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Assessment of Coffea Shade Value through Comparison of Mountainous Area with Farm Land Coverage,in Arsi Gololcha District,Oromia,Ethiopia
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作者 Alemayehu Diriba Roba 《Journal of Botanical Research》 2021年第4期29-36,共8页
Coffea cultivation with shade tree is used for improving soil health,increasing coffea production,sustaining agro ecology.The study was attended in two kebele,on 36 farmers’fields,at Gololcha district of East Arsi zo... Coffea cultivation with shade tree is used for improving soil health,increasing coffea production,sustaining agro ecology.The study was attended in two kebele,on 36 farmers’fields,at Gololcha district of East Arsi zone.The study was intended to assess the influence of coffea shade trees on farm lands versus mountainous area.Household interviews were used to get imperative separately,i.e.from old farmers,middle age farmers and young farmers.Significant difference value was observed between farm land and mountainous area coverage.Based on this respondents’idea,before 25-30 years;the‘condition of tree coverage at mountainous’area in Arsi Gololcha district was‘medium condition’but not normal that means as deforestation of mountainous area have been starting before 30 years’time;while the condition of tree coverage at farmland area also has been starting before 30 years’time.The third respondents’idea was interpreted with the real situation of the district,that it gave us a constructive inspiration on the role of coffea shade tree to enable the farm land to be taken as regular natural forest.The existing coffea shade trees are Cordia africana followed by Erythrina abyssinica and Acacia senegal.Farmers accounted 95%of coffea shade users and 4.6%without shade users.The respondents said that even if the rainfall intensity is increasing at farmland rather than mountainous area occasionally due to shade tree effect.On the contrary side,mountainous area exposed to deforestation since the farmers have been shifting to hilly side for their livelihood dependency. 展开更多
关键词 farm lands versus mountainous areas Ecological value of Coffea shade trees
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The Impacts and Causes of Land Fragmentation on Farm Productivity: Case Review of East African Countries
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作者 Joseph Mayindo Mayele Jacob B. Kolleh Joel Emmanuel Saburi 《Open Journal of Ecology》 2024年第5期455-482,共28页
This report provides an overall assessment of land fragmentation problems in East Africa. Many parts of East Africa have become highly fragmented, putting development systems and activities in these areas at risk of c... This report provides an overall assessment of land fragmentation problems in East Africa. Many parts of East Africa have become highly fragmented, putting development systems and activities in these areas at risk of complete collapse. Land fragmentation occurs when land gets converted for agriculture, industrialization, or urbanization, invaded by non-local plants, or enclosed for individual use and by subdividing farmlands into subsequent smaller units called parcels with varying average farm sizes. Fragmentation results from inappropriate agricultural development processes and ineffective land use planning that fails to recognize how farmland is used, and the importance of its interconnected areas. Insecurity of tenure and resource rights are key factors in making this possible. Land fragmentation is one of the key reasons why the ability of most resources in East Africa becomes scarcer, and those remaining become “privatized” by more powerful community members—keen to maintain their access to them. Such individualistic attitudes are new and disadvantage the poorest even further by affecting the traditional customary safety nets and agricultural outputs. Neither the government nor customary governance systems effectively protect resource access for the poorest. This review summary report identifies the key causes, measures, and implications, government interventions, and the common remedies to land fragmentation problems in the East African Countries of Kenya, Uganda, Rwanda, and Tanzania including neighboring Ethiopia, and the Sudan. The findings indicated from 2005 to 2015, the population kept increasing for all the named countries in East Africa with Rwanda and Uganda having a substantial increase in population density. The study review further explores the trend in the performance of agriculture by average farm sizes within the intervals of five years by highlighting their strong linkages and found that the average farm size has declined drastically, especially