scholarly journals Determination of Occurrences, Distribution, Health Impacts of Organochlorine Pesticides in Soils of Central China

2019 ◽  
Vol 16 (1) ◽  
pp. 146 ◽  
Author(s):  
Tekleweini Gereslassie ◽  
Ababo Workineh ◽  
Onyango Janet Atieno ◽  
Jun Wang
Keyword(s):  
Land Use ◽  
Organochlorine Pesticides ◽  
Solid Phase ◽  
Total Concentration ◽  
Soil Layer ◽  
Central China ◽  
Composition Analysis ◽  
Barren Land ◽  
Land Use Types ◽  
Subsurface Soil

Organochlorine pesticides are groups of chemicals applied to prevent pest and insect infestation. This study was aimed at investigating the concentration, potential sources, cancer risk and ecological toxicity of organochlorine pesticides (OCPs) in Huangpi district, Wuhan, China. Eight OCPs in soil samples collected from four land-use types at depths of 0–10 and 10–20 cm were examined. Sample extraction was carried out by solid phase matrix extraction method and analyzed using Agilent gas chromatograph 7890B equipped with electron capture detectors (ECD). The total concentration of OCPs ranged from 0.00–32.7 ng g−1 in the surface and 0.01–100.45 ng g−1 in the subsurface soil layer. Beta hexachlorocyclohexanes (β-HCH) with 2.20 and 7.71 ng g−1 in the surface and subsurface soil layers, respectively, was the dominant compound. The mean concentrations of OCPs in all samples were less than the threshold values for hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethane (DDTs) in China soil. Concentration of OCPs in the four land-use types were in the order of: paddy field > barren land > farmland > plastic greenhouse. Results of composition analysis revealed recent application of lindane as a major and historical use of new technical HCHs as a minor source of HCHs. On the other hand, application of new technical p,p’-DDT is the main source of DDTs in the study area. The estimated lifetime average daily dose, incremental lifetime cancer risks and hazard quotient values revealed that there is less likelihood of carcinogenic and noncarcinogenic health risks on the local residents.

scholarly journals EVALUATION OF SOILBORNE PLANT PATHOGENIC FUNGAL COUNT IN VARIOUS LAND USE TYPES OF DISTRICT OKARA

2018 ◽  
Vol 30 (1) ◽  
pp. 69
Author(s):  
Sumaira Naz ◽  
Salik N. Khan ◽  
Muhammad N. Chaudhry
Keyword(s):  
Land Use ◽  
Fungal Pathogens ◽  
Soil Samples ◽  
Malt Extract ◽  
Forest Land ◽  
Barren Land ◽  
Land Use Types ◽  
Different Depths ◽  
Penicillium Spp ◽  
Made In

A field survey was conducted in district Okara to determine existing plant pathogenic fungal count in various land use types. The target sites were classified as orchard, barren land, fallow land, cultivated land and forest land use types. Field soil samples were collected from these land use types at different depths of 15, 30 and 45 cm respectively. Dilution of soil samples was made in sterilized distilled water and 1ml was poured on to the malt extract agar (MEA) medium in 90 mm diameter Petri plates incubated at 25±2°C for 5-7 days. Purified fungal colonies of Mucor spp., Fusarium solani, Aspergillus niger, Penicillium spp., Alternaria alternata, Curvularia spp., Rhizopus spp., and Helminthosporium spp. on potato dextrose agar (PDA) medium were identified based on their morphological descriptions. These fungal counts were recovered from the soil at 30 cm depth which indicates an alarming situation for deep-rooted crops to soilborne fungal pathogens infestation in future.

scholarly journals Improving Parcel-Level Mapping of Smallholder Crops from VHSR Imagery: An Ensemble Machine-Learning-Based Framework

2021 ◽  
Vol 13 (11) ◽  
pp. 2146
Author(s):  
Peng Zhang ◽  
Shougeng Hu ◽  
Weidong Li ◽  
Chuanrong Zhang ◽  
Peikun Cheng
Keyword(s):  
Machine Learning ◽  
Land Use ◽  
Precision Agriculture ◽  
Agricultural Land ◽  
Spatial Information ◽  
Classification Performance ◽  
Central China ◽  
Ensemble Machine Learning ◽  
Land Use Types ◽  
Crop Mapping

