Impacts of Urban Expansion on the Loss and Fragmentation of Cropland in the Major Grain Production Areas of China

The continuous expansion of urban land has led to massive encroachment upon cropland. To examine the impacts of urban expansion on the loss and fragmentation of cropland in China’s nine major grain production areas (MGPAs), we used standard deviation ellipse, land use transfer matrix, land use dynamic degree, and landscape metric to explore the spatio-temporal evolutions, mutual transfer, and landscape patterns of cropland and urban land. The results show the following: (1) From 1995 to 2018, the areas of cropland in MGPAs showed a trend of “short-term increase—long-term decrease—short-term increase”, while that of urban land grew continuously; (2) Urban expansion is the main cause of cropland loss. The cropland area converted to urban land accounts for a large proportion (49.26%) of the total transfer of cropland to other land types, especially in the densely populated, rapidly urbanizing and industrializing Taihu Lake Plain, Jianghuai Region, and Pearl River Delta; (3) In most MGPAs, urban expansion has led to fragmentation of cropland, especially in the Pearl River Delta, as indicated by the significant change of patch density. However, in the Sanjiang Plain and Songnen Plain, a less pronounced or even reduced cropland fragmentation was observed due to the significant conversion of other land types to cropland under specific land policies. From these results, we suggest that the government should regulate the encroachment of urban land on cropland and the transfer of natural land to it, and encourage the rural land consolidation to increase the cropland.

Agroecological land typification

The minimum required information and the sequence of agroecological land type allocation on the land management territory of the experimental station (ES) located in the forest-steppe of the Priob'ye region of Novosibirsk is described. Two agroecological land types are distinguished: the first type (upland lands) is represented by leached chernozem in combination with common, podzolized and dark-grey forest soils; the second type (slightly erosive lands) is represented by leached chernozem in combination with dark-grey forest soils. Soil cover of ES in both types of lands is represented by leached chernozem (Lch-2-2s), the share of which for the first type is 75.26%, for the second - 76.26% of the total area of the types. The first agroecological land type is characterized by a range of heights from 134 to 165 m. The working areas are located on the slopes between 0 and 3 degrees in relation to the terrain angle. Vertical dissection of the relief averages 1.3 m, horizontal dissection by erosion forms is 0.8 km/km2. The second type of land is characterized by an elevation of 113 to 137 meters above sea level and a slope of 1 to 4 degrees. Vertical dissection of the terrain averages 1.7 m, horizontal dissection by erosion forms 0.9 km/km2. Typification was carried out with the help of a generated Digital Land Use Model (DLM) of the ES based on the analysis of geographical information, remote sensing materials (ERS) and cadastral map. The DLM consists of the following geo-information layers: topography, land cover, digital elevation model (DEM), working areas. The DEM includes information on slope steepness and exposure, vertical and horizontal dissection.

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.

Soybean in Indonesia: Current Status, Challenges and Opportunities to Achieve Self-Sufficiency

Soybean is the third important food crop in Indonesia after rice and maize, particularly as a good source of protein. The demand for soybean consumption tends to increase annually. In 2020, the figure was about 3.28 million tons, while the domestic production was 0.63 million tons, thus around 81% of the soybean needed was imported. Efforts to increase the domestic soybean production have been conducted since the last decade, which is concerned with increasing the current productivity (1.5 t/ha) through introducing the high-yielding improved varieties and extending the harvested area, particularly to outside of Java. The potential planting area is focused on the irrigated lowland after rice (optimal land) and suboptimal lands (dry, acid, tidal, and shaded lands). The series of the study showed that the yield potential of soybean grown in such lands varied from 1.8 t/ha to 3.0 t/ha. A number of soybeans improved varieties adapted to different land types or agro-ecological conditions also have been released and supported with advanced cultivation technology. The results, challenges, and opportunities to achieve soybean self-sufficiency are discussed in this paper.