for Kenya. This can only mean that small farms kept becoming smaller and smaller and that there were more small-scale farmers. The results further depicted that the major and commonly cultivated food crops among the East African countries include maize, sorghum, rice, cassava, sweet potatoes, bananas, Irish potatoes, beans, peas, etc., with maize yields (Mt/ha) in 2003 for Uganda being the highest (1.79 Mt/ha) and the lowest in Rwanda (0.77 Mt/ha) respectively. Therefore, from the review results, recommendations are being made as to how the negative impacts of land fragmentation on agricultural productivity can be reduced or mitigated. One way is by community sensitization and awareness about the importance of land consolidation and its proposition on farm productivity. 展开更多
关键词 land Fragmentation land Consolidation farm Productivity INDUSTRIALIZATION Impacts CAUSES Average farm Size Population East Africa
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The Impact of Nitrogen-Fixing Bacteria, Iron, and Zinc Foliar Application on Dry Land Yellow Mustard (Brassica juncea) Grain and Oil Production
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作者 Saeid Zehtab Salmasi Haleh Nasiri +2 位作者 Rezvan Heshmati Mohammad Reza Sarikhani Yagoub Raei 《Agricultural Sciences》 2024年第7期719-728,共10页
The study, conducted at the Research Farm of the College of Agriculture, University of Tabriz in 2021, focused on the effects of various nitrogen-fixing bacterial isolates, biofertilizers containing nitrogen and phosp... The study, conducted at the Research Farm of the College of Agriculture, University of Tabriz in 2021, focused on the effects of various nitrogen-fixing bacterial isolates, biofertilizers containing nitrogen and phosphorus, as well as iron and zinc foliar applications on mustard growth under rainfed conditions. The results indicated that biofertilizers, whether used alone or in combination with chemical fertilizers, produced comparable grain and oil outputs compared to chemical fertilizers alone. Additionally, the application of iron and zinc through foliar spraying significantly enhanced both grain and oil production. These findings suggest that integrating nitrogen-fixing bacteria and biofertilizers could reduce reliance on chemical nitrogenous fertilizers, leading to decreased production expenses, improved product quality, and minimized environmental impact. This study highlights the potential for sustainable agricultural practices in dry land farming as a viable alternative to traditional chemical-intensive methods. Substituting chemical nitrogenous fertilizers with nitrogen-fixing bacteria or biofertilizers could result in cost savings in mustard grain and oil production while promoting environmental sustainability. 展开更多
关键词 Nitrogen Fixing Bacteria Yellow Mustard Dry land farming IRON ZINC Foliar Application
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Developmental Tendency of Dry Land Farming Technologies 被引量:10
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作者 SHAN Lun(Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Northwest Sci-Tech University of Agriculture and Forestry, Yangling 712100, P. R . China ) 《Agricultural Sciences in China》 CAS CSCD 2002年第8期934-944,共11页
The developmental tendency of dry land farming technologies in the semiarid area of China were reviewed based on the overview of recent progress in dry land farming researches from China and oversea. It was emphasized... The developmental tendency of dry land farming technologies in the semiarid area of China were reviewed based on the overview of recent progress in dry land farming researches from China and oversea. It was emphasized that conservation tillage, limited irrigation, genetic modification and chemical control are the important aspects for the dry land farming research and development of the future. In addition, some consid- 展开更多
关键词 Dry land farming Conservation tillage Limited irrigation Genetic modification Chemical control
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Effects of land-use types on soil organic carbon stocks:a case study across an altitudinal gradient within a farmpastoral area on the eastern Qinghai-Tibetan Plateau, China 被引量:1
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作者 WANG Fang-ping WANG Xin-chuan +5 位作者 YAO Bu-qing ZHANG Zhong-hua SHI Guo-xi MA Zhen CHEN Zhi ZHOU Hua-kun 《Journal of Mountain Science》 SCIE CSCD 2018年第12期2693-2702,共10页
