The spatial optimization of best management practices(BMPs) plays a critical role in precise watershed pollution control. However, the effectiveness of BMPs exhibits a complex nonlinear dependence on both configuratio...The spatial optimization of best management practices(BMPs) plays a critical role in precise watershed pollution control. However, the effectiveness of BMPs exhibits a complex nonlinear dependence on both configuration unit scale and rainfall intensity, often leading to widespread spatiotemporal mismatches during implementation. To fill this gap, this study proposes a new framework:(a) delineating configuration units based on the implementation scale differences between structural and nonstructural BMPs;(b) incorporating BMP reduction thresholds to enable dynamic adjustment of design scales according to inflow loads;and(c) developing a staged allocation strategy tailored to varying rainfall scenarios. The framework is exemplified by an agricultural catchment in the southeastern Liaohe watershed, China. The results showed that the framework could improve the assessment accuracy and cost-effectiveness of pollution control. Specifically, neglecting BMP reduction thresholds resulted in a 51.35% underestimation of treatment costs. Incorporating these thresholds and dynamically adjusting BMP design scales reduced treatment costs by 62.70%. Furthermore, the framework facilitated more precise localization of structural BMPs(1 km^(2)) and improved optimization efficiency by 95.91%. The proposed staged allocation strategy ensured water quality compliance under varying rainfall intensities. Structural BMPs primarily addressed pollution from light to moderate rainfall in the initial stage, while nonstructural BMPs targeted heavy rainfall pollution in the subsequent stage. The proposed framework may enhance the spatiotemporal adaptability of BMP configuration to respond to the threats posed by climate change and human activities. It can also be extended to other agriculture-dominated watersheds.展开更多
Changes in both soil organic C storage and soil respiration in farmland ecosystems may affect atmospheric CO2 concentration and global C cycle. The objective of this field experiment was to study the effects of three ...Changes in both soil organic C storage and soil respiration in farmland ecosystems may affect atmospheric CO2 concentration and global C cycle. The objective of this field experiment was to study the effects of three crop field management practices on soil CO2 emission and C balance in a cotton field in an arid region of Northwest China. The three management practices were irrigation methods（drip and flood）, stubble managements（stubble-incorporated and stubble-removed） and fertilizer amendments（no fertilizer（CK）, chicken manure（OM）, inorganic N, P and K fertilizer（NPK）, and inorganic fertilizer plus chicken manure（NPK＋OM））. The results showed that within the C pool range, soil CO2 emission during the whole growing season was higher in the drip irrigation treatment than in the corresponding flood irrigation treatment, while soil organic C concentration was larger in the flood irrigation treatment than in the corresponding drip irrigation treatment. Furthermore, soil CO2 emission and organic C concentration were all higher in the stubble-incorporated treatment than in the corresponding stubble-removed treatment, and larger in the NPK＋OM treatment than in the other three fertilizer amendments within the C pool range. The combination of flood irrigation, stubble incorporation and application of either NPK＋OM or OM increased soil organic C concentration in the 0-60 cm soil depth. Calculation of net ecosystem productivity（NEP） under different management practices indicated that the combination of drip irrigation, stubble incorporation and NPK＋OM increased the size of the C pool most, followed by the combination of drip irrigation, stubble incorporation and NPK. In conclusion, management practices have significant impacts on soil CO2 emission, organic C concentration and C balance in cotton fields. Consequently, appropriate management practices, such as the combination of drip irrigation, stubble incorporation, and either NPK＋OM or NPK could increase soil C storage in cotton fields of Northwest China.展开更多
The effects of selected land management practices （cross-sloping tillage, ridge culture, organic manure, and straw mulch） on soil water conservation in a southwestern mountainous area, China, were studied during Nov...The effects of selected land management practices （cross-sloping tillage, ridge culture, organic manure, and straw mulch） on soil water conservation in a southwestern mountainous area, China, were studied during November 2002 to November 2004. The experimental field is divided into three parts based on soil layer depths, 0-60 cm （part Ⅰ）, 0-40 cm （part Ⅱ）, and 0- 20 cm （part Ⅲ）, and they all had the same slope azimuth （SE）, slope （10°）, and slope type （linear）. The experimental plots were subjected to the following treatments： cross-sloping tillage （CST）; cross-sloping tillage with organic manure （CST/ OM）; cross-sloping tillage with straw mulch （CST/SM）; contour ridge culture （CRC）; contour ridge culture with organic manure （CRC/OM）; and contour ridge culture with straw mulch （CRC/SM）, to identify the effects of management practices on soil water. Water contents were determined for soil samples collected, using a 2.2 cm diameter manual probe. Soil water was monitored once every five days from Nov. 20, 2002 to Nov. 20, 2004. The results indicated that, in the study stages, an integration of rainfall, evaporative losses, and crop transcription controlled the basic tendencies of profile （mean） soil water, while land management practices, to a certain extent, only modified its amount, distribution, and routing. Moreover, these modifications also mainly focused on the first 20 cm depth of topsoil layer. When each management practice was compared with control treatment, season changes of profile （mean） soil water were pronounced, while interannual changes among them were not significant. More comparisons indicated that, in the study stages, contour ridge culture had better effects than cross-sloping tillage. And under the same tillage, the combination of organic manure could achieve more than straw mulch. These management practices should be recommended considering the effectiveness of soil and water management techniques in the southwestern mountainous area, China.展开更多
<span style="font-family:Verdana;">This study was conducted in Shabelle zone of Somali Regional State to assess management practices and production constraints of indigenous Somali Cattle. A total of 2...<span style="font-family:Verdana;">This study was conducted in Shabelle zone of Somali Regional State to assess management practices and production constraints of indigenous Somali Cattle. A total of 200 household heads were selected from four cattle potential districts;Dhanan, Ber’ano, Godey & Adadle. The relevant information was collected through semi-structured questionnaire, focus group discussion, key informants interview, and personal observations. Majority of the respondents were illiterate. The average cattle holding size was 8.97 heads/household and cattle were mainly kept for milk production. The major feed resources in the study area were natural pasture and crop residue, and communal grazing was the most important feeding system in the area. Feed shortage was a problem hindering cattle production in the study area during dry season mainly January up to March. Animals traveled long distances to watering points (>5 km) during dry season, while in wet season, animals were watered in nearby water sources. Cattle housing was open kraal fenced with the thorned plenty acacia trees and calves were housed separately from other cattle. Breeding in the study area was uncontrolled and was bred with their own or neighbors’ bull. Age at first mating, age at first calving and calving interval were 3.25 years, 4.05 years and 16.56 months, respectively. The daily milk yield and lactation length were 2.22 liters and 8.07 months, respectively. The production and reproduction performance of Somali cattle was relatively higher than other local breeds in the country mainly in terms of milk yield and fertility potential under the existing environmental conditions. </span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">The major constraints of cattle production were feed shortage, disease, water scarcity, lack of veterinary services, marketing problem and predator. Among those constraints, inadequate supply of quality feed, diseases and water shortage were the main reasons for low productivity of cattle and are the major factors limiting productivity. Therefore, to sustain the production system in the study areas, it is recommended to improve the current condition of communal rangelands through management of degraded areas by awareness creation on the value of these common resources and development of rules and regulation to sustain the existing resource and implement over the utilization of communal/pastoral rangeland management systems to reduce constraints such as shortage of feed, drought and grazing land deterioration which perpetuated through time due to land-use changes and seasonal fluctuation).</span></span></span>展开更多
