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Yan, Huimin, Wenpeng Du, Ying Zhou, Liang Luo, and Zhong’en Niu. "Satellite-Based Evidences to Improve Cropland Productivity on the High-Standard Farmland Project Regions in Henan Province, China." Remote Sensing 14, no. 7 (April 2, 2022): 1724. http://dx.doi.org/10.3390/rs14071724.
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Under the pressure of limited arable land and increasing demand for food, improving the quality of existing arable land has become a priority to ensure food security. The Chinese government gives great importance to improving cropland productivity by focusing on the construction of high-standard farmland (HSF). The government puts forward the goal of constructing 1.2 billion mu (100 mu ≈ 6.67 hectares) of HSF by 2030. Therefore, how to apply remote sensing to monitor the ability to increase and stabilize yields in HSF project regions has become an essential task for proving the efficiency of HSF construction. Based on HSF project distribution data, Moderate Resolution Imaging Spectroradiometer (MODIS) data and Landsat-8 Operational Land Imager (Landsat8-OLI) data, this study develops a method to monitor cropland productivity improvement by measuring cropland productivity level (CPL), disaster resistance ability (DRA) and homogeneous yield degree (HYD) in the HSF project region. Taking China’s largest grain production province (Henan Province) as a case study area, research shows that a light use efficiency model that includes multiple cropping data can effectively detect changes in cropland productivity before and after HSF construction. Furthermore, integrated Landsat8-OLI and MODIS data can detect changes in DRA and HYD before and after HSF construction with higher temporal and spatial resolution. In 109 HSF project regions concentrated and distributed in contiguous regions in Henan Province, the average cropland productivity increased by 145 kg/mu; among the eight sample project regions, DRA was improved in seven sample project regions; and the HYD in all eight sample project regions was greatly improved (the degree of increase is more than 75%). This evidence from satellites proves that the Chinese HSF project has significantly improved the CPL, DRA and HYD of cropland, while this study also verifies the practicability of the three indices to monitor the efficiency of HSF construction.
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Yang, Guang Hua, Yao Qi Yang, Yang Gao, Yang Yu, Shan Lin, and Yao Li. "Farmland Damage and Treatment Status in Coal Mining Subsidence Area with High Phreatic Water Level." Advanced Materials Research 838-841 (November 2013): 2190–94. http://dx.doi.org/10.4028/www.scientific.net/amr.838-841.2190.
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It is a typical and representative problem which coal mining has been causing serious damage in the Eastern Plains of China with high phreatic water level. Based on GIS technology, we analyzed the characters of cropland and coal resources, the results showed that the area of the overlapped areas of cropland and coal resources was 1.28 × 105km2, which accounted for 38.22% of the total arable land of the study area. Based on investigation and statistics, we investigated and forecast the farmland damage and analyzed the comprehensive treatment status in the typical region, the results showed that coal mining led to farmland subsided depth and perennial water, the recovery rate of cultivated land was between 50% and 70% in the treated area and more lower in the untreated area, the trend of arable land area continued to reduce would be hard to contain, the local governments faced unprecedented pressure on cultivated land protection.
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Beule, Lukas, and Petr Karlovsky. "Tree rows in temperate agroforestry croplands alter the composition of soil bacterial communities." PLOS ONE 16, no. 2 (February 10, 2021): e0246919. http://dx.doi.org/10.1371/journal.pone.0246919.
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Background Tree-based intercropping (agroforestry) has been advocated to reduce adverse environmental impacts of conventional arable cropping. Modern agroforestry systems in the temperate zone are alley-cropping systems that combine rows of fast-growing trees with rows of arable crops. Soil microbial communities in these systems have been investigated intensively; however, molecular studies with high taxonomical resolution are scarce. Methods Here, we assessed the effect of temperate agroforestry on the abundance, diversity and composition of soil bacterial communities at three paired poplar-based alley cropping and conventional monoculture cropland systems using real-time PCR and Illumina sequencing of bacterial 16S rRNA genes. Two of the three systems grew summer barley (Hordeum vulgare); one system grew maize (Zea mays) in the sampling year. To capture the spatial heterogeneity induced by the tree rows, soil samples in the agroforestry systems were collected along transects spanning from the centre of the tree rows to the centre of the agroforestry crop rows. Results Tree rows of temperate agroforestry systems increased the abundance of soil bacteria while their alpha diversity remained largely unaffected. The composition of the bacterial communities in tree rows differed from those in arable land (crop rows of the agroforestry systems and conventional monoculture croplands). Several bacterial groups in soil showed strong association with either tree rows or arable land, revealing that the introduction of trees into arable land through agroforestry is accompanied by the introduction of a tree row-associated microbiome. Conclusion The presence of tree row-associated bacteria in agroforestry increases the overall microbial diversity of the system. We speculate that the increase in biodiversity is accompanied by functional diversification. Differences in plant-derived nutrients (root exudates and tree litter) and management practices (fertilization and tillage) likely account for the differences between bacterial communities of tree rows and arable land in agroforestry systems.
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Nguyen, Lan, Deepak Joshi, and Geoffrey Henebry. "Improved Change Detection with Trajectory-Based Approach: Application to Quantify Cropland Expansion in South Dakota." Land 8, no. 4 (April 3, 2019): 57. http://dx.doi.org/10.3390/land8040057.
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The growing demand for biofuel production increased agricultural activities in South Dakota, leading to the conversion of grassland to cropland. Although a few land change studies have been conducted in this area, they lacked spatial details and were based on the traditional bi-temporal change detection that may return incorrect rates of conversion. This study aimed to provide a more complete view of land conversion in South Dakota using a trajectory-based analysis that considers the entire satellite-based land cover/land use time series to improve change detection. We estimated cropland expansion of 5447 km2 (equivalent to 14% of the existing cropland area) between 2007 and 2015, which matches much more closely the reports from the National Agriculture Statistics Service—NASS (5921 km2)—and the National Resources Inventory—NRI (5034 km2)—than an estimation from the bi-temporal approach (8018 km2). Cropland gains were mostly concentrated in 10 counties in northern and central South Dakota. Urbanizing Lincoln County, part of the Sioux Falls metropolitan area, is the only county with a net loss in cropland area over the study period. An evaluation of land suitability for crops using the Soil Survey Geographic Database (SSURGO) indicated a scarcity in high-quality arable land available for cropland expansion.
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Feng, Haiying, and Victor Squires. "The temporal and spatial scales of arable land loss and its impact in Guangxi, China: A Commentary." Advances in Social Sciences Research Journal 9, no. 1 (January 13, 2022): 76–84. http://dx.doi.org/10.14738/assrj.91.11512.
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Cropland abandonment because of rural depopulation or policy interventions has become a key issue in Chinese mountainous areas. One such region is the Guangxi Karst Mountainous Area (GKMA), a zone where more than 59% of total land area is hilly and arable land of a commercially viable size is almost non-existent. The rugged terrain and land fragmentation in upland karst areas result in the scarcity of land suitable for cultivation. Although depopulation and declining agriculture since 2000 within the GKMA have led to vast areas of abandoned cropland, the spatiotemporal distribution that underlies this pattern as well as its causes remain little understood.
Geomorphic features also bring about differences in the distribution of settlements. Settlements with different degrees of distribution are accompanied by spatial differences in cultivated land resources, which lead to differences in the sufficiency of cultivated land resources. In this paper we provide an overview of the magnitude of the problem of arable land loss.
settlements and analyze the spatial distribution and the spatial agglomeration of the cultivated land.
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Squire, Geoffrey R., Mark Young, Linda Ford, Gillian Banks, and Cathy Hawes. "Defining Targets for Reversing Declines of Soil Carbon in High-Intensity Arable Cropping." Agronomy 10, no. 7 (July 6, 2020): 973. http://dx.doi.org/10.3390/agronomy10070973.
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Soil organic carbon (SOC) is declining globally due to intensification of agriculture. Reversing declines should reduce soil erosion, maintain yields, raise the soil’s atmospheric carbon sink, and improve habitat for biodiversity. Commercial fields were sampled in a diverse European Atlantic zone cropland to relate SOC status to cropping intensity and to define a realistic target for restoration. SOC (%C by mass) decreased from 4% to 2% as the proportion of high-intensity crops increased from zero to 55% (linear regression, F pr. < 0.001). In further sampling in and around high-intensity fields, mean SOC increased from 2.4% in cultivated soil to 3.3% in field margins and 4.8% in nearby uncultivated land (F pr. < 0.001). Three broad zones of SOC in close spatial proximity were then defined: 1) high-intensity arable from 1% to 3%, 2) mid-intensity arable and arable-grass from 3% to 5% and 3) uncultivated and semi-natural land from 5% upwards. C:N ratio was constrained around 12, unaffected by cropping intensity, but slightly lower in fields than in margins and uncultivated land (F pr. < 0.001). A feasible target SOC of just above 3% was defined for high-intensity sites. There should be no biophysical obstacle to raising SOC above 3% in the high-input sector. Results argue against treating cropland of this type as uniform: assessment and restoration should be implemented field by field.
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Wu, Zhongrong, Xiulin Ye, Zhongfan Kuang, Hui Ye, and Xumao Zhao. "Positive Effects of Land Use Change on Wintering Bar-Headed Geese between 2010 and 2021." Animals 12, no. 22 (November 14, 2022): 3142. http://dx.doi.org/10.3390/ani12223142.
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Human-induced land use change often drives species losses, yet some species can derive benefits from particular land use changes. Thus, case studies of how specific land use changes affect population size for species of interest are essential to their conservation. In this study, wintering bar-headed geese in Caohai, in Guizhou Province in China, were fitted with satellite trackers to assess their use of different land types and the impact of land use changes occurring between 2010 and 2021. We found that bar-headed geese preferentially spent time in arable lands, grasslands, and open water; most foraging occurred in cropland (59.5%) and grasslands (26.4%), while resting occurred in open water (68.3%) and in grasslands (43.5%). The population of wintering bar-headed geese in Caohai increased in size from 1366 to 2803 between 2010 and 2021. A concomitant decrease in cropland area (10.7%) and increase in open water (5.52%) and grasslands (48.45%) positively affected population growth. The use of abandoned croplands reduced human disturbance of goose foraging, while larger water and grassland areas provided more foraging and resting opportunities for bar-headed geese. Our study reveals a positive impact of recent land use changes on waterbird populations and provides a case study for managing human–wildlife relationships and protecting waterbirds and other wildlife.