A crucial region for China's ‘Grain-forGreen Policy' is located within a traditional farmpastoral area, between 2000 to 3000 m above sea level, on the eastern Qinghai-Tibetan Plateau.However, the responses of... A crucial region for China's ‘Grain-forGreen Policy' is located within a traditional farmpastoral area, between 2000 to 3000 m above sea level, on the eastern Qinghai-Tibetan Plateau.However, the responses of soil organic carbon(SOC) to different land-use patterns in this region are unclear. Here, we determined the SOC(0–20 cm) content of grasslands and forests that are being converted from farmlands, as well as in abandoned arable land and arable land in this region. The factors influencing the reclaimed lands were analyzed along altitudes from 2030 to 3132 m. Our results showed that SOC content was higher for grassland and abandoned arable land than forest and arable land. The SOC content increased with the increase in altitude for total land-use patterns. Further, the grassland and abandoned arable land had higher SOC content than the forest with almost parallel trends along the increase in altitude. However, the proportion of regulated factors of altitude and species richness varied among forest, grassland, and abandoned arable land. Our results indicated that the land-use pattern of returning farmland to grassland and abandoned arable land was more effective in terms of the SOC storage in the superficial layer in this altitude range in the Qinghai-Tibetan Plateau, thereby being beneficial to optimizing land management in this region. 展开更多
关键词 Soil organic carbon GRAIN for Green program farmING land Qinghai-Tibetan PLATEAU
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The Effect of Land Degradation on Farm Size Dynamics and Crop-Livestock Farming System in Ethiopia: A Review 被引量:3
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作者 Assemu Tesfa Shigdaf Mekuriaw 《Open Journal of Soil Science》 2014年第1期1-5,共5页
Ethiopia is among the poorest countries in which poverty, land and resource degradation appear to feed off each other. The irony is that Ethiopia is a country with high biodiversity and distinctive ecosystems and the ... Ethiopia is among the poorest countries in which poverty, land and resource degradation appear to feed off each other. The irony is that Ethiopia is a country with high biodiversity and distinctive ecosystems and the natural resource base is critical to the economy and the livelihood of a high percentage of the population. Being the owner of varying agro ecology, the country’s agricultural production system had practiced for decades with a maximum potential. However, because of the presence of interrelated problems, the productivity had not sustained as its potential. From the interrelated problems, land degradation takes the first and challengeable problem in many countries. Land degradation refers to a temporary or permanent decline in the productive capacity of the land, or its potential for environmental management as a result;the long-term biological and environmental potential of the land has been compromised. Land degradation in the Ethiopian highlands (i.e. areas above 1500 m.a.s.l.) has been a concern for many years and is a great threat for the future that requires great effort and resources to ameliorate. It had adverse effect on lowering of livestock production by shrinking grazing land, the fertile soil types were washed and the grazing land was dominantly covered by unpalatable pastures and grasses which had low nutritive value and fertility for crop-livestock production system. In other cases, degradation induces farmers to convert land to lower-value uses;for instance, cropland converted to grazing land, or grazing lands converted to shrubs or forests. Equitable and secure access to land is a critical factor for the rural poor, especially livestock owners, who depend on agriculture and animal-related activities for their livelihood. Having secure access to land for agriculture and pastoral activities reduces their vulnerability and enhances their opportunities to invest in land for agriculture and livestock activities. Historical patterns of feudal ownership of land followed by government ownership and despite policy change uncertain status of land ownership. These land distribution and ownership patterns coupled with continuous fragmentations and degradation disrupt the balance between crop, livestock, and forest production. These things nowadays enforce Ethiopian farmers to put more land into crop production than working on livestock sector. Livelihoods are complex, dependent on animal and crop production based on land and water resources, with emerging market opportunities. And from year to year, the size of farms is getting minimized because of land degradation and segmentations, and these make a change in farm size dynamics and farming shift. Currently, there is a great scenario towards the land policy pattern and agricultural production system, which is the backbone of the country’s economy. Therefore, the aim of this paper is to review the effect of land degradation on farm size dynamics and crop-livestock production since the impact of these things is not well measured. 展开更多
