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Homestead reconstruction is one of the most effective means to govern rural planning. Traditional research cannot fully consider the individual differences of rural homesteads, easily leading to uneven spatial development, and even social and economic problems. In this study, a novel framework of rural settlement was reconstructed to integrate the land suitability and reconstruction urgency of rural homesteads. The individual differences were considered in the rural homesteads using a questionnaire survey in Pingba Village, Chongqing City, in southwest China. This framework combined the differentiated characteristics of rural homesteads, in terms of the concentration ratio, utilization status, livelihood, travel convenience, and willingness to relocate. A comprehensive evaluation index was established to divide the rural homesteads into different reconstruction types. Participatory rural assessment (PRA) was selected to conduct the questionnaire survey in all 292 peasant households living in the study area. The results show that: 1) more than half of the rural settlements were distributed in the highsuitability areas before reconstruction. A trend of agglomeration was found under the complex terrain and location conditions in the mountainous areas. 2) The scale of rural homesteads were expanded three times that need to be optimized in the study area after considering individual differences, compared with only land suitability. The newly added rural homesteads shared the land suitability, but there was low utilization or a conflict between the expected production output and lifestyle. 143 rural homesteads were then determined to be optimized using reconstruction, according to their own utilization problems. The obstacles of these homesteads were identified, in terms of the utilization status, travel convenience, and concentration ratio. 3) The land suitability and individual needs were comprehensively considered to divide into five types: the retained, locally rebuilt, integrated, production-, and travel-based relocated homestead. The proportions of the five types of homesteads were 34.79%, 22.89%, 9.04%, 16.94%, and 16.34%, respectively. Furthermore, the types were varied in the different reconstruction needs. Among them, the retained homesteads were the fundamental reconstruction. Production- and travel-based relocated homesteads needed to be optimized and reconstructed after relocation. 4) The five types of homesteads constituted of three optimization modes: relocation, integration, and space replacement. The new spatial pattern of rural settlements was established after rebuilding, relocating, and replacing the five types. Finally, 10.34 hm² of construction land resources were saved after optimization, which was far greater than the amount of the conserved when considering only the land suitability. The integration and replacement modes were added to produce the more complex reconstruction of rural homesteads within the village, compared with the simple demolition and relocation. The rural homesteads were shifted from areas of low or no suitability into high ones, indicating the increasing number. Therefore, the larger scale of rural homesteads in the regions with the higher suitability was conducive to the realization of a new pattern with the moderately centralized residency in the mountainous villages. The reconstruction significantly improved the level of agricultural suitability in the rural homesteads, fully meeting the differentiated needs of farmers for utilization. The finding can provide a new perspective on rural planning and space governance. An exploratory tool can be expected for rural space optimization, considering the influence of individual differences in the rural homesteads on the rural reconstruction plans. [ABSTRACT FROM AUTHOR]

Regional Production-Living-Ecological Space (PLES) has been one of the most important indicators in territorial space planning. Spatial-temporal evolution and development trends can be greatly contributed to the orderly utilization, renovation, and restoration of regional territorial space in the future. In this study, a transfer matrix and dynamic attitude model was proposed to analyze the dynamic evolution characteristics of the scale, structure, and pattern of PLES from 1990 to 2020. A Future Land Use Simulation (FLUS) model was then used to simulate the land spatial pattern of Shizhu County, Chongqing City, China in 2035. Three scenarios were performed on natural development, cultivated land protection, and ecological protection. The results showed that: 1) The ecological space was the main area, followed by the production space, and the living space with the least proportion. In general, the production space was the main area in the west, whereas, the ecological space was in the east. The PLES was also dominated by the green ecological, and agricultural production space, accounting for over 65% and 30%, respectively. As such, diversified geographical characteristics were created in this case. Among them, the green ecological space was distributed in the Fangdu Mountain Range and the Qiyao Mountain Range, leading to two natural ecological space barriers running diagonally across the whole territory. Agricultural production space was mainly distributed in the trough and valley between the two mountain ranges and along the Yangtze River in the western part of the county. 2) The production space decreased slightly during the study period. By contrast, there were slight and significant increases in the ecological and living space, respectively. The transfer of PLES showed the spatial characteristics of “overall dispersion and local concentration”. The expansion of industrial production space was mainly distributed in Xituo Town along the Yangtze River and Xilu Street in the study area. In addition, the urban area was located, while other townships were scattered. The expansion of urban living space was mainly distributed in Wanan and Nanbin Street, where the urban area was located, while other new spaces were scattered throughout the county. 