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Orłowski, Grzegorz. "Cropland use by birds wintering in arable landscape in south-western Poland." Agriculture, Ecosystems & Environment 116, no. 3-4 (September 2006): 273–79. http://dx.doi.org/10.1016/j.agee.2006.03.005.
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Li, Chaofan, Qifei Han, Geping Luo, Chengyi Zhao, Shoubo Li, Yuangang Wang, and Dongsheng Yu. "Effects of Cropland Conversion and Climate Change on Agrosystem Carbon Balance of China’s Dryland: A Typical Watershed Study." Sustainability 10, no. 12 (November 29, 2018): 4508. http://dx.doi.org/10.3390/su10124508.
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Remarkable warm‒wet climate shifts and intensive cropland expansion strongly affected carbon (C) cycle and threaten agricultural sustainability in northwest China. In this study, we integrated a process-based ecosystem model and an empirical C bookkeeping model to investigate the coupled and isolated effects of arable land conversions and climate change (CLM) on regional C balance in a typical watershed of northwest China. Results revealed that the farmland area increased by 3367.31 km2 during 1979–2014. The combined effects of CLM with net cropland expansion enlarged the vegetation C (VEGC) and the soil organic C (SOC) stock by 2.83 and 11.83 Tg, respectively, and were strongest in 2008–2014. The conversions between desert grassland and cropland were the major driving forces for regional C balance. Cropland expansion shared equal effects on VEGC increase with CLM, but its effect on SOC increment was 53 times larger than CLM’s. VEGC was more responsive to CLM, whereas SOC gained more benefits from land management. The C sink from reclamation suffered from high water consumption and is facing great threats due to glaciers and mountain lake shrinking and groundwater overpumping. Water-saving irrigation techniques and environmentally friendly water use strategies are essential for local agricultural sustainability.
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Barrow, C. J. "The Present Position and Future Development of Rain-Fed Agriculture in the Tropics." Outlook on Agriculture 17, no. 3 (September 1988): 112–19. http://dx.doi.org/10.1177/003072708801700304.
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By 2000 AD approximately 84 per cent of the world's arable cropland will rely on rainfall. Throughout developing countries the yields of many rain-fed farmers are falling and their ability to sustain production seems uncertain. Land degradation must be halted, security of harvests improved, and wherever necessary yields increased, crops diversified, and the area cultivated extended. For the most cultivators some form of improved rain-fed agriculture is likely to be the only practical route to such goals.
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Beule, Lukas, and Petr Karlovsky. "Early response of soil fungal communities to the conversion of monoculture cropland to a temperate agroforestry system." PeerJ 9 (October 5, 2021): e12236. http://dx.doi.org/10.7717/peerj.12236.
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Background Alley-cropping systems in the temperate zone are a type of agroforestry in which rows of fast-growing trees are alternated with rows of annual crops. With numerous environmental benefits, temperate agroforestry is considered a promising alternative to conventional agriculture and soil fungi may play a key in maintaining productivity of these systems. Agroforestry systems that are established for more than 10 years have shown to increase the fungal biomass and impact the composition of soil fungal communities. Investigations of soil fungi in younger temperate agroforestry systems are scarce and the temporal dynamic of these changes is not understood. Methods Our study was conducted in a young poplar-based alley cropping and adjacent monoculture cropland system in an Arenosol soil in north-west Germany. We investigated the temporal dynamics of fungal populations after the establishment of agroforestry by collecting soil samples half, one, and one and a half years after conversion of cropland to agroforestry. Samples were collected within the agroforestry tree row, at 1, 7, and 24 m distance from the tree row within the crop row, and in an adjacent conventional monoculture cropland. The biomass of soil fungi, Asco-, and Basidiomycota was determined by real-time PCR. Soil fungal community composition and diversity were obtained from amplicon sequencing. Results Differences in the community composition of soil fungi in the tree row and arable land were detected as early as half a year following the conversion of monoculture cropland to agroforestry. In the tree row, soil fungal communities in the plots strongly diverged with the age of the system. The presence of young trees did not affect the biomass of soil fungi. Conclusions The composition of soil fungal communities responded rapidly to the integration of trees into arable land through agroforestry, whereas the fungal biomass was not affected during the first one and a half years after planting the trees. Fungal communities under the trees gradually diversified. Adaptation to spatially heterogeneous belowground biomass of the trees and understory vegetation or stochastic phenomena due to limited exchange among fungal populations may account for this effect; long-term monitoring might help unravelling the cause.
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Beule, Lukas, and Petr Karlovsky. "Early response of soil fungal communities to the conversion of monoculture cropland to a temperate agroforestry system." PeerJ 9 (October 5, 2021): e12236. http://dx.doi.org/10.7717/peerj.12236.
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Background Alley-cropping systems in the temperate zone are a type of agroforestry in which rows of fast-growing trees are alternated with rows of annual crops. With numerous environmental benefits, temperate agroforestry is considered a promising alternative to conventional agriculture and soil fungi may play a key in maintaining productivity of these systems. Agroforestry systems that are established for more than 10 years have shown to increase the fungal biomass and impact the composition of soil fungal communities. Investigations of soil fungi in younger temperate agroforestry systems are scarce and the temporal dynamic of these changes is not understood. Methods Our study was conducted in a young poplar-based alley cropping and adjacent monoculture cropland system in an Arenosol soil in north-west Germany. We investigated the temporal dynamics of fungal populations after the establishment of agroforestry by collecting soil samples half, one, and one and a half years after conversion of cropland to agroforestry. Samples were collected within the agroforestry tree row, at 1, 7, and 24 m distance from the tree row within the crop row, and in an adjacent conventional monoculture cropland. The biomass of soil fungi, Asco-, and Basidiomycota was determined by real-time PCR. Soil fungal community composition and diversity were obtained from amplicon sequencing. Results Differences in the community composition of soil fungi in the tree row and arable land were detected as early as half a year following the conversion of monoculture cropland to agroforestry. In the tree row, soil fungal communities in the plots strongly diverged with the age of the system. The presence of young trees did not affect the biomass of soil fungi. Conclusions The composition of soil fungal communities responded rapidly to the integration of trees into arable land through agroforestry, whereas the fungal biomass was not affected during the first one and a half years after planting the trees. Fungal communities under the trees gradually diversified. Adaptation to spatially heterogeneous belowground biomass of the trees and understory vegetation or stochastic phenomena due to limited exchange among fungal populations may account for this effect; long-term monitoring might help unravelling the cause.
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Seifert, Charlotte, Christoph Leuschner, and Heike Culmsee. "Arable plant diversity on conventional cropland—The role of crop species, management and environment." Agriculture, Ecosystems & Environment 213 (December 2015): 151–63. http://dx.doi.org/10.1016/j.agee.2015.07.017.
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Wilken, Florian, Peter Fiener, Michael Ketterer, Katrin Meusburger, Daniel Iragi Muhindo, Kristof van Oost, and Sebastian Doetterl. "Assessing soil redistribution of forest and cropland sites in wet tropical Africa using <sup>239+240</sup>Pu fallout radionuclides." SOIL 7, no. 2 (July 8, 2021): 399–414. http://dx.doi.org/10.5194/soil-7-399-2021.
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Abstract. Due to the rapidly growing population in tropical Africa, a substantial rise in food demand is predicted in upcoming decades, which will result in higher pressure on soil resources. However, there is limited knowledge on soil redistribution dynamics following land conversion into arable land in tropical Africa that is partly caused by infrastructure limitations for long-term landscape-scale monitoring. In this study, fallout radionuclides 239+240Pu are used to assess soil redistribution along topographic gradients at two cropland sites and at three nearby pristine forest sites located in the DR Congo, Uganda and Rwanda. In the study area, a 239+240Pu baseline inventory is found that is higher than typically expected for tropical regions (mean forest inventory 41 Bq m−2). Pristine forests show no indication of soil redistribution based on 239+240Pu along topographical gradients. In contrast, soil erosion and sedimentation on cropland reached up to 37 cm (81 Mg ha−1 yr−1) and 40 cm (87 Mg ha−1 yr−1) within the last 55 years, respectively. Cropland sites show high intra-slope variability with locations showing severe soil erosion located in direct proximity to sedimentation sites. This study shows the applicability of a valuable method to assess tropical soil redistribution and provides insight into soil degradation rates and patterns in one of the most socio-economically and ecologically vulnerable regions of the world.
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Manzoor, Syed Amir, Geoffrey Hugh Griffiths, Elizabeth Robinson, Kikuko Shoyama, and Martin Lukac. "Linking Pattern to Process: Intensity Analysis of Land-Change Dynamics in Ghana as Correlated to Past Socioeconomic and Policy Contexts." Land 11, no. 7 (July 13, 2022): 1070. http://dx.doi.org/10.3390/land11071070.
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Spatio-temporal analysis of transitions in land cover is critical to understanding many ecological challenges, especially in environmentally vulnerable regions. For instance, in Sub-Saharan Africa, large-scale cropland expansion is expected due to the increasing demand for fuel, food, and fibre. Clearing land for cropland expansion is a driving factor in the degradation of natural ecosystems. We present a spatio-temporal analysis of land-cover change in Ghana’s Northern, Upper East, and Upper West provinces using Intensity Analysis on the periods from 1992 to 2003 and 2003 to 2015. The objectives of this study were to determine whether the intensity of land-use and land-cover (LULC) change is consistent between the two periods and to investigate the direction and extent of change for different LULC categories in northern Ghana. The methodology measures land-cover changes at the interval, category, and transition levels. The results suggest that the annual rate of land change was higher between 1992 and 2003 compared to that between 2003 and 2015. Furthermore, the category-level analysis reveals that the gains in the arable land and tree/forest-cover classes during both time intervals were higher than the uniform intensity. The transition-level analysis results indicate that most of the gains in arable land and tree/forest-cover came at the cost of semi-arid shrublands during both periods. There is also evidence of local increases in forest-cover, likely linked to afforestation policies established by the Ghanian government; however, overall, there has been a loss of natural habitat. The study provides data to improve our understanding of the magnitude and direction of land-cover change, essential for the development of policies designed to mitigate the impact of land-cover change on the livelihoods of local people and the environment at the national and sub-national levels.
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Porwollik, Vera, Susanne Rolinski, Jens Heinke, Werner von Bloh, Sibyll Schaphoff, and Christoph Müller. "The role of cover crops for cropland soil carbon, nitrogen leaching, and agricultural yields – a global simulation study with LPJmL (V. 5.0-tillage-cc)." Biogeosciences 19, no. 3 (February 15, 2022): 957–77. http://dx.doi.org/10.5194/bg-19-957-2022.