关键词 Crop-Livestock farmING System farmERS farm Size DYNAMICS land Degradation
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Farming systems and crop-livestock land use consensus. Tanzanian perspectives 被引量:1
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作者 Dunstan Gabriel Msuya 《Open Journal of Ecology》 2013年第7期473-481,共9页
Agriculture is an important source of economic survival of rural populations, and with great power for poverty reduction in the economy. For this reason farming systems that are most efficient have to be sought. This ... Agriculture is an important source of economic survival of rural populations, and with great power for poverty reduction in the economy. For this reason farming systems that are most efficient have to be sought. This paper explores crop-based and pastoralism farming systems under conflicting land use relations. Incidences of violent conflicts are highlighted, which usually assume a depoliticised expression as inter-group conflicts. Competition for resources (land and water) is an important reason for such conflict, but the role of the state in protection of property rights is also advocated to nurture rivalry. Very wide difference in conception, that to the pastoralists property is cattle, land is common property open to herds, while to crop farmers land is property, which is divided between households, complicates the conflict resolution. State bias exists in the protection of property rights. Mechanisms for the state bias arebriefly cited. This paper suggests a farming systems educational approach as a way to reduce environmentally stressful practice, and strengthen the study of administrative regulation that harmonizes equity in conflicting land use. 展开更多
关键词 farmING Systems Pastoralism land Use CHOICES farmer-Herder Conflicts
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Do Land Characteristics Affect Farmers' Soil Fertility Management? 被引量:6
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作者 TAN Shu-hao 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2014年第11期2546-2557,共12页
Soil fertility management (SFM) has important implications for sustaining agricultural development and food self-sufifciency. Better understanding the determinants of farmers’ SFM can be a great help to the adoptio... Soil fertility management (SFM) has important implications for sustaining agricultural development and food self-sufifciency. Better understanding the determinants of farmers’ SFM can be a great help to the adoption of effective SFM practices. Based on a dataset of 315 plots collected from a typical rice growing area of South China, this study applied statistical method and econometric models to examine the impacts of land characteristics on farmers’ SFM practices at plot scale. Main results showed that in general land characteristics affected SFM behaviors. Securer land tenure arrangements facilitated effective practices of SFM through more diversiifed and more soil-friendly cropping pattern choices. Plot size signiifcantly reduced the intensities of phosphorus and potassium fertilizer application. Given other factors, 1 ha increase in plot size might reduce 3.0 kg ha-1 P2O5 and 1.8 kg ha-1 K2O. Plots far from the homestead were paid less attention in terms of both chemical fertilizers and manure applications. Besides, plots with better quality were put more efforts on management by applying more nitrogen and manure, and by planting green manure crops. Signiifcant differences existed in SFM practices between the surveyed villages with different socio-economic conditions. The ifndings are expected to provide important references to the policy-making incentive for improving soil quality and crop productivity. 展开更多
关键词 land characteristics soil fertility management farm household rice cropping South China
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Modeling the relationship of land use change and some geophysical indicators for the interlock area of farming and pasturing in China 被引量:19
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作者 DENG Xiangzheng, LIU Jiyuan, ZHUANG Dafang, ZHAN Jinyan, ZHAO Tao(Inst. of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China) 《Journal of Geographical Sciences》 SCIE CSCD 2002年第4期397-404,共8页
