Distribution Of Cultivated Land Research Articles

Spatiotemporal Characteristics of Land Cover Change in the Yellow River Basin over the Past Millennium

Investigating the ecological and environmental impacts stemming from historical land use and land cover change (LUCC) holds paramount importance in systematically comprehending the fundamental human-land relationship, a pivotal focus within geographical research. The Yellow River Basin (YRB), often referred to as the cradle of Chinese civilization, ranks as the fifth-largest river basin globally. Early inhabitants made significant alterations to the landscape, resulting in substantial damage to natural vegetation, giving rise to prominent regional ecological challenges. By now, the examination of historical LUCC in the YRB over the past millennium remains in the qualitative research stage, primarily due to the limited availability of high-confidence gridded historical LUCC data. This study aims to advance the current historical LUCC research in the YRB from primarily qualitative analysis to an exploration incorporating timing, positioning, and quantification. Based on reconstructed historical cropland, forest, and grassland grid data of 10 km × 10 km from 1000 AD to 2000 AD, the degree of cropland development and the depletion of forests and grasslands were calculated, respectively. Then, the kernel density method was employed for spatiotemporal analysis and interpretation of dynamic changes in land cover. Subsequently, a cartographic visualization depicting the migration trajectories of the land cover gravity centers was generated, allowing for an assessment of the distance and direction of the centroids’ movement of cropland, forest, and grassland. The results indicate that the cropland coverage in the YRB escalated from the initial 11.65% to 29.97%, while the forest and grassland coverage dropped from 63.36% to 44.49%. The distribution of cultivated land continually expanded outward from the southeast of the Loess Plateau and the southwest of the North China Plain. All three types of land cover experienced a westward shift in their gravity centers between 1000 and 2000 AD. Besides the population growth and technological advancements, the regime shifts induced by wars, along with land use policies in distinct periods, always served as the predominant factors influencing the conversion between different land covers. This research will present a paradigmatic regional case study contributing to the investigation of historical changes in land use and land cover. Additionally, it will offer historical perspectives beneficial for the advancement of China’s objectives in “Ecological Conservation and High-Quality Development of the Yellow River Basin”.

A Spatio-Temporal Analysis of the Ecological Compensation for Cultivated Land in Northeast China

Ecological compensation for cultivated land is a prominent means to coordinate the protection and utilization of cultivated land ecosystems. This study assessed the ecological compensation for cultivated land, considering both the ecological footprint and value of ecosystem services. We used the ecological footprint model to calculate the ecological footprint and ecological carrying capacity of cultivated land, combined with the value of its ecosystem services, with a focus on estimating its ecological compensation standard, and we analyzed the temporal and spatial distribution characteristics of Northeast China. We found that the ecological footprint and ecological carrying capacity of cultivated land showed a fluctuating growth trend in Northeast China from 2000 to 2020, increasing by 288.83 × 105 ha and 131.37 × 105 ha, respectively. The spatial distribution of cultivated land’s ecological footprint and ecological carrying capacity showed growth from the southwest to the northeast. The value of its ecosystem services presented an overall trend of growth over the past 20 years, increasing by CNY 13.64 billion, or an increase of 12.47%. In terms of spatial distribution, the trends of the ecological compensation for cultivated land showed obvious differences. This study mainly focused on black soil cultivated land, and its results are helpful for governments in different countries solving similar problems in terms of the ecological compensation for cultivated land. This study will provide a valuable reference to measure the compensation standard scientifically and to provide policy recommendations for sustainable cultivated land’s protection and utilization.