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Abstract. Land management practices can reduce the environmental impact of agricultural land use and production, improve productivity, and transform cropland into carbon sinks. In our study we assessed the biophysical and biogeochemical impacts and the potential contribution of cover crop practices to sustainable land use. We applied the process-based, global dynamic vegetation model LPJmL (Lund–Potsdam–Jena managed Land) V. 5.0-tillage-cc with a modified representation of cover crops to simulate the growth of grasses on cropland in periods between two consecutive main crops' growing seasons for near-past climate and land use conditions. We quantified simulated responses of agroecosystem components to cover crop cultivation in comparison to bare-soil fallowing practices on global cropland for a period of 50 years. For cover crops with tillage, we obtained annual global median soil carbon sequestration rates of 0.52 and 0.48 t C ha−1 yr−1 for the first and last decades of the entire simulation period, respectively. We found that cover crops with tillage reduced annual nitrogen leaching rates from cropland soils by medians of 39 % and 54 % but also the productivity of the following main crop by an average of 1.6 % and 2 % for the 2 analyzed decades. The largest reductions in productivity were found for rice and modestly lowered ones for maize and wheat, whereas the soybean yield revealed an almost homogenously positive response to cover crop practices replacing bare-soil fallow periods. The obtained simulation results of cover crop with tillage practices exhibit a good ability of the model version to reproduce observed effects reported in other studies. Further, the results suggest that having no tillage is a suitable complementary practice to cover crops, enhancing soil carbon sequestration and the reduction in nitrogen leaching, while reducing potential trade-offs with the main-crop productivity due to their impacts on soil nitrogen and water dynamics. The spatial heterogeneity of simulated impacts of cover crops on the variables assessed here was related to the time period since the introduction of the management practice as well as to environmental and agronomic conditions of the cropland. This study supports findings of other studies, highlighting the substantial potential contribution of cover crop practices to the sustainable development of arable production.
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Deák, Balázs, Orsolya Valkó, Csaba Albert Tóth, Ágnes Botos, and Tibor József Novák. "Legacies of past land use challenge grassland recovery – An example from dry grasslands on ancient burial mounds." Nature Conservation 39 (June 4, 2020): 113–32. http://dx.doi.org/10.3897/natureconservation.39.52798.
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Due to large-scale agricultural intensification, grasslands are often restricted to habitat islands in human-transformed landscapes. There are approximately half a million ancient burial mounds built by nomadic steppic tribes in the Eurasian steppe and forest steppe zones, which act as habitat islands for dry grassland vegetation. Land use intensification, such as arable farming and afforestation by non-native woody species are amongst the major threats for Eurasian dry grasslands, including grasslands on mounds. After the launch of the Good Agricultural and Environmental Condition framework of the European Union, in Hungary there is a tendency for ceasing crop production and cutting non-native woody plantations, in order to conserve these unique landmarks and restore the historical grassland vegetation on the mounds. In this study, restoration prospects of dry grassland habitats were studied on kurgans formerly covered by croplands and Robinia pseudoacacia plantations. Soil and vegetation characteristics were studied in thespontaneously recovering grasslands. The following questions were addressed: 1; How does site history affect the spontaneous grassland recovery? 2; Do residual soil nutrients play a role in grassland recovery? In former croplands, excess phosphorus, while in former Robinia plantations, excess nitrogen was present in the soil even four years after the land use change and grassland vegetation was in an early or mid-successional stage both on the mounds. The results showed that, without proper management measures, recovery of grassland vegetation is slow on mounds formerly used as cropland or black locust plantation. However, restoration efforts, focused on the restoration of mounds formerly covered by croplands, can be more effective compared to the restoration of mounds formerly covered by forest plantations.
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Powlson, David S., Paul R. Poulton, Margaret J. Glendining, Andy J. Macdonald, and Keith W. T. Goulding. "Is it possible to attain the same soil organic matter content in arable agricultural soils as under natural vegetation?" Outlook on Agriculture 51, no. 1 (February 21, 2022): 91–104. http://dx.doi.org/10.1177/00307270221082113.
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Clearing natural vegetation to establish arable agriculture (cropland) almost invariably causes a loss of soil organic carbon (SOC). Is it possible to restore soil that continues in arable agriculture to the pre-clearance SOC level through modified management practices? To address this question we reviewed evidence from long-term experiments at Rothamsted Research, UK, Bad Lauchstädt, Germany, Sanborn Field, USA and Brazil and both experiments and surveys of farmers’ fields in Ethiopia, Australia, Zimbabwe, UK and Chile. In most cases SOC content in soil under arable cropping was in the range 38–67% of pre-clearance values. Returning crop residues, adding manures or including periods of pasture within arable rotations increased this, often to 60–70% of initial values. Under tropical climatic conditions SOC loss after clearance was particularly rapid, e.g. a loss of >50% in less than 10 years in smallholder farmers’ fields in Zimbabwe. If larger yielding crops were grown, using fertilizers, and maize stover returned instead of being grazed by cattle, the loss was reduced. An important exception to the general trend of SOC loss after clearance was clearing Cerrado vegetation on highly weathered acidic soils in Brazil and conversion to cropping with maize and soybean. Other exceptions were unrealistically large annual applications of manure and including long periods of pasture in a highly SOC-retentive volcanic soil. Also, introducing irrigated agriculture in a low rainfall region can increase SOC beyond the natural value due to increased plant biomass production. For reasons of sustainability and soil health it is important to maintain SOC as high as practically possible in arable soils, but we conclude that in the vast majority of situations it is unrealistic to expect to maintain pre-clearance values. To maintain global SOC stocks at we consider it is more important to reduce current rates of land clearance and sustainably produce necessary food on existing agricultural land.
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Launay, Camille, Julie Constantin, Florent Chlebowski, Sabine Houot, Anne‐Isabelle Graux, Katja Klumpp, Raphaël Martin, Bruno Mary, Sylvain Pellerin, and Olivier Therond. "Estimating the carbon storage potential and greenhouse gas emissions of French arable cropland using high‐resolution modeling." Global Change Biology 27, no. 8 (February 2021): 1645–61. http://dx.doi.org/10.1111/gcb.15512.
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Montoya, Mónica, Antonio Castellano-Hinojosa, Antonio Vallejo, José Manuel Álvarez, Eulogio J. Bedmar, Jaime Recio, and Guillermo Guardia. "Zinc fertilizers influence greenhouse gas emissions and nitrifying and denitrifying communities in a non-irrigated arable cropland." Geoderma 325 (September 2018): 208–17. http://dx.doi.org/10.1016/j.geoderma.2018.03.035.
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Han, Xiaoliang, Peiyi Lv, Sen Zhao, Yan Sun, Shiyu Yan, Minghao Wang, Xiaona Han, and Xiuru Wang. "The Effect of the Gully Land Consolidation Project on Soil Erosion and Crop Production on a Typical Watershed in the Loess Plateau." Land 7, no. 4 (September 30, 2018): 113. http://dx.doi.org/10.3390/land7040113.
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The Gully Land Consolidation Project (GLCP) was launched to create more arable land by excavating soil from the slopes on both sides of gullies, combined with simultaneous comprehensive gully prevention and control measures. The purpose of the GLCP is to increase crop production and reduce soil erosion to achieve ecological and agricultural sustainability. In this study, we assess the effects of the GLCP on soil erosion and crop production by studying the BaoChengGou Watershed in the Loess Plateau, primarily by means of high spatial-resolution satellite images (taken by the GF-1 and ZY-3 satellites) combined with the InVEST model and field investigations. Sloping cropland, sparse forestland, and natural grassland are the main land use types in the study area. After implementing the GLCP, consolidated land in the cropland increased by 7.35%, an increase that has come largely at the expense of grassland and forestland. The GLCP has markedly reduced soil erosion in the BaoChengGou Watershed, especially in the sense that soil erosion intensity was also reduced significantly in the project region on the whole, despite intensifying in certain places, such as excavated slopes; furthermore, it has improved crop yields in the study area by 10.9%. Comprehensive measurement shows the GLCP to be scientific, reasonable, and clearly efficacious. This study presents findings regarding the positive significance of the GLCP in promoting ecological and agricultural sustainability in the Loess Plateau.
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Zhelezova, Alena, Timofey Chernov, Dmitry Nikitin, Azida Tkhakakhova, Natalia Ksenofontova, Aleksei Zverev, Olga Kutovaya, and Mikhail Semenov. "Seasonal Dynamics of Soil Bacterial Community under Long-Term Abandoned Cropland in Boreal Climate." Agronomy 12, no. 2 (February 19, 2022): 519. http://dx.doi.org/10.3390/agronomy12020519.
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The collapse of collective farming in Russia after 1990 led to the abandonment of 23% of the agricultural area. Microbial biomass is a transit pool between fresh and soil organic matter; therefore, structural changes in soil microbial community determine the carbon cycle processes caused by self-restoration of arable lands after abandonment. Here, we assessed the influence of monthly changes in moisture and temperature on the bacterial community structure and abundance in Retisols under long-term abandoned cropland. Two periods with pronounced differences in bacterial properties were revealed: the growing period from March to September and the dormant period from October to February. The growing period was characterized by higher bacterial abundance and diversity compared to the dormant period. The relative abundances of the bacterial community dominants (Alpha-, Gamma- and Deltaproteobacteria, subgroup 6 of phylum Acidobacteria) did not change significantly over the year, either in total or active communities. The relative abundances of Bacteroidetes and Verrucomicrobia increased in the growing period, whereas Actinobacteria and Chloroflexi were more abundant in the dormant period. The microbial gene abundances positively correlated with soil and air temperature, but not with soil moisture. Thus, the seasonal dynamics of soil microbial communities are closely related to soil temperature and should be considered when assessing carbon cycles in abandoned lands.
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Li, Qiang, Yuchi Pu, and Yang Zhang. "Study on the Spatio-Temporal Evolution of Land Use in Resource-Based Cities in Three Northeastern Provinces of China—An Analysis Based on Long-Term Series." Sustainability 14, no. 20 (October 21, 2022): 13683. http://dx.doi.org/10.3390/su142013683.