This paper discusses land-use changes in the interlock area of farming and pasturing (IAFP) in northern China. It presents detailed analyses of land-use features in the IAFP, which are controlled by the macro geomorph... This paper discusses land-use changes in the interlock area of farming and pasturing (IAFP) in northern China. It presents detailed analyses of land-use features in the IAFP, which are controlled by the macro geomorphic units and geophysical conditions-constraints or advantages. Additionally, it selects some indicators, according to the availability in acquiring and processing their quantitative data, to analyze the canonical correlations between the typical conversion of grassland and geophysical conditions. The preliminary study indicates that the physical conditions are of great advantages to the development of grassland. There exists significant correlation between land use change and some geophysical conditions. 展开更多
关键词 land use driving force interlock area of farming and pasturing China
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Research on Farmers' Response to Microeconomic Policies and Its Impact on Land Degradation in Zhaodong Heilongjiang Province
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作者 JIA Li LI You-hua GUO Dong-qing 《Journal of Northeast Agricultural University(English Edition)》 CAS 2005年第2期182-185,共4页
The livelihoods of farmers are responding to the mioroeconomic policies and result in many changes in the landuse pattern and landscape, and the farmer's attitude to the natural resources conservation, specifically i... The livelihoods of farmers are responding to the mioroeconomic policies and result in many changes in the landuse pattern and landscape, and the farmer's attitude to the natural resources conservation, specifically in the land degradation. In order to find the relationship between the farmers' response to the microeeonomic policies and land degradation, the authors surveyed 120 household in three villages in the black soil zone in Heilongjiang Province. Based on the feedback of the questionnaires, the authors established a model to analyze the impact. The results demonstrated that land degradation was impacted by farmers behaviors in the process of the adjustment of agricultural structures in the city of Zhaodong. And the main factors acted on the land degradation were the agricultural labour education level, the transfer of the labour from agricultural production, the price of the agricultural production materials, and the land scale management. The authors put forward some suggestions for sustainable agriculture based on the analysis on the topic. 展开更多
关键词 microeconomic policy farm household land degradation Heilongjiang Province
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Does labor off-farm employment inevitably lead to land rent out?Evidence from China
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作者 DENG Xin XU Ding-de +1 位作者 ZENG Miao QI Yan-bin 《Journal of Mountain Science》 SCIE CSCD 2019年第3期689-700,共12页
The focus of land economics is on how to decrease the misallocation of resources to achieve an optimal allocation of resources. Both the theories of new economics of labor migration(NELM) and the conclusions of empiri... The focus of land economics is on how to decrease the misallocation of resources to achieve an optimal allocation of resources. Both the theories of new economics of labor migration(NELM) and the conclusions of empirical studies reveal that land resources will inevitably be reallocated(e.g., rented out) if the resources of family labor are reallocated(e.g., off-farm employment). However, this study reveals that off-farm employment does not inevitably lead to land rent out. More precisely, this study uses survey data on 8031 peasant households from 27 provinces in China and explores the relationship between off-farm employment and land rent out by describing spatial features and through empirical analysis(e.g., IV-Probit model and IV-Tobit model). The results show the following: 1) There is an indirect relationship between off-farm employment and land rent out regarding spatial area aggregation, i.e., regions with a higher ratio of off-farm employment also have a lower area of land rent out. 2) Off-farm employment is significantly positively correlated with the behavior of land rent out, but its square is significantly negatively correlated with the behavior, i.e., there is an inverted U-shaped relationship between off-farm employment and the behavior of land rent out, with the turning point being 55.55% offfarm employment. 3) Off-farm employment is significantly positively correlated with the area of land rent out, but its square is significantly negatively correlated with the area, i.e., there is an inverted Ushaped relationship between off-farm employment and the area of land rent out, with the turning point being 56.22% off-farm employment. This study helps explain why China has a high ratio of off-farm employment but a lower rate of land rent out. 展开更多
