming a central problem in Asir region. Thus, in this way, the application of the universal equation of soil loss was very helpful to explain and predict the role of each factor. Nevertheless, extreme caution and great care must be taken because of the application of this model outside its frame.
{"title":"Assessment of Soil Loss in the Mirabah Basin: An Overview of the Potential of Agricultural Terraces as Ancestral Practices (Saudi Arabia)","authors":"Naima Azaiez, Ansar Alleoua, Narjes Baazaoui, Nawal Qhtani","doi":"10.4236/ojss.2020.105008","DOIUrl":"https://doi.org/10.4236/ojss.2020.105008","url":null,"abstract":"Water erosion remains the major problem in many countries, especially those with an extension in the arid and semi-arid area and those marked by a long dry season. The intensification of land degradation which is a result of the strong erosive dynamics on a global scale has stimulated the initiative of multidisciplinary researchers investigate the issue of water erosion from its various facets [1] [2]. The goal is to preserve water and soil, two resources threatened. Multiple attempts were made to diagnose and implement empirical and experimental methods for quantitative estimation of soil loss caused by diffuse erosion. Indeed, the Eastern slope of the high mountains of Asir (Saudi Arabia), formerly worn and cut by the depression of rivers and undeniable branching of the river system, deserves to be studied in detail given the release of a huge erosive potential that is responsible for soil losses that are increasing gradually and continuously. The purpose of this paper was to validate the suitability of agricultural terraces in terms of soil preservation, using the results of the soil loss application as an indicator of the state of function of these latter. Many studies have addressed the agricultural terraces, however, only a few of them have focused on the relationship between erosion and agricultural terraces through an experimental approach. Previous work has concentrated mainly on their socio-economic impact; whilst the knowledge of their environmental impact remained scarce. In terms of the climate change context, soil erosion is becoming a central problem in Asir region. Thus, in this way, the application of the universal equation of soil loss was very helpful to explain and predict the role of each factor. Nevertheless, extreme caution and great care must be taken because of the application of this model outside its frame.","PeriodicalId":57369,"journal":{"name":"土壤科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41442949","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 : 2020-04-30DOI: 10.4236/ojss.2020.104007
S. Cram, P. Fernández, H. Carranza, M. Hernández, C. P. Leon, Ana M. Noguez Gálvez
Urban agriculture plays an important role in supplying produces to big cities; however, the quality of water used for irrigation can hinder this activity. Hence, the purpose of this study was to evaluate metal inputs, as well as their transfer and translocation factors, in lettuce (Lactuca sativa L.) crops cultivated in an urban plot. The research was conducted during the dry and rainy seasons. In the former, crops were irrigated with treated wastewater, whereas during the latter, crops were maintained just with rainwater. Composite samples for soils and plants were collected from the same plot during two crop cycles in 2013. Some edaphic variables were measured. Total metal concentration was determined, for both, soils and lettuce plants (leaves and roots). Water soluble and exchangeable soil metal fractions were also analyzed. A multivariate analysis of variance was performed to test for differences between seasons, among the variables analyzed. There were significant differences in edaphic characteristics between seasons. However, there was no difference in total metal content, except for Mn. Concentration of soluble metals was lower than exchangeable metal concentration, for both seasons. There was no correlation in total metal concentration between soils and plants. Transfer factor values were higher for Cd, Mn and Zn for the dry season, while for Cu, Fe and Pb were higher during the rainy season, as well as the translocation factors for all metals. Soil characteristics, together with transfer and translocation factors, showed temporal variations, leading to different metal concentrations in the edible lettuce tissues between the two analyzed crop cycles. The incorporation of metals is particular for each site, season and crop management type. Our results indicate that the metal concentration in lettuce tissues places no harm to human health. However, management strategies for urban agriculture must consider specific studies for each site.
