An agent-based model of agricultural land expansion in the mountain forest of Timor Island,Indonesia

The Mutis-Timau Forest Complex,located on Timor Island,Indonesia,is a mountainous tropical forest area that gradually decreases due to deforestation and forest degradation.Previous modelling studies based on patterns indicate that deforestation primarily occurs at lower elevations and near the boundaries of forests and settlements,often associated with shifting cultivation by local farmers.This study adopts a process-based modelling approach,specifically the agent-based model,to simulate land changes,particularly farmers'expansion of agricultural land around the Mutis mountain forest.The underlying concept of this agent-based approach is the interaction between the human and environmental systems.Farmers,representing the human system,interact with the land,which represents the environmental system,through land use decision-making mechanisms.The research was conducted in the Community Forest of the Timor Tengah Utara District,one of the sites within the Mutis-Timau Forest Complex with the highest deforestation rate.Land use change simulations were performed using agent-based modelling from 1999 to 2030,considering the socio-economic conditions of farmers,spatial preferences,land use decisions,and natural transitions.The results revealed that the agricultural area increased by 14%under the Business as Usual scenario and 5%under the Reducing Emission from Deforestation and Forest Degradation scenario,compared to the initial agricultural area of 245 hectares.The probability of farmers deciding to extend agricultural activities was positively associated with the number of livestock maintained by farmers and the size of the village area.Conversely,the likelihood of farmers opting for agricultural extensification decreased with an increase in the area of private land and the farmer's age.These findings are crucial for the managers of the Mutis-Timau Forest Complex and other relevant stakeholders,as they aid in arranging actions to combat deforestation,designing proper forest-related policies,and providing support for initiatives such as reducing emissions from deforestation and forest degradation programs or further incentive schemes.

Extensive identification of landslide boundaries using remote sensing images and deep learning method

The frequent occurrence of extreme weather events has rendered numerous landslides to a global natural disaster issue.It is crucial to rapidly and accurately determine the boundaries of landslides for geohazards evaluation and emergency response.Therefore,the Skip Connection DeepLab neural network(SCDnn),a deep learning model based on 770 optical remote sensing images of landslide,is proposed to improve the accuracy of landslide boundary detection.The SCDnn model is optimized for the over-segmentation issue which occurs in conventional deep learning models when there is a significant degree of similarity between topographical geomorphic features.SCDnn exhibits notable improvements in landslide feature extraction and semantic segmentation by combining an enhanced Atrous Spatial Pyramid Convolutional Block(ASPC)with a coding structure that reduces model complexity.The experimental results demonstrate that SCDnn can identify landslide boundaries in 119 images with MIoU values between 0.8and 0.9;while 52 images with MIoU values exceeding 0.9,which exceeds the identification accuracy of existing techniques.This work can offer a novel technique for the automatic extensive identification of landslide boundaries in remote sensing images in addition to establishing the groundwork for future inve stigations and applications in related domains.

Salinity status of the 2011 Tohoku-oki tsunami affected agricultural lands in northeast Japan

As Japan has abundant annual rainfall(1,000 to 2,500 mm),soil salinity of agricultural lands has rarely been a major problem.Following the 2011 earthquake in the Pacific,large stretches of land along the coast in northeast Japan were devastated by a powerful tsunami.Saltwater damage of agricultural lands was so severe that agricultural crops could not be grown on large parts of the tsunami-inundated farmlands even two years after the disaster.This paper summarizes the status of agricultural lands in northeast Japan’s Tohoku region that were affected by the tsunami.The paper presents the results of a field study of agricultural lands in Miyagi Prefecture,where the extent of the seawater damage was the most severe,representing 67%of the total tsunami-affected agricultural lands.Forty samples from surface and underlying(undisturbed)soil were collected from 30 different locations in coastal and tsunami-inundated farmlands and from inland sites located beyond the limit of the tsunami inundation.The analyses and measurements showed that the extent of soil salinity varied greatly across these sites,with the highest electrical conductivity(EC)value of 3.72 dS m^(-1) found in the surface soil of Minamisanriku cho.In addition,two study sites adjacent to each other,Watari cho and Yamamoto cho,had maximum and minimum EC values of 2.0 dS m^(-1) and 0.21 dS m^(-1),respectively,in their underlying soils.A comparison of the major soil properties revealed that the salinity status of the tsunami-inundated farmlands was dependent on particle size distribution and therefore on the infiltration rate of the soil,as well as the relative physical position(elevation)of the farmland.This study led us to carry out further investigations and experiments(still on-going)related to restoration and mitigation work in the tsunami-inundated agricultural lands,giving the highest priority to the major soil properties of different field sites in Miyagi Prefecture.