关键词 RURAL LABOR Off-farm EMPLOYMENT land RENT OUT RENT OUT area China
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Heavy Metal Pollution and Ecological Risk Assessment of Cultivated Land Soil in the Farming Areas of Coastal China:A Case Study of Donghai County,Jiangsu Province 被引量:2
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作者 Ligang LYU Xiaorui WANG +3 位作者 Xueyan SUI Zhenyu LIU Yong YUAN Chen LIN 《Agricultural Biotechnology》 CAS 2018年第6期125-129,共5页
Classical statistics,Inverse Distance Weighted and Hakasnson potential ecological index were used to study the distribution characteristics of 8 kinds of heavy metals( Cr,Ni,Cu,Zn,As,Cd,Pb and Hg) as well as their pot... Classical statistics,Inverse Distance Weighted and Hakasnson potential ecological index were used to study the distribution characteristics of 8 kinds of heavy metals( Cr,Ni,Cu,Zn,As,Cd,Pb and Hg) as well as their potential ecological risks in the topsoil( 0-20 cm) of cultivated land in Donghai County,a typical agricultural area along the Southeast Coast of China.The results showed that the average content of heavy metals in the cultivated soil of Donghai County was not over the risk screening values set in the Environmental Quality Standard for Soils.However,it was worth noting that in some of the sampling points,the content of Cr exceeded the risk screening value,and the standard exceeding points accounted for 24.74% of the total.In addition,the average content of Cr,Ni,As,Cd,Pb and Hg exceeded the soil background values of Jiangsu Province,and values for Cd,Cr and Pb were more than 1.5 times of the soil background value of Jiangsu Province.The heavy metals were at the medium integrated potential ecological risk level,and the potential ecological risk indices were high in the east and low in the west,and distributed in interlaced island shape.The potential ecological risk indices of the plains in the east were higher than those of the central gentle slope area and the western hillock area.The potential ecological risk was at a high level in Niushan Town which was situated the county center and in some regions with high urbanization levels. 展开更多
关键词 Heavy metal contamination CULTIVATED land ECOLOGICAL risk assessment farmING area Donghai COUNTY
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Characterization of Farming Systems Using Land as a Driver of Production and Sustainability in the Vhembe District, Limpopo, South Africa
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作者 Fenji Materechera Mary Cathrine Scholes 《Agricultural Sciences》 2021年第11期1352-1373,共22页
South African agricultural farming systems are characterised by a duality in which there exists large-scale commercial farmers and small-scale farmers. Large-scale commercial farmers, historically identified as capita... South African agricultural farming systems are characterised by a duality in which there exists large-scale commercial farmers and small-scale farmers. Large-scale commercial farmers, historically identified as capital intensive and characterized by the size of the landholdings, are considered as the main drivers of national food security. Small-scale farmers on the other hand are viewed as important drivers of food security at the household level. These two main farming systems can be found within the Vhembe district municipality of the Limpopo Province and are characterised differently according to land descriptors. The study used an analysis of primary data obtained from in-depth interviews and secondary data obtained from an agricultural database to identify and characterize large- and small-scale farming systems within the Vhembe district. The study examined the land resource namely farm size and land ownership, topography and soil description, rainfall and its variability and threats and hazards used under three different high value crop (HVC) commodities, macadamia nuts, mangos and avocado pears. The study further examined yield and income from farming as drivers of production that would ensure the sustainability of long-term food security at both national and household level. The study revealed that gender of farmers within the farming systems was predominantly (79%) male across all commodities. Age distribution results showed an aging population of farmers mostly (90%) above the age of 51. Communal land ownership was the dominant (74%) land ownership amongst participants. Yield is not solely dependent on farm size and requires consideration of a broader array of land management aspects. There was a strong, significant correlation between income and farm size. These factors have implications for sustainability of the two farming systems and illustrate how certain aspects of land as a driver of production such as land ownership, rainfall variability, yield and income from farming can impact sustainability. 展开更多