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Land is the basis of development, and the unique patterns of the spatio-temporal evolution of land use in resource-based cities can reflect regional development, help land resources to be used efficiently and rationally, promote scientific regulation, and achieve high-quality development. Based on the land use data of resource-based cities in three northeastern provinces from 1980 to 2020, the spatio-temporal evolution characteristics and driving factors of land use in the sample study area were studied by the Markov transfer matrix and a parametric optimal geographic detector model. The results showed that: (1) From the perspective of time, the land use changes in the sample study area were active, mainly reflected in the continuous conversion of forest land transfer-out (11.66%) and arable land transfer-in (11.28%), and the dynamic attitude of forest land showed a trend of decreasing, then increasing and then decreasing, while the dynamic attitude of arable land showed a trend of increasing, then decreasing and then increasing. (2) Spatially, the areas where land conversion occurred were mainly concentrated in the northern part of the study area and the border area in the east, which is also the area where forest land was converted to arable land and grassland was converted to arable land, and the expansion of construction land was more common; (3) In terms of influencing factors, land conversion before 2000 was mainly influenced by socio-economic factors, and population quantity and urbanization rate had stronger explanatory power. The spatial and temporal evolution of forest land conversion to arable land was realized by the interaction of various factors, and the driver interactions were all non-linearly enhanced and bi-factor enhanced. (4) In terms of influencing factors, land conversion before 2000 was mainly influenced by socio-economics, with population quantity and urbanization rate having a stronger explanatory power; after 2000, land conversion was mainly influenced by physical geography, with precipitation and temperature having a stronger explanatory power. (5) The spatio-temporal evolution of forest land conversion to cropland was realized by the interaction between various factors, and the driving factor interactions all showed non-linear enhancement and bifactor enhancement.
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Singh, Pardeep, Pradipkumar Adhale, Amit Guleria, Priya Brata Bhoi, Akash Kumar Bhoi, Manlio Bacco, and Paolo Barsocchi. "Crop Diversification in South Asia: A Panel Regression Approach." Sustainability 14, no. 15 (July 30, 2022): 9363. http://dx.doi.org/10.3390/su14159363.
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The South Asian agricultural sector has experienced vigorous growth and structural transformation over the last few decades, albeit differently across the region. This study examines the crop diversification status and various determinants, such as socioeconomic (per capita gross domestic product, population, arable land, and cropland), soil/agronomic (root zone moisture), agricultural inputs (fertilizer and pesticide consumption), the productivity of food and non-food crops, international trade, and climate (maximum and minimum temperature and rainfall) factors. The share of cereals has decreased in most countries, but they continue to dominate South Asian agriculture. The area under high-value crops in India has increased significantly, replacing the area under cereal cultivation during the study period. Similar results were seen in the Maldives, where vegetables replaced oilseeds. The Hausman model test suggested a random-effects model for analyzing the determinants. All the determinants considered in the study explain 69 percent of the variation in the crop diversification index. The crop diversification in South Asia was influenced by per capita gross domestic product (G.D.P.), minimum temperature, pesticide consumption, food crop yield index, and non-food crop yield index during the study period. Cropland percentage and population, on the other hand, reduce crop diversification. The price factor contributed more than half to agricultural growth. It remained the primary source of growth in all South Asian countries, followed by yield, which is identified as the second most crucial factor. The contribution of crop diversification to agricultural growth has been declining over time.
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Adugna, Alemayehu, Assefa Abegaz, Asmamaw Legass, and Diogenes L. Antille. "RANDOM AND SYSTEMATIC LAND-COVER TRANSITIONS IN NORTH-EASTERN WOLLEGA, ETHIOPIA." BOIS & FORETS DES TROPIQUES 332 (September 18, 2017): 3–15. http://dx.doi.org/10.19182/bft2017.332.a31329.
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Africa has seen significant changes in land cover at different spatial scales. Changes in Land Use and Land Cover (LULC) include deforestation and subse- quent use of the land for arable cropping, conversion to grassland or urbanization. The work reported in this article was conducted to examine land cover transi- tions in north-eastern Wollega (Ethiopia) between 2005 and 2015. The analysis focused on land cover transitions that occurred systematically or randomly, and identified the main drivers for these changes. Landsat data from 2005 and 2015 were examined to better unders- tand the various dimensions of land cover transitions, namely: swaps, losses, gains, persistency and vulnerability. Results showed that shrubland exhibited the largest gain (22%), with a 63% gain- to-loss ratio, a 47% gain-to-persistence ratio and a positive net change-to-persis- tence ratio of 46%. Cropland showed the largest loss (19%) while grassland was the most stable type of land cover des- pite some fluctuation (»10%) observed during the 10-year period. The land cover transition was dominated by systematic processes, with few random processes of change. Systematic land cover transitions such as agricultural abandonment and vegetation re-growth were attributed to regular or common processes of change. This study suggests that the implementa- tion of practices conducive to sustainable intensification of existing agricultural land, supported by policies that promote increased diversification of Ethiopian agriculture, would mitigate pressure on forests by avoiding their future conver- sion to cropland.
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Chen, Guokun, Zengxiang Zhang, Qiankun Guo, Xiao Wang, and Qingke Wen. "Quantitative Assessment of Soil Erosion Based on CSLE and the 2010 National Soil Erosion Survey at Regional Scale in Yunnan Province of China." Sustainability 11, no. 12 (June 12, 2019): 3252. http://dx.doi.org/10.3390/su11123252.
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Regional soil loss assessment is the critical method of incorporating soil erosion into decision-making associated with land resources management and soil conservation planning. However, data availability has limited its application for mountainous areas. To obtain a clear understanding of soil erosion in Yunnan, a pixel-based estimation was employed to quantify soil erosion rate and the benefits of soil conservation measures based on Chinese Soil Loss Equation (CSLE) and data collected in the national soil erosion survey. Results showed that 38.77% of the land was being eroded at an erosion rate higher than the soil loss tolerance, the average soil erosion rate was found to be 12.46 t∙ha−1∙yr−1, resulting in a total soil loss of 0.47 Gt annually. Higher erosion rates mostly occurred in the downstream areas of the major rivers as compared to upstream areas, especially for the southwest agricultural regions. Rain-fed cropland suffered the most severe soil erosion, with a mean erosion rate of 47.69 t∙ha−1∙yr−1 and an erosion ratio of 64.24%. Lands with a permanent cover (forest, shrub, and grassland) were mostly characterized by erosion rates an order of magnitude lower than those from rain-fed cropland, except for erosion from sparse woods, which was noticeable and should not be underestimated. Soil loss from arable land, woodland and grassland accounted for 52.24%, 35.65% and 11.71% of the total soil loss, respectively. We also found significant regional differences in erosion rates and a close relationship between erosion and soil conservation measures adopted. The CSLE estimates did not compare well with qualitative estimates from the National Soil Erosion Database of China (NSED-C) and only 47.77% of the territory fell within the same erosion intensity for the two approaches. However, the CSLE estimates were consistent with the results from a national survey and local assessments under experimental plots. By advocating of soil conservation measures and converting slope cropland into grass/forest and terraced field, policy interventions during 2006–2010 have reduced soil erosion on rain-fed cropland by 20% in soil erosion rate and 32% in total soil loss compared to the local assessments. The quantitative CSLE method provides a reliable estimation, due to the consideration of erosion control measures and is potentially transferable to other mountainous areas as a robust approach for rapid assessment of sheet and rill erosion.
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Yu, Yi, Tingbao Xu, and Tao Wang. "Outmigration Drives Cropland Decline and Woodland Increase in Rural Regions of Southwest China." Land 9, no. 11 (November 11, 2020): 443. http://dx.doi.org/10.3390/land9110443.
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Rapid urbanisation in China has led to massive outmigration in rural regions, which has changed the regional labour force structure and can have various profound impacts as a result. This research used a case study in Southwest China to investigate how regional land use patterns have been changed in the context of rural outmigration and assessed the resulting dynamics on local ecological environment. The key findings include: (1) The local land conversion process was mainly characterised by the conversion of farmland (−18.3%) to residential area (+268.3%) and woodland (+55.6%) during 2000–2018; (2) about 83.7% of area showed a statistically significant increase in the normalised difference vegetation index (NDVI), which was not due to human interference factors (e.g., afforestation). Correlation analyses showed that depopulation (R = −0.514, p < 0.01) and local mild temperature (R = 0.505, p < 0.01) could be the main contributors. Only 2.5% of the area had decreased NDVI and this was directly caused by human activities (e.g., urban area expansion). These results implied that vegetation improvement can occur in the context of depopulation and farmland reduction, which did not significantly threaten the local agricultural sector. It then could be a good choice to allow those high-slope and biophysically poor farmlands to undergo forest succession rather than cultivation. Farmers in Southwest China should make a full use of the existing low-slope arable land to curb the declining trend of local farmland amount, in order to meet the future challenges brought by urbanisation. Enhanced agricultural infrastructure, mechanised farming and guide from local government can help achieve this goal. This study provided new insights and more realistic scenarios for rural development in Southwest China. The research findings are expected to provide a better understanding to enable sustainable land use management in Southwest China.
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Radočaj, Dorijan, Irena Jug, Vesna Vukadinović, Mladen Jurišić, and Mateo Gašparović. "The Effect of Soil Sampling Density and Spatial Autocorrelation on Interpolation Accuracy of Chemical Soil Properties in Arable Cropland." Agronomy 11, no. 12 (November 29, 2021): 2430. http://dx.doi.org/10.3390/agronomy11122430.
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Knowledge of the relationship between soil sampling density and spatial autocorrelation with interpolation accuracy allows more time- and cost-efficient spatial analysis. Previous studies produced contradictory observations regarding this relationship, and this study aims to determine and explore under which conditions the interpolation accuracy of chemical soil properties is affected. The study area covered 823.4 ha of agricultural land with 160 soil samples containing phosphorus pentoxide (P2O5) and potassium oxide (K2O) values. The original set was split into eight subsets using a geographically stratified random split method, interpolated using the ordinary kriging (OK) and inverse distance weighted (IDW) methods. OK and IDW achieved similar interpolation accuracy regardless of the soil chemical property and sampling density, contrary to the majority of previous studies which observed the superiority of kriging as a deterministic interpolation method. The primary dependence of interpolation accuracy to soil sampling density was observed, having R2 in the range of 56.5–83.4% for the interpolation accuracy assessment. While this study enables farmers to perform efficient soil sampling according to the desired level of detail, it could also prove useful to professions dependent on field sampling, such as biology, geology, and mining.