This research was carried out to evaluate the preference and adoption of harvesting, uprooting, stump burning, pruning and thinning practices for controlling the spread ofProsopisjuliflora （prosopis） within Marigat ...This research was carried out to evaluate the preference and adoption of harvesting, uprooting, stump burning, pruning and thinning practices for controlling the spread ofProsopisjuliflora （prosopis） within Marigat Division of the Baringo District, Kenya. A survey methodology was employed using a random sample of 25 Farmer Field School （FFS） members and 5 non=FFS members from each of the five locations of Marigat Division. In total, 100 FFS members and 25 non-FFS members participated in the study; addi- tional supplementary data were collected from the Kenya Forestry Research Institute （KEFRI）, a major facilitator and trainer of the identified FFS activities and practices in the study area since 2004. More than 80% of the local community never undertook any form of prosopis management practice; however, this changed after FFS training, indicating an acquisition and retention of knowledge which probably diffused to the non-FFS counterparts, through either formal or informal ways. Harvesting was the most preferred （100%） and stump burning the least preferred （46%） practice of managing the spread of prosopis. The success and preference of any prosopis management practice was attributed to wood and non-wood benefits derived from prosopis and growing of animal fodder and food crops on rehabilitated land. More than 80% of respondents attributed ineffectiveness of any prosopis management practice to coppicing and viable seed banks of the tree, while 50% highlighted a lack of consistency and integration in carrying out manage- ment practices. The reported negative attitude towards prosopis changed after training with none of the view to eradicate it. Labor intensity and frequent regeneration of seedlings were identified as the major challenges faced during the implementation of proso- pis management practices. In conclusion, the study shows that harvesting, uprooting, stump burning, pruning and thinning realized through consistent holistic integration contribute to containing the spread of prosopis trees in Baringo, Kenya.展开更多
The study was conducted in Godey town of Shebelle zone, Somali Regional State, Ethiopia. The objective of the study was to assess management practices, utilization, and challenges of donkey. A total of 200 households ...The study was conducted in Godey town of Shebelle zone, Somali Regional State, Ethiopia. The objective of the study was to assess management practices, utilization, and challenges of donkey. A total of 200 households who own working donkeys were selected purposely for this study. Data were collected using semi-structured questionnaires, key informants interviews, focus group discussions with communities who own donkeys and personal observations. The study revealed that the majority of the respondents were illiterate which might be associated with poor education access in the area. The study further revealed that 92% of working donkeys were involved in drought work, whereas 18% were used for pack work. The common feed resources for donkeys were feeds obtained from natural pasture, green maize leaves, hay, household wastes and grain supplements. Pipe water, river water, and pond water were the main water sources for working donkeys in the study area. About 91% of households kept their donkeys in an open backyard, while 9% of them kept them in a separate shed built adjacent to or a short distance away from the family home. Donkeys provide cart services in the study area, transporting various items weighing more than 300 kg in order to obtain a high benefit in a short period of time and are more than six days per week. Working donkeys in the current study area had a life span of fewer than 6 years, 7 - 10 years, and more than 10 years, with 18.5%, 75.5%, and 6%, respectively. The most important constraints that affect donkey production and utilization in the study area were a lack of feed, health problems (sickness, wounds, etc.), overloading and overworking, poor road and harnessing problems, and poor attitude/lack of awareness. As a result, in order to enhance working donkey management concerns, area-based development interventions that can overcome current constraints should be employed.展开更多
The study was carried out to assess the effect of management practices on agronomic parameters of cocoa agroecosystems in the peripheral zone of Ebo Forest Reserve. Purposive random sampling was conducted to establish...The study was carried out to assess the effect of management practices on agronomic parameters of cocoa agroecosystems in the peripheral zone of Ebo Forest Reserve. Purposive random sampling was conducted to establish experimental plots on the farms of willing farmers. Demonstration plots were established and agronomic parameters were monitored for “farmers’ practice (FP) and integrated crop pest and disease management (ICPM) practice” using indicators of Cocoa agro-ecosystem analysis (AESA). The FP and ICPM treatments were replicated in ten sites. From AESA records of agronomic parameters, the “observe, learn, decide and act” (OLDA) model was implemented in the ICPM treatments only. The effects of management practices were analyzed using a two-way analysis of variance (ANOVA), and treatment means compared using Turkey’s T-test at 5% probability. Results of ANOVA between the two Management practices showed that over 50% of the response variables were statistically significant. Means separated through GLM ANOVA with Tukey pairwise comparisons at α = 0.05 showed that 14 (53.8%) out of 26 response variables monitored were statistically significant between the two management practices. Pruning, shade management, phytosanitary harvest, rational use of pesticides, farm sanitation, pod harvesting, breaking, fermentation of beans and drying were regular in the ICPM treatment and time-bound in the FP treatment. The average total production varied from 385.83 kg/ha in FP treatment to 572.8 kg/ha in the ICPM treatment, still below the average standard of 1000 kg/ha. The OLDA model applied in ICPM treatment following AESA is a relevant tool to enhance sustainability in the management of cocoa agroecosystems. Farmers should be sensitized and trained on appropriate farm management techniques and enhance access to extension services as well as make available improved and grafted planting materials to ensure appropriate productivity levels.展开更多