Can We Prevent Irreversible Decline? A Comprehensive Analysis of Natural Conditions and Quality Factor Thresholds of Cultivated Land in China

Over the past two decades, China’s spatial distribution of cultivated land has been stable, yet there remains an urgent need to amplify grain productivity. The central scientific question addressed in this study is: How can we effectively evaluate the natural resource thresholds of cultivated land at a regional scale? Despite existing systems, there is a noticeable gap, particularly in this area of inquiry. Recognizing the present state of these resources and introducing more efficient management strategies is pivotal. This paper aims to research the restrictive situation of the natural resources background quality (NRB-quality) of China’s cultivated land by developing an innovative classification method and a short-board identification method and adopting cluster analysis and other technical methods. The results showed that (1) China mainly maintains medium-quality land (57.30%). The soil texture displayed a fine average grade of 1.39, while the biodiversity, soil pH, secondary land types, and cropping systems indicated poor conditions, with average scores of 2.01, 2.06, 2.26, and 2.33. (2) A notable difference in the restrictive factors of cultivated land quality emerged, with secondary land types of cultivated land (including paddy field, irrigated land, and dry land) being the only national short-board factor. Regionally, the cropping system, secondary land types of cultivated land, and natural region were identified as short-board factors in 31, 24, and 23 natural regions. (3) The regional difference in cultivated land quality leads to six different management strategies. Eastern regions emphasized stabilizing land distribution and infrastructure enhancement, while China’s western areas advocated cautious development and heightened ecological protection. The findings demonstrated regional differences in the status of cultivated land quality factors; implementing classified management approaches for cultivated land quality factors based on their characteristics is vital to preventing irreversible decline. The study serves as an important basis for the protection and utilization of cultivated land in the new era to clarify the NRB-quality differences of cultivated land in China.

Sustainable use of gully agricultural land and water resources for sustainable development goals: A case study in the Loess Plateau of China

AbstractIn the context of global advocacy for Sustainable Development Goals (SDGs), agriculture and rural areas as the main carrying place of human production activities, is not only the focus area of SDGs, but also the focus point for the implementation of SDGs. Gully agricultural land and water resources (GALWR) sustainable use in China's Loess Plateau is vital to the evolution law of human–earth relationships and agricultural multi‐functional transformation for SDGs. However, the characteristics and patterns of GALWR and the optimization strategy are still unclear. Here, we identified the spatial distribution characteristics of GALWR and evaluated the carrying capacity of GALWR in the loess hilly and gully region (LHGR). We further investigated the driving factors for GALWR sustainable use and the optimization strategy of the dual guidance of economy and society as well as resources and ecology. The following results were obtained: (1) The distribution of cultivated land in the LHGR largely differed among districts and counties, with a higher distribution in the middle and a lower one on both sides. The matching degree of the GALWR was low, and the sensitivity analysis showed that the per capita water resources, the proportion of primary production, the drought index, and the vegetation coverage were the sensitive factors affecting the sustainable use of the GALWR in the LHGR. (2) There were obvious differences in the coupling and coordination of GALWR in the LHGR in 2020, and was a lack of synchronization regarding the GALWR use. (3) In order to form a gully rural regional functionalized and structured spatial structure system, the optimized strategy of GALWR for SDGs in the Loess Plateau was proposed according to adaptive management and the multi‐element coupling process of “water‐land‐climate‐crop” to protect gullies, rivers, forests, farmlands, and lakes in a coordinated way and in combination with land engineering control measures. This study provides a guideline for the transformation of agriculture and the construction of a new pattern of high‐quality agricultural development in the Loess Plateau.

Spatial differentiation and scenario simulation of cultivated land in mountainous areas of Western Hubei, China: a PLUS model.

A useful spatial pattern of cultivated land utilization in mountainous areas is a basic prerequisite for promoting efficient utilization of cultivated land and has a practical use for ensuring regional food security and rural revitalization. In this paper, we use Enshi and Lichuan cities as case studies and the PLUS model to analyze the spatial differentiation characteristics of cultivated land from 2000 to 2020. In addition, we simulated the spatial pattern of cultivated land in 2030 concerning the ecological priority scenario (scenario I) and the ecological and economic coordination scenario (scenario II). The results show that (1) the degree of cultivated land fragmentation from 2000 to 2020 is characterized as "high in the east and low in the west," and the spatial aggregation of cultivated land decreases slightly over time and that there is a risk of increasing fragmentation of cultivated land in the future. (2) The complexity of cultivated land shape shows a fluctuating decrease between 2000 and 2030, and an overall trend of landscape homogenization. (3) The spatial distribution of cultivated land is concentrated in the peak cluster depressions and river valleys. The imbalance in the distribution of cultivated land has increased in the past two decades which should be curbed in the future. (4) In 2030, concerning the ecological priority development scenario, cultivated land use tends to evolve in the direction of balanced distribution and a relatively complex shape. (5) Concerning the coordinated ecological and economic development scenario, the spatial aggregation of cultivated land is higher and the patches of cultivated land are more regular, but the distribution imbalance is more serious. The results can provide scientific references for sustainable and effective use of cultivated land in mountainous areas.