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Wesemael, Bas van, Suzanna Lettens, Caroline Roelandt, and Jos Van Orshoven. "Modelling the evolution of regional carbon stocks in Belgian cropland soils." Canadian Journal of Soil Science 85, Special Issue (September 1, 2005): 511–21. http://dx.doi.org/10.4141/s04-085.
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In long-term experiments, it has been demonstrated that management of cropland influences the evolution of soil organic carbon (SOC ) stocks. National inventories of SOC stocks in Belgium have recently been compiled, and show an evolution of SOC stocks of arable land from 1960 to 1990 and 2000. In order to analyse the driving forces of these changes, we concentrate on the SOC evolution in the soil associations of three of the 13 Belgian agricultural regions (Dunes-Polders, Loam belt and Condroz). The small confidence limits around the mean SOC values within some soil associations (0.412.7 t C ha-1) allow us to compare the observed values with the results of the RothC soil carbon model and hence quantify the most important driving forces. After estimating the local parameters by fitting the model to SOC values from a longterm experiment in central Belgium, the model was run from 1960 to 2000 for typical soil profiles of soil associations in the three agricultural regions. The main factors inducing changes in SOC stocks are the increase in plough depth as a result of continued mechanisation in the 1960s and the sustained input of organic amendments in the form of farmyard manure and slurry. In contrast to earlier publications on CO2 emissions from agricultural soils, the model did not predict a decrease in SOC stocks for the period 1990-2000. A slight increase was observed, although this increase is not significant for most soil associations. The comparison between modelled and observed SOC data at two time slices allows the uncertainty of the model results to be estimated. This uncertainty ranges from 7.5 to 14.4% of the SOC stock and is in the same order of magnitude as the uncertainty around SOC modelling for the long-term experiments both in Belgium and elsewhere in Europe. The organic matter concentration in the topsoil, an indicator for soil quality, was in the range of 1.5 to 3.3%. Organic matter content increased in the Dunes-Polders and decreased in the Loam belt and the Condroz from 1960 to 2000. Many soils in the Loam belt are now close to the critical level of 2% under which the soils are vulnerable to compaction and erosion. Key words: Soil organic carbon, regional modelling, soil-land-unit, Belgium
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Mashame, Gofamodimo, and Felicia Akinyemi. "TOWARDS A REMOTE SENSING BASED ASSESSMENT OF LAND SUSCEPTIBILITY TO DEGRADATION: EXAMINING SEASONAL VARIATION IN LAND USE-LAND COVER FOR MODELLING LAND DEGRADATION IN A SEMI-ARID CONTEXT." ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences III-8 (June 7, 2016): 137–44. http://dx.doi.org/10.5194/isprsannals-iii-8-137-2016.
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Land degradation (LD) is among the major environmental and anthropogenic problems driven by land use-land cover (LULC) and climate change worldwide. For example, poor LULC practises such as deforestation, livestock overstocking, overgrazing and arable land use intensification on steep slopes disturbs the soil structure leaving the land susceptible to water erosion, a type of physical land degradation. Land degradation related problems exist in Sub-Saharan African countries such as Botswana which is semi-arid in nature. LULC and LD linkage information is still missing in many semi-arid regions worldwide.Mapping seasonal LULC is therefore very important in understanding LULC and LD linkages. This study assesses the impact of seasonal LULC variation on LD utilizing Remote Sensing (RS) techniques for Palapye region in Central District, Botswana. LULC classes for the dry and rainy seasons were classified using LANDSAT 8 images at Level I according to the Food and Agriculture Organization (FAO) International Organization of Standardization (ISO) code 19144. Level I consists of 10 LULC classes. The seasonal variations in LULC are further related to LD susceptibility in the semi-arid context. The results suggest that about 985 km² (22%) of the study area is susceptible to LD by water, major LULC types affected include: cropland, paved/rocky material, bare land, built-up area, mining area, and water body. Land degradation by water susceptibility due to seasonal land use-land cover variations is highest in the east of the study area where there is high cropland to bare land conversion.
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Mashame, Gofamodimo, and Felicia Akinyemi. "TOWARDS A REMOTE SENSING BASED ASSESSMENT OF LAND SUSCEPTIBILITY TO DEGRADATION: EXAMINING SEASONAL VARIATION IN LAND USE-LAND COVER FOR MODELLING LAND DEGRADATION IN A SEMI-ARID CONTEXT." ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences III-8 (June 7, 2016): 137–44. http://dx.doi.org/10.5194/isprs-annals-iii-8-137-2016.
Full textAbstract:
Land degradation (LD) is among the major environmental and anthropogenic problems driven by land use-land cover (LULC) and climate change worldwide. For example, poor LULC practises such as deforestation, livestock overstocking, overgrazing and arable land use intensification on steep slopes disturbs the soil structure leaving the land susceptible to water erosion, a type of physical land degradation. Land degradation related problems exist in Sub-Saharan African countries such as Botswana which is semi-arid in nature. LULC and LD linkage information is still missing in many semi-arid regions worldwide.Mapping seasonal LULC is therefore very important in understanding LULC and LD linkages. This study assesses the impact of seasonal LULC variation on LD utilizing Remote Sensing (RS) techniques for Palapye region in Central District, Botswana. LULC classes for the dry and rainy seasons were classified using LANDSAT 8 images at Level I according to the Food and Agriculture Organization (FAO) International Organization of Standardization (ISO) code 19144. Level I consists of 10 LULC classes. The seasonal variations in LULC are further related to LD susceptibility in the semi-arid context. The results suggest that about 985 km² (22%) of the study area is susceptible to LD by water, major LULC types affected include: cropland, paved/rocky material, bare land, built-up area, mining area, and water body. Land degradation by water susceptibility due to seasonal land use-land cover variations is highest in the east of the study area where there is high cropland to bare land conversion.
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Sabbatini, S., N. Arriga, T. Bertolini, S. Castaldi, T. Chiti, C. Consalvo, S. Njakou Djomo, B. Gioli, G. Matteucci, and D. Papale. "Greenhouse gas balance of cropland conversion to bioenergy poplar short-rotation coppice." Biogeosciences 13, no. 1 (January 15, 2016): 95–113. http://dx.doi.org/10.5194/bg-13-95-2016.
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Abstract. The production of bioenergy in Europe is one of the strategies conceived to reduce greenhouse gas (GHG) emissions. The suitability of the land use change from a cropland (REF site) to a short-rotation coppice plantation of hybrid poplar (SRC site) was investigated by comparing the GHG budgets of these two systems over 24 months in Viterbo, Italy. This period corresponded to a single rotation of the SRC site. The REF site was a crop rotation between grassland and winter wheat, i.e. the same management of the SRC site before the conversion to short-rotation coppice. Eddy covariance measurements were carried out to quantify the net ecosystem exchange of CO2 (FCO2), whereas chambers were used to measure N2O and CH4 emissions from soil. The measurements began 2 years after the conversion of arable land to SRC so that an older poplar plantation was used to estimate the soil organic carbon (SOC) loss due to SRC establishment and to estimate SOC recovery over time. Emissions from tractors and from production and transport of agricultural inputs (FMAN) were modelled. A GHG emission offset, due to the substitution of natural gas with SRC biomass, was credited to the GHG budget of the SRC site. Emissions generated by the use of biomass (FEXP) were also considered. Suitability was finally assessed by comparing the GHG budgets of the two sites. CO2 uptake was 3512 ± 224 g CO2 m−2 at the SRC site in 2 years, and 1838 ± 107 g CO2 m−2 at the REF site. FEXP was equal to 1858 ± 240 g CO2 m−2 at the REF site, thus basically compensating for FCO2, while it was 1118 ± 521 g CO2 m−2 at the SRC site. The SRC site could offset 379.7 ± 175.1 g CO2eq m−2 from fossil fuel displacement. Soil CH4 and N2O fluxes were negligible. FMAN made up 2 and 4 % in the GHG budgets of SRC and REF sites respectively, while the SOC loss was 455 ± 524 g CO2 m−2 in 2 years. Overall, the REF site was close to neutrality from a GHG perspective (156 ± 264 g CO2eq m−2), while the SRC site was a net sink of 2202 ± 792 g CO2eq m−2. In conclusion the experiment led to a positive evaluation from a GHG viewpoint of the conversion of cropland to bioenergy SRC.
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Bianchini, Leonardo, Gianluca Egidi, Ahmed Alhuseen, Adele Sateriano, Sirio Cividino, Matteo Clemente, and Vito Imbrenda. "Toward a Dualistic Growth? Population Increase and Land-Use Change in Rome, Italy." Land 10, no. 7 (July 17, 2021): 749. http://dx.doi.org/10.3390/land10070749.
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The spatial mismatch between population growth and settlement expansion is at the base of current models of urban growth. Empirical evidence is increasingly required to inform planning measures promoting urban containment in the context of a stable (or declining) population. In these regards, per-capita indicators of land-use change can be adopted with the aim at evaluating long-term sustainability of urbanization processes. The present study assesses spatial variations in per-capita indicators of land-use change in Rome, Central Italy, at five years (1949, 1974, 1999, 2008, and 2016) with the final objective of quantifying the mismatch between urban expansion and population growth. Originally specialized in agricultural productions, Rome’s metropolitan area is a paradigmatic example of dispersed urban expansion in the Mediterranean basin. By considering multiple land-use dynamics, per-capita indicators of landscape change delineated three distinctive waves of growth corresponding with urbanization, suburbanization, and a more mixed stage with counter-urbanization and re-urbanization impulses. By reflecting different socioeconomic contexts on a local scale, urban fabric and forests were identified as the ‘winner’ classes, expanding homogeneously over time at the expense of cropland. Agricultural landscapes experienced a more heterogeneous trend with arable land and pastures declining systematically and more fragmented land classes (e.g., vineyards and olive groves) displaying stable (or slightly increasing) trends. The continuous reduction of per-capita surface area of cropland that’s supports a reduced production base, which is now insufficient to satisfy the rising demand for fresh food at the metropolitan scale, indicates the unsustainability of the current development in Rome and more generally in the whole Mediterranean basin, a region specialized traditionally in (proximity) agricultural productions.
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Vorobyova, Tatiana, and Yelaman Smagulov. "Mapping dynamics of agricultural land use in the dry steppe zone of the Northern Кazakhstan." InterCarto. InterGIS 27, no. 4 (2021): 5–18. http://dx.doi.org/10.35595/2414-9179-2021-4-27-5-18.