The rapid evolution of the political,economic,and social landscape has generated increased interest in understanding the contextual application of management styles and behaviours toward employees.In this context,orga...The rapid evolution of the political,economic,and social landscape has generated increased interest in understanding the contextual application of management styles and behaviours toward employees.In this context,organizations must comprehend and assess employee satisfaction to enhance productivity and realize their strategic and economic goals.Therefore,this study aims to investigate the prevailing and significant management behaviours toward employees in large German companies and their impact on employee satisfaction and job commitment.To achieve the research objective,the study will employ a qualitative method to explore management behaviours toward employees.Data were collected through interviews with randomly selected managers from different companies and departments.The study aims to uncover discrepancies or variations in employee expectations regarding management behaviour.The findings will provide a better understanding of the most prevalent and significant management behaviours toward employees in large German companies and their impact on employee satisfaction and job commitment.The results will be valuable to management in adopting suitable leadership styles and improving employee satisfaction,leading to increased productivity and organizational performance.The research will contribute to the existing body of knowledge in the field of management and human resource management by providing insights into the impact of management behaviours on employees.It will also offer recommendations to management on how to enhance employee satisfaction and job commitment,leading to improved organizational performance.In conclusion,this study will investigate the prevailing management behaviours toward employees in large German companies and their impact on employee satisfaction and job commitment.展开更多
In this paper, we analyzed the status of human resource management practices in western China state-owned and state holding enterprises azld private enterprises, and found that there are differences in the nature of t...In this paper, we analyzed the status of human resource management practices in western China state-owned and state holding enterprises azld private enterprises, and found that there are differences in the nature of the business combination of different patterns of human resource management practices.展开更多
Experience shows that sustainable development of natural resources cannot be made without the full support of the local community and participation of indigenous people at the local level.In Xishuangbanna of Yunnan,th...Experience shows that sustainable development of natural resources cannot be made without the full support of the local community and participation of indigenous people at the local level.In Xishuangbanna of Yunnan,the indigenous people have established a close relati onship with their natural resources and lively environment,which is based on practices for the sustainable development and conservation of these resources.Genetic diversity of plants like rattan is managed and enhanced among indigenous communities through their agriculture and forestry practices,such as folk classification,Sangpabawa,and Qeiya-aneya,which are discussed in the paper.展开更多
The study analyzed awareness,attitude and behavioural intentions of medium and large scale poultry producers to poultry waste management practices in Lagos State with reference to problems of poor on-farm harness of e...The study analyzed awareness,attitude and behavioural intentions of medium and large scale poultry producers to poultry waste management practices in Lagos State with reference to problems of poor on-farm harness of excessive poultry waste,retrogression/unmet global environmental and economic waste management standards,exorbitant waste management charges imposed by LAWMA.Purposive and simple random sampling(using the lottery draw approach)was used in the selection of sixty(60)medium scale poultry farmers and forty(40)large scale poultry farmers,making a grand total of one hundred(100)medium and large scale poultry farmers interviewed in the study.A semi-structured questionnaire was used to collect data from the selected medium and large scale poultry farmers with the aid of a list provided by the Poultry Association of Nigeria(PAN),Lagos chapter.Principal Component Analysis(PCA)was used to analyse the data.In the principal component analysis for medium scale poultry farmers,the key component named was that LAWMA should offer special service for isolated dead bird collection(V75);and for large scale poultry farmers,the key component was that the disposal of poultry waste in an environmentally friendly way is LAWMA’s duty(V76).The study recommended that the government makes provisions to offer awareness campaigns in order to improve environmental knowledge and encourage environmental enthusiasm amongst society.展开更多
Background: Patient care management behavior in diabetes is an essential component of maintaining diabetes under control, and roughly 95% of illness management is typically undertaken by the patients themselves and/or...Background: Patient care management behavior in diabetes is an essential component of maintaining diabetes under control, and roughly 95% of illness management is typically undertaken by the patients themselves and/or their families. This study aimed to identify the association between self-care management practices of patients with diabetes and their demographic factors within the last three months. Methods: The design of this study was cross-sectional. 150 participants from four different hospitals in the Makkah region, Saudi Arabia participated in the study. Descriptive statistics, independent t-tests, and one-way analysis of variance were used to measure differences in self-care management practices concerning patients ’ demographic factors. Results: The results of the study showed that there were no significant differences in the mean score of five areas of self-care management patients ’ practices regarding diet, exercise, foot care, testing blood sugar, and medication concerning their gender ( P > 0.05), employment status ( P > 0.05), their marital status ( P > 0.05), their income ( P > 0.05), and comorbidities ( P > 0.05). There was also no significant difference in the mean score of patients ’ HgbA1c and demographic factors. However, patients with diabetes who have a university education have significantly higher mean scores of testing blood sugar than patients with diabetes who have below secondary school ( P = 0.019). Conclusion: Although the study reported no significant differences in the mean score of self-care practices of patients with diabetes regarding their gender, income, age, education (except testing Blood Sugar), marital status, income, and employment status. This is still needed to counsel and educate every patient regarding reasonable glycaemic control as the study included participants with poor diabetic control (HbA1c > 7). Furthermore, it is recommended to replicate the study with a large sample size to explore the significant differences.展开更多
This study evaluated the reduction effect of non-point source pollution by applying best management practices （BMPs） to a 1.21 km^2 small agricultural watershed using a SWAT （Soil and Water Assessment Tool） model....This study evaluated the reduction effect of non-point source pollution by applying best management practices （BMPs） to a 1.21 km^2 small agricultural watershed using a SWAT （Soil and Water Assessment Tool） model. Two meter QuickBird land use data were prepared for the watershed. The SWAT was calibrated and validated using dally streamflow and monthly water quality （total phosphorus （TP）, total nitrogen （TN）, and suspended solids （SS）） records from 1999 to 2000 and from 2001 to 2002. The average Nash and Sutcliffe model efficiency was 0.63 for the streamflow and the coefficients of determination were 0.88, 0.72, and 0.68 for SS, TN, and TP, respectively. Four BMP scenarios viz. the application of vegetation filter strip and riparian buffer system, the regulation of Universal Soil Loss Equation P factor, and the fertilizing control amount for crops were applied and analyzed.展开更多