Explicit spatial information about crop types on smallholder farms is important for the development of local precision agriculture. However, due to highly fragmented and heterogeneous cropland landscapes, fine-scale mapping of smallholder crops, based on low- and medium-resolution satellite images and relying on a single machine learning (ML) classifier, generally fails to achieve satisfactory performance. This paper develops an ensemble ML-based framework to improve the accuracy of parcel-level smallholder crop mapping from very high spatial resolution (VHSR) images. A typical smallholder agricultural area in central China covered by WorldView-2 images is selected to demonstrate our approach. This approach involves the task of distinguishing eight crop-level agricultural land use types. To this end, six widely used individual ML classifiers are evaluated. We further improved their performance by independently implementing bagging and stacking ensemble learning (EL) techniques. The results show that the bagging models improved the performance of unstable classifiers, but these improvements are limited. In contrast, the stacking models perform better, and the Stacking #2 model (overall accuracy = 83.91%, kappa = 0.812), which integrates the three best-performing individual classifiers, performs the best of all of the built models and improves the classwise accuracy of almost all of the land use types. Since classification performance can be significantly improved without adding costly data collection, stacking-ensemble mapping approaches are valuable for the spatial management of complex agricultural areas. We also demonstrate that using geometric and textural features extracted from VHSR images can improve the accuracy of parcel-level smallholder crop mapping. The proposed framework shows the great potential of combining EL technology with VHSR imagery for accurate mapping of smallholder crops, which could facilitate the development of parcel-level crop identification systems in countries dominated by smallholder agriculture.

scholarly journals Analysis of soil moisture condition under different land uses in the arid region of Horqin sandy land, northern China

Solid Earth ◽  
2015 ◽  
Vol 6 (4) ◽  
pp. 1157-1167 ◽  
Author(s):  
C. Y. Niu ◽  
A. Musa ◽  
Y. Liu
Keyword(s):  
Land Use ◽  
Soil Moisture ◽  
Soil Water ◽  
Soil Layer ◽  
Temporal Variations ◽  
Land Uses ◽  
Deep Soil ◽  
Moisture Condition ◽  
Soil Moisture Condition ◽  
Land Use Types

Abstract. Land use plays an important role in controlling spatial and temporal variations of soil moisture by influencing infiltration rates, runoff and evapotranspiration, which is important to crop growth and vegetation restoration in semiarid environments, such as Horqin sandy land in north China. However, few studies have been conducted comparing differences of dynamics of soil water conditions and the responses of soil to infiltration under different land use types in semiarid area. Five different land use types were selected to analyze soil moisture variations in relation to land use patterns during the growing season of 2 years. Results showed that soil moisture condition was affected by different land uses in semi-arid sandy soils. The higher soil moisture content among different land uses was exhibited by the grassland, followed by cropland, poplar land, inter-dunes and shrub land. The temporal variations of soil moisture in different land uses were not always consistent with the rainfall due to the dry sequence. Moreover, soil water at the surface, in the root zone and at the deep soil layer indicated statistical differences for different types of land cover. Meanwhile, temporal variations of soil moisture profile changed with precipitation. However, in the deep soil layer, there was a clear lag in response to precipitation. In addition, seasonal variations of profile soil moisture were classified into two types: increasing and waving types. And the stable soil water layer was at 80–120 cm. Furthermore, the infiltration depth exhibited a positive correlation with precipitation under all land uses. This study provided an insight into the implications for land and agricultural water management in this area.

scholarly journals Sloping land use affects the complexity of soil moisture and temperature changes in the loess hilly region of China

PLoS ONE ◽  
2022 ◽  
Vol 17 (1) ◽  
pp. e0262445
Author(s):  
Chao Zhang ◽  
Min Tang ◽  
Xiaodong Gao ◽  
Qiang Ling ◽  
Pute Wu
Keyword(s):  
Land Use ◽  
Soil Moisture ◽  
Soil Temperature ◽  
Soil Depth ◽  
Soil Layer ◽  
Temperature Changes ◽  
Growing Seasons ◽  
Land Use Types ◽  
Hilly Region ◽  
Sloping Land