Soil Organic Carbon Stock Variation under Different Soil Types and Land Uses in the Sub-Humid Noun Plain, Western Cameroon

This study was conducted to assess the current stock of soil organic carbon under different agricultural land uses, soil types and soil depths in the Noun plain in western Cameroon. Three sites were selected for the study, namely Mangoum, Makeka and Fossang, representative of the three dominant soil types of the noun plain (Andosols, Acrisols and Ferralsols). Three land uses were selected per site including natural vegetation, agroforest and crop field. Soil was sampled at three depths;0 - 20 cm, 20 - 40 cm, and 40 - 60 cm. Analysis of variance showed that soil type did not significantly influence carbon storage, but rather land uses and soil depth. SOCS decreased significantly with depth in all the sites, with an average stock of 66.3 ± 15.8 tC/ha at 0 - 20 cm, compared to an average stock of 33.3 ± 7.4 tC/ha at 40 - 60 cm. SOCS was significantly highest in the natural formation with 57.2 ± 19.7 tC/ha, and lowest in cultivated fields, at 37.7 ± 10.6 tC/ha. Andosols, with their high content of coarse fragments, stored less organic carbon than Ferralsols and Acrisols.

Variations in Soil Organic Matter Content in Cultivated and Uncultivated Calcareous Soils from the Mediterranean Island of Malta after 15 Years of Cultivation

The soils of Malta are calcareous and generally undeveloped. Organic matter (OM) in these soils is low and farmers are constantly urged to increase it. The objective of this study was to evaluate any temporal variation in soil OM after 15 years of cultivation, and determine whether soil series, soil depth, and cultivation influence variation. OM was determined in the topsoil and subsoil of 7 agricultural and 4 non-agricultural sites. The sites represented 7 different soil series that are present on the island. In sampling periods 1 (t = 0 years) and 2 (t =15 years), the OM content in the collective (all soil series) bulk (topsoil and subsoil) uncultivated soil was 3.9 % and 3.8 % respectively. This was significantly greater than that of the collective bulk cultivated soil (2.4% and 2.3%). The OM in the collective uncultivated topsoil was 5.4% and 5.2% in periods 1 and 2 and was significantly higher than that of the cultivated topsoil (2.5% in both periods). The OM content in the collective uncultivated subsoil was 2.3% and 2.5% in periods 1 and 2 respectively but only that measured in period 2 was significantly higher than that of the cultivated subsoil (2.2% in both periods). On an individual soil series basis, the OM in the uncultivated topsoils was significantly higher than that of their cultivated counterparts. The differences in the subsoils were not significant. Across the uncultivated soil series, OM was significantly higher in the topsoil than in the subsoil but in the cultivated soil series the differences between topsoil and subsoil were not significant. There was no significant difference in OM between the uncultivated soils of different series, but in the cultivated the OM content was higher in soils that were more mature. After 15 years, no significant change in OM occurred in both the collective cultivated and uncultivated bulk soils, the collective topsoil and subsoil, and in most of the individual series. The OM content of each soil series was also similar to what was reported 60 and 50 years earlier by other researchers.

Studies of Nitrous Oxide Emission from Farmlands in North China

Measurements of nitrous oxide emission from agricultural lands were conducted. The results show that nitrous oxide fluxes on several soils are at the range of 2-60 μg . N / m2 h. Factors influencing the production rates of nitrous oxide from the soils, such as soil temperature, soil moisture and fertilization, are discussed. The calculated amount of nitrous oxide emission from China farmlands is 9.8 × 107 Kg . N per year, which accounts for about 10% of the total source strength in China areas.

How Could Agricultural Land Systems Contribute to Raise Food Production Under Global Change?