3) There were significant changes in the PLES under the three scenarios. Specifically, the agricultural production space was transferred into other spaces under the natural development scenario. A good balance was also gained in the area of transferring. By contrast, there were different degrees of expansion in other spaces. A significant shrinkage trend was found in the green ecological space. Moreover, the transfer out of agricultural production space was strictly controlled under the scenario of arable land protection. As such, the arable land was effectively protected during this time. However, the green ecological space was the largest transfer out space. Furthermore, the ecological space pattern was effectively protected with the increased area under the ecological protection scenario. But, the agricultural production space shrunk significantly, while the area of all other types of space increased. These results were better correspondent with the socio-economic development trend and regional development pattern in the study area. The finding can provide theoretical support for territorial space management and optimization. A recommendation was made on the national spatial control to improve the level of intensive use of living space, for the better protection of agricultural production space, as well as the protection and restoration of ecological space in the future. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In recent years, the pneumatic centralized fertilizing and seeding methods were developing rapidly. The pneumatic centralized fertilizing system was mainly used for layered fertilizing operation. The fertilizing pipes of the fertilizer discharging system were connected with the fertilizer outlet of the layered fertilizing shovel. Under the actions of air flow, the fertilizer was transported to the outlet of the fertilizing shovel quickly and remotely, so as to realize the layered application of the fertilizer in the soil. In this paper, in view of the problems such as the fertilizer falling into the inlet was not smooth and the airflow velocity at the outlet was too high, which leading to fertilizer bounce and dust when the fertilizer discharging system and layered deep fertilizing shovel were combined, the relationship between the structure of each part of the fertilizer discharging system and the working parameters was studied through the test-bench of the pneumatic centralized fertilizer discharging system, and the structure of the fertilizing system was optimized. An air-fertilizer separation device was designed, which was installed between the distributor outlet and the fertilizer discharging pipe of the layered deep fertilization shovel, part of the airflow from the fertilizing system was discharged by the air-fertilizer separation device in advance to reduce the airflow velocity at the fertilizer outlet of fertilizing system. The structure and basic working parameters of each component of fertilizing system were determined through theoretical analysis and parameter calculation. In specific, the airflow velocity of the fertilizing system inlet should be greater than 25 m/s, the diameter of the air-fertilizer conveying pipe, fertilizer inlet and fertilizer outlet was 76, 55 and 20 mm, respectively. The main factors affecting the airflow velocity at fertilizer outlet and inlet of fertilizing system were also determined through analysis. Taking the exhaust outlet area of the air-fertilizer separation device (A), the airflow velocity of the fertilizing system inlet (B) and the fertilizing rate (C) as the test factors, the quadratic regression rotary orthogonal platform experiment was conducted. According to the test results, the mathematical regression model between the test indexes and the influencing factors was established. The results showed that the exhaust outlet area of air-fertilizer separation device, airflow velocity of the fertilizing system inlet and fertilizing rate had a significant effect on airflow velocity at fertilizer outlet of fertilizing system, and exhaust outlet area of air-fertilizer separation device had a significant effect on the airflow velocity at inlet of fertilizing system. The optimized parameters were conducted by fitting and optimizing the test results. It was obtained that airflow velocity at fertilizer outlet, fertilizer inlet of fertilizing system was 5.91 and 3.94 m/s, respectively, the exhaust outlet area of the air-fertilizer separation device, airflow velocity of the fertilizing system inlet and fertilizing rate were 798.0 mm², 28.10 m/s and 0.28 kg/s, respectively. The verification test results showed that the airflow velocity at fertilizer outlet and fertilizer inlet of the system was 6.02 and 4.11 m/s, the fertilizer at the inlet of the fertilizer discharging system falled smoothly and stably. [ABSTRACT FROM AUTHOR]

Cultivated land fallow pattern is an important part for the implementation of the arable land fallow system. Therefore, it is necessary to explore different fallow patterns for the fully utilization of farmlands in China. This paper aims to refine the differentiated fallow pattern of cultivated land using literature analysis and case studies, together with field data collected from the main pilot areas of cultivated land fallow in China. Results showed that: 1) the pattern design of cultivated land fallow depends on three factors, including system subject, system object and system environment, in the specific land fallow system. The guideline of pattern design can be based on the principle of available local conditions, food security, the trinity of social, economic and ecological benefits, and the main standard of "rest, maintain and utilization" for fallow land. In pattern design of differentiated cultivated land fallow, the main contents include the pattern definitions, pattern categories, applicable areas, case areas of pattern, and typical fallow technical measures. 