In 2011, Yunnan provincial committee and government proposed the strat- egy of constructing mountainous cities in order to protect farmlands and guarantee crop safety, which makes full use of hills and gentle-slopes a...In 2011, Yunnan provincial committee and government proposed the strat- egy of constructing mountainous cities in order to protect farmlands and guarantee crop safety, which makes full use of hills and gentle-slopes and transforms land use pattern. However, social and economic development performs unevenly in Yun- nan, supplemented by varied geographical conditions, so that constructing mountain- ous cities should proceed as per local conditions. The research proposed the con- trol of constructing mountainous cities provided crop safety under the principle of farmland protection and measured the quantities of demanded construction lands ac- cording to science of population prediction and ekistics, based on which the control scales of constructing mountainous cities were determined by multiplying basic farm- land coefficient and the area of newly increased construction lands. The research is of significance for guiding the construction of mountainous cities and avoiding the occupation of construction lands on farmlands.展开更多
Soil enzymes activities and microbial biomass have an important influence on nutrient cycling. The spatial distribution of soil enzymes activities and microbial biomass were examined along a latitudinal gradient in fa...Soil enzymes activities and microbial biomass have an important influence on nutrient cycling. The spatial distribution of soil enzymes activities and microbial biomass were examined along a latitudinal gradient in farmlands of Songliao Plain, Northeast China to assess the impact of climatic changes along the latitudinal transect on nutrient cycling in agroecosystems. Top soils (0-20 cm depth) were sampled in fields at 7 locations from north (Hallun) to south (Dashiqiao) in the end of October 2005 after maize harvest. The contents of total C, N, and P, C/N, available N, and available P increased with the latitude. The activities of invertase and acid phosphatase, microbial biomass (MB) C and N, and MBC/MBN were significantly correlated with latitude (P 〈 0.05, r^2 = 0.198, 0.635, 0.558, 0.211 and 0.317, respectively), that is, increasing with the latitude. Significant positive correlations (P 〈 0.05) were observed between invertase activity and the total N and available P, and between acid phosphatase activity and the total C, C/N, available N, total P and available P. The urease, acid phosphatase, and dehydrogenase activities were significantly correlated with the soil pH and electrical conductivity (EC) (P 〈 0.05). MBC and MBN were positively correlated with the total C, C/N, and available P (P 〈 0.05). The MBC/MBN ratio was positively correlated with the total C, total N, C/N, and available N (P 〈 0.05). The spatial distribution of soil enzyme activities and microbial biomass resulted from the changes in soil properties such as soil organic matter, soil pH, and EC, partially owing to variations in temperature and rainfall along the latitudinal gradient.展开更多
In this paper, the history, current status, and research approaches to nitrogen pollution were reviewed using systems analysis and deductions. The seriousness of N pollution world-wide was highlighted and recommendati...In this paper, the history, current status, and research approaches to nitrogen pollution were reviewed using systems analysis and deductions. The seriousness of N pollution world-wide was highlighted and recommendations were made to address the situation. A new hypothesis based on phytoremediation, which means the use of plants to directly or indirectly degrade or remove contaminats from soil and water, was proposed.展开更多
pH, exchangeable Ca2+ and Mg2+ of soil can influence the yield and quality of flue-cured tobacco. Xuancheng city is the dominant tobacco-planting region in Anhui province since 2008. A general soil survey was conducte...pH, exchangeable Ca2+ and Mg2+ of soil can influence the yield and quality of flue-cured tobacco. Xuancheng city is the dominant tobacco-planting region in Anhui province since 2008. A general soil survey was conducted in Xuancheng city to understand the current situations of pH, exchangeable Ca2+ and Mg2+ of farmlands under tobacco-rice rotation and to decide whether continuous applying dolomite powders to abate soil acidification. In total 124 topsoil samples (0-20 cm) were collected from the typical farmlands and soil pH, exchangeable Ca2+ and Mg2+ were measured. The results showed that soil pH and Ca2+ and Mg2+ in Xuancheng city were generally in the suitable grades, pH ranged from 4.56 to 8.42 with an average of 5.87, exchangeable Ca2+ ranged from 1.01 cmol(1/2Ca2+) kg-1 to 100.55 cmol(1/2Ca2+) kg-1 with an average of 11.07 cmol(1/2Ca2+) kg-1, and exchangeable Mg2+ ranged from 0.14 cmol(1/2Mg2+) kg-1 to 2.86 cmol(1/2Mg2+) kg-1 with an average of 0.81 cmol(1/2Mg2+) kg-1, all spanned from the low grades to the high grades. To the whole Xuancheng city, 37.10%, 62.10% and 72.58% of the surveyed farmlands were in the low grades of pH, exchangeable Ca2+ and Mg2+, respectively, while 52.42%, 25.00% and 20.97% of the farmlands were in the suitable grades, respectively. pH had an extremely significantly positive Napierian logarithm correlation with exchangeable Ca2+ and an extremely significantly positive power correlation with exchangeable Mg2+. In total about 338.2 kg·hm-2 of Ca2+ and 202.4 kg·hm-2 of Mg2+ are annually input into the farmlands, while about 110.4 kg·hm-2 of Ca2+ and 7.4 kg·hm-2 of Mg2+ are annually moved out from the farmlands, exchangeable Ca2+ and Mg2+ were annually increased by 225.2 kg·hm-2 and 187.6 kg·hm-2 in the farmlands, respectively. It is necessary to monitor the farmlands dynamically in order to decide whether continuous applying dolomite powders which should be dependent upon the specific conditions of individual farmlands.展开更多
The report of the 19th National Congress of the Communist Party of China stated that it was necessary to establish and practice the concept that lucid waters and lush mountains are invaluable assets,treat the ecologic...The report of the 19th National Congress of the Communist Party of China stated that it was necessary to establish and practice the concept that lucid waters and lush mountains are invaluable assets,treat the ecological environment as life,and coordinate the management of mountains,rivers,forests,farmlands,lakes and grasslands.In recent years,China has organized a series of pilot projects for the ecological protection and restoration of mountains,rivers,forests,farmlands,lakes and grasslands,breaking the boundary between administrative divisions,departmental management and ecological elements,and implementing conservation and restoration oriented towards the improvement of ecosystem services,so as to solve the problem of the lack of overall planning for ecological protection and restoration projects and the separated management of ecological elements.This study systematically elaborated the theoretical basis and connotation characteristics of ecological protection and restoration of mountains,rivers,forests,farmlands,lakes and grasslands.It proposed the implementation path of ecological protection and restoration project of mountains,rivers,forests,farmlands,lakes and grasslands by taking the water source conservation area of Beijing-Tianjin-Hebei as a case,so as to provide reference for the implementation and decision-making management of ecological protection and restoration projects in various regions.展开更多
[Objective] The aim was to analyze nutrients distribution and proportion in soils of farmlands of Gonggar County in Tibet. [Method] According to survey of soils in Tibet, nutrients of farmlands in Gonggar County were ...[Objective] The aim was to analyze nutrients distribution and proportion in soils of farmlands of Gonggar County in Tibet. [Method] According to survey of soils in Tibet, nutrients of farmlands in Gonggar County were analyzed and the countermeasures were proposed to achieve sustainable development of nutrients in soils. [Result] In Gonggar County in Tibet, farmlands with insufficient and less organic matter occupy 58.38%; farmlands with moderate contents of total N occupy 47.71%; farmlands with insufficient and less alkali-hydrolyzable nitrogen represent 82.36%; the farmlands with moderate and rich total P take up 49.40% and 21.59% ; farmlands with insufficient and less rapidly available P represent 67.33%; farmlands with richer and rich total K occupy 76.14% ; farmlands with moderate and insufficient rapidly available K represent 72.21%. [Conclusion] Based on nutrients in soils of farmlands, the countermeasures for sustainable utilization of nutrients in farmlands are proposed, including increase of organic fertilizer, soil testing and formulated fertilization and adjustment of acid-base balance.展开更多
In recent years,benefiting from the unique natural conditions and the promotion and application of agricultural science and technology,the level of maize production in Tunliu County continues to increase,and many tonn...In recent years,benefiting from the unique natural conditions and the promotion and application of agricultural science and technology,the level of maize production in Tunliu County continues to increase,and many tonnage farmlands are emerging. East Ligao Village in Ligao Town is famous for its tonnage farmlands throughout the county. Through a lot of research,maize cultivation techniques in tonnage farmlands are summed up in this paper from the aspects of plot selection,intensive cultivation,high-quality manure application,chemical fertilizers scientific application,disease-resistant high-yield superior varieties selection,reasonable close planting and strengthening field management,etc,which has certain guiding significance for the high yield of maize.展开更多
The practicable solution to the problem of degradation of mountainous pastures/hayfields provoked by unplanned and unregulated use of farmlands is considered in the article. With the view of developing animal husbandr...The practicable solution to the problem of degradation of mountainous pastures/hayfields provoked by unplanned and unregulated use of farmlands is considered in the article. With the view of developing animal husbandry and managing pastures/hayfields, in 2011-2012, the Government of the Republic of Armenia under support of the World Bank implemented a Farm Resources Management and Competitiveness Program. The goal of the Program is ceasing a trend to overgrazing and degradation of close-to-village sites, using remote pastures/hayfields in the best effective manner, improving feed production and animal feeding networks, and promoting a growth in animal feed production volumes. To achieve that, the following works were planned and implemented successfully in 23 rural communities of six marzes of the RA (Republic of Armenia), which was done by three stages. For the 23 communities series of cartographic layers was produced and a relevant database was compiled and mapped.展开更多
The aim of this study was to determine the nitrate pollution status of soil, groundwater, and vegetable from three typical farmlands (croplands, vegetable fields, and orchards) in Beijing region. During the investig...The aim of this study was to determine the nitrate pollution status of soil, groundwater, and vegetable from three typical farmlands (croplands, vegetable fields, and orchards) in Beijing region. During the investigation, hundreds of the soil, groundwater, and vegetable samples from three typical farmlands were collected and analyzed. In addition, attributes of all samples were recorded for data analysis. The results showed that nitrate was substantially accumulated in soil profiles, while the soil nitrate concentrations of vegetable fields and orchards were higher than those of croplands. Nitrate concentration in 0-30 cm soil of vegetable field and orchard were 3.8 and 1.2 times of that of cropland, respectively. Nitrate content of groundwater in vegetable field was 13.8 mg L-1 (with the over-standard ratio 44.8%), which was 2.8 folds of that in cropland. Nitrate concentration of groundwater under orchard was 9.3 mg L-1 (with the over-standard ratio 23.5%), which was 1.9 folds of that in cropland. High concentrations of the nitrate in vegetables were detected, particularly green leafy vegetables ranked first with 2 685.5 mg kg-1, followed by rhizome vegetables, cabbages, and fruit vegetables. The nitrate over-standard ratios of rhizome vegetables, green leafy vegetables, fruit vegetables, and cabbages were 80.9, 37.9, 29.7, and 2.2%, respectively. The results revealed that the high nitrate concentrations of soil, vegetable, and groundwater might result from the high fertilization dose.展开更多
Soil organic carbon(SOC)and total nitrogen(N)concentrations from bulk soils and soil particle size fractions in the different extent of desertified farmlands(potential, light, medium, severe, and most severe desertifi...Soil organic carbon(SOC)and total nitrogen(N)concentrations from bulk soils and soil particle size fractions in the different extent of desertified farmlands(potential, light, medium, severe, and most severe desertified farmlands)were examined to quantitatively elucidate losses of carbon and nitrogen and its mechanisms in the desertification process. Particle size fractions(2 -0.1 mm, 0.1 - 0.05 mm, <0.05 mm)were obtained by granulometric wet sieving from 30 sandy soils(0 - 15cm depth)of different desertified extent. It was shown that soil physical stability index(St)in most severe desertified farmlands was 5 -7% and St in other farmlands was less than 5 %, which contributed to very low soil organic matter content. This was the intrinsic cause that sandy farmlands in Horqin sandy land was subject to risk of desertification. Desertification resulted in considerable losses of SOC and N. Regression analysis indicated that SOC and N content reduced 0.169 g kg-1 and 0.0215 g kg-1 respectively with one percent loss of soil silt and clay content. Losses of SOC and N were mostly the removal of fine particle size fractions(silt and clay, and a less extent very fine sand)from the farmlands by wind erosion, which were rich in organic matter and nutrients, as well as the depletion of organic C and N associated with coarse particles(>0. 05 mm)in desertification process. The concentrations of C and N associated with sand(2 - 0.1 mm and 0.1 - 0.05 mm)significantly decreased with increase of desertified extent. Silt and clay associated C and N concentrations, however, were less changed, and in contrast, were higher in soils under most severe desertified extent than in soils under potential and severe desertified extent. The percentage of distribution in sand(>0.05 mm)associated C and N significantly increased with increase of desertified extent, suggesting that stability of SOC decreased in the desertification process.展开更多
There are numerous valley farmlands on the Chinese Loess Plateau(CLP),where suffers from low soil quality and high risk of soil salinization due to the shallow groundwater table and poor drainage system.Currently,rese...There are numerous valley farmlands on the Chinese Loess Plateau(CLP),where suffers from low soil quality and high risk of soil salinization due to the shallow groundwater table and poor drainage system.Currently,research on the evolution processes and mechanisms of soil quality and salinization in these dammed-valley farmlands on the CLP is still inadequately understood.In this study,three kinds of dammed-valley farmlands in the hilly-gully areas of the northern CLP were selected,and the status of soil quality and the impact factors of soil salinization were examined.The dammed-valley farmlands include the new farmland created by the project of Gully Land Consolidation,the 60-a farmland created by sedimentation from check dam,and the 400-a farmland created by sedimentation from an ancient landslide-dammed lake.Results showed that(1)the newly created farmland had the lowest soil quality in terms of soil bulk density,porosity,soil organic carbon and total nitrogen among the three kinds of dammed-valley farmlands;(2)soil salinization occurred in the middle and upper reaches of the new and 60-a valley farmlands,whereas no soil salinization was found in the 400-a valley farmland;and(3)soil salinization and low soil nutrient were determined to be the two important factors that impacted the soil quality of the valley farmlands in the hilly-gully mountain areas of the CLP.We conclude that the dammed-valley farmlands on the CLP have a high risk of soil salinization due to the shallow groundwater table,alkalinity of the loessial soil and local landform feature,thus resulting in the low soil quality of the valley farmlands.Therefore,strengthening drainage and decreasing groundwater table are extremely important to improve the soil quality of the valley farmlands and guarantee the sustainable development of the valley agriculture on the CLP.展开更多
The available contents of microelements in the topsoil can influence the yield and quality of flue-cured tobacco. Xuancheng is the dominant tobacco-planting region in Anhui province since 2008. In this paper, the tops...The available contents of microelements in the topsoil can influence the yield and quality of flue-cured tobacco. Xuancheng is the dominant tobacco-planting region in Anhui province since 2008. In this paper, the topsoil available Fe, Mn, Cu and Zn contents of 4197 farmlands mainly under rice-rice rotation and wheat-rice rotation in 2008 and of 124 typical farmlands under tobacco-rice rotation in 2015 in Xuancheng city were analyzed in order to disclose the changes and spatial distributions of these microelements and to instruct the reasonable application of the microelement fertilizers. The results showed that the topsoil average available contents in the farmlands under rice-rice rotation or wheat-rice rotation in 2008 were 105.9 mg·kg-1 for Fe, 19.6 mg·kg-1 for Mn, 4.5 mg·kg-1 for Cu, and 3.0 mg·kg-1 for Zn, respectively, increased by 33.14%, 64.29%, 51.11% and 36.67%, respectively, compared with those in the 2nd Soil Survey in 1980s, and the historic, once intensive and overall application of microelement fertilizers was attributed to the great increases. The topsoil average available contents in the farmlands under tobacco-rice rotation in 2015 were 31.1 mg·kg-1 for Fe, 9.8 mg·kg-1 for Mn, 2.1 mg·kg-1 for Cu, and 0.3 mg·kg-1 for Zn, respectively, decreased by 70.63%, 50.00%, 53.33% and 90.00%, respectively, compared with those of the farmlands under rice-rice rotation or wheat-rice rotation in 2008, and the net deficiencies in the input and output of microelements were attributed to the significant decreases in the topsoil microelements. It is necessary to monitor the farmlands under tobacco-rice rotation dynamically and in time in order to decide whether applying microelement fertilizers or not.展开更多
An environmental investigation of soil, water and vegetable around Asphalt production plant for heavy metals;Zinc (Zn), Manganese (Mn), Cadmium (Cd), Lead (Pb), Cobalt (Co), Nickel (Ni) and Chromium (Cr) was carried o...An environmental investigation of soil, water and vegetable around Asphalt production plant for heavy metals;Zinc (Zn), Manganese (Mn), Cadmium (Cd), Lead (Pb), Cobalt (Co), Nickel (Ni) and Chromium (Cr) was carried out. Their mean concentrations in soil, water and vegetable were Zn (13.84 mg/Kg, 12.949 mg/L and 11.177 mg/Kg), Mg (3.728 mg/Kg, 0.125 mg/L and 21.837 mg/Kg), Cd (0.012 mg/Kg, 0.018 mg/L and 0.028 mg/Kg) and Pb (0.011 mg/Kg). Co, Ni and Cr were not detected. The results of physiocochemical parameters (pH, moisture content (%), conductivity (μS/cm), organic matter (%), organic carbon (%), CEC (cmol/Kg) and soil composition (%)) were all within the permissible limits by NAFDAC and NDWQS. Results of mineral composition of soil include (N (%) of 0.42, K (cmol/kg) 0.32, Na (cmol/kg) 0.28, Mg (cmol/kg) 3.40, Ca (cmol/kg) 3.80, ?(cmol/kg) 0.46 and (cmol/kg) 0.49);analytical results were within the acceptable range. The chemical parameters investigated for water samples are (Cl- (mg/L) = 1871.20, ?(mg/L) = 12.60, ?(mg/L) = 10.20, NH3 (mg/L) = 8.20, DO (mg/L) = 9.40, BOD (mg/L) = 6.40 and COD (mg/L) = 12.80) within agricultural farmlands around the Asphalt production plant. From the analytical results, conductivity (μS/cm), N (%), ?(mg/L) were significantly different (p which are also the predominant mineral composition in the soil.展开更多
Plastic is considered one of the most indispensable commodities in our daily life.At the end of life,the huge ever-growing pile of plastic waste(PW)causes serious concerns for our environment,including agricultural fa...Plastic is considered one of the most indispensable commodities in our daily life.At the end of life,the huge ever-growing pile of plastic waste(PW)causes serious concerns for our environment,including agricultural farmlands,groundwater quality,marine and land ecosystems,food toxicity and human health hazards.Lack of proper infrastructure,financial backup,and technological advancement turn this hazardous waste plastic management into a serious threat to developing countries,especially for Bangladesh.A comprehensive review of PW generation and its consequences on environment in both global and Bangladesh contexts is presented.The dispersion routes of PW from different sources in different forms(microplastic,macroplastic,nanoplastic)and its adverse effect on agriculture,marine life and terrestrial ecosystems are illustrated in this work.The key challenges to mitigate PW pollution and tackle down the climate change issue is discussed in this work.Moreover,way forward toward the design and implementation of proper PW management strategies are highlighted in this study.展开更多
Food security is a strategic priority for a country’s economic development.In China,high-standard farmland construction(HSFC)is an important initiative to stabilize grain production and increase grain production capa...Food security is a strategic priority for a country’s economic development.In China,high-standard farmland construction(HSFC)is an important initiative to stabilize grain production and increase grain production capacity.Based on panel data from 31 sample provinces,autonomous regions,and municipalities in China from 2005–2017,this study explored the impact of HSFC on grain yield using the difference-in-differences(DID)method.The results showed that HSFC significantly increased total grain production,which is robust to various checks.HSFC increased grain yield through three potential mechanisms.First,it could increase the grain replanting index.Second,it could effectively reduce yield loss due to droughts and floods.Last,HSFC could strengthen the cultivated land by renovating the low-and medium-yielding fields.Heterogeneity analysis found that the HSFC farmland showed a significant increase in grain yield only in the main grain-producing areas and balanced areas.In addition,HSFC significantly increased the yields of rice,wheat,and maize while leading to a reduction in soybean yields.The findings suggest the government should continue to promote HSFC,improve construction standards,and strictly control the“non-agriculturalization”and“non-coordination”of farmland to increase grain production further.At the same time,market mechanisms should be used to incentivize soybean farming,improve returns and stabilize soybean yields.展开更多
Landslides are one of the most dangerous natural hazards that cause significant property damage and loss of life.Landslides often destroy farmland,villages,houses,factories,schools,roads and other facilities,injuring ...Landslides are one of the most dangerous natural hazards that cause significant property damage and loss of life.Landslides often destroy farmland,villages,houses,factories,schools,roads and other facilities,injuring humans and livestock.Sometimes,entire towns are devastated by landslides.Due to their pervasiveness,varied triggering factors,and sudden occurrence,landslides are currently one of the most challenging natural disasters to prevent and mitigate.展开更多
Suffering from adverse weather conditions,Malawi’s farmers savour the prospect of exporting soya beans to the lucrative Chinese market.Like many farmers,Monica Haraba wakes up at 5:00 a.m.to get ready to harvest her ...Suffering from adverse weather conditions,Malawi’s farmers savour the prospect of exporting soya beans to the lucrative Chinese market.Like many farmers,Monica Haraba wakes up at 5:00 a.m.to get ready to harvest her soya bean crop at her farmland located on the outskirts of Lilongwe,Malawi’s capital.But like last year,she is expecting lower output due to adverse weather,especially draught.展开更多
In the heart of South Africa’s rugged Swartberg and Koue Bokkeveld mountains lies the alps towering majestically above fertile citrus farmland,forming a wall that sustains enough rainfall to attract farmers to the so...In the heart of South Africa’s rugged Swartberg and Koue Bokkeveld mountains lies the alps towering majestically above fertile citrus farmland,forming a wall that sustains enough rainfall to attract farmers to the south.Siabonga Mbete,34,grows tangerine-a small seedless fruit of the citrus family that is turning South African farmers into millionaires.展开更多
Plastic debris as new pollutants attracts much attention in the recent years.The plastic mulching films is one of the most important plastic debirs source in the environment.The aim of this work was to investigate the...Plastic debris as new pollutants attracts much attention in the recent years.The plastic mulching films is one of the most important plastic debirs source in the environment.The aim of this work was to investigate the current status of pesticide residues on the plastic mulching films.Based on the QuEChERS method,multi-residue methods for detection of pesticide residues with gas chromatography tandem mass spectrum(GC-MS)and high performance liquid chromatography tandem mass spectrum(HPLC-MS)were developed for the analysis of the pesticides residues in plastic film and soil samples from Tianjin,Hebei and Shandong.The total concentrations of pesticide residues were in the range of 86.4-22213.2 ng/g in plastic film debris,which was about 20 times higher than that in soil(9.3—535.3 ng/g).Residual level of pesticides varied greatly in different samples.The historical usage and recent application of pesticides were the main sources for pesticide residues on plastic films and soil.In short,plastic mulching films could act as a sink for pesticides in farmland and the ubiquitous pesticide residues on plastic films should draw more attention.展开更多
The application of autonomous agricultural vehicles is gaining popularity as a way to increase production efficiency and lower operational costs.To achieve high performance,perception tasks(such as obstacle detection,...The application of autonomous agricultural vehicles is gaining popularity as a way to increase production efficiency and lower operational costs.To achieve high performance,perception tasks(such as obstacle detection,road extraction,and drivable area extraction)are of great importance.Compared with structured roads,field roads between farmlands,including unstructured roads and semi-structured roads,are unfavorable for autonomous agricultural vehicle driving due to their bumpiness and unstructured nature.This study proposed an extraction method for the straight field roads between farmlands.The proposed method was based on the point cloud data acquired by LiDAR(Velodyne VLP-16)mounted on a John Deere 12046B-1204 tractor.The proposed method has three aspects:Euclidean Clustering-based extraction,boundary-based extraction,and road point cloud curve segment modification.Firstly,Euclidean Clustering with K-Dimensional(KD)-Tree data structure was adopted to extract the road curve segments close to the LiDAR composed of road points.Secondly,the boundary lines constraint was constructed to extract the distant road curve segments.Thirdly,the local distance ratio was used to modify the extracted road curve segments.The average extraction accuracy for both semi-structured and unstructured roads exceeded 98%,and the false positive rate(FPR)was less than 0.5%.These experimental findings demonstrated that the proposed road extraction method was precise and effective.The proposed method of this study can be applied to enhance the perception ability of autonomous agricultural vehicles thereby increasing the efficiency and safety of field road driving.展开更多
基金Supported by National Natural Science Foundation of China(41261018)Scientific Research Foundation of Yunnan Education Committee(2015YUFEYC011)~~
文摘In 2011, Yunnan provincial committee and government proposed the strat- egy of constructing mountainous cities in order to protect farmlands and guarantee crop safety, which makes full use of hills and gentle-slopes and transforms land use pattern. However, social and economic development performs unevenly in Yun- nan, supplemented by varied geographical conditions, so that constructing mountain- ous cities should proceed as per local conditions. The research proposed the con- trol of constructing mountainous cities provided crop safety under the principle of farmland protection and measured the quantities of demanded construction lands ac- cording to science of population prediction and ekistics, based on which the control scales of constructing mountainous cities were determined by multiplying basic farm- land coefficient and the area of newly increased construction lands. The research is of significance for guiding the construction of mountainous cities and avoiding the occupation of construction lands on farmlands.
基金the National Key Basic Research Support Foundation of China (No.2005CB121105)theNational Natural Science Foundation of China (No.30670379).
文摘Soil enzymes activities and microbial biomass have an important influence on nutrient cycling. The spatial distribution of soil enzymes activities and microbial biomass were examined along a latitudinal gradient in farmlands of Songliao Plain, Northeast China to assess the impact of climatic changes along the latitudinal transect on nutrient cycling in agroecosystems. Top soils (0-20 cm depth) were sampled in fields at 7 locations from north (Hallun) to south (Dashiqiao) in the end of October 2005 after maize harvest. The contents of total C, N, and P, C/N, available N, and available P increased with the latitude. The activities of invertase and acid phosphatase, microbial biomass (MB) C and N, and MBC/MBN were significantly correlated with latitude (P 〈 0.05, r^2 = 0.198, 0.635, 0.558, 0.211 and 0.317, respectively), that is, increasing with the latitude. Significant positive correlations (P 〈 0.05) were observed between invertase activity and the total N and available P, and between acid phosphatase activity and the total C, C/N, available N, total P and available P. The urease, acid phosphatase, and dehydrogenase activities were significantly correlated with the soil pH and electrical conductivity (EC) (P 〈 0.05). MBC and MBN were positively correlated with the total C, C/N, and available P (P 〈 0.05). The MBC/MBN ratio was positively correlated with the total C, total N, C/N, and available N (P 〈 0.05). The spatial distribution of soil enzyme activities and microbial biomass resulted from the changes in soil properties such as soil organic matter, soil pH, and EC, partially owing to variations in temperature and rainfall along the latitudinal gradient.
基金supported by the National Key Technology R&D Program of China (2006BAD02A15&2007BAD89B01)
文摘In this paper, the history, current status, and research approaches to nitrogen pollution were reviewed using systems analysis and deductions. The seriousness of N pollution world-wide was highlighted and recommendations were made to address the situation. A new hypothesis based on phytoremediation, which means the use of plants to directly or indirectly degrade or remove contaminats from soil and water, was proposed.
文摘pH, exchangeable Ca2+ and Mg2+ of soil can influence the yield and quality of flue-cured tobacco. Xuancheng city is the dominant tobacco-planting region in Anhui province since 2008. A general soil survey was conducted in Xuancheng city to understand the current situations of pH, exchangeable Ca2+ and Mg2+ of farmlands under tobacco-rice rotation and to decide whether continuous applying dolomite powders to abate soil acidification. In total 124 topsoil samples (0-20 cm) were collected from the typical farmlands and soil pH, exchangeable Ca2+ and Mg2+ were measured. The results showed that soil pH and Ca2+ and Mg2+ in Xuancheng city were generally in the suitable grades, pH ranged from 4.56 to 8.42 with an average of 5.87, exchangeable Ca2+ ranged from 1.01 cmol(1/2Ca2+) kg-1 to 100.55 cmol(1/2Ca2+) kg-1 with an average of 11.07 cmol(1/2Ca2+) kg-1, and exchangeable Mg2+ ranged from 0.14 cmol(1/2Mg2+) kg-1 to 2.86 cmol(1/2Mg2+) kg-1 with an average of 0.81 cmol(1/2Mg2+) kg-1, all spanned from the low grades to the high grades. To the whole Xuancheng city, 37.10%, 62.10% and 72.58% of the surveyed farmlands were in the low grades of pH, exchangeable Ca2+ and Mg2+, respectively, while 52.42%, 25.00% and 20.97% of the farmlands were in the suitable grades, respectively. pH had an extremely significantly positive Napierian logarithm correlation with exchangeable Ca2+ and an extremely significantly positive power correlation with exchangeable Mg2+. In total about 338.2 kg·hm-2 of Ca2+ and 202.4 kg·hm-2 of Mg2+ are annually input into the farmlands, while about 110.4 kg·hm-2 of Ca2+ and 7.4 kg·hm-2 of Mg2+ are annually moved out from the farmlands, exchangeable Ca2+ and Mg2+ were annually increased by 225.2 kg·hm-2 and 187.6 kg·hm-2 in the farmlands, respectively. It is necessary to monitor the farmlands dynamically in order to decide whether continuous applying dolomite powders which should be dependent upon the specific conditions of individual farmlands.
文摘The report of the 19th National Congress of the Communist Party of China stated that it was necessary to establish and practice the concept that lucid waters and lush mountains are invaluable assets,treat the ecological environment as life,and coordinate the management of mountains,rivers,forests,farmlands,lakes and grasslands.In recent years,China has organized a series of pilot projects for the ecological protection and restoration of mountains,rivers,forests,farmlands,lakes and grasslands,breaking the boundary between administrative divisions,departmental management and ecological elements,and implementing conservation and restoration oriented towards the improvement of ecosystem services,so as to solve the problem of the lack of overall planning for ecological protection and restoration projects and the separated management of ecological elements.This study systematically elaborated the theoretical basis and connotation characteristics of ecological protection and restoration of mountains,rivers,forests,farmlands,lakes and grasslands.It proposed the implementation path of ecological protection and restoration project of mountains,rivers,forests,farmlands,lakes and grasslands by taking the water source conservation area of Beijing-Tianjin-Hebei as a case,so as to provide reference for the implementation and decision-making management of ecological protection and restoration projects in various regions.
基金Supported by Fund from Science and Technology Department of Tibet Autonomous Region ([2009]162)~~
文摘[Objective] The aim was to analyze nutrients distribution and proportion in soils of farmlands of Gonggar County in Tibet. [Method] According to survey of soils in Tibet, nutrients of farmlands in Gonggar County were analyzed and the countermeasures were proposed to achieve sustainable development of nutrients in soils. [Result] In Gonggar County in Tibet, farmlands with insufficient and less organic matter occupy 58.38%; farmlands with moderate contents of total N occupy 47.71%; farmlands with insufficient and less alkali-hydrolyzable nitrogen represent 82.36%; the farmlands with moderate and rich total P take up 49.40% and 21.59% ; farmlands with insufficient and less rapidly available P represent 67.33%; farmlands with richer and rich total K occupy 76.14% ; farmlands with moderate and insufficient rapidly available K represent 72.21%. [Conclusion] Based on nutrients in soils of farmlands, the countermeasures for sustainable utilization of nutrients in farmlands are proposed, including increase of organic fertilizer, soil testing and formulated fertilization and adjustment of acid-base balance.
文摘In recent years,benefiting from the unique natural conditions and the promotion and application of agricultural science and technology,the level of maize production in Tunliu County continues to increase,and many tonnage farmlands are emerging. East Ligao Village in Ligao Town is famous for its tonnage farmlands throughout the county. Through a lot of research,maize cultivation techniques in tonnage farmlands are summed up in this paper from the aspects of plot selection,intensive cultivation,high-quality manure application,chemical fertilizers scientific application,disease-resistant high-yield superior varieties selection,reasonable close planting and strengthening field management,etc,which has certain guiding significance for the high yield of maize.
文摘The practicable solution to the problem of degradation of mountainous pastures/hayfields provoked by unplanned and unregulated use of farmlands is considered in the article. With the view of developing animal husbandry and managing pastures/hayfields, in 2011-2012, the Government of the Republic of Armenia under support of the World Bank implemented a Farm Resources Management and Competitiveness Program. The goal of the Program is ceasing a trend to overgrazing and degradation of close-to-village sites, using remote pastures/hayfields in the best effective manner, improving feed production and animal feeding networks, and promoting a growth in animal feed production volumes. To achieve that, the following works were planned and implemented successfully in 23 rural communities of six marzes of the RA (Republic of Armenia), which was done by three stages. For the 23 communities series of cartographic layers was produced and a relevant database was compiled and mapped.
基金the Special Fund for Agro-Scientific Research in the Public Interest, China (20100314)the Major Projects of Water Pollution Control and Treatment, China (2008ZX07425)+1 种基金the Agriculture Resources and Environment Protection Fiscal Project of Ministry of Agriculture, China, the SciTech New Star Plan of Beijing City, China (2007B045)the China Project of IPNI
文摘The aim of this study was to determine the nitrate pollution status of soil, groundwater, and vegetable from three typical farmlands (croplands, vegetable fields, and orchards) in Beijing region. During the investigation, hundreds of the soil, groundwater, and vegetable samples from three typical farmlands were collected and analyzed. In addition, attributes of all samples were recorded for data analysis. The results showed that nitrate was substantially accumulated in soil profiles, while the soil nitrate concentrations of vegetable fields and orchards were higher than those of croplands. Nitrate concentration in 0-30 cm soil of vegetable field and orchard were 3.8 and 1.2 times of that of cropland, respectively. Nitrate content of groundwater in vegetable field was 13.8 mg L-1 (with the over-standard ratio 44.8%), which was 2.8 folds of that in cropland. Nitrate concentration of groundwater under orchard was 9.3 mg L-1 (with the over-standard ratio 23.5%), which was 1.9 folds of that in cropland. High concentrations of the nitrate in vegetables were detected, particularly green leafy vegetables ranked first with 2 685.5 mg kg-1, followed by rhizome vegetables, cabbages, and fruit vegetables. The nitrate over-standard ratios of rhizome vegetables, green leafy vegetables, fruit vegetables, and cabbages were 80.9, 37.9, 29.7, and 2.2%, respectively. The results revealed that the high nitrate concentrations of soil, vegetable, and groundwater might result from the high fertilization dose.
文摘Soil organic carbon(SOC)and total nitrogen(N)concentrations from bulk soils and soil particle size fractions in the different extent of desertified farmlands(potential, light, medium, severe, and most severe desertified farmlands)were examined to quantitatively elucidate losses of carbon and nitrogen and its mechanisms in the desertification process. Particle size fractions(2 -0.1 mm, 0.1 - 0.05 mm, <0.05 mm)were obtained by granulometric wet sieving from 30 sandy soils(0 - 15cm depth)of different desertified extent. It was shown that soil physical stability index(St)in most severe desertified farmlands was 5 -7% and St in other farmlands was less than 5 %, which contributed to very low soil organic matter content. This was the intrinsic cause that sandy farmlands in Horqin sandy land was subject to risk of desertification. Desertification resulted in considerable losses of SOC and N. Regression analysis indicated that SOC and N content reduced 0.169 g kg-1 and 0.0215 g kg-1 respectively with one percent loss of soil silt and clay content. Losses of SOC and N were mostly the removal of fine particle size fractions(silt and clay, and a less extent very fine sand)from the farmlands by wind erosion, which were rich in organic matter and nutrients, as well as the depletion of organic C and N associated with coarse particles(>0. 05 mm)in desertification process. The concentrations of C and N associated with sand(2 - 0.1 mm and 0.1 - 0.05 mm)significantly decreased with increase of desertified extent. Silt and clay associated C and N concentrations, however, were less changed, and in contrast, were higher in soils under most severe desertified extent than in soils under potential and severe desertified extent. The percentage of distribution in sand(>0.05 mm)associated C and N significantly increased with increase of desertified extent, suggesting that stability of SOC decreased in the desertification process.
基金This study was funded by the National Natural Science Foundation of China(41790444)the Strategic Priority Research Program of Chinese Academy of Sciences(XDB40000000)the National Key Research and Development Program of China(2018YFC1504701).
文摘There are numerous valley farmlands on the Chinese Loess Plateau(CLP),where suffers from low soil quality and high risk of soil salinization due to the shallow groundwater table and poor drainage system.Currently,research on the evolution processes and mechanisms of soil quality and salinization in these dammed-valley farmlands on the CLP is still inadequately understood.In this study,three kinds of dammed-valley farmlands in the hilly-gully areas of the northern CLP were selected,and the status of soil quality and the impact factors of soil salinization were examined.The dammed-valley farmlands include the new farmland created by the project of Gully Land Consolidation,the 60-a farmland created by sedimentation from check dam,and the 400-a farmland created by sedimentation from an ancient landslide-dammed lake.Results showed that(1)the newly created farmland had the lowest soil quality in terms of soil bulk density,porosity,soil organic carbon and total nitrogen among the three kinds of dammed-valley farmlands;(2)soil salinization occurred in the middle and upper reaches of the new and 60-a valley farmlands,whereas no soil salinization was found in the 400-a valley farmland;and(3)soil salinization and low soil nutrient were determined to be the two important factors that impacted the soil quality of the valley farmlands in the hilly-gully mountain areas of the CLP.We conclude that the dammed-valley farmlands on the CLP have a high risk of soil salinization due to the shallow groundwater table,alkalinity of the loessial soil and local landform feature,thus resulting in the low soil quality of the valley farmlands.Therefore,strengthening drainage and decreasing groundwater table are extremely important to improve the soil quality of the valley farmlands and guarantee the sustainable development of the valley agriculture on the CLP.
文摘The available contents of microelements in the topsoil can influence the yield and quality of flue-cured tobacco. Xuancheng is the dominant tobacco-planting region in Anhui province since 2008. In this paper, the topsoil available Fe, Mn, Cu and Zn contents of 4197 farmlands mainly under rice-rice rotation and wheat-rice rotation in 2008 and of 124 typical farmlands under tobacco-rice rotation in 2015 in Xuancheng city were analyzed in order to disclose the changes and spatial distributions of these microelements and to instruct the reasonable application of the microelement fertilizers. The results showed that the topsoil average available contents in the farmlands under rice-rice rotation or wheat-rice rotation in 2008 were 105.9 mg·kg-1 for Fe, 19.6 mg·kg-1 for Mn, 4.5 mg·kg-1 for Cu, and 3.0 mg·kg-1 for Zn, respectively, increased by 33.14%, 64.29%, 51.11% and 36.67%, respectively, compared with those in the 2nd Soil Survey in 1980s, and the historic, once intensive and overall application of microelement fertilizers was attributed to the great increases. The topsoil average available contents in the farmlands under tobacco-rice rotation in 2015 were 31.1 mg·kg-1 for Fe, 9.8 mg·kg-1 for Mn, 2.1 mg·kg-1 for Cu, and 0.3 mg·kg-1 for Zn, respectively, decreased by 70.63%, 50.00%, 53.33% and 90.00%, respectively, compared with those of the farmlands under rice-rice rotation or wheat-rice rotation in 2008, and the net deficiencies in the input and output of microelements were attributed to the significant decreases in the topsoil microelements. It is necessary to monitor the farmlands under tobacco-rice rotation dynamically and in time in order to decide whether applying microelement fertilizers or not.
文摘An environmental investigation of soil, water and vegetable around Asphalt production plant for heavy metals;Zinc (Zn), Manganese (Mn), Cadmium (Cd), Lead (Pb), Cobalt (Co), Nickel (Ni) and Chromium (Cr) was carried out. Their mean concentrations in soil, water and vegetable were Zn (13.84 mg/Kg, 12.949 mg/L and 11.177 mg/Kg), Mg (3.728 mg/Kg, 0.125 mg/L and 21.837 mg/Kg), Cd (0.012 mg/Kg, 0.018 mg/L and 0.028 mg/Kg) and Pb (0.011 mg/Kg). Co, Ni and Cr were not detected. The results of physiocochemical parameters (pH, moisture content (%), conductivity (μS/cm), organic matter (%), organic carbon (%), CEC (cmol/Kg) and soil composition (%)) were all within the permissible limits by NAFDAC and NDWQS. Results of mineral composition of soil include (N (%) of 0.42, K (cmol/kg) 0.32, Na (cmol/kg) 0.28, Mg (cmol/kg) 3.40, Ca (cmol/kg) 3.80, ?(cmol/kg) 0.46 and (cmol/kg) 0.49);analytical results were within the acceptable range. The chemical parameters investigated for water samples are (Cl- (mg/L) = 1871.20, ?(mg/L) = 12.60, ?(mg/L) = 10.20, NH3 (mg/L) = 8.20, DO (mg/L) = 9.40, BOD (mg/L) = 6.40 and COD (mg/L) = 12.80) within agricultural farmlands around the Asphalt production plant. From the analytical results, conductivity (μS/cm), N (%), ?(mg/L) were significantly different (p which are also the predominant mineral composition in the soil.
文摘Plastic is considered one of the most indispensable commodities in our daily life.At the end of life,the huge ever-growing pile of plastic waste(PW)causes serious concerns for our environment,including agricultural farmlands,groundwater quality,marine and land ecosystems,food toxicity and human health hazards.Lack of proper infrastructure,financial backup,and technological advancement turn this hazardous waste plastic management into a serious threat to developing countries,especially for Bangladesh.A comprehensive review of PW generation and its consequences on environment in both global and Bangladesh contexts is presented.The dispersion routes of PW from different sources in different forms(microplastic,macroplastic,nanoplastic)and its adverse effect on agriculture,marine life and terrestrial ecosystems are illustrated in this work.The key challenges to mitigate PW pollution and tackle down the climate change issue is discussed in this work.Moreover,way forward toward the design and implementation of proper PW management strategies are highlighted in this study.
基金supported by the National Natural Science Foundation of China(41871184)the National Social Science Fund of China(21ZDA056)the Scientific and Technological Innovation Project of the Chinese Academy of Agricultural Sciences(10-IAED-ZT-01-2023and 10-IAED-RC-07-2023)。
文摘Food security is a strategic priority for a country’s economic development.In China,high-standard farmland construction(HSFC)is an important initiative to stabilize grain production and increase grain production capacity.Based on panel data from 31 sample provinces,autonomous regions,and municipalities in China from 2005–2017,this study explored the impact of HSFC on grain yield using the difference-in-differences(DID)method.The results showed that HSFC significantly increased total grain production,which is robust to various checks.HSFC increased grain yield through three potential mechanisms.First,it could increase the grain replanting index.Second,it could effectively reduce yield loss due to droughts and floods.Last,HSFC could strengthen the cultivated land by renovating the low-and medium-yielding fields.Heterogeneity analysis found that the HSFC farmland showed a significant increase in grain yield only in the main grain-producing areas and balanced areas.In addition,HSFC significantly increased the yields of rice,wheat,and maize while leading to a reduction in soybean yields.The findings suggest the government should continue to promote HSFC,improve construction standards,and strictly control the“non-agriculturalization”and“non-coordination”of farmland to increase grain production further.At the same time,market mechanisms should be used to incentivize soybean farming,improve returns and stabilize soybean yields.
文摘Landslides are one of the most dangerous natural hazards that cause significant property damage and loss of life.Landslides often destroy farmland,villages,houses,factories,schools,roads and other facilities,injuring humans and livestock.Sometimes,entire towns are devastated by landslides.Due to their pervasiveness,varied triggering factors,and sudden occurrence,landslides are currently one of the most challenging natural disasters to prevent and mitigate.
文摘Suffering from adverse weather conditions,Malawi’s farmers savour the prospect of exporting soya beans to the lucrative Chinese market.Like many farmers,Monica Haraba wakes up at 5:00 a.m.to get ready to harvest her soya bean crop at her farmland located on the outskirts of Lilongwe,Malawi’s capital.But like last year,she is expecting lower output due to adverse weather,especially draught.
文摘In the heart of South Africa’s rugged Swartberg and Koue Bokkeveld mountains lies the alps towering majestically above fertile citrus farmland,forming a wall that sustains enough rainfall to attract farmers to the south.Siabonga Mbete,34,grows tangerine-a small seedless fruit of the citrus family that is turning South African farmers into millionaires.
基金This work was supported by the National Major Science and Technology Projects of China(No.2017ZX07107-001)Beijing Science and Technology Planning Project(No.Z181100005418010).
文摘Plastic debris as new pollutants attracts much attention in the recent years.The plastic mulching films is one of the most important plastic debirs source in the environment.The aim of this work was to investigate the current status of pesticide residues on the plastic mulching films.Based on the QuEChERS method,multi-residue methods for detection of pesticide residues with gas chromatography tandem mass spectrum(GC-MS)and high performance liquid chromatography tandem mass spectrum(HPLC-MS)were developed for the analysis of the pesticides residues in plastic film and soil samples from Tianjin,Hebei and Shandong.The total concentrations of pesticide residues were in the range of 86.4-22213.2 ng/g in plastic film debris,which was about 20 times higher than that in soil(9.3—535.3 ng/g).Residual level of pesticides varied greatly in different samples.The historical usage and recent application of pesticides were the main sources for pesticide residues on plastic films and soil.In short,plastic mulching films could act as a sink for pesticides in farmland and the ubiquitous pesticide residues on plastic films should draw more attention.
基金financially supported by the National Key Research&Development Project(Grant No.2021YFB3901302)the Beijing Municipal Science and Technology Project(Grant No.Z201100008020008).
文摘The application of autonomous agricultural vehicles is gaining popularity as a way to increase production efficiency and lower operational costs.To achieve high performance,perception tasks(such as obstacle detection,road extraction,and drivable area extraction)are of great importance.Compared with structured roads,field roads between farmlands,including unstructured roads and semi-structured roads,are unfavorable for autonomous agricultural vehicle driving due to their bumpiness and unstructured nature.This study proposed an extraction method for the straight field roads between farmlands.The proposed method was based on the point cloud data acquired by LiDAR(Velodyne VLP-16)mounted on a John Deere 12046B-1204 tractor.The proposed method has three aspects:Euclidean Clustering-based extraction,boundary-based extraction,and road point cloud curve segment modification.Firstly,Euclidean Clustering with K-Dimensional(KD)-Tree data structure was adopted to extract the road curve segments close to the LiDAR composed of road points.Secondly,the boundary lines constraint was constructed to extract the distant road curve segments.Thirdly,the local distance ratio was used to modify the extracted road curve segments.The average extraction accuracy for both semi-structured and unstructured roads exceeded 98%,and the false positive rate(FPR)was less than 0.5%.These experimental findings demonstrated that the proposed road extraction method was precise and effective.The proposed method of this study can be applied to enhance the perception ability of autonomous agricultural vehicles thereby increasing the efficiency and safety of field road driving.