Non-point source water pollution generated by agricultural production is considered a major environmental issue in the Three Gorges Reservoir Area （TGRA） of China. The Annualised Agricultural Non-Point Source Pollut...Non-point source water pollution generated by agricultural production is considered a major environmental issue in the Three Gorges Reservoir Area （TGRA） of China. The Annualised Agricultural Non-Point Source Pollution （AnnAGNPS） model was selected to assess the impact of the application of various management treats, including seven crops, five fertilizer levels and three-group management practice scenarios, on water quality from Heigou River Watershed in TGRA. The scenario subsets include conservation tillage practice （CTP）, conservation reserve program （CRP） and conversion of cropland into forestland program （CCFP）. Results indicated that tea can not be replaced by other crops because comparatively tea resulted in a higher sediment yield. CTP with no-tillage was more effective to reduce sediment yield, but could increased nutrient loss. CRP reduced sediment yield significantly, but slightly benefited on nutrient loss. CCFP reduced not only sediment yield but also the nutrient loss significantly. The conversion of cropland with a slope greater than 10° into forestland was found to be the best scenario as the sediment yield export is less than 5 tons/ha and nutrient loss is within the permissible limit.展开更多
The study was conducted to assess management practices and constraints of Black head Somali sheep in Awbarre district of Fafen zone, Somali regional state, Ethiopia. A total of 120 households were purposively selected...The study was conducted to assess management practices and constraints of Black head Somali sheep in Awbarre district of Fafen zone, Somali regional state, Ethiopia. A total of 120 households were purposively selected for this study using purposive sampling technique. The data were collected through the questionnaire, key informants interview, focus group discussions & field observations. The primary purpose of keeping sheep was for income generation followed by saving, meat production, milk, social and cultural functions. The main feeds for sheep during wet season were communal & private natural pastures. In dry season, communal natural pasture, crop residues & private natural pasture were used. The major source of water during wet season was dam/pond, whereas in the dry season spring & pipe water were used. The majority of the respondents (85.8%) used houses enclosed with thorn woody trees and houses enclosed with stone/brick fence were also reported. Majority of the respondents used controlled mating system and sheep are bred to lamb when forage is plentiful because they are less drought tolerant than goats and to avoid unwanted lambing in dry season. Majority (90%) of respondents own their breeding ram and those who have no breeding males used their neighbors’ rams and borrow from others. The breeding rams were born in the flock implying that animals within the flock are very closely related which leads to inbreeding. The most important health problems affecting sheep were circling disease, sheep pox, tick lameness (tick paralysis), Peste des Petits Ruminants (PPR), bloating, and Foot & mouth disease (FMD). The major constraints hindering sheep production in the study area were shortage of veterinary service, feed shortage, scarcity of water, predators, diseases, and marketing. Therefore, to improve and increase the productivity of sheep production in the study area, better management practices and establishing of veterinary service centers are necessary.展开更多
This research observed and evaluated the sustainability practices in universities. This study emphasizes the connection between theory and practice in research frame. It is intended by this research using content anal...This research observed and evaluated the sustainability practices in universities. This study emphasizes the connection between theory and practice in research frame. It is intended by this research using content analysis of UI GreenMetric, universities＇ websites and sustainability annual reports observing universities＇ practices related to sustainability to answer the research question, which is： How are university managements embedding sustainability-oriented practices in sustainability focused European universities as far as CORE system （Curriculum, Operations, Research, and Engagement） is considered？ The employed research methodology mainly relies on content analysis of the studied universities from the UI GreenMetric Sustainable University assessment and ranking index. The UI GreenMetric Sustainable University assessment and ranking index was selected since it considers the Operations, Curriculum, Research, and Engagements （CORE system） of universities with indicators such as Setting and Infrastructure, Energy and Climate Change, Waste, Water, Transportation, and Education. This covers the triple bottom line of sustainability （Environment, Economy, and Society） and other indexes like GASU, AASHE, STARS and others, focused mostly on operational Eco-efficiency. UI GreenMetric index is the first and the only ranking that measures each participating university＇s commitment in developing an ＂environmentally friendly＂ infrastructure. The total sample of the study observed and evaluated in this study are five （5） top European Sustainable Universities according to UI GreenMetric sustainable ranking index. The result shows a significant progress in Operational practices except in the area of Campus Setting and Infrastructure. There was a less significant progress in the Curriculum, Research, and Engagement practices of the CORE system of sustainability-oriented practices which are being integrated into the studied universities. This research provides a state of the art result regarding the embeddedness of sustainable practice in European universities. It has the potential to help any university to better integrate sustainability in their management system.展开更多
A range of land management practices are available to achieve better soil quality,but their combined effects remain understudied.We hypothesize that more diverse management practices,meaning higher dissimilarity,lead ...A range of land management practices are available to achieve better soil quality,but their combined effects remain understudied.We hypothesize that more diverse management practices,meaning higher dissimilarity,lead to stronger effects on soil functions and properties.Eight practices(biochar,compost,clay,amorphous silica,basalt,microbial inoculum,reduced physical disturbance and organic matter diversity)were selected with 20 replicates for treatments involving 2,4,or 6 factors and 10 replicates for 8 factor treatments.We investigated the impact of individual factors,factor number,factor dissimilarity and factor composition on soil respiration,soil enzymatic activities(β-glucosidase,β-Dcellobiosidase,β-N-acetylglucosaminidase and phosphatase),soil pH,water stable aggregates and permanganate oxidizable carbon fraction.By including dissimilarity in addition to factor number,variance explained for soil respiration and enzymatic activities increased up to 54.21%.For soil pH and water-stable aggregates,explained variability increased to 65.57%and 57.38%,respectively.More diverse management practices boosted soil microbial activities,enhanced soil aggregate stability,improved soil pH while reducing labile carbon,whereas factor number only influenced water stable aggregates and soil pH.Our study highlights the importance of management practices diversity in soil functions and properties and calls for further research on synergistic combinations of diverse interventions.展开更多
Agricultural Best Management Practices （BMPs） are effective ways to reduce agricultural nonpoint source pol ution from their source area to receiving water bodies. Characterization of BMPs in a watershed model is a ...Agricultural Best Management Practices （BMPs） are effective ways to reduce agricultural nonpoint source pol ution from their source area to receiving water bodies. Characterization of BMPs in a watershed model is a critical prerequisite for evaluating their impacts on water quantity and water quality in a complex system. However, limited research has reported about the representation of BMPs in fully distributed models. This paper presents a stepwise procedure for representation of several BMPs and assessment of their hydrologic impacts with a ful y distributed model, SEIM （Spatially Explicit Integrated Modeling）. A case study is conducted in the 73 km2 Luoyugou watershed located in the Loess Plateau of China, where rainstorm erosion accounts for more than 60%of annual sediment load in average. Three BMPs are selected in this study including （i） conversion from farmland to forest, （i ） terrace, and （i i） no-til farming. These management practices are represented in the model through the alteration of model parameters characterizing their physical processes in the ifeld. The results of scenario assessment for a historical storm event showed that the maximum sediment reduction after terrace is about 97.3%, the average sediment reduction after no-till farming is about 9.5%, and the average sediment reduction after conversion from farmland to forest is 75.6%.展开更多