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The agricultural use of land resources in the dry steppe regions of Northern Kazakhstan has undergone significant changes over the past century and continues to change at the present time. The middle position in the region is occupied by the Akmola region, one of the leading agricultural regions, where 9.3 % of the country’s gross agricultural output is produced. The main branches of agriculture in the region are grain farming and dairy and beef cattle breeding. The study of the change in the ratio of the areas of arable and pasture lands, the changes that have occurred in the state of agricultural landscapes as a result of long-term use is important for the further development of the agricultural industry in the region. Using the example of the Astrakhan district of the Akmola region, typical for the dry steppe zone, an analysis of changes in the structure of agricultural land from 1953 to 2020 was carried out. with the help of a series of digital maps compiled from detailed maps of scientific reference atlases of Northern Kazakhstan in 1964, 1970, remote sensing data of different times, archival materials and data of modern statistics. The resulting maps visualize significant changes in cropland areas within the study area over the past 70 years. Seven main periods were identified, during which the most significant changes in the structure of land use occurred as a result of political, economic and natural factors. During the years of development of virgin and fallow lands, the highest rates of increase in arable land were observed, which continued on a smaller scale until 1990. The period from 1991-1999 characterized by a large-scale reduction of arable land and abandonment of pastures. This was followed by two periods of gradual restoration of the use of arable and rangelands. Compiled comprehensive map of the dynamics of agricultural land use from 1988 to 2020 made it possible to identify spatial and temporal patterns in changes in the structure of agricultural land use, to determine to which specific natural types of lands the abandoned lands belonged and to which restored ones. Spatial analysis showed that over the past 30, more than half of the area’s area has not changed the type of land use. The results obtained are used to select the optimal ratio of arable and pasture lands in the structure of agricultural land use, as well as to develop a strategy for the rational use of agricultural land in the zone of risky farming.
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Carr, Tony W., Juraj Balkovič, Paul E. Dodds, Christian Folberth, Emil Fulajtar, and Rastislav Skalsky. "Uncertainties, sensitivities and robustness of simulated water erosion in an EPIC-based global gridded crop model." Biogeosciences 17, no. 21 (November 5, 2020): 5263–83. http://dx.doi.org/10.5194/bg-17-5263-2020.
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Abstract. Water erosion on arable land can reduce soil fertility and agricultural productivity. Despite the impact of water erosion on crops, it is typically neglected in global crop yield projections. Furthermore, previous efforts to quantify global water erosion have paid little attention to the effects of field management on the magnitude of water erosion. In this study, we analyse the robustness of simulated water erosion estimates in maize and wheat fields between the years 1980 and 2010 based on daily model outputs from a global gridded version of the Environmental Policy Integrated Climate (EPIC) crop model. By using the MUSS water erosion equation and country-specific and environmental indicators determining different intensities in tillage, residue handling and cover crops, we obtained the global median water erosion rates of 7 t ha−1 a−1 in maize fields and 5 t ha−1 a−1 in wheat fields. A comparison of our simulation results with field data demonstrates an overlap of simulated and measured water erosion values for the majority of global cropland. Slope inclination and daily precipitation are key factors in determining the agreement between simulated and measured erosion values and are the most critical input parameters controlling all water erosion equations included in EPIC. The many differences between field management methods worldwide, the varying water erosion estimates from different equations and the complex distribution of cropland in mountainous regions add uncertainty to the simulation results. To reduce the uncertainties in global water erosion estimates, it is necessary to gather more data on global farming techniques to reduce the uncertainty in global land-use maps and to collect more data on soil erosion rates representing the diversity of environmental conditions where crops are grown.
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Al-Graiti, Thulfiqar, Gergely Jakab, Noémi Ujházy, Anna Vancsik, Nándor Fodor, Tamás Árendás, Balázs Madarász, Zoltán Barcza, Károly Márialigeti, and Zoltán Szalai. "The Composition of Dissolved Organic Matter in Arable Lands: Does Soil Management Practice Matter?" Agronomy 12, no. 11 (November 10, 2022): 2797. http://dx.doi.org/10.3390/agronomy12112797.
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Dissolved organic matter (DOM) is a key soil quality property, indicative of the organic matter stored in the soil, which may also be a function of temporal variation. This study examines whether DOM is a robust property of the soil, controlling fertility, or if it may change with time. Altogether eight sets of soil samples were collected in 2018 and 2019 from the cultivated topsoil (0–10 cm) of cropland and from a nearby grassland near Martonvásár, Hungary. The study sites were characterized by Chernozem soil and were part of a long-term experimental project comparing the effects of manure application and fertilization to the control under maize and wheat monocultures. DOM was extracted from the samples with distilled water. The dissolved organic carbon (DOC), total dissolved nitrogen (DN), biological index (BIX), fluorescence index (FI), humification index (HIX), carbon nitrogen (C/N) ratio and specific ultraviolet absorbance at 254 nm (SUVA254) index were studied in the arable soils, and the results showed that all the DOM samples were humified, suggesting relevant microbiological contributions to the decomposition of OM and its conversion into more complex molecules (FI = 1.2–1.5, BIX = ~0.5, and HIX = ~0.9). Temporal variations were detected only for the permanent grassland where higher DOM concentration was found in spring. This increased DOM content mainly originated from humified, solid phase associated, recalcitrant OM. In contrast, there were no differences among fertilization treatments and sampling dates under cropfield conditions. Moreover, climatic conditions were not proven as a general ruler of DOM properties. Therefore, momentary DOM alone is not necessarily the direct property of soil organic matter under cropfield conditions. The application of this measure needs further details of sampling conditions to achieve adequate comparability.
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Qian, Tana, Atsushi Tsunekawa, Tsugiyuki Masunaga, and Tao Wang. "Analysis of the Spatial Variation of Soil Salinity and Its Causal Factors in China’s Minqin Oasis." Mathematical Problems in Engineering 2017 (2017): 1–9. http://dx.doi.org/10.1155/2017/9745264.
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Land salinization and water resource deterioration negatively affect irrigated agriculture in arid and semiarid areas by limiting the area of arable land and reducing crop yields. The spatial variation of soil salinity is affected by many factors, and their interactions are complex. In this study, we utilized grey relational analysis to evaluate the factors that affect soil salinity in China’s Minqin Oasis and the interactions among them and then ranked the significance of their impacts on soil salinity for different land use and cover types. The data used in this study include data obtained from soil chemical analyses based on field sampling in 2015 and hydrological data obtained from local government agencies. We found that the main factors that affect soil salinity in the region’s sparse grassland are groundwater salinity and vegetation cover; the least important factor was the distance to the nearest irrigation canal. For cropland, the most important factors were the distance to irrigation canals and hydrological factors. By accounting for these factors, it should be possible to manage the region’s limited natural water and soil resources more efficiently, while allowing remediation of existing salinized land and helping to maintain sustainable agriculture in this arid land.
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Wu, Minghua, Guangsheng Liu, Siyang She, and Lesong Zhao. "Factors influencing abandoned farmland in hilly and mountainous areas, and the governance paths: A case study of Xingning City." PLOS ONE 17, no. 7 (July 18, 2022): e0271498. http://dx.doi.org/10.1371/journal.pone.0271498.
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The current global pandemic has laid bare the importance of national food security to human survival. Many cultivated lands in the hilly, mountainous, and other marginalized areas have been abandoned on a large scale, resulting in a tremendous waste of agricultural resources, thereby threatening national food security. Here, we studied abandoned farmland in Xingning City, a mountainous area in northern Guangdong province. According to the "seeding—growing—harvesting" life cycle of cultivated plots, spatial superposition method and remote sensing change detection method were applied to identify abandoned arable land. Logistic regression model was used to reveal the influencing factors and occurrence mechanism of abandoned cropland at plot scale, and cluster analysis was used to discuss the classification and management strategies. Result showed that 16.83% of the cultivated land in the study area was severely abandoned, attributed to poor location, poor basic conditions, and fragmentation of the land. Further, the abandoned farmland was divided into output-driving type, cultivation condition-driving type, and plot-condition driving type. Based on these types, we proposed some countermeasures, such as adjusting agricultural structures, tamping agricultural infrastructures, strengthening land circulation, popularizing appropriate scale operations. These measures provide a reference to effectively curb abandoned farmland and improving the utilization efficiency of cultivated land, especially in recent years.
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Pywell, Richard F., Matthew S. Heard, Ben A. Woodcock, Shelley Hinsley, Lucy Ridding, Marek Nowakowski, and James M. Bullock. "Wildlife-friendly farming increases crop yield: evidence for ecological intensification." Proceedings of the Royal Society B: Biological Sciences 282, no. 1816 (October 7, 2015): 20151740. http://dx.doi.org/10.1098/rspb.2015.1740.
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Ecological intensification has been promoted as a means to achieve environmentally sustainable increases in crop yields by enhancing ecosystem functions that regulate and support production. There is, however, little direct evidence of yield benefits from ecological intensification on commercial farms growing globally important foodstuffs (grains, oilseeds and pulses). We replicated two treatments removing 3 or 8% of land at the field edge from production to create wildlife habitat in 50–60 ha patches over a 900 ha commercial arable farm in central England, and compared these to a business as usual control (no land removed). In the control fields, crop yields were reduced by as much as 38% at the field edge. Habitat creation in these lower yielding areas led to increased yield in the cropped areas of the fields, and this positive effect became more pronounced over 6 years. As a consequence, yields at the field scale were maintained—and, indeed, enhanced for some crops—despite the loss of cropland for habitat creation. These results suggested that over a 5-year crop rotation, there would be no adverse impact on overall yield in terms of monetary value or nutritional energy. This study provides a clear demonstration that wildlife-friendly management which supports ecosystem services is compatible with, and can even increase, crop yields.
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Karstens, Kristine, Benjamin Leon Bodirsky, Jan Philipp Dietrich, Marta Dondini, Jens Heinke, Matthias Kuhnert, Christoph Müller, et al. "Management-induced changes in soil organic carbon on global croplands." Biogeosciences 19, no. 21 (November 10, 2022): 5125–49. http://dx.doi.org/10.5194/bg-19-5125-2022.