Water-Land-Food Nexus for Sustainable Agricultural Development in Main Grain-Producing Areas of North China Plain.

Stable and sustainable food production is an important guarantee for national security and social stability. The uneven distribution of cultivated land and water resources will threaten national food security. In this study, we adopt the Gini coefficient and water-land matching coefficient for exploring the water-land nexus in the main grain-producing areas of North China Plain (NCP) from 2000 to 2020. The water-land-food nexus considering grain crop production structure is further explored from spatial and temporal multi-scales. The results show the following: (1) The Gini coefficient presents an increasing trend in the NCP, indicating an increasing imbalance in the water-land matching degree among inter-regions. (2) There are significant differences in the WL nexus and WLF nexus among regions, showing a spatial pattern of "worse in the north and better in the south". (3) The cities which belonged to the low WL-low WLF and high WL-low WLF should be considered as key targets when formulating policies. (4) Adjusting the wheat-maize biannual system, optimizing the grain cultivation structure, promoting semi-dryland farming, and developing low water-consuming and high-yielding crop varieties are essential measures for these regions. The research results provide significant reference for the optimal management and sustainable agricultural development of agricultural land and water resources in NCP.

Spatial-Temporal Evolution and Driving Forces of Cultivated Land Based on the PLUS Model: A Case Study of Haikou City, 1980–2020

The security of cultivated land is the foundation for stable social and economic development. In recent years, with rapid economic development, urbanization around the world has been accelerating. The demand for urban construction expansion is increasing day by day and lands used for cultivation are being infiltrated by construction, posing a serious threat to food security. This study used the land-use data from Haikou City in 1980, 2000, 2010 and 2020, to generate a transfer matrix, kernel density analysis and landscape pattern index to analyze the spatial-temporal evolution of cultivated land in Haikou. The PLUS model was used to explore potential factors driving land-use evolution. Results show that cultivated land in Haikou was continuously lost from 1980 to 2020 and the area of cultivated land decreased by 7020.58 ha. Loss was most significant during 2010–2020 when cultivated land ascended into construction land in the northern region of the city. Spatial distribution of cultivated land in Haikou is generally characterized by “dense in the southwest and sparse in the northwest”, and the spatial density of cultivated land in the northwest continuously decreased from 1980 to 2020. In the past 40 years, the degree of spatial aggregation for cultivated land in Haikou has decreased and the degree of fragmentation has increased. The primary factors driving changes in spatial-temporal patterns over the past 40 years has been the distance from roads and high-speed railways and the distance from water. During the 40-year timespan, Haikou continued to lose cultivated land areas due to the interaction of social and natural factors such as road traffic and water resources. The juxtaposition between the demand for urban construction lands and the protection of cultivated land has become increasingly evident. Due to the threat cultivated lands are facing in the northern area of Haikou, we suggest future expansion of construction development land should be strictly controlled.