To feed the increasing world population, more food needs to be produced from agricultural land systems. Solutions to produce more food with fewer resources while minimizing adverse environmental and ecological consequences require sustainable agricultural land use practices as supplementary to advanced biotechnology and agronomy. This review paper, from a land system perspective, systematically proposed and analyzed three interactive strategies that could possibly raise future food production under global change. By reviewing the current literatures, we suggest that cropland expansion is less possible amid iferce land competition, and it is likely to do less in increasing food production. Moreover, properly allocating crops in space and time is a practical way to ensure food production. Climate change, dietary shifts, and other socio-economic drivers, which would shape the demand and supply side of food systems, should be taken into consideration during the decision-making on rational land management in respect of sustainable crop choice and allocation. And ifnally, crop-speciifc agricultural intensiifcation would play a bigger role in raising future food production either by increasing the yield per unit area of individual crops or by increasing the number of crops sown on a particular area of land. Yet, only when it is done sustainably is this a much more effective strategy to maximize food production by closing yield and harvest gaps.

Regional disparity in the changes of agricultural land use intensity in China during 1980-2002

Based on the cost-benefit data （1980-2002） of farm products and China Agriculture Yearbooks, this paper studies the regional disparity in the changes of the agricultural land use in China during the period 1980-2002 from three aspects such as the degree of intensity, the sown area and the abandoned farmland. The results show that： （1） The degree of intensity of land use in the westena region during 1980-2000 has a strong uptrend, but in the eastern and central regions the degree of intensity descends obviously and has shown a continuous downtrend since 1997. （2） The total sown area shrinks notably in the eastern region, while it enlarges constantly in the western region. （3） The sown area in the eastern, central and western regions has gone through a similar cyclic process： down （1980-1985）-up （1985-1991）-down （1991-1994）-up （1994-1999）-down （1999-2002）. However, there are obvious differences in amplitude variation and tendency among them. The sown area has shrunk in the eastern region and expanded in the central and western regions especially before 1999. （4） The most cases of abandoned farmland are reported in the central region, the second in the eastern region and the least in the western region. The abandonment phenomena chiefly occurred during 1992-1995 in the eastern region, and during 1998-2002 in the central region.

Effectiveness of sloping agricultural land technology on soil fertility status of mid-hills in Nepal

Hedgerows with intercropping systems were established at the ICIMOD test and demonstration site at Godawari to assess the effective- ness of Sloping Agricultural Land Technology （SALT） in reducing run- off water volume, controlling soil loss, increasing crop production, and improving soil fertility in the mid-hills of Nepal. Runoff water volume （1996-2002）, soil loss （1996-2002） and maize yield （1995-2001）, and soil fertility-related parameters were assessed on SALT models with three factors： the type of nitrogen-fixing plant, the farmers＇ practice, and fertilizer use. Results showed a significant effect of Alnus nepalensis and/or Indigofera dosua on runoff water volume, soil loss, crop produc- tion, soil water retention, and soil nutrients （NPK）. Farmers＇ practice and fertilization did not play a significant role in reducing runoff water and soil loss. However, farmers＇ practice significantly increased crop produc- tion. Therefore, integrating soil conservation approaches on SALT sys- tems enhances stable economic output to hills and mountain farmers.

Function of Agricultural Land Use and Its Evolvement in Peri-urban Area: A Case Study of Beijing

Rapid urbanization in Beijing stimulates the urban land expansion and diminishes available agricultural land. Monofunctional agricultural land use can not meet the demand of the devel- opment of the multifunctional agriculture and urbanization any more, so multifunctional agricultural land use is going to be promoted in the city. This article proposes the evolvement of the land use change from 1992 to 2004 and discusses some evolvement views.

Sustainable Utilization of Agricultural Land in Chengdu Metropolitan Area Based on Emergy Analysis

[Objectives]This study aimed to analyze the sustainable use of agricultural land in the Chengdu metropolitan area from 2006 to 2016.[Methods]Using Odum's emergy theory,an index system was constructed to evaluate the sustainable use of agricultural land,including total emergy input-output ratio,industrial emergy input-output ratio,environmental load index and sustainable use index of agricultural land based on emergy,to reflect the sustainable use of agricultural land in the Chengdu metropolitan area.The data base was a unified standard that was converted from various types of energy stored and flowing in the agricultural land system of the Chengdu metropolitan area,that is,emergy.[Results]From 2006 to 2016,the total emergy input-output ratio of agricultural land in the metropolitan area fluctuated and decreased,lower than the national average.The industrial emergy input-output ratio was generally in a fluctuating downward trend.The environmental load index of agricultural land in the metropolitan area was lower than the national average.However,it has been on the rise since 2012.During the corresponding period,the sustainable use index of the region also showed a downward trend.[Conclusions]The utilization rate of emergy in this area was low.The dependence of industrial emergy input-output ratio on industrial subsidiary energy and the degree of agricultural mechanization are constantly improving.The environmental resources in this area still have room for accommodation and have not been fully utilized.The sustainable use of agricultural land has been declining.