2) Five fallow patterns of cultivated land in China mainly are: fallow pattern of water-saving and retention in the groundwater funnel area, fallow pattern of clean decontamination in the land pollution area, fallow pattern types of ecological restoration in the ecologically degraded area, productivity conservation of cultivated land in highly intensive cultivation area, and the pattern of "transfer + fallow" in the seriously abandoned area of cultivated land. 3) Technical measures of fallow patterns are related to fallow time, fallow cultivation and fertilization, fallow tillage, fallow experiment and demonstration fields. The fallow time of pattern design can be divided long-term, short-term and seasonal fallow. The fallow fertilization of patterns consists of no-till net green manure, less tillage with green manure and bean rotation, no-tillage green manure mixed with grass, no tillage manure returned to the field, straw returning, and organic fertilizer (fertilized farmyard manure), and mixing with the above various ways. The fallow tillage mainly includes crushing and returning green manure to the field, fallow shallowing, deep turning and drying, and rotary tillage, and other related technical systems. The fallow patterns of experiment and demonstration fields include a variety of screening test, fallow time test, determination test of soil index, and comparison test between fallow and uncultivated farmland. 4) The typical fallow experimental demonstration fields in Huanxian county, Gansu Province, can be expected to popularize in different fallow areas of China. [ABSTRACT FROM AUTHOR]

Coordination between rural residents and rural settlements is an important goal in man-land relationship system. However, the research on rural residents change and rural settlements change from rural perspective is relatively weak due to urban bias. There are few researches focusing on the coupling relationship between human-land relationship changes. Based on existing researches and cross-section data of Chongqing in 2010 and 2016, this paper first analyzed the change types of rural residents and rural settlements. The change types were divided into four types: rapidly increase type, steady increase type, steady decrease type and rapidly decrease type. Secondly, through the coupling analysis of the two, four models of the change of rural resident and rural settlements are constructed: residents decrease settlements increase, residents increase settlements decrease, residents and settlements decrease, resident and settlement increase. Finally, in order to further demonstrate the spatial trend of the coupling relationship between rural residents and rural settlements change, Rongcheng and Yangchuan were taken as transverse sample zones of western Chongqing based on the comprehensive analysis of the economic development and geographical features of the city and the availability of data; Fuling, Fengdu, Zhongxian were taken as transverse sample zones along the Yangtze river; Wenzhou and Kaizhouas longitudinal sample zones in northeast Chongqingwere used to analyze the correlation between inhabitant elasticity coefficient, economic development and topographic conditions. The results show that: 1) The change of rural residents and rural settlements in town shows more heterogeneity. Under the general trend of decreasing in number and structure of rural resident in the whole city, 43.93% of rural settlements in town area increased, and 40.60% of rural resident in town area increased. 2) There is obvious spatial correlation between the land use of rural settlements and the changing pattern of rural residents and there is a spatial overlap between high value area and low value area of number change of rural settlements. Types of “residents decrease settlements increase” and “residents increase settlement decrease” are mainly distributed in highly impoverished areas while types of residents and settlements decrease, resident and settlement increase are mainly distributed in western Chongqing and main urban areas. 3) The coupling relationship between rural residents and rural settlements change has significant zonal differentiation characteristics. Along Yangtze river and in North-South direction, the residential elasticity coefficient shows obvious zonal distribution rules. In the short term, geographical conditions have no significant effect on the coupling relationship between the number of rural settlements and the change of rural residents. However, the coupling relationship between the number of rural settlements and the change of rural residents is significantly affected by economic development. Focusing on the relationship between rural settlements and rural residents changes in towns will provide reference for the formulation of land use policies in line with the reality of rural development. [ABSTRACT FROM AUTHOR]

It is a long-term strategy of “storing grain in the ground and storing grain in the technology” for China to carry out rotation and fallow of cultivated land as a system at present. The paper is based on the exploration of the key issues of the spatio-temporal collocation of the cultivated land fallow in China. With the deepening of the pilot work of cultivated land fallow in China, how do we coordinate the spatio-temporal collocation of cultivated land fallow to achieve maximum comprehensive benefits? Following the logical thinking of “experiencing typical national and regional practices, extracting theoretical results, discussing key issues” from the disciplines of geography, agronomy, land science and management, the paper uses the methods of literature, comparison law, induction and field survey, summarizes the practical results of typical countries and regions, and discusses the key problems of the spatio-temporal collocation of cultivated land fallow in China. The following main results are obtained: (1) There are mainly 4 types of spatio-temporal collocation of the cultivated land fallow in typical countries and regions: the aim-oriented spatio-temporal collocation, the execution-oriented spatio-temporal collocation, and the multi-condition-constraint-oriented spatio-temporal collocation, and the technology-oriented spatio-temporal collocation. (2) The connotation essence of the spatio-temporal collocation of cultivated land fallow is to realize the macro-control of “positioning, quantification, and timing” of fallow land, which includes mainly the fallow aim, fallow spatial layout and fallow time arrangement. First, the spatio-temporal