Evaluation of Cultivated Land Quality in Semiarid Sandy Areas: A Case Study of the Horqin Zuoyihou Banner

Objective: The evaluation of cultivated land quality from the regional perspective and the clear level and change in cultivated land quality in the whole region can better guide the construction of cultivated land quality, carry out scientific optimization allocation, improve grain production capacity, and promote the sustainable use of cultivated land. Research methods: The utilization of local resources and natural conditions were comprehensively considered, and the evaluation was carried out from the four dimensions of ecology, quantity, spatial structure and scale to comprehensively reflect the level of regional cultivated land utilization. Results: (1) The cultivated land quality level of the Horqin Zuoyihou Banner is low, and the pressure of regional water resources is great. Some cultivated land is located in the area with poor natural conditions, and there are many thin and narrow cultivated areas of land. The area of cultivated land that can be carried by regional water resources under current irrigation is 184,492.17 hm2, and that under water-saving irrigation is 259,703.72 hm2, which are lower than the current cultivated land areas. (2) During the study period, the total amount and spatial distribution of cultivated land changed greatly, and there were good natural conditions and utilization conditions of newly added cultivated land, but the quality of cultivated land from the regional perspective showed a downward trend. The dynamic attitude of cultivated land change was 0.99%. (3) According to the evaluation results, the cultivated land was divided into the following four categories: priority protection type, optimization and coordination type, gradual conversion type and priority conversion type, which accounted for 34.18%, 30.59%, 28.83% and 6.40% of the total cultivated land area, respectively. Conclusions: There is a sharp contradiction between the supply and demand of water resources, and the quality of cultivated land in the region is low and shows a downward trend, which is not conducive to the sustainable use of regional land resources. In this regard, the Horqin Zuoyihou Banner should actively curb the growth of cultivated land, develop water-saving irrigation processes, strengthen ecological environment protection, and systematically optimize the layout of cultivated land on the premise of ensuring ecological security according to the actual conditions of different regions.

Analysis of Vegetable Waste Pollution Risk and Resource Potential Based on Geographical Information System and Remote Sensing

Land resources are an important foundation for human survival and development. In recent years, land resources have experienced rapid industrialization and urbanization. With the expansion of urban construction land and the sharp decline of natural and agricultural landscapes, ecological and social problems have gradually surfaced. Based on the intuitive interpretation of LandsatTM/ETM +/OLI image data from 2016 to 2020, this work created an annual land use reference database. The use of resources and the recovery of nutrients from vegetable waste are necessary measures to achieve sustainable and environmentally friendly agriculture. Collecting and analyzing data from the literature are to determine the risk of vegetable waste pollution and the possibility of resource utilization. The amount of vegetable waste produced and the total amount of nitrogen, total phosphorus, and total potassium pollution in the study area are estimated, and ArcGIS is used to characterize TN (total nitrogen) and TP (total phosphorus). The spatial distribution of TK (total potassium) pollution intensity and pollution risk comprehensive index determines the key areas of vegetable waste nonpoint source pollution control in the region and compares the resource utilization potential of vegetable waste based on the demand for fertilizer. This paper combines the research of the subject; takes cultivated land as the research object; clarifies the main pollutants, contaminated area, content, and distribution of cultivated land; uses factor analysis method to conduct a preliminary study on the causes of heavy metal contaminated soil in the study area; and adopts a source-sink balance model, analyze the cumulative characteristics of soil pollution. Based on geographical information system (GIS) and remote sensing technology, this paper investigates the risk assessment of vegetable waste pollution and discusses the analysis of resource potential.

Spatial Pattern and Influencing Factors of Rural Settlements in Qinba Mountains, Shaanxi Province, China

Spatial patterns and the influencing determinants of rural settlements are the most important indicators for understanding the constituent structure of rural regional systems. However, there is little knowledge addressing the characteristics from the settlement perspective by realizing the spatial reconstruction and sustainable development of rural settlements. Therefore, in this study, we analyzed the geographical, size, and morphological properties of rural settlement patterns in the Qinba Mountains in southern Shaanxi Province, China, using rural settlement and remote sensing data through spatial measurement index, gradient transects, demographic-economic index, and geodetector analysis. The results show the following: (1) Overall, rural settlements have spatial characteristics of “high-density multi-core clusters (0.8–1.6/km2) and low-density broadly scattered (<0.08/km2)”. There is a significant positive correlation between the scale of rural settlement density and the characteristics of high-value agglomeration. (2) The spatial disparities of morphological traits of settlement shapes are significant. Furthermore, 1840 NP/piece of plain basin landform types provide high-value areas for each settlement feature value, and locations with moderate slopes are best for settlement dispersal. Moreover, rivers, roads, and distance from township centers are all examples of beneficial directivity. There is consistency between the spatial differentiation of rural settlement areas per capita and the distribution of settlement scale. Conversely, the settlement density is inconsistent with the agricultural production value density’s spatial distribution features. (3) The impact of geographical factors on the diversification of settlement characteristics has significant spatial differences. Moreover, natural ecological characteristics such as elevation and landform and the distribution of cultivated land strongly influence the spatial pattern of the study region. Finally, the study findings can be beneficial for land and space planning and rural governments to develop sustainable rural settlements.