This paper provides a broad review of the existing study on soil aggregate and its responses to land management practices. Soil aggregate is used for structural unit, which is a group of primary soil particles that co...This paper provides a broad review of the existing study on soil aggregate and its responses to land management practices. Soil aggregate is used for structural unit, which is a group of primary soil particles that cohere to each other more strongly than other surrounding particles. The mechanism of soil particle aggregation may be expressed by a hierarchical model, which is based upon the hypothesis that macroaggregates （〉250μm） are collections of smaller microaggregates （〈250μm） held together with organic binding agents. Primary particles form microaggregates and then macroaggregates. Carbon （C）-rich young plant residues form and stabilize macroaggregates, whereas old organic C is occluded in the microaggregates. The interaction of aggregate dynamics with soil organic carbon （SOC） is complex and embraces a range of spatial and temporal processes within macroaggregates and microaggregates. The nature and properties of aggregates are determined by the quantity and quality of coarse residues and humic compounds and by the degree of their interaction with soil particles. The mechanisms resulting in the binding of primary soil particles into stable aggregates vary with soil parent material, climate, vegetation, and land management practices. Land management practices, including tillage methods, residue management, amendments, and soil fertility management, enhance soil aggregation. However, there is still much uncertainty in the dynamics of organic matter in macroaggregation and microaggregation, and research is still needed to understand further the mechanisms of aggregate formation and its responses to human activities.展开更多
基金supported by the Fund for Innovative Research Group of the National Natural Science Foundation of China (Grant No.52221003)。
文摘The spatial optimization of best management practices(BMPs) plays a critical role in precise watershed pollution control. However, the effectiveness of BMPs exhibits a complex nonlinear dependence on both configuration unit scale and rainfall intensity, often leading to widespread spatiotemporal mismatches during implementation. To fill this gap, this study proposes a new framework:(a) delineating configuration units based on the implementation scale differences between structural and nonstructural BMPs;(b) incorporating BMP reduction thresholds to enable dynamic adjustment of design scales according to inflow loads;and(c) developing a staged allocation strategy tailored to varying rainfall scenarios. The framework is exemplified by an agricultural catchment in the southeastern Liaohe watershed, China. The results showed that the framework could improve the assessment accuracy and cost-effectiveness of pollution control. Specifically, neglecting BMP reduction thresholds resulted in a 51.35% underestimation of treatment costs. Incorporating these thresholds and dynamically adjusting BMP design scales reduced treatment costs by 62.70%. Furthermore, the framework facilitated more precise localization of structural BMPs(1 km^(2)) and improved optimization efficiency by 95.91%. The proposed staged allocation strategy ensured water quality compliance under varying rainfall intensities. Structural BMPs primarily addressed pollution from light to moderate rainfall in the initial stage, while nonstructural BMPs targeted heavy rainfall pollution in the subsequent stage. The proposed framework may enhance the spatiotemporal adaptability of BMP configuration to respond to the threats posed by climate change and human activities. It can also be extended to other agriculture-dominated watersheds.
基金jointly funded by the National Basic Research Program of China (2006CB708401)the Doctor Subject Foundation of the Ministry of Education of China (20116518110002)
文摘Changes in both soil organic C storage and soil respiration in farmland ecosystems may affect atmospheric CO2 concentration and global C cycle. The objective of this field experiment was to study the effects of three crop field management practices on soil CO2 emission and C balance in a cotton field in an arid region of Northwest China. The three management practices were irrigation methods（drip and flood）, stubble managements（stubble-incorporated and stubble-removed） and fertilizer amendments（no fertilizer（CK）, chicken manure（OM）, inorganic N, P and K fertilizer（NPK）, and inorganic fertilizer plus chicken manure（NPK＋OM））. The results showed that within the C pool range, soil CO2 emission during the whole growing season was higher in the drip irrigation treatment than in the corresponding flood irrigation treatment, while soil organic C concentration was larger in the flood irrigation treatment than in the corresponding drip irrigation treatment. Furthermore, soil CO2 emission and organic C concentration were all higher in the stubble-incorporated treatment than in the corresponding stubble-removed treatment, and larger in the NPK＋OM treatment than in the other three fertilizer amendments within the C pool range. The combination of flood irrigation, stubble incorporation and application of either NPK＋OM or OM increased soil organic C concentration in the 0-60 cm soil depth. Calculation of net ecosystem productivity（NEP） under different management practices indicated that the combination of drip irrigation, stubble incorporation and NPK＋OM increased the size of the C pool most, followed by the combination of drip irrigation, stubble incorporation and NPK. In conclusion, management practices have significant impacts on soil CO2 emission, organic C concentration and C balance in cotton fields. Consequently, appropriate management practices, such as the combination of drip irrigation, stubble incorporation, and either NPK＋OM or NPK could increase soil C storage in cotton fields of Northwest China.
文摘The effects of selected land management practices （cross-sloping tillage, ridge culture, organic manure, and straw mulch） on soil water conservation in a southwestern mountainous area, China, were studied during November 2002 to November 2004. The experimental field is divided into three parts based on soil layer depths, 0-60 cm （part Ⅰ）, 0-40 cm （part Ⅱ）, and 0- 20 cm （part Ⅲ）, and they all had the same slope azimuth （SE）, slope （10°）, and slope type （linear）. The experimental plots were subjected to the following treatments： cross-sloping tillage （CST）; cross-sloping tillage with organic manure （CST/ OM）; cross-sloping tillage with straw mulch （CST/SM）; contour ridge culture （CRC）; contour ridge culture with organic manure （CRC/OM）; and contour ridge culture with straw mulch （CRC/SM）, to identify the effects of management practices on soil water. Water contents were determined for soil samples collected, using a 2.2 cm diameter manual probe. Soil water was monitored once every five days from Nov. 20, 2002 to Nov. 20, 2004. The results indicated that, in the study stages, an integration of rainfall, evaporative losses, and crop transcription controlled the basic tendencies of profile （mean） soil water, while land management practices, to a certain extent, only modified its amount, distribution, and routing. Moreover, these modifications also mainly focused on the first 20 cm depth of topsoil layer. When each management practice was compared with control treatment, season changes of profile （mean） soil water were pronounced, while interannual changes among them were not significant. More comparisons indicated that, in the study stages, contour ridge culture had better effects than cross-sloping tillage. And under the same tillage, the combination of organic manure could achieve more than straw mulch. These management practices should be recommended considering the effectiveness of soil and water management techniques in the southwestern mountainous area, China.