Extraction of Kenyan Grassland Information Using PROBA-V Based on RFE-RF Algorithm

Africa has the largest grassland area among all grassland ecosystems in the world. As a typical agricultural and animal husbandry country in Africa, animal husbandry plays an important role in this region. The investigation of grassland resources and timely grasping the quantity and spatial distribution of grassland resources are of great significance to the stable development of local animal husbandry economy. Therefore, this paper uses Kenya as the study area to investigate the effective and fast approach for grassland mapping with 100-m resolution using the open resources in the Google Earth Engine cloud platform. The main conclusions are as follows. (1) In the feature combination optimization part of this paper, the machine learning algorithm is used to compare the scores and standard deviations of several common algorithms combined with RFE. It is concluded that the combination of RFE and random forest algorithm has the highest stability in modeling and the best feature optimization effect. (2) After feature optimization by the RFE-RF algorithm, the number of features is reduced from 12 to 8, which compressed the original feature space and reduced the redundancy of features. The optimal combination features are applied to random forest classification, and the overall accuracy and Kappa coefficient of classification are 0.87 and 0.85, respectively. The eight features are: elevation, NDVI, EVI, SWIR, RVI, BLUE, RED, and LSWI. (3) There are great differences in topographic features among the local land types in the study area, and the addition of topographic features is more conducive to the recognition and classification of various land types. There exists “salt-and-pepper phenomenon” in pixel-oriented classification. Later research focus will combine the RFE-RF algorithm and the segmentation algorithm to achieve object-oriented land cover classification.

Effects of Arctic Warming on Microbes and Methane in Different Land Types in Svalbard

Climate change is having a profound impact on Arctic microbiomes and their living environments. However, we have only incomplete knowledge about the seasonal and inter-annual variations observed among these microbes and about their methane regulation mechanisms with respect to glaciers, glacial melting, snow lakes and coastal marine water. This gap in our knowledge limits our understanding of the linkages between climate and environmental change. In the Arctic, there are large reservoirs of methane which are sensitive to temperature changes. If global warming intensifies, larger quantities of methane stored in deep soil and sediments will be released into the atmosphere, causing irreversible effects on the global ecosystem. Methane production is mainly mediated by microorganisms. Although we have some knowledge of microbial community structure, we know less about the methane-correlated microbes in different land types in the Svalbard archipelago, and we do not have a comprehensive grasp of the relationship between them. That is the main reason we have written this paper, in which current knowledge of microorganisms and methane-correlated types in High Arctic Svalbard is described. The problems that need to be addressed in the future are also identified.

Dampak Dana Alokasi Khusus Pertanian dan Irigasi Terhadap Produksi Padi Sawah dan Ketahanan Pangan Kabupaten/Kota di Provinsi Jambi

How important is the impact of special allocation funds (DAK) on agriculture and irrigation as policy input in food production and food security in the regions. To answer these problems, a study was conducted with the objectives of: 1) formulating an economic model for lowland rice commodity related to the financing of special allocation funds (DAK) for agriculture and irrigation in Jambi Province; and 2) analysis of the impact of funding for the special allocation fund (DAK) for agriculture and irrigation on the area of irrigation, rice fields and food security in districts / cities in Jambi Province. The simulation results show that an increase in the supply of financing from special allocation funds (agriculture and irrigation) can have a positive impact on increasing resources (irrigation area), food production, and regional food security. In order to be more effective in allocating funds, it is advisable to synergize with the allocation of subsidized fertilizers and seeds in each district / city in Jambi Province. Besides being aimed at maintaining and repairing irrigation networks in several districts / cities, the DAK irrigation program needs to be expanded to develop small - medium scale irrigation models for potential wetlands (rainfed, swamp, tidal) for the production of rice and other food crops. The potential available land types require a suitable location-specific technology package for rice and other food crops. Likewise, the use of cheaper alternative inputs. Reorientation of programs funded by DAK for agriculture in each district / city in Jambi province is needed to achieve effectiveness and impact on increasing lowland rice production and food security in the regions.Keywords: Allocation Funds, Food Security, Irrigation, Paddy, Simultaneity Model

Analysis on the Travel Characteristics of Sharing Bikes Connected with Different Types of Public Transportation Stations

In order to better solve the problem of unbalanced supply and demand of connected shared bikes, this paper takes shared bikes as the research object, analyzes the usage characteristics of connected bikes in different types of public transport stations, and puts forward a data-based feature extraction method of shared bikes. Firstly, the usage data of shared bikes were collected, and the starting and finishing points were decoded. The public transport stations were divided into five typical types according to the decoded longitude, latitude and surrounding land types. Secondly, the connectivity activity, connectivity distance and user loyalty are put forward as the characteristic indicators of bike-sharing travel. Finally, taking the bicycle data of Chaoyang District of Beijing as an example, the travel characteristic indexes of shared bikes are analyzed. The results show that, as the “last kilometer” travel connecting tool of public transport, the peak of the use of shared bikes connecting residential stations is 6:30 to 9:30, and that of other stations is 7:30 to 9:30. The connecting distance of shared bikes is generally less than 2km, but the connecting distance of office sites can reach 3km, and this site has the highest user loyalty.