Using time series vector features for annual cultivated land mapping: A trial in northern Henan, China.

Annual monitoring of the spatial distribution of cultivated land is important for maintaining the ecological environment, achieving a status quo of land resource management, and guaranteeing agricultural production. With the gradual development of remote sensing technology, it has become a common practice to obtain cultivated land boundary information on a large scale with the help of satellite Earth observation images. Traditional land use classification methods are affected by multiple types of land cover, which leads to a decrease in the accuracy of cultivated land mapping. In contrast, although the current advanced methods (such as deep learning) can obtain more accurate cultivated land mapping results than traditional methods, such methods often require the use of a massive amount of training samples, large computing power, and highly complex model tuning processes, increasing the cost of mapping and requiring the involvement of more professionals. This has hindered the promotion of related methods in mapping institutions. This paper proposes a method based on time series vector features (MTVF), which uses vector thinking to establish the features. The advantage of this method is that the introduction of vector features enlarges the differences between the different land cover types, which overcomes the loss of mapping accuracy caused by the influences of the spectra of different ground objects and ensures the calculation efficiency. Moreover, the MTVF uses a traditional method (random forest) as the classification core, which makes the MTVF less demanding than advanced methods in terms of the number of training samples. Sentinel-2 satellite images were used to carry out cultivated land mapping for 2020 in northern Henan Province, China. The results show that the MTVF has the potential to accurately identify cultivated land. Furthermore, the overall accuracy, producer accuracy, and user accuracy of the overall study area and four sub-study areas were all greater than 90%. In addition, the cultivated land mapping accuracy of the MTVF is significantly better than that of the maximum likelihood, support vector machine, and artificial neural network methods.

What Is the Operation Logic of Cultivated Land Protection Policies in China? A Grounded Theory Analysis

Cultivated land protection policies (CLPP) are essential for maintaining social stability, guaranteeing food security, and ensuring sustainable development. However, a mismatch exists between policy performance and the objectives that influence the implementation of CLPP, and the system mechanisms of CLPP must be revealed and explored. Based on the literature review, this paper summarizes the current dilemmas of China’s cultivated land protection at the theoretical level, and preliminarily depicts the external foundation of CLPP in view of China’s topography and spatial distribution of cultivated land. This paper uses CLPP texts as research samples based on grounded theory to construct an analytical framework. The results show that the operation logic of the CLPP is founded on situation–structure–motivation–action–space–outcome. Accordingly, systematic analysis and in-depth understanding of the operation logic of CLPP will help to re-examine the profound relationship between policy text and implementation effect from such perspectives as transnational, trans-regional, and multi-scale. It also helps to reveal the hidden scientific value of spatiotemporal pattern for cultivated land protection, and serve the formulation and implementation of relevant policies in the future. Under the background of the new era of ecological civilization, it is urgent to enhance the operational effectiveness of the CLPP, identifying the focus of policy implementation, and scientifically formulating the CLPP is of great significance to its success.