Assessment of China's economic loss resulting from the degradation of agricultural land in the end of 20th century

Land degradation is a consequence stemming from both natural processes and social economic activities. On the bases of analyzing general situation of agricultural land degradation in China, the monetary estimating methods such as market value method and shadow engineering method were used to quantitatively assess the economic loss resulting from land deterioration. Results showed that the economic loss in 1999 was 326 81 billion RMB Yuan, which accounted for 4 1% of GDP in the same year of China. If taking five items namely farmland conversion, soil erosion, salinization, decline in reservoir functions, and siltation in waterways and, comparing with that in 1992, the percentage of economic loss to GDP has increased by 1 5 in the only 7 years.

Evaluation on the Influencing Factors of Agricultural Land Productivity in Huang-Huai Plain,China

Taking Huang-Huai Plain as an example,evaluation index system is established from four aspects,including the resources condition,the social and economic condition,the agricultural science and technology condition,and the disaster resistant and sustainable production condition.Correlation coefficient method and expert consultation method are used to determine the weight of evaluation index.After the standardization of extreme value,weighted sum method and multiple regression method are adopted to evaluate the influencing factors of agricultural land productivity in Huang-Huai Plain,China.Evaluation result shows that agricultural science and technology condition has a lower contribution rate to the productivity of Huang-Huai Plain than that to Henan Province.Resources condition has a higher contribution rate to the productivity of Huang-Huai Plain than that to Henan Province.Both the social and economic condition and the disaster control and sustainable production condition show relatively small contribution rate to the productivity of Huang-Huai Plain.It can be concluded that the main factors affecting the productivity of Huang-Huai Plain are the backward agricultural science and technology level,the poor farmland quality and the farmland infrastructure.Based on this,relevant suggestions are put forward to improve the farmland productivity of Huang-Huai Plain.

Spatio-Temporal Patterns of Nitrogen and Phosphorus Stoichiometry in Cascade Ponds in an Agricultural Small Watershed and Their Influencing Factors

Ecological stoichiometry of nitrogen and phosphorus is an important indicator to characterize the nitrogen and phosphorus trophic status in aquatic ecosystems. The study of the spatio-temporal patterns of nitrogen and phosphorus stoichiometry is beneficial to the nitrogen and phosphorus pollution management in pond ecosystems. In this study, 18 groups (36 in total) of typical cascade ponds were selected as long-term observations to investigate the spatial distribution patterns of nitrogen and phosphorus component ratios (ratio of total nitrogen to phosphorus: TN:TP, ratio of dissolved nitrogen to phosphorus: TDN:TDP, ratio of particulate nitrogen to phosphorus: PN:PP) in water bodies in the tropical agricultural watershed of Jinjing. The results showed that the average values of TN:TP and TDN:TDP in the upstream ponds were 26.4 and 53.4, respectively, and were more than those in the downstream (22.95 and 48.1, respectively). In contrast, the PN:PP (13.78) in the upstream was significantly lower than that of the downstream (30.39). Furthermore, the factors of rainfall, agricultural land use and fish farming influenced the spatio-temporal variability of the N:P ratios. The ratios of TN:TP and TDN:TDP were higher in the wet season and lower in the dry season. Agricultural land use and fish farming reduced the ratios of the above three nitrogen and phosphorus components in cascade ponds in the study area. Our results show that strengthening agricultural land pollution control and aquaculture management could help to improve water quality of pond ecosystems in the study area.

Analysis of the Price of Development Right of Agricultural Land in China

According to the viewpoints of predecessors, we define the signification of development right of agricultural land and connotation of the price of development right of agricultural land as follows: the development right of agricultural land is to change the former use nature of agricultural land, so as to become the right of construction use land; the price of development right of agricultural land refers to the price that is difference between the price of construction use land, and summation of the price of former agricultural land, the expense of developing agricultural land, the expense of management, and profit, after the agricultural land is transformed into non-agricultural construction use land. By using the principle of economics of land, this paper expounds the generation mechanism of the price of development right of agricultural land, namely the diversity of agricultural land use and the change of demand and supply of development right of agricultural land. The influencing factors of the development right of agricultural land are analyzed, and there are mainly the price of agricultural land, the price of construction use land, the contradiction of demand and supply of urban land, land use, and agricultural land.