关键词 High-Value Horticulture Crop Systems PRODUCTION farm-Size land SUSTAINABILITY Food Security
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Work Organization at Farm Level: A Process-Led Approach to Understand Land Use Changes
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作者 S. Madelrieux L. Dobremez B. Dedieu 《Journal of Agricultural Science and Technology》 2010年第4期57-66,共10页
In the French Alps, some grasslands have been abandoned, others are invaded by scrub whereas they are still used by farmers What are the relationships between land use changes and other changes at farm level that lead... In the French Alps, some grasslands have been abandoned, others are invaded by scrub whereas they are still used by farmers What are the relationships between land use changes and other changes at farm level that lead to scrub invasion? We hypothesize that they are linked by two work organization processes: process of changes (changes in the household and farm) leading to less intensive land use; and annual processes (sequences of activities during the year) and their repetition from one year to another, leading to insufficient land maintenance. In this paper, we present a study carried out in the Northern French Alps, based on surveys with livestock farmers. It appears that land use changes are often the consequence of other changes made to address work problems, and land use sequences are defined according to workforce and prioritization of tasks. This highlights the importance of considering farmers as workers in order to evaluate land use changes at the farm level and to link them to the human dimension within farming systems. 展开更多
关键词 land use farm process work organization
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Quantity Calculation of the Land Unsuitable for Farming: A Case Study of Anze County in Shanxi Province
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作者 Kangkang CHANG Longyi XUE Tao XUE 《Asian Agricultural Research》 2016年第5期67-70,共4页
Adhering to the " red line" of 1800 million mu of arable land is China's arable land protection guideline and policy,and the " red line" places emphasis on both quantity and quality of arable l... Adhering to the " red line" of 1800 million mu of arable land is China's arable land protection guideline and policy,and the " red line" places emphasis on both quantity and quality of arable land. Taking Shanxi's Anze County as an example,based on ecological safety and natural suitability criteria,we select 10 evaluation indicators to evaluate the farming suitability of existing land in the county. Results show that Anze County needs to reuse 48. 7% of the existing arable land for ecological purpose in order to ensure ecological safety. It still retains 51. 3%of existing arable land after abandoning tillage,which can ensure 0. 15 ha of arable land per capita,743. 12 kg of grain per capita and 170%of food self-sufficiency rate,thereby fully ensuring food safety. The farming suitability evaluation of land resources should not only consider the natural suitability of land,but also consider ecological safety. Faced with the new situation of arable land protection,it is necessary to explore new farmland protection theories and indicator systems based on actual conditions,to meet the requirements of sustainable development of population,resources and ecology. 展开更多
关键词 ECOLOGICAL COUNTY farmING SUITABILITY Minimum per capita area of ARABLE land
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The Influence of Land Use and Fish Farming on the Contents of Ca<sup>2+</sup>, Mg<sup>2+</sup>, K<sup>+</sup>and Na<sup>+</sup>in Pond and Reservoir Ecosystems in an Agricultural Small Watershed, China
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作者 Jiaogen Zhou Caiyun Zhang 《Journal of Environmental Protection》 2021年第12期1174-1184,共11页