Temporal and Spatial Differentiation of Cultivated Land and Its Response to Climatic Factors in Complex Geomorphic Areas—A Case Study of Sichuan Province of China

Analyzing the distribution characteristics and influencing factors of cultivated land in complex geomorphic areas is significant in evaluating the agricultural farming environment and formulating cultivated land protection measures. This study extracted cultivated land information based on multi-source remote sensing data, and analyzed the geomorphic differentiation of cultivated land distribution and climate response from 2000 to 2020 using the Gini coefficient, spatial autocorrelation analysis and geographic detector. The results show that cultivated land is mainly distributed in low-altitude hills and low-altitude small undulating mountains, and secondarily in low-altitude alluvial and proluvial plains and platforms. Moreover, from 2000 to 2020, the cultivated land in the high-altitude and high-altitude undulating mountains and medium and high-altitude undulating mountains in the Northwest Plateau of Sichuan showed an upward trend, while the cultivated land in the Sichuan Basin mainly increased from the north and south to the middle of the basin. In addition, the highest temperature has the strongest ability to explain the spatial heterogeneity of cultivated land. From the calculation results of the influence coefficient of a single climatic factor and the combined effect of multiple climatic factors, the main factors that affect the distribution of cultivated land are different in different geomorphological regions. Finally, it is proposed to formulate a long-term strategy for agricultural production to adapt to climate change in complex geomorphic areas in order to reduce the negative impact of environmental change on agricultural production.

Geological Resource Planning and Environmental Impact Assessments Based on GIS

The purpose is to study the geological resource planning and environmental impact assessments based on the geographic information system (GIS). In this study, the land resources of Yinan County in southeastern Shandong Province are taken as the research object. Based on a GIS, the current situation of land resource development is analyzed, land resource planning is carried out, and environmental impact mitigation measures are evaluated and analyzed through the environmental impact. The results obtained depict the distribution of cultivated land; the development area is 1617.31 hm2, of which 577.32 hm2 is cultivated land, 30.43 hm2 is garden land, 399.66 hm2 is forest land, 40.87 hm2 is urban and rural construction land, 10.11 hm2 is traffic water conservancy and other construction land, and 558.92 hm2 is natural reserve land. In the layout of the construction land, the development area is 841.94 hm2, of which 175.44 hm2 is cultivated land, 47.88 hm2 is garden land, 100.54 hm2 is forest land, 0.1 hm2 is other agricultural land, 90.45 hm2 is urban and rural construction land, 3.66 hm2 is traffic water conservancy and other construction land, 11.33 hm2 is water area, and 412.54 hm2 is natural reserve land. The impact of the implementation of planning on most indicators is positive and beneficial, while the impact of negative indicators is relatively small. It is revealed that the implementation of the plan has little impact on most of the ecological environment indicators. Construction and cultivated land development further improve the level of urbanization. In the process of planning implementation, corresponding measures should be taken to slow down or eliminate the negative development of the ecological environment.

Cultivated Land Fragmentation and Its Influencing Factors Detection: A Case Study in Huaihe River Basin, China.

The booming population and accelerating urbanization in the Huaihe River Basin have sped up the land use transformation and the cultivated land fragmentation (CLF), seriously impeded the advancement of agricultural modernization, and threatened regional stability and national food security as well. The analysis of CLF degree and its spatiotemporal distribution characteristics, along with the influencing factors in the Huaihe River Basin, is of great significance for promoting the intensive and efficient utilization of cultivated land resources and maintaining food security. Previous studies lack the measurement and cause analysis of CLF in Huaihe River Basin. To bridge the gap, this study introduces Fragstats4.2 and ArcGIS10.3 to analyze the spatiotemporal characteristics of CLF in county units in the Huaihe River Basin from 2000 to 2018 through the Lorentz curve, entropy method, and spatial auto-correlation method while the causes of the spatiotemporal differentiation of CLF in the basin were explored with the help of a geographic detector. The results show that the spatial distribution of cultivated land in the Huaihe River Basin is relatively balanced, and the Gini coefficients of cultivated land from 2000 to 2018 were 0.105, 0.108, and 0.113, respectively. More than 56% of the counties in the basin have a location entropy greater than 1. the percentage of landscape, area-weighted mean patch area, patch cohesion index, and aggregation index decrease year by year while the patch density and splitting index show an upward trend. The landscape pattern of cultivated land is highly complex, and the overall fragmentation degree is increasing. The county distribution pattern of the CLF degree with random and agglomeration is generally stable. The spatiotemporal differentiation of CLF in the Huaihe River Basin is affected by multiple factors, among which the influences of the normalized difference vegetation index, per capita cultivated land area, and intensity of human activity obviously stronger than other factors, and the contribution rate of the factors reached more than 0.4. The interaction effect among the factors is stronger than that of single factor, with dual-factor enhancement and nonlinear enhancement dominating. The results of this study have important implications for optimizing the agricultural structure in the Huaihe River Basin and alleviating the CLF in important grain production areas.