collocation is oriented towards fallow aim, and fallow aims at the entire process of spatio-temporal collocation. Second, the fallow spatial layout is to optimize and combine the fallow scale and the fallow area, which are mutually restricted and synchronized. The fallow spatial layout should be considered as national scale and regional scale, including national, provincial, municipal and county scale, and the fallow spatial layout constraints or evaluation index systems at different spatial scales are different. The minimal spatial scale of the fallow scale is county level, while the minimal spatial scale of the fallow area is parcel of land. Third, the fallow time arrangement is regulating and controlling the fallow time series and the fallow time length, which are respectively configured according to the fallow emergency degree and the expected benefits in this area. The fallow time series can be divided into short term, medium term and long term, and the fallow time length can be divided into season break, annual rest and rest of many years. In addition, the spatio-temporal collocation of cultivated land fallow is also controlled by the national conditions and the land system in China, and is shown in the fallow aim or the fallow constraints. (3) The spatio-temporal collocation process of cultivated land fallow is “fallow aim, constraint, spatial layout, time arrangement”, and each link is connected with each other. The constraints mainly include grain market, food security, ecological security, cultivated land quality and social economy, and can be transformed with the fallow aim. The fallow spatial layout and fallow time arrangement are subject to constraints, and using different spatial-scale forecasting models or evaluation index systems, and making full use of “3S” (remote sensing, global position system, and geographic information system), monitoring, and surveying and mapping are the technical foundations for rational collocation. (4) The key issues that need to be solved in the spatio-temporal collocation of cultivated land fallow in China are as follows: The first issue is the spatial layout of cultivated land fallow at different spatial scales. Grain security is the primary constraint condition at the national scale, and the geographical spatial difference between grain supply and demand, the quality and ecological condition of cultivated land and the level of regional social economy is the comprehensive constraint condition at regional scale. The second issue is the fallow time arrangement of cultivated land in different regions. According to the urgency level and the expected benefits of the regional fallow, the time series and the multiple fallow lengths of the cultivated land fallow are determined respectively. In fact, the improvement of the cultivated land fallow system in any country is the result of continuous attempts among academics, policymakers and farmers. At present, the pilot work of the cultivated land fallow in China has been explored for more than 2 years, and many problems encountered in the pilot process are still to be thought out in order to improve the timeliness of the spatio-temporal collocation of the cultivated land fallow. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Currently, the Chinese social economic transition has been in a critical period when more resistance and frictions for such transitions are occurring. The social and economic transition and urban-rural restructuring have been real issues for social economic transition, and adjustment time for China’s social economic policy development, we established rural residential land use map at village level, spatial attribute data of rural residential land at peasant household level and social economic data during different time using the method of field research called Participatory Rural Appraisal. Based on rural residential land evolution process at spatial and time dimensions and its characteristics in Guni village of Chongqing in resent 30 years since 1980, we analyzed evolution characteristics of rural residential land scale, space form, structure system and landscape pattern at village level, and summed up general rule of rural residential land evolution in space and time dimensions. The results showed that rural residential land area in Guni village was 22.79 hm2 in 1980, and increased to 33.47 hm2 in 2012. The average annual growth reached 1.21%. Rural residential land patch had been in a central tendency at time dimension, and expansion rate of rural residential land experienced a process from pure extension to coexistence of expansion and tightening. Rural residential land patch was in an irregular shape, which was departed from circular and square at spatial and time dimensions. The spatial structure of rural residential land presented an evolution tendency from relatively centralized to comparatively decentralized, while spatial structure system of main settlements had an acute evolution with unreasonable grade. The landscape diversity of rural residential land patch and its uniform distribution degree had a further improvement at village level, but the landscape heterogeneity had been further stood out at group level. Leading factors (total population, quantity of labor force and peasant household) could promote the expansion of rural residential land scale. However, its influence had a downward trend with time scale. Economic development level factors such as average income were inducement factors, and its driving force had further strengthened with time. Locations along the highway were one of the leading driving forces of newly-added rural residential land expansion, and the expansion of rural residential land since 2005 had been the result of new rural reconstruction policy-driven. Based on driving force model of rural residential land evolution from “nature-economy-position” aspects，it could reveal that increase number of farmers is a main factor to promote the expansion of rural residential land scale. At time level, the driving force of rural residential land growth at micro level has experienced among population driving, economy driving and environment policies driving. [ABSTRACT FROM AUTHOR]