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Abstract. Soil organic carbon (SOC), one of the largest terrestrial carbon (C) stocks on Earth, has been depleted by anthropogenic land cover change and agricultural management. However, the latter has so far not been well represented in global C stock assessments. While SOC models often simulate detailed biochemical processes that lead to the accumulation and decay of SOC, the management decisions driving these biophysical processes are still little investigated at the global scale. Here we develop a spatially explicit data set for agricultural management on cropland, considering crop production levels, residue returning rates, manure application, and the adoption of irrigation and tillage practices. We combine it with a reduced-complexity model based on the Intergovernmental Panel on Climate Change (IPCC) tier 2 method to create a half-degree resolution data set of SOC stocks and SOC stock changes for the first 30 cm of mineral soils. We estimate that, due to arable farming, soils have lost around 34.6 GtC relative to a counterfactual hypothetical natural state in 1975. Within the period 1975–2010, this SOC debt continued to expand by 5 GtC (0.14 GtC yr−1) to around 39.6 GtC. However, accounting for historical management led to 2.1 GtC fewer (0.06 GtC yr−1) emissions than under the assumption of constant management. We also find that management decisions have influenced the historical SOC trajectory most strongly by residue returning, indicating that SOC enhancement by biomass retention may be a promising negative emissions technique. The reduced-complexity SOC model may allow us to simulate management-induced SOC enhancement – also within computationally demanding integrated (land use) assessment modeling.
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Soares, Anaysa Borges, Jonathan Gonçalves Silva, Gabrielli Martinelli, Miguel Reis Brandão, and Clandio Favarini Ruviaro. "Reducing losses in food production in Brazil: its impacts on the economy, land-use change and greenhouse gas emissions." Desenvolvimento Socioeconômico em Debate 7, no. 2 (February 24, 2022): 122. http://dx.doi.org/10.18616/rdsd.v7i2.6474.
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The reduction of food losses is an important measure to ensure food security, as it affects food availability, the environment and economic development. To this end, it is necessary to reduce waste from production to final consumption. This paper analyzes the economic impacts in Brazil from reducing food losses at the production stage between 2021 and 2030. In addition, it assesses the effects of policies on land allocation and its consequences in terms of greenhouse gas emissions. A computable general-equilibrium model was used to estimate the consequences arising from the reduction of losses on the different sectors of the economy as a result of the application of shocks of productivity gains to the production of some of the main crops in Brazil. The results show that reduction of waste is feasible and beneficial for the Brazilian economy, as it promotes regional and national economic growth, which leads to an increase in consumption by households and the government, and to investments and production levels. One of the main results identified was the Borlaug effect, since different agricultural activities grew in volume by increasing productivity on current cropland, thereby avoiding the conversion of large areas of native vegetation into arable land. Furthermore, the results may offer a new perspective on this topic to countries with economies similar to Brazil's, particular since only a few studies use this approach exist.
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Wang, Li, and Yong Zhou. "Combining Multitemporal Sentinel-2A Spectral Imaging and Random Forest to Improve the Accuracy of Soil Organic Matter Estimates in the Plough Layer for Cultivated Land." Agriculture 13, no. 1 (December 20, 2022): 8. http://dx.doi.org/10.3390/agriculture13010008.
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Soil organic matter (SOM) is vital for assessing the quality of arable land. A fast and reliable estimation of SOM is important to predict the soil carbon stock in cropland. In this study, we aimed to explore the potential of combining multitemporal Sentinel-2A imagery and random forest (RF) to improve the accuracy of SOM estimates in the plough layer for cultivated land at a regional scale. The field data of SOM content were utilized along with multitemporal Sentinel-2A images acquired over three years during the bare soil period to develop spectral indices. The best bands and spectral indices were selected as prediction variables by using the RF algorithm. Partial least squares (PLS), geographically weighted regression (GWR), and RF were employed to calibrate spectral indices for the SOM content, and the optimal calibration model was used for the mapping of the SOM content in arable land at a regional scale. The results showed the following. (1) The multitemporal image estimation model outperformed the single-temporal image estimation model. The estimation model that utilized the optimal bands and spectral indices as prediction variables usually had better accuracy than the models based on full spectral data. (2) For the SOM content estimates, the performance was better with RF than with PLS and GWR in almost all cases. (3) The most accurate SOM estimation in the case area was achieved by using multitemporal images from 2018 and the RF calibration model based on the optimal bands and spectral indices as prediction variables, with R2val (coefficient of determination of the validation data set) = 0.67, RMSEval (root mean square error of the validation dataset) = 2.05, and RPIQval(ratio of performance to interquartile range of the validation dataset) = 3.36. (4) The estimated SOM content in the plough layer for cultivated land throughout the study area ranged from 16.17 to 36.98 g kg−1 and exhibited an increasing trend from north to south. In the current study, we developed a framework that combines multitemporal remote sensing imagery and RF for the SOM estimation, which can improve the accuracy of quantitative SOM estimations, provide a dynamic, rapid, and low-cost technique for understanding soil fertility, and offer an early warning of changes in soil quality.
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Shaloo, Rishi Pal Singh, Himani Bisht, Rajni Jain, Truptimayee Suna, Ram Swaroop Bana, Samarth Godara, et al. "Crop-Suitability Analysis Using the Analytic Hierarchy Process and Geospatial Techniques for Cereal Production in North India." Sustainability 14, no. 9 (April 26, 2022): 5246. http://dx.doi.org/10.3390/su14095246.
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Identification of cropland suitability is obligatory to adapting to the increased food needs driven by population expansion, environmental contamination, and climate change. Given this, the present study was conducted to assess cereal crops’ suitability in India’s Haryana state by integrating Analytic Hierarchy Process (AHP) and geographic information system (GIS) technique. Multiple factors were considered for this study, such as rainfall, temperature, soil texture, drainage density, pH, organic carbon, electrical conductivity, and slope. The AHP technique was utilized to decide the weights of each individual parameter using experts’ opinions. The crop-suitability model was developed using the model builder module in ArcGIS 10.8, and each input parameter was reclassified as per the optimum crop-growth requirement and overlaid utilizing the reclassify tool and weighted overlay analysis. The crop suitability classes were estimated as highly suitable, S1 (6%); moderately suitable, S2 (71%); and marginally suitable, S3 (23%) for the calculated arable land for the wheat crop. Similarly, the crop suitability class of rice S2 (28%); S3 (72%), for sorghum S1 (28%); S2 (71%); S3 (1%), for maize S2 (85%); S3 (15%) and for pearl millet S1 (60%); S2 (40%) were also estimated. The study has observed that, as per the soil physico-chemical characteristics and climate, the area is moderately fertile. Therefore, agricultural production can be improved by cultivating the crop in highly and moderately suitable zones. Diversification of marginally suitable regions for crops other than that for which it is not suitable can be taken up, which will also ensure the income security of marginal farmers.
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Wingate, Vladimir R., Felicia O. Akinyemi, Chima J. Iheaturu, and Chinwe Ifejika Speranza. "A Remote Sensing-Based Inventory of West Africa Tropical Forest Patches: A Basis for Enhancing Their Conservation and Sustainable Use." Remote Sensing 14, no. 24 (December 9, 2022): 6251. http://dx.doi.org/10.3390/rs14246251.
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The rate of tropical deforestation is increasing globally, and the fragmentation of remaining forests is particularly high in arable landscapes of West Africa. As such, there is an urgent need to map and monitor these remnant forest patches/fragments and so identify their multiple benefits and values. Indeed, recognizing their existence will help ensure their continued provision of ecosystem services while facilitating their conservation and sustainable use. The aim of this study is therefore to inventory and characterise the current extent and change of remnant forest patches of West Africa, using multi-source remote sensing products, time-series analyses, and ancillary datasets. Specifically, we collate and analyse descriptive and change metrics to provide estimates of fragment size, age, biophysical conditions, and relation to social-ecological change drivers, which together provide novel insights into forest fragment change dynamics for over four decades. We map forests patches outside protected areas with a tree cover ≥30%, a tree height of ≥5 m, an area ≥1 km2 and ≤10 km2. Appended to each patch are descriptive and change dynamics attributes. We find that most fragments are small, secondary forest patches and these cumulatively underwent the most forest loss. However, on average, larger patches experience more loss than smaller ones, suggesting that small patches persist in the landscape. Primary forest patches are scarce and underwent fewer losses, as they may be less accessible. In 1975 most patches were mapped as secondary, degraded forests, savanna, woodland, and mangrove, and relatively few comprised cropland, settlements, and agriculture, suggesting that new forest patches rarely emerged from arable land over the past 45 years (1975–2020), but rather are remnants of previously forested landscapes. Greening is widespread in larger secondary fragments possibly due to regrowth from land abandonment and migration to urban areas. Forest loss and gain are greater across fragments lying in more modified landscapes of secondary forests, while forest loss increases with distance to roads. Finally, larger forest patches harbour a denser tree cover and higher trees as they may be less impacted by human pressures. The number and extent of West African forest patches are expected to further decline, with a concurrent heightening of forest fragmentation and accompanying edge effects. Lacking any conservation status, and subject to increasing extractive demands, their protection and sustainable use is imperative.
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Marcella, Marc P., and Elfatih A. B. Eltahir. "Introducing an Irrigation Scheme to a Regional Climate Model: A Case Study over West Africa." Journal of Climate 27, no. 15 (July 29, 2014): 5708–23. http://dx.doi.org/10.1175/jcli-d-13-00116.1.
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Abstract This article presents a new irrigation scheme and biome to the dynamic vegetation model, Integrated Biosphere Simulator (IBIS), coupled to version 3 of the Regional Climate Model (RegCM3-IBIS). The new land cover allows for only the plant functional type (crop) to exist in an irrigated grid cell. Irrigation water (i.e., negative runoff) is applied until the soil root zone reaches relative field capacity. The new scheme allows for irrigation scheduling (i.e., when to apply water) and for the user to determine the crop to be grown. Initial simulations show a large sensitivity of the scheme to soil texture types, how the water is applied, and the climatic conditions over the region. Application of the new scheme is tested over West Africa, specifically Mali and Niger, to simulate the potential irrigation of the Niger River. A realistic representation of irrigation of the Niger River is performed by constraining the land irrigated by the annual flow of the Niger River and the amount of arable land in the region as reported by the Food and Agriculture Organization of the United Nations (FAO). A 30-yr simulation including irrigated cropland is compared to a 30-yr simulation that is identical but with no irrigation of the Niger. Results indicate a significant greening of the irrigated land as evapotranspiration over the crop fields largely increases—mostly via increases in transpiration from plant growth. The increase in the evapotranspiration, or latent heat flux (by 65–150 W m−2), causes a significant decrease in the sensible heat flux while surface temperatures cool on average by nearly 5°C. This cooling is felt downwind, where average daily temperatures outside the irrigation are reduced by 0.5°–1.0°C. Likewise, large increases in 2-m specific humidity are experienced across the irrigated cropland (on the order of 5 g kg−1) but also extend farther north and east, reflecting the prevailing surface southwesterlies. Changes (decreases) in rainfall are found only over the irrigated lands of west Mali. The decrease in rainfall can be explained by the large surface cooling and collapse of the boundary layer (by approximately 500 m). Both lead to a reduction in the triggering of convection as the convective inhibition, or negative buoyant energy, is never breached. Nevertheless, the new scheme and land cover allows for a novel line of research that can accurately reflect the effects of irrigation on climate and the surrounding environment using a dynamic vegetation model coupled to a regional climate model.