{"title":"Metal Input in Lettuce Grown in Urban Agricultural Soils","authors":"S. Cram, P. Fernández, H. Carranza, M. Hernández, C. P. Leon, Ana M. Noguez Gálvez","doi":"10.4236/ojss.2020.104007","DOIUrl":"https://doi.org/10.4236/ojss.2020.104007","url":null,"abstract":"Urban agriculture plays an important role in supplying produces to big cities; however, the quality of water used for irrigation can hinder this activity. Hence, the purpose of this study was to evaluate metal inputs, as well as their transfer and translocation factors, in lettuce (Lactuca sativa L.) crops cultivated in an urban plot. The research was conducted during the dry and rainy seasons. In the former, crops were irrigated with treated wastewater, whereas during the latter, crops were maintained just with rainwater. Composite samples for soils and plants were collected from the same plot during two crop cycles in 2013. Some edaphic variables were measured. Total metal concentration was determined, for both, soils and lettuce plants (leaves and roots). Water soluble and exchangeable soil metal fractions were also analyzed. A multivariate analysis of variance was performed to test for differences between seasons, among the variables analyzed. There were significant differences in edaphic characteristics between seasons. However, there was no difference in total metal content, except for Mn. Concentration of soluble metals was lower than exchangeable metal concentration, for both seasons. There was no correlation in total metal concentration between soils and plants. Transfer factor values were higher for Cd, Mn and Zn for the dry season, while for Cu, Fe and Pb were higher during the rainy season, as well as the translocation factors for all metals. Soil characteristics, together with transfer and translocation factors, showed temporal variations, leading to different metal concentrations in the edible lettuce tissues between the two analyzed crop cycles. The incorporation of metals is particular for each site, season and crop management type. Our results indicate that the metal concentration in lettuce tissues places no harm to human health. However, management strategies for urban agriculture must consider specific studies for each site.","PeriodicalId":57369,"journal":{"name":"土壤科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47565380","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 : 2020-03-03DOI: 10.4236/ojss.2020.103005
G. Akolgo, F. Kemausuor, E. A. Awafo, E. Amankwah, T. Atta-Darkwa, E. O. Essandoh, A. Bart-Plange, C. Maia
Ghana’s soil is continuously declining in fertility due to continuous cultivation and rapid mineralization of its soil organic matter. Previous studies have touted the potential of biochar to help improve soil properties and increase the yield of crops. This study investigated the effects of the application of biochar on physicochemical properties of soil and the yield of maize and cabbage in Ghana. The study indicated that application of biochar significantly increased soil organic matter (SOM) from 3.88% (for control) to 5.72% (for biochar application rate 20 ton/ha and 0 ton/ha of NPK). It also increased soil pH from 6.55 in (for control) to 7.30 (for biochar application rate 20 ton/ha) and 0 ton/ha of nitrogen (N), phosphorus (P) and potassium (K) which can help ameliorate the soil acidity problem of Ghanaian soils. This field study, demonstrated that addition of biochar from sawdust increased the yield (between the control (0 ton/ha of biochar, 0% of recommended dose of NPK) and 20 ton/ha, 0% recommended dose of NPK) of maize and cabbage by 6.66% and 7.57% respectively. This study concluded that application of biochar offers a great potential to improve soil quality and the yield of maize and cabbage in Ghana.
由于持续耕种和土壤有机质的快速矿化，加纳的土壤肥力不断下降。以前的研究吹捧了生物炭帮助改善土壤性质和增加作物产量的潜力。本研究探讨了施用生物炭对加纳土壤理化性质及玉米和卷心菜产量的影响。研究表明，施用生物炭显著提高了土壤有机质(SOM)，对照由3.88%提高到5.72%(施用生物炭20 t / hm2和施用氮磷钾0 t / hm2)。它还将土壤pH值从6.55 in(对照)提高到7.30 in(生物炭施用量为20吨/公顷)和0吨/公顷的氮(N)、磷(P)和钾(K)，有助于改善加纳土壤的酸性问题。田间试验表明，在对照(0吨/公顷生物炭，0%氮磷钾推荐用量)和20吨/公顷氮磷钾推荐用量之间，添加木屑生物炭可使玉米和卷心菜的产量分别提高6.66%和7.57%。本研究的结论是，在加纳，应用生物炭对改善土壤质量和玉米和卷心菜的产量具有很大的潜力。
{"title":"Biochar as a Soil Amendment Tool: Effects on Soil Properties and Yield of Maize and Cabbage in Brong-Ahafo Region, Ghana","authors":"G. Akolgo, F. Kemausuor, E. A. Awafo, E. Amankwah, T. Atta-Darkwa, E. O. Essandoh, A. Bart-Plange, C. Maia","doi":"10.4236/ojss.2020.103005","DOIUrl":"https://doi.org/10.4236/ojss.2020.103005","url":null,"abstract":"Ghana’s soil is continuously declining in fertility due to continuous cultivation and rapid mineralization of its soil organic matter. Previous studies have touted the potential of biochar to help improve soil properties and increase the yield of crops. This study investigated the effects of the application of biochar on physicochemical properties of soil and the yield of maize and cabbage in Ghana. The study indicated that application of biochar significantly increased soil organic matter (SOM) from 3.88% (for control) to 5.72% (for biochar application rate 20 ton/ha and 0 ton/ha of NPK). It also increased soil pH from 6.55 in (for control) to 7.30 (for biochar application rate 20 ton/ha) and 0 ton/ha of nitrogen (N), phosphorus (P) and potassium (K) which can help ameliorate the soil acidity problem of Ghanaian soils. This field study, demonstrated that addition of biochar from sawdust increased the yield (between the control (0 ton/ha of biochar, 0% of recommended dose of NPK) and 20 ton/ha, 0% recommended dose of NPK) of maize and cabbage by 6.66% and 7.57% respectively. This study concluded that application of biochar offers a great potential to improve soil quality and the yield of maize and cabbage in Ghana.","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":"44480928","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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