It is not understood well that how the effects of land use and fish farming on the contents of alkali metals (Ca<sup>2+</sup>, Mg<sup>2+</sup>, K<sup>+</sup> and Na<sup>+</... It is not understood well that how the effects of land use and fish farming on the contents of alkali metals (Ca<sup>2+</sup>, Mg<sup>2+</sup>, K<sup>+</sup> and Na<sup>+</sup>) in small water bodies of pond and reservoir ecosystems at the watershed scale. In this study, the concentrations of Ca<sup>2+</sup>, Mg<sup>2+</sup>, K<sup>+</sup> and Na<sup>+</sup> in water bodies were measured for 103 ponds and reservoirs used as fish farming or surrounded by different agricultural land use types in the subtropical hilly watershed of Jinjing (105 km<sup>2</sup>), China. The two important environmental factors of fishing farming and agricultural land use influenced the spatial variation the contents of alkali metals. The ponds and reservoirs in residential area had significantly higher concentrations of Ca<sup>2+</sup> and Na<sup>+</sup> than those with other land use types, reflecting the influence of domestic wastewater. Compared with those of natural ponds with non-fish farming, no significant increase of alkali metal contents occurred in fish farming ponds, due to the regular cleaning of ponds by farmers. However, the effect of fish culture on alkali metal contents was still supported indirectly by the fact that the alkali metal contents significantly correlated with nitrate contents in fish farming ponds and but high related with that of DIP in natural ponds. The suitability assessment for irrigation on the pond water indicated that almost all of ponds were suitable for irrigation except some ponds surrounded by residential area and tea plantation. Generally, our results demonstrated that fish farming and agricultural land use affected the contents of alkali metals in ponds and reservoirs. The agricultural water irrigation would be with caution from the ponds with tea plantation and residential area in the subtropical hilly watershed. 展开更多
关键词 land Use Alkali Metals Fish farming Agricultural Small Watershed Pond and Reservoir
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中国陆上风电开发土地需求的定量研究
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作者 张力小 陈云钊 +3 位作者 张鹏鹏 李雨芩 武子凡 杨娜 《中国人口·资源与环境》 CSSCI CSCD 北大核心 2024年第5期46-57,共12页
随着气候变化、能源短缺等问题的日益突出,大规模开发可再生清洁能源已成为世界各国的普遍选择。其中,陆上风电以其技术成熟、安全高效的优势,在全球能源转型的进程中发挥着重要作用。然而,风能资源具有能量密度低、不稳定和空间分散等... 随着气候变化、能源短缺等问题的日益突出,大规模开发可再生清洁能源已成为世界各国的普遍选择。其中,陆上风电以其技术成熟、安全高效的优势,在全球能源转型的进程中发挥着重要作用。然而,风能资源具有能量密度低、不稳定和空间分散等特点,大规模开发陆上风电需要大量土地资源支撑。为保障碳中和目标下风电发展的土地资源需求,该研究对中国陆上风电的土地占用情况进行了定量研究。首先,以排他性为界定标准,从时空维度重新划分了风电场土地占用类型。其次,融合样本参数法和α形状算法,分类核算了中国现有陆上风电场的占地面积。最后,综合考虑风电技术发展趋势,系统模拟预测了碳中和目标下不同发展情景的中国风电用地需求。结果表明:①基于排他性原则,风电场总占地面积在空间维度上可分为直接影响区域和间接影响区域两部分;直接影响区域在时间维度上可分为永久用地和临时用地两部分。②2022年中国陆上风电场风机基础占地、永久用地、临时用地和直接影响区域占地面积分别达到48.28 km^(2)、352.08 km^(2)、1234.86 km^(2)和1638.81 km^(2)。③2022年中国陆上风电场间接影响区域占地面积和总占地面积分别达到了9.81×10^(4)km^(2)和9.99×10^(4)km^(2),总占地面积几乎与全国城镇总用地面积相当。④与当前技术水平情景相比,技术进步与风机换代情景下,2060年中国风电各类用地需求均有大幅下降,且用地需求在2050年前后达到峰值,风电机组的大型化替代对土地资源的节约潜力巨大。因此,完善风电建设用地标准、提升风电开发用地效率、统筹推进海上风电建设,是协同风能资源开发与土地资源可持续利用的重要路径。 展开更多
关键词 风电场 排他性 用地强度 面积核算 土地需求
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耕地非农化的时空演变及对粮食生产的影响——以江汉平原湖北省为例
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作者 刘静 姚志 刘健 《天津农业科学》 CAS 2024年第8期75-85,共11页
为探究非农化耕地的时空演变特征与估计耕地非农化对粮食生产的影响,以湖北省为研究区域,采用1980—2020年县级耕地利用栅格数据,对湖北省耕地非农化时空演变特征进行系统性研究,并建立固定效应模型探究耕地非农化对粮食生产的影响。结... 为探究非农化耕地的时空演变特征与估计耕地非农化对粮食生产的影响,以湖北省为研究区域,采用1980—2020年县级耕地利用栅格数据,对湖北省耕地非农化时空演变特征进行系统性研究,并建立固定效应模型探究耕地非农化对粮食生产的影响。结果表明:随着城镇化和工业化加速推进,城乡基本建设用地不断扩大,耕地非农化导致湖北省耕地面积下降。1980—2020年,耕地面积由72103.42 km^(2)减少至66984.31 km^(2),年平均减少127.98 km^(2);1980—2020年,湖北省耕地非农化面积在4个时期内呈波动增长趋势,耕地非农化等级高值区域主要集中在平原地区,而低值区集中在以山地为主的西南和东南地区;湖北省耕地非农化空间分布具有非均衡性,并呈向西北方向偏移的趋势,重心迁移的距离先增加后减小;耕地非农化呈现出空间正相关性,空间集聚程度总体呈现集聚性逐渐减弱趋势;耕地非农化对粮食生产产生显著的负向影响。基于上述结论,本文提出因地制宜治理耕地非农化行为、建设集约型城市、控制城市建设用地扩张规模、强化耕地用途管制、加强耕地资源保护等建议。 展开更多
关键词 耕地非农化 时空演变特征 粮食生产 固定效应模型
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互联网使用对农户优化生产要素配置的影响——基于CFPS数据的实证分析
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作者 王少国 句国艳 《经济与管理研究》 CSSCI 北大核心 2024年第7期77-97,共21页
本文通过建立一个典型农户模型,从理论上推导互联网使用对农户生产要素配置决策的影响机制,并基于2014—2020年中国家庭追踪调查(CFPS)数据,使用联立方程模型进一步实证检验互联网使用在农户非农就业、土地流转和风险投资方面的作用。... 本文通过建立一个典型农户模型,从理论上推导互联网使用对农户生产要素配置决策的影响机制,并基于2014—2020年中国家庭追踪调查(CFPS)数据,使用联立方程模型进一步实证检验互联网使用在农户非农就业、土地流转和风险投资方面的作用。研究结果表明,互联网使用对农户生产要素配置决策的影响是逐步递进的,总体而言能够促进农户参与非农就业、土地流转和风险投资,且该影响主要通过提升农户生产组织水平和增加农户信息获取渠道两条途径得以实现。同时,互联网使用对所在地区、经济状况和土地稳定性不同的农户的生产要素配置表现出差异化影响效果,因此可以根据农户各自特征优化其生产要素配置决策,从而改善农户收入状况。 展开更多
关键词 互联网使用 农户生产要素配置 非农就业 土地流转 风险投资
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农村新一轮土地延包30年效率与公平的研究——来自Y省J区D村调利不调地的案例证据 被引量:1
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作者 娄磊 洪名勇 钱龙 《华中农业大学学报(社会科学版)》 CSSCI 北大核心 2024年第2期188-196,共9页
农村第二轮土地承包30年期限已经陆续到期。基于Y省J区D村新一轮土地延包30年试点工作中形成的以调利不调地为核心要义的资源配置方式,深入探究农村第二轮土地承包到期后再延长30年试点工作中效率与公平的关系。结果表明,以调利不调地... 农村第二轮土地承包30年期限已经陆续到期。基于Y省J区D村新一轮土地延包30年试点工作中形成的以调利不调地为核心要义的资源配置方式,深入探究农村第二轮土地承包到期后再延长30年试点工作中效率与公平的关系。结果表明,以调利不调地为核心要义的资源配置方式,一方面通过借助社会大规模参与脱贫攻坚以及乡村振兴战略的制度遗产,满足了极少数无地少地农户的利益需求,在集体层面上保障了全体集体经济组织成员的公平公正;另一方面,对绝大多数农户采取顺延承包的土地延包方式,不断放活农地经营权的自由流转,推动了新一轮土地延包30年试点工作高效开展,进而实现了效率与公平的有机统一。同时,构建开展新一轮土地延包30年试点工作的分析框架,进一步拓展了社会分配理论的应用场景。 展开更多
关键词 新一轮土地延包 调利不调地 效率与公平 社会分配
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