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Mahmoud, Shereif H., and A. A. Alazba. "Surface energy balance algorithm for land-based consumption water use of different land use-cover types in arid-semiarid regions." Water Supply 16, no. 6 (April 29, 2016): 1497–513. http://dx.doi.org/10.2166/ws.2016.077.
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Spatiotemporal distributions of water consumption for various land use-cover types over the Eastern province of Saudi Arabia were estimated using Surface Energy Balance Algorithm. Water consumption of various land use and cover classes shows similar seasonal dynamic trends. The spatial distribution of annual actual evapotranspiration (AET) shows low values in the Empty Quarter (231–438 mm/yr), and moderate values in the Eastern Province borders (439–731 mm/yr). Very high AET values were observed in irrigated croplands in the Northern plains, Hafar Al-Batin, the central coastal lowlands, and the southern coastal lowlands, where annual AET ranged from 732 to 1,790 mm/yr, representing the majority of the study area agricultural land. Evaporative behavior of land use-cover types indicated that irrigated cropland, which occupies 0.37% of the study area, has an average daily AET ranging from 9.2 mm/day in January to a maximum value in April (30 mm/day). Average annual water use by irrigated cropland is relatively very high and it is roughly 1,786.9 mm/yr, while water bodies, which cover 0.023% (121.2 km2) of the study area, also had relatively high mean AET (660.8 mm/yr). Overall, AET rates for irrigated cropland are much higher than for other land uses.
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Weijers, J. W. H., G. L. B. Wiesenberg, R. Bol, E. C. Hopmans, and R. D. Pancost. "Carbon isotopic composition of branched tetraether membrane lipids in soils suggest a rapid turnover and a heterotrophic life style of their source organism(s)." Biogeosciences Discussions 7, no. 3 (May 21, 2010): 3691–734. http://dx.doi.org/10.5194/bgd-7-3691-2010.
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Abstract. Branched Glycerol Dialkyl Glycerol Tetraethers (GDGTs) are membrane spanning lipids synthesised by as yet unknown bacteria that thrive in soils and peat. In order to obtain more information on their ecological niche, the stable carbon isotopic composition of branched GDGT-derived alkanes, obtained upon ether bond cleavage, has been determined in various soils, i.e. peat, forest, grassland and cropland, covered by various vegetation types, i.e., C3- vs. C4-plant type. These δ13C values are compared with those of bulk organic matter and higher plant derived n-alkanes from the same soils. With average δ13C values of −28‰, branched GDGTs in C3 soils are only slightly depleted (ca. 1‰) relative to bulk organic carbon and on average 8.5‰ enriched relative to plant wax-derived long-chain n-alkanes (nC29–nC33). In an Australian soil covered with C4 type vegetation, the branched GDGTs have a δ13C value of −18‰, clearly higher than observed in soils with C3 type vegetation. As with C3 vegetated soils, branched GDGT δ13C values are slightly depleted (1‰) relative to bulk organic carbon and enriched (ca. 5‰) relative to n-alkanes in this soil. The δ13C values of branched GDGT lipids being similar to bulk organic carbon and their co-variation with those of bulk organic carbon and plant waxes, suggest a heterotrophic life style and assimilation of relatively heavy and likely labile substrates for the as yet unknown soil bacteria that synthesise the branched GDGT lipids. However, a chemoautotrophic lifestyle, i.e. consuming respired CO2, could not be fully excluded based on these data alone. Based on a natural labelling experiment of a C3/C4 crop change introduced on one of the soils 23 years before sampling and based on a free air CO2 enrichment experiment with labelled CO2 on another soil, a turnover time of ca. 17 years has been estimated for branched GDGTs in these arable soils.
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Weijers, J. W. H., G. L. B. Wiesenberg, R. Bol, E. C. Hopmans, and R. D. Pancost. "Carbon isotopic composition of branched tetraether membrane lipids in soils suggest a rapid turnover and a heterotrophic life style of their source organism(s)." Biogeosciences 7, no. 9 (September 28, 2010): 2959–73. http://dx.doi.org/10.5194/bg-7-2959-2010.
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Abstract. Branched Glycerol Dialkyl Glycerol Tetraethers (GDGTs) are membrane spanning lipids synthesised by as yet unknown bacteria that thrive in soils and peat. In order to obtain more information on their ecological niche, the stable carbon isotopic composition of branched GDGT-derived alkanes, obtained upon ether bond cleavage, has been determined in a peat and various soils, i.e. forest, grassland and cropland, covered by various vegetation types, i.e., C3- vs. C4-plant type. These δ13C values are compared with those of bulk organic matter and higher plant derived n-alkanes from the same soils. With average δ13C values of −28‰, branched GDGTs in C3 soils are only slightly depleted (ca. 1‰) relative to bulk organic carbon and on average 8.5‰ enriched relative to plant wax-derived long-chain n-alkanes ( nC29–nC33). In an Australian soil dominantly covered with C4 type vegetation, the branched GDGTs have a δ13C value of −18‰, clearly higher than observed in soils with C3 type vegetation. As with C3 vegetated soils, branched GDGT δ13C values are slightly depleted (1‰) relative to bulk organic carbon and enriched (ca. 5‰) relative to n-alkanes in this soil. The δ13C values of branched GDGT lipids being similar to bulk organic carbon and their co-variation with those of bulk organic carbon and plant waxes, suggest a heterotrophic life style and assimilation of relatively heavy and likely labile substrates for the as yet unknown soil bacteria that synthesise the branched GDGT lipids. However, a chemoautotrophic lifestyle, i.e. consuming respired CO2, could not be fully excluded based on these data alone. Based on a natural labelling experiment of a C3/C4 crop change introduced on one of the soils 23 years before sampling and based on a free-air CO2 enrichment experiment with labelled CO2 on another soil, a turnover time of ca. 18 years has been estimated for branched GDGTs in these arable soils.
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Buryak, Zhanna, Fedor Lisetskii, Artyom Gusarov, Anastasiya Narozhnyaya, and Mikhail Kitov. "Basin-Scale Approach to Integration of Agro- and Hydroecological Monitoring for Sustainable Environmental Management: A Case Study of Belgorod Oblast, European Russia." Sustainability 14, no. 2 (January 14, 2022): 927. http://dx.doi.org/10.3390/su14020927.
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The quantitative and qualitative depletion of water resources (both surface and groundwater) is closely related to the need to protect soils against degradation, rationalization of land use, and regulation of surface water runoff within the watershed area. Belgorod Oblast (27,100 km2), one of the administrative regions of European Russia, was chosen as the study area. It is characterized by a high activity of soil erosion (the share of eroded soils is about 48% of the total area of arable land). The development phase of the River Basin Environmental Management Projects (217 river basins from the fourth to seventh order) allowed for the proceeding of the development of an integrated monitoring system for river systems and river basin systems. The methods used to establish a geoecological network for regional monitoring include the selection and application of GIS techniques to quantify the main indicators of ecological state and predisposition of river basins to soil erosion (the share of cropland and forestland, the share of the south-oriented slopes, soil erodibility, Slope Length and Steepness (LS) factor, erosion index of precipitation, and the river network density) and the method of a hierarchical classification of cluster analysis for the grouping of river basins. An approach considering the typology of river basins is also used to expand the regional network of hydrological gauging stations to rationalize the national hydrological monitoring network. By establishing 16 additional gauging stations on rivers from the fourth to seventh order, this approach allows for an increase in the area of hydro-agroecological monitoring by 1.26 times (i.e., up to 77.5% of the total area of Belgorod Oblast). Some integrated indicators of agroecological (on the watershed surface) and hydroecological (in river water flow) monitoring are proposed to improve basin environmental management projects. Six-year monitoring showed the effectiveness of water quality control measures on an example of a decrease in the concentrations of five major pollutants in river waters.
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Aweke, KA, F. Habtamu, and G. Akalu. "Nutritional status of children in food insecure households in two districts of North Showa Zone, Ethiopia." African Journal of Food, Agriculture, Nutrition and Development 12, no. 50 (April 11, 2012): 5915–27. http://dx.doi.org/10.18697/ajfand.50.11240.
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Malnutrition is one of the leading causes of morbidity and mortality of children in Ethiopia. However, little information is available on nutritional status of the lower socioeconomic segment of the community to devise targeted tackling solutions and overcome severe malnutrition. Therefore, the objective of this study is to assess nutritional status of children and other related information in food insecure households. Two hundred food insecure households (HHs) were selected from two districts of North Showa zone of Amhara in 2007. The criteria for inclusion were being landless, oxen-less, and/ or female headed. Anthropometric and clinical data were collected from a total of 239 (151 < 5yrs and 88, 6-12yrs) children. Data on demographic, childcare, feeding practices and morbidity status of children were collected using an interview, community focus group discussion and secondary data from district offices. The overall prevalence of stunting, underweight and wasting was 54.2%, 40.2% and 10.6 %, respectively. Prevalence of night blindness and Bitot's spot were 3.1% and 3.5%, respectively. The median level of urinary iodine excretion by 6-12 years children was 1.5μg/L. Seventeen percent of the children were found iron deficient. Exclusive breastfeeding up to 6 month was practiced by less than 20% of the households. About fifty six percent of the households have cropland less than half a hectare and 50.8% of the households are getting water from unprotected well or spring. The main type of toilet facility being used was open bush/field (84.5%). The main income of the households was agriculture. The majority (45-50%) of the household heads in both districts are in the age ranges of 20-30 years. Fifty percent of the household heads can read and write. Lack of enough arable land, unreliable rain fall, extension of desertification, lack of scientific agricultural knowledge, absence of irrigation schemes, and shortage of skill in land use and management are some of the problems reported to contribute to food insecurity. The households are under severe malnutrition, food insecurity and poor childcare. Therefore, improvement of household resources by initiation of income generating livelihood options and knowledge based agriculture is needed.