文摘<span style="font-family:Verdana;">This study was conducted in Shabelle zone of Somali Regional State to assess management practices and production constraints of indigenous Somali Cattle. A total of 200 household heads were selected from four cattle potential districts;Dhanan, Ber’ano, Godey & Adadle. The relevant information was collected through semi-structured questionnaire, focus group discussion, key informants interview, and personal observations. Majority of the respondents were illiterate. The average cattle holding size was 8.97 heads/household and cattle were mainly kept for milk production. The major feed resources in the study area were natural pasture and crop residue, and communal grazing was the most important feeding system in the area. Feed shortage was a problem hindering cattle production in the study area during dry season mainly January up to March. Animals traveled long distances to watering points (>5 km) during dry season, while in wet season, animals were watered in nearby water sources. Cattle housing was open kraal fenced with the thorned plenty acacia trees and calves were housed separately from other cattle. Breeding in the study area was uncontrolled and was bred with their own or neighbors’ bull. Age at first mating, age at first calving and calving interval were 3.25 years, 4.05 years and 16.56 months, respectively. The daily milk yield and lactation length were 2.22 liters and 8.07 months, respectively. The production and reproduction performance of Somali cattle was relatively higher than other local breeds in the country mainly in terms of milk yield and fertility potential under the existing environmental conditions. </span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">The major constraints of cattle production were feed shortage, disease, water scarcity, lack of veterinary services, marketing problem and predator. Among those constraints, inadequate supply of quality feed, diseases and water shortage were the main reasons for low productivity of cattle and are the major factors limiting productivity. Therefore, to sustain the production system in the study areas, it is recommended to improve the current condition of communal rangelands through management of degraded areas by awareness creation on the value of these common resources and development of rules and regulation to sustain the existing resource and implement over the utilization of communal/pastoral rangeland management systems to reduce constraints such as shortage of feed, drought and grazing land deterioration which perpetuated through time due to land-use changes and seasonal fluctuation).</span></span></span>
文摘This research was carried out to evaluate the preference and adoption of harvesting, uprooting, stump burning, pruning and thinning practices for controlling the spread ofProsopisjuliflora （prosopis） within Marigat Division of the Baringo District, Kenya. A survey methodology was employed using a random sample of 25 Farmer Field School （FFS） members and 5 non=FFS members from each of the five locations of Marigat Division. In total, 100 FFS members and 25 non-FFS members participated in the study; addi- tional supplementary data were collected from the Kenya Forestry Research Institute （KEFRI）, a major facilitator and trainer of the identified FFS activities and practices in the study area since 2004. More than 80% of the local community never undertook any form of prosopis management practice; however, this changed after FFS training, indicating an acquisition and retention of knowledge which probably diffused to the non-FFS counterparts, through either formal or informal ways. Harvesting was the most preferred （100%） and stump burning the least preferred （46%） practice of managing the spread of prosopis. The success and preference of any prosopis management practice was attributed to wood and non-wood benefits derived from prosopis and growing of animal fodder and food crops on rehabilitated land. More than 80% of respondents attributed ineffectiveness of any prosopis management practice to coppicing and viable seed banks of the tree, while 50% highlighted a lack of consistency and integration in carrying out manage- ment practices. The reported negative attitude towards prosopis changed after training with none of the view to eradicate it. Labor intensity and frequent regeneration of seedlings were identified as the major challenges faced during the implementation of proso- pis management practices. In conclusion, the study shows that harvesting, uprooting, stump burning, pruning and thinning realized through consistent holistic integration contribute to containing the spread of prosopis trees in Baringo, Kenya.
文摘The study was conducted in Godey town of Shebelle zone, Somali Regional State, Ethiopia. The objective of the study was to assess management practices, utilization, and challenges of donkey. A total of 200 households who own working donkeys were selected purposely for this study. Data were collected using semi-structured questionnaires, key informants interviews, focus group discussions with communities who own donkeys and personal observations. The study revealed that the majority of the respondents were illiterate which might be associated with poor education access in the area. The study further revealed that 92% of working donkeys were involved in drought work, whereas 18% were used for pack work. The common feed resources for donkeys were feeds obtained from natural pasture, green maize leaves, hay, household wastes and grain supplements. Pipe water, river water, and pond water were the main water sources for working donkeys in the study area. About 91% of households kept their donkeys in an open backyard, while 9% of them kept them in a separate shed built adjacent to or a short distance away from the family home. Donkeys provide cart services in the study area, transporting various items weighing more than 300 kg in order to obtain a high benefit in a short period of time and are more than six days per week. Working donkeys in the current study area had a life span of fewer than 6 years, 7 - 10 years, and more than 10 years, with 18.5%, 75.5%, and 6%, respectively. The most important constraints that affect donkey production and utilization in the study area were a lack of feed, health problems (sickness, wounds, etc.), overloading and overworking, poor road and harnessing problems, and poor attitude/lack of awareness. As a result, in order to enhance working donkey management concerns, area-based development interventions that can overcome current constraints should be employed.
文摘The study was carried out to assess the effect of management practices on agronomic parameters of cocoa agroecosystems in the peripheral zone of Ebo Forest Reserve. Purposive random sampling was conducted to establish experimental plots on the farms of willing farmers. Demonstration plots were established and agronomic parameters were monitored for “farmers’ practice (FP) and integrated crop pest and disease management (ICPM) practice” using indicators of Cocoa agro-ecosystem analysis (AESA). The FP and ICPM treatments were replicated in ten sites. From AESA records of agronomic parameters, the “observe, learn, decide and act” (OLDA) model was implemented in the ICPM treatments only. The effects of management practices were analyzed using a two-way analysis of variance (ANOVA), and treatment means compared using Turkey’s T-test at 5% probability. Results of ANOVA between the two Management practices showed that over 50% of the response variables were statistically significant. Means separated through GLM ANOVA with Tukey pairwise comparisons at α = 0.05 showed that 14 (53.8%) out of 26 response variables monitored were statistically significant between the two management practices. Pruning, shade management, phytosanitary harvest, rational use of pesticides, farm sanitation, pod harvesting, breaking, fermentation of beans and drying were regular in the ICPM treatment and time-bound in the FP treatment. The average total production varied from 385.83 kg/ha in FP treatment to 572.8 kg/ha in the ICPM treatment, still below the average standard of 1000 kg/ha. The OLDA model applied in ICPM treatment following AESA is a relevant tool to enhance sustainability in the management of cocoa agroecosystems. Farmers should be sensitized and trained on appropriate farm management techniques and enhance access to extension services as well as make available improved and grafted planting materials to ensure appropriate productivity levels.