Various land use types have been implemented by the government in the loess hilly region of China to facilitate sustainable land use. Understanding the variability in soil moisture and temperature under various sloping land use types can aid the ecological restoration and sustainable utilization of sloping land resources. The objective of this study was to use approximate entropy (ApEn) to reveal the variations in soil moisture and temperature under different land use types, because ApEn only requires a short data series to obtain robust estimates, with a strong anti-interference ability. An experiment was conducted with four typical land use scenarios (i.e., soybean sloping field, maize terraced field, jujube orchard, and grassland) over two consecutive plant growing seasons (2014 and 2015), and the time series of soil moisture and temperature within different soil depth layers of each land use type were measured in both seasons. The results showed that the changing amplitude, degree of variation, and active layer of soil moisture in the 0–160 cm soil depth layer, as well as the changing amplitude and degree of variation of soil temperature in the 0–100 cm soil layer increased in the jujube orchard over the two growing seasons. The changing amplitude, degree of variation, and active layer of soil moisture all decreased in the maize terraced field, as did the changing amplitude and degree of variation of soil temperature. The ApEn of the soil moisture series was the lowest in the 0–160 cm soil layer in the maize terraced field, and the ApEn of the soil temperature series was the highest in the 0–100 cm layer in the jujube orchard in the two growing seasons. Finally, the jujube orchard soil moisture and temperature change process were more variable, whereas the changes in the maize terraced field were more stable, with a stable soil moisture and temperature. This work highlights the usefulness of ApEn for revealing soil moisture and temperature changes and to guide the management and development of sloping fields.

scholarly journals An Analysis of Hydraulic Properties of Soil Based on Soil Texture in Chiti Areas of Lamjung District In Nepal

2018 ◽  
Vol 11 ◽  
pp. 63-76
Author(s):  
Jyoti Karki ◽  
Umesh Kumar Mandal ◽  
Chabi Lal Chidi ◽  
Jitan Dahal ◽  
Narendra Raj Khanal ◽  
...  
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Bulk Density ◽  
Soil Texture ◽  
Hydraulic Properties ◽  
Land Use Land Cover ◽  
Soil Hydraulic Properties ◽  
Barren Land ◽  
Land Use Types ◽  
Soil Hydraulic

Soil hydraulic properties play crucial role for having sustainable growth of vegetation and also required for carrying out environmental studies especially subsurface ground water. Since, its direct measurement is time consuming and therefore costly, indirect methods such as pedotransfer functions have been used to estimate hydraulic properties. Soil hydraulic properties: bulk density, available water, permanent wilting point, field capacity and water retention capacity and saturated hydraulic conductivity are essential to be studied. These factors affect soil productivity and the environment. The knowledge of soil water properties for different land-use and land cover types based on soil textural classes are important for re-growth of plants and agriculture crops and ultimately efficient soil and water management. The aim of this paper is to measure soil hydraulic properties based on soil textural classes for different land use types. Furthermore, the use of the soil texture triangle: hydraulic properties calculator has been assessed. The comparison of the soil hydraulic properties obtained from textural triangle for different land use land and cover types has also been analyzed. Moreover, an analysis of variance (ANOVA) of soil hydraulic properties among different land use types has been performed. The soil reaction (pH) value ranges from 4.69 to 6.69 and as a mean of 5.51 indicating slight acidic. The analysis showed barren land occupying 14.3 percent of total land use/land cover is found to be suitable for plant growth since it has loam texture having bulk density less than 1.6 g/cm3.The analysis of bulk density showed that barren land is significantly different at the 0.05 level from both agriculture and forest, whereas agriculture and forests  are not different even at 0.05 significant levels. It verifies the fact that mean bulk density at the depth of 0.15 cm is affected by land use land cover types.The Geographical Journal of NepalVol. 11: 63-76, 2018