Characteristics and Driving Forces of Non-Grain Production of Cultivated Land from the Perspective of Food Security

A large proportion of the cultivated land in China has been used for non-grain production purposes. As food insecurity is worsening worldwide, this issue has attracted attention from the Chinese government. In order to curb this trend and to ensure food security, this paper explores the quantitative characteristics and spatial distribution of cultivated land used for non-grain purposes in Liyang City, Jiangsu Province, and discusses the clustering characteristics and mechanisms behind this based on spatial autocorrelation analysis and geographically weighted regression (GWR). The results show that most of the cultivated land in Liyang City has not been used for non-grain purposes, and the cultivated land reserve is abundant. Among all land types, irrigable land has the largest non-grain production rate of cultivated land. There is no significant spatial correlation of cultivated land for non-grain purposes in most towns in Liyang, among which Kunlun Street is in the High-High (HH) zone and Daibu Town in the Low-High (LH) zone. It is also found that the same factor has various impacts on the non-grain production of cultivated land in different towns, and the number of enterprises is the core factor that leads to the non-grain use of cultivated land in Liyang city. Low food prices lead some farmers to plant other crops with higher economic benefits, and also lead to the outflow of the rural labor force. This will not only accelerate the non-grain production of cultivated land, but also cause a large amount of cultivated land to be in a state of unmanned cultivation, further aggravating the proportion of non-grain production in cultivated land.

The effects of rural development on main sources of farm households

In line with the development of the rural villages, rural employment changes. Consequently, the job opportunities of some farmers will also change. This study aims to estimate the effect of rural development and some other factors on the primary source of household income of farmers in several agroecosystems. The data analyzed were the 2013 Agricultural Census, Village Potential and “PATANAS” data. The results showed that farmers’ opportunity of leaving agriculture as the main source of household income increased if cultivated land was smaller and the inequality of landholding in the village increased. In the set of variables that determine rural development, improvements in the dimensions of basic services and basic infrastructure of non-accessibility/transportation positively affect the opportunities of farmers’ households to make non-agricultural work as their source of income. Improvements in the accessibility/transportation dimension, on the other hand, strengthen the ability of farm households to rely on agriculture as a source of household income. Based on the research results, increasing the agricultural sector as a significant contributor to farmer household income can be achieved by increasing accessibility/transportation facilities and improving the distribution of cultivated land.

Combining MaxEnt model and landscape pattern theory for analyzing interdecadal variation of sugarcane climate suitability in Guangxi, China

Guangxi is the primary producer of sugarcane in China and provides a highly suitable habitat for sugarcane growth. However, its distribution range has changed significantly in recent years due to climate change as well as human factors. Without extensive knowledge of the changing trends in suitable sugarcane planting areas, efforts to improve its productivity in Guangxi may be insufficient. In this study, the interdecadal change in sugarcane distribution in Guangxi in response to climate change from 1960 to 2019 was estimated using the MaxEnt model and the landscape pattern of land use in the suitable sugarcane area was analyzed. In addition, we discuss the effects of global warming on sugarcane production in the sustainable development of the sugar industry in Guangxi. Our results indicate: (1) from 1960 to 2019, approximately 65% of Guangxi Province could grow sugarcane. Chongzuo City, Nanning City and Parts of Baise City, are highly suitable areas, and unsuitable areas are mainly concentrated in the north. In general, sugarcane climate suitability extended further in low-altitude areas, and then extended to high- altitude areas. However, from the 2000s to the 2010s, climate suitability showed a decreasing trend, decreasing from 16.036 × 106 ha to 15.4985 × 106 ha (2) The order of land use area in the suitable sugarcane climate range was as follows: woodland > cropland > grassland > construction land > water. With the increase in climate suitability, the distribution of cultivated land expanded. From 1980 to 2005, cropland in suitable areas showed a fragmentation trend. By 2010, the cropland patches disappeared after fragmentation. (3) Due to landscape constraints, infertile soil, and labor costs, the sugar industry faces various challenges. The evaluation of climate suitability could provide a theoretical reference for a planting layout of sugarcane, and landscape pattern analysis of suitable sugarcane climate areas is conducive to the integration of small pieces of land into large ones, making mechanization possible. Overall, strict layout and management measures are required in sugarcane planting areas.