文摘The rapid evolution of the political,economic,and social landscape has generated increased interest in understanding the contextual application of management styles and behaviours toward employees.In this context,organizations must comprehend and assess employee satisfaction to enhance productivity and realize their strategic and economic goals.Therefore,this study aims to investigate the prevailing and significant management behaviours toward employees in large German companies and their impact on employee satisfaction and job commitment.To achieve the research objective,the study will employ a qualitative method to explore management behaviours toward employees.Data were collected through interviews with randomly selected managers from different companies and departments.The study aims to uncover discrepancies or variations in employee expectations regarding management behaviour.The findings will provide a better understanding of the most prevalent and significant management behaviours toward employees in large German companies and their impact on employee satisfaction and job commitment.The results will be valuable to management in adopting suitable leadership styles and improving employee satisfaction,leading to increased productivity and organizational performance.The research will contribute to the existing body of knowledge in the field of management and human resource management by providing insights into the impact of management behaviours on employees.It will also offer recommendations to management on how to enhance employee satisfaction and job commitment,leading to improved organizational performance.In conclusion,this study will investigate the prevailing management behaviours toward employees in large German companies and their impact on employee satisfaction and job commitment.
文摘In this paper, we analyzed the status of human resource management practices in western China state-owned and state holding enterprises azld private enterprises, and found that there are differences in the nature of the business combination of different patterns of human resource management practices.
文摘Experience shows that sustainable development of natural resources cannot be made without the full support of the local community and participation of indigenous people at the local level.In Xishuangbanna of Yunnan,the indigenous people have established a close relati onship with their natural resources and lively environment,which is based on practices for the sustainable development and conservation of these resources.Genetic diversity of plants like rattan is managed and enhanced among indigenous communities through their agriculture and forestry practices,such as folk classification,Sangpabawa,and Qeiya-aneya,which are discussed in the paper.
文摘The study analyzed awareness,attitude and behavioural intentions of medium and large scale poultry producers to poultry waste management practices in Lagos State with reference to problems of poor on-farm harness of excessive poultry waste,retrogression/unmet global environmental and economic waste management standards,exorbitant waste management charges imposed by LAWMA.Purposive and simple random sampling(using the lottery draw approach)was used in the selection of sixty(60)medium scale poultry farmers and forty(40)large scale poultry farmers,making a grand total of one hundred(100)medium and large scale poultry farmers interviewed in the study.A semi-structured questionnaire was used to collect data from the selected medium and large scale poultry farmers with the aid of a list provided by the Poultry Association of Nigeria(PAN),Lagos chapter.Principal Component Analysis(PCA)was used to analyse the data.In the principal component analysis for medium scale poultry farmers,the key component named was that LAWMA should offer special service for isolated dead bird collection(V75);and for large scale poultry farmers,the key component was that the disposal of poultry waste in an environmentally friendly way is LAWMA’s duty(V76).The study recommended that the government makes provisions to offer awareness campaigns in order to improve environmental knowledge and encourage environmental enthusiasm amongst society.
文摘Background: Patient care management behavior in diabetes is an essential component of maintaining diabetes under control, and roughly 95% of illness management is typically undertaken by the patients themselves and/or their families. This study aimed to identify the association between self-care management practices of patients with diabetes and their demographic factors within the last three months. Methods: The design of this study was cross-sectional. 150 participants from four different hospitals in the Makkah region, Saudi Arabia participated in the study. Descriptive statistics, independent t-tests, and one-way analysis of variance were used to measure differences in self-care management practices concerning patients ’ demographic factors. Results: The results of the study showed that there were no significant differences in the mean score of five areas of self-care management patients ’ practices regarding diet, exercise, foot care, testing blood sugar, and medication concerning their gender ( P > 0.05), employment status ( P > 0.05), their marital status ( P > 0.05), their income ( P > 0.05), and comorbidities ( P > 0.05). There was also no significant difference in the mean score of patients ’ HgbA1c and demographic factors. However, patients with diabetes who have a university education have significantly higher mean scores of testing blood sugar than patients with diabetes who have below secondary school ( P = 0.019). Conclusion: Although the study reported no significant differences in the mean score of self-care practices of patients with diabetes regarding their gender, income, age, education (except testing Blood Sugar), marital status, income, and employment status. This is still needed to counsel and educate every patient regarding reasonable glycaemic control as the study included participants with poor diabetic control (HbA1c > 7). Furthermore, it is recommended to replicate the study with a large sample size to explore the significant differences.
基金supported by a grant (code # 2-2-3) from Sustainable Water Resources Research Center of 21st Century Frontier Research Programthe Development of The Third Korea Multe-Purpose Satellite funded by Ministry of Education Science
文摘This study evaluated the reduction effect of non-point source pollution by applying best management practices （BMPs） to a 1.21 km^2 small agricultural watershed using a SWAT （Soil and Water Assessment Tool） model. Two meter QuickBird land use data were prepared for the watershed. The SWAT was calibrated and validated using dally streamflow and monthly water quality （total phosphorus （TP）, total nitrogen （TN）, and suspended solids （SS）） records from 1999 to 2000 and from 2001 to 2002. The average Nash and Sutcliffe model efficiency was 0.63 for the streamflow and the coefficients of determination were 0.88, 0.72, and 0.68 for SS, TN, and TP, respectively. Four BMP scenarios viz. the application of vegetation filter strip and riparian buffer system, the regulation of Universal Soil Loss Equation P factor, and the fertilizing control amount for crops were applied and analyzed.
基金supported by the 11th-Five Year Scientific Support Program of China (No.2006BAD03A13,2006BAD03A07)
文摘Non-point source water pollution generated by agricultural production is considered a major environmental issue in the Three Gorges Reservoir Area （TGRA） of China. The Annualised Agricultural Non-Point Source Pollution （AnnAGNPS） model was selected to assess the impact of the application of various management treats, including seven crops, five fertilizer levels and three-group management practice scenarios, on water quality from Heigou River Watershed in TGRA. The scenario subsets include conservation tillage practice （CTP）, conservation reserve program （CRP） and conversion of cropland into forestland program （CCFP）. Results indicated that tea can not be replaced by other crops because comparatively tea resulted in a higher sediment yield. CTP with no-tillage was more effective to reduce sediment yield, but could increased nutrient loss. CRP reduced sediment yield significantly, but slightly benefited on nutrient loss. CCFP reduced not only sediment yield but also the nutrient loss significantly. The conversion of cropland with a slope greater than 10° into forestland was found to be the best scenario as the sediment yield export is less than 5 tons/ha and nutrient loss is within the permissible limit.