Ecological Risks of Agricultural Land Capitalization and Their Prevention

The capitalization of agricultural land as an institutional innovation in land use is of great significance to revitalize China's land resources, change land use and improve land use efficiency. With the gradual implementation of the capitalization of agricultural land, however, environmental problems brought by capitalization have restricted the sustainable and efficient utilization of agricultural land. This study, from the perspective of ecology, discusses ecological risks of agricultural land capitalization, analyzes the ecological risks of agricultural land capitalization in terms of the amount of land and land quality as well as the formation mechanism of the ecological risks of agricultural land capitalization. It is found that the logic of the capital itself, the profitability of the subject and the fragility of the ecological environment are the internal and external factors of the ecological risks of agricultural land. Thereupon authors put forward policy suggestions to prevent the ecological risks of agricultural land capitalization in terms of large-scale agricultural operations in diverse forms, the development of green agriculture, the protection of agricultural land quality and green finance, with a view to resolving the ecological risks of agricultural land capitalization and realizing the benign operation of agricultural land capitalization.

A Study on Agricultural Land Consolidation Potential in Changfeng County

In this paper,we study the agricultural land consolidation quantity potential( including theoretical quantity potential and actual quantity potential) and quality potential in Changfeng County,use the new arable land area to denote the quantity potential,and use the food production improved after agricultural land consolidation to represent quality potential. On this basis,we measure and evaluate the agricultural land consolidation potential in Changfeng County.

Analysis on the Influencing Factors and Control Measures of "Non-Grain Conversion" of Cultivated Land in Agricultural Land Transfer

Through the method of literature analysis,this paper analyzes the present situation of the"non-grain conversion"of cultivated land in the transfer of agricultural land in China,summarizes the influencing factors and consequences of the phenomenon of"non-grain conversion"of cultivated land in the transfer of agricultural land,and finally puts forward some measures.The study found that costs and benefits are the fundamental factors affecting the"non-grain conversion"of cultivated land in agricultural land transfer,and other main factors include government and policy guidance,industrial and commercial capital to the countryside,labor transfer and so on.The"non-grain conversion"of cultivated land in the transfer of agricultural land is a serious threat to China s food security,leading to the decline of the quality of agricultural land and the destruction of the ecological environment,as well as the risk of breach of contract in"industrial and commercial capital to the countryside".Based on the understanding of the influencing factors of non-grain conversion,this paper puts forward the following measures:strengthening the control of the use of cultivated land in agricultural land transfer;implementing accurate subsidies for grain cultivation and ensuring the benefit of grain growers;adopting grain planting incentive mechanism to increase grain enthusiasm;strengthening media publicity and education to enhance food security awareness.The improvement of the current situation of the"non-grain conversion"of cultivated land in the transfer of agricultural land will be of great significance to the protection of agricultural land and food security in China.

Theoretical Study on the Regional Comprehensive Price of Expropriated Agricultural Land Based on the Benchmark Land Price

So far,the work of calculating the regional comprehensive price of expropriated agricultural land has been carried out for more than ten years,but in the specific calculation process,the concept and calculation method of the regional comprehensive price of expropriated land are still lack of unified standards.In this paper,from the point of view of the benchmark land price,the regional comprehensive price of expropriated agricultural land is calculated by using the relatively mature benchmark land price.

Importance and Countermeasures of Curbing the Conversion of Agricultural Land to Non-agricultural Land under the Background of the Rural Revitalization Strategy

Farmland is the most basic element for farmers’survival and development,and has a social security function.The conversion of agricultural land to non-agricultural land has gradually become the primary factor in the reduction of agricultural land in various regions of China,seriously endangering China’s food security.Under the background of the rural revitalization strategy,the emergence of the conversion of agricultural land to non-agricultural land and the inevitability of its development were analyzed from both the acceleration of urbanization and the increase in land demand by using the literature research method.The importance of curbing the conversion of agricultural land to non-agricultural land to achieve the grand goal of strong agriculture,beautiful rural areas,and rich farmers was clarified,and then countermeasures and suggestions to curb the conversion of agricultural land to non-agricultural land were put forward,which is of great significance to promoting the effective implementation of China’s rural revitalization strategy.