Assessment of the feasibility of hybrid renewable power for supply pumping system for irrigation

Crop identification is vital to make an inventory of the crops grown in a given area and their cultivation period. The Remote sensing (RS) techniques can provide information on the distribution of cultivated land, crop types, and areas for the agricultural sector's effective management.
 In remote sensing, various vegetation indices (VI) can analyze and evaluate multiple phenomena and themes. The Normalized Difference Vegetation Index (NDVI) is an essential and highly significant remote measurement widely used in agriculture for phenological monitoring and crop health (Ray and Dadhwal, 2001).
 In this work, we present a methodology for the contribution of NDVI from Landsat 7 (TM) and (ETM+) images to crop mapping in the Gharb region using a classification based on the pixel approach and estimating rice crop coefficient from NDVI.
 The classification results concern six main types of crops planted in this region (beet, maize, sugar cane, market gardening, cereals, and rice). The classification map showed differences in agricultural practices adopted by farmers in crop spatial distribution. The classification results showed the ability of this methodology to discriminate between crops.
 Crop coefficients were deduced from the NDVI extracted from the images. Due to meteorological data collected from the meteorological station TCSC of SK Tlet, the estimation of the reference evapotranspiration was made and subsequently the potential evapotranspiration of each crop during the agricultural season 2019-2020.
 The highest values for ETC were obtained when the crop was in its full development when water was mainly lost through transpiration after a slight decrease in the ratio values observed during the phase of the vegetative cycle (maturity).
 The water requirements (daily, monthly and annual) for the crops were determined and their electrical energy consumption.
 Renewable energy can be an effective solution to meet the energy needs of plots , greenhouses and large farms.
 A technical-economic study of different combinations of autonomous hybrid renewable energy systems (HRES) in order to meet the power supply needs of the above mentioned crops in the Gharb region. The renewable energy sources considered are solar, wind and biomass. The results show that for an average energy requirement of 92 kWh/day and a peak load of 6.5 kW, the unit energy cost of the optimal configuration scenario A (PV-wind-biomass-battery) is 0.19 $/kWh. Therefore, the design, development and implementation of the proposed system is a promising solution for the security of energy supply. For a 100% integration of renewable energy, the HRES produces electricity according to the following distribution: 11% from wind, 41% from solar and 48% from biomass.

An extraction method of cultivated land in karst area based on Landsat time series

It is of great significance to grasp the distribution of cultivated land in karst area for protecting cultivated land and maintaining regional food security. Based on Landsat 8 OLI remote sensing images, this paper took Fuyuan County of Yunnan Province as an example, used a classification method combining multi-feature construction with random forest to extract the distribution of cultivated land in Fuyuan County in 2019. The experimental results showed that the overall accuracy was 0.93, and the Kappa coefficient was 0.90. This method could reduce the interference of mixed pixels to a certain extent and had a better classification effect. The cultivated land area in Fuyuan County was 1200.42 km2. The cultivated land was distributed in all townships of the whole county, and it was mainly concentrated in the northwest, central and part of the southern regions of Fuyuan County, such as Housuo Town, Zhong’an Town, Dahe Town, Yingshang Town, Zhuyuan Town, and Shibalianshan Town.