文摘The study was conducted to assess management practices and constraints of Black head Somali sheep in Awbarre district of Fafen zone, Somali regional state, Ethiopia. A total of 120 households were purposively selected for this study using purposive sampling technique. The data were collected through the questionnaire, key informants interview, focus group discussions & field observations. The primary purpose of keeping sheep was for income generation followed by saving, meat production, milk, social and cultural functions. The main feeds for sheep during wet season were communal & private natural pastures. In dry season, communal natural pasture, crop residues & private natural pasture were used. The major source of water during wet season was dam/pond, whereas in the dry season spring & pipe water were used. The majority of the respondents (85.8%) used houses enclosed with thorn woody trees and houses enclosed with stone/brick fence were also reported. Majority of the respondents used controlled mating system and sheep are bred to lamb when forage is plentiful because they are less drought tolerant than goats and to avoid unwanted lambing in dry season. Majority (90%) of respondents own their breeding ram and those who have no breeding males used their neighbors’ rams and borrow from others. The breeding rams were born in the flock implying that animals within the flock are very closely related which leads to inbreeding. The most important health problems affecting sheep were circling disease, sheep pox, tick lameness (tick paralysis), Peste des Petits Ruminants (PPR), bloating, and Foot & mouth disease (FMD). The major constraints hindering sheep production in the study area were shortage of veterinary service, feed shortage, scarcity of water, predators, diseases, and marketing. Therefore, to improve and increase the productivity of sheep production in the study area, better management practices and establishing of veterinary service centers are necessary.
文摘This research observed and evaluated the sustainability practices in universities. This study emphasizes the connection between theory and practice in research frame. It is intended by this research using content analysis of UI GreenMetric, universities＇ websites and sustainability annual reports observing universities＇ practices related to sustainability to answer the research question, which is： How are university managements embedding sustainability-oriented practices in sustainability focused European universities as far as CORE system （Curriculum, Operations, Research, and Engagement） is considered？ The employed research methodology mainly relies on content analysis of the studied universities from the UI GreenMetric Sustainable University assessment and ranking index. The UI GreenMetric Sustainable University assessment and ranking index was selected since it considers the Operations, Curriculum, Research, and Engagements （CORE system） of universities with indicators such as Setting and Infrastructure, Energy and Climate Change, Waste, Water, Transportation, and Education. This covers the triple bottom line of sustainability （Environment, Economy, and Society） and other indexes like GASU, AASHE, STARS and others, focused mostly on operational Eco-efficiency. UI GreenMetric index is the first and the only ranking that measures each participating university＇s commitment in developing an ＂environmentally friendly＂ infrastructure. The total sample of the study observed and evaluated in this study are five （5） top European Sustainable Universities according to UI GreenMetric sustainable ranking index. The result shows a significant progress in Operational practices except in the area of Campus Setting and Infrastructure. There was a less significant progress in the Curriculum, Research, and Engagement practices of the CORE system of sustainability-oriented practices which are being integrated into the studied universities. This research provides a state of the art result regarding the embeddedness of sustainable practice in European universities. It has the potential to help any university to better integrate sustainability in their management system.
基金the China Scholarship Council for a scholarship(CSC number 202108080156 and 202106320023)Open Access funding enabled and organized by Projekt DEAL.
文摘A range of land management practices are available to achieve better soil quality,but their combined effects remain understudied.We hypothesize that more diverse management practices,meaning higher dissimilarity,lead to stronger effects on soil functions and properties.Eight practices(biochar,compost,clay,amorphous silica,basalt,microbial inoculum,reduced physical disturbance and organic matter diversity)were selected with 20 replicates for treatments involving 2,4,or 6 factors and 10 replicates for 8 factor treatments.We investigated the impact of individual factors,factor number,factor dissimilarity and factor composition on soil respiration,soil enzymatic activities(β-glucosidase,β-Dcellobiosidase,β-N-acetylglucosaminidase and phosphatase),soil pH,water stable aggregates and permanganate oxidizable carbon fraction.By including dissimilarity in addition to factor number,variance explained for soil respiration and enzymatic activities increased up to 54.21%.For soil pH and water-stable aggregates,explained variability increased to 65.57%and 57.38%,respectively.More diverse management practices boosted soil microbial activities,enhanced soil aggregate stability,improved soil pH while reducing labile carbon,whereas factor number only influenced water stable aggregates and soil pH.Our study highlights the importance of management practices diversity in soil functions and properties and calls for further research on synergistic combinations of diverse interventions.
基金the Major Science and Technology Program for Water Pollution Control and Treatment(No.2013ZX07103006-005)the National Science and Technology Support Program(No.2013BAC08B03-4)
文摘Agricultural Best Management Practices （BMPs） are effective ways to reduce agricultural nonpoint source pol ution from their source area to receiving water bodies. Characterization of BMPs in a watershed model is a critical prerequisite for evaluating their impacts on water quantity and water quality in a complex system. However, limited research has reported about the representation of BMPs in fully distributed models. This paper presents a stepwise procedure for representation of several BMPs and assessment of their hydrologic impacts with a ful y distributed model, SEIM （Spatially Explicit Integrated Modeling）. A case study is conducted in the 73 km2 Luoyugou watershed located in the Loess Plateau of China, where rainstorm erosion accounts for more than 60%of annual sediment load in average. Three BMPs are selected in this study including （i） conversion from farmland to forest, （i ） terrace, and （i i） no-til farming. These management practices are represented in the model through the alteration of model parameters characterizing their physical processes in the ifeld. The results of scenario assessment for a historical storm event showed that the maximum sediment reduction after terrace is about 97.3%, the average sediment reduction after no-till farming is about 9.5%, and the average sediment reduction after conversion from farmland to forest is 75.6%.
文摘This paper provides a broad review of the existing study on soil aggregate and its responses to land management practices. Soil aggregate is used for structural unit, which is a group of primary soil particles that cohere to each other more strongly than other surrounding particles. The mechanism of soil particle aggregation may be expressed by a hierarchical model, which is based upon the hypothesis that macroaggregates （〉250μm） are collections of smaller microaggregates （〈250μm） held together with organic binding agents. Primary particles form microaggregates and then macroaggregates. Carbon （C）-rich young plant residues form and stabilize macroaggregates, whereas old organic C is occluded in the microaggregates. The interaction of aggregate dynamics with soil organic carbon （SOC） is complex and embraces a range of spatial and temporal processes within macroaggregates and microaggregates. The nature and properties of aggregates are determined by the quantity and quality of coarse residues and humic compounds and by the degree of their interaction with soil particles. The mechanisms resulting in the binding of primary soil particles into stable aggregates vary with soil parent material, climate, vegetation, and land management practices. Land management practices, including tillage methods, residue management, amendments, and soil fertility management, enhance soil aggregation. However, there is still much uncertainty in the dynamics of organic matter in macroaggregation and microaggregation, and research is still needed to understand further the mechanisms of aggregate formation and its responses to human activities.
