scholarly journals Assessment of Influencing Factors on the Spatial Variability of SOM in the Red Beds of the Nanxiong Basin of China, Using GIS and Geo-Statistical Methods

2021 ◽