Atmospheric dry and wet nitrogen deposition on three contrasting land use types of an agricultural catchment in subtropical central China

2013 ◽  
Vol 67 ◽  
pp. 415-424 ◽  
Author(s):  
Jianlin Shen ◽  
Yong Li ◽  
Xuejun Liu ◽  
Xiaosheng Luo ◽  
Hong Tang ◽  
...  
Keyword(s):  
Land Use ◽  
Nitrogen Deposition ◽  
Central China ◽  
Land Use Types

A review of the impacts of land use change, climate zone, forest type and age on soil organic carbon and other soil quality indicators following afforestation

2020 ◽  
Author(s):  
Yang Guo ◽  
Mohamed Abdalla ◽  
Mikk Espenberg ◽  
Astley Hastings ◽  
Paul Hallett ◽  
...  
Keyword(s):  
Land Use ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Forest Type ◽  
Soil Depth ◽  
Soil Layer ◽  
Limiting Factor ◽  
Barren Land ◽  
Soil Layers ◽  
Climate Zone

<p>The main aim of this global review and systematic analysis was to investigate the impacts of previous land use system, climate zone and forest type and age on soil organic carbon (SOC), total nitrogen (TN) and total phosphorus (TP), in the different soil layers (0-20, 20-60 and 60-100 cm), following afforestation. We collected 85 publications on SOC, TN and TP stock changes, covering different countries and climate zones. The data were classified into groups depending on these investigated parameters and analyzed using R version 3.6.1. We found that afforestation significantly increased SOC and TN stocks in the 0-20 and 20-60 soil layers, with values of 45% and 44% for SOC, 30% and 22% for TN, respectively, but had no impact on TP stock. Previous land use systems had the largest influence on SOC, TN and TP stocks, with greater accumulations on barren land compared to cropland and grassland. Climate zone influenced SOC, TN and TP stocks, with significant accumulations in the moist than in the dry climate zone. Afforestation with broadleaf deciduous and broadleaf evergreen forests led to greater SOC, TN and TP accumulations in each soil layer throughout the investigated profile (0-100 cm), compared to coniferous forests. Afforestation for <20 years had significantly increased SOC and TN stocks only at the soil surface (0-20 cm) whilst afforestation for ≥ 20 years had significantly accumulated them up to 100 cm soil depth. TP stock did not change with the forest age, suggesting that it may become a limiting factor for carbon sequestration under the older-age forest. Following afforestation, the change of soil bulk density had inverse relationships with SOC or TN stocks changes but had no effect on TP stock change.</p>

LAND USE TYPES AND SOIL CHARACTERISTICTS: A CASE STUDY IN HUONG VINH COMMUNE, HUONG TRA TOWN, THUA THIEN HUE PROVINCE

2017 ◽  
Vol 126 (4B) ◽  
Author(s):  
Trần Thanh Đức
Keyword(s):  
Land Use ◽  
Sweet Potato ◽  
Soil Analysis ◽  
Soil Characteristics ◽  
Low Ph ◽  
Clay Loam ◽  
Total N ◽  
Land Use Types ◽  
Total P

This research carried out in Huong Vinh commune, Huong Tra town, Thua Thien Hue province aimed to identify types of land use and soil characteristics. Results showed that five crops are found in Huong Vinh commune including rice, peanut, sweet potato, cassava and vegetable. There are two major soil orders with four soil suborders classified by FAO in Huong Vinh commune including Fluvisols (Dystric Fluvisols<em>, </em>Gleyic Fluvisols and Cambic Fluvisols) and Arenosols (Haplic Arenosols). The results from soil analysis showed that three soil suborders including Dystric Fluvisols<em>, </em>Gleyic Fluvisols and Cambic Fluvisols belonging to Fluvisols were clay loam in texture, low pH, low in OC, total N, total P<sub>2</sub>O<sub>5</sub> and total K<sub>2</sub>O. Meanwhile, the Haplic Arenosols was loamy sand in texture, poor capacity to hold OC, total N, total P<sub>2</sub>O<sub>5</sub> and total K<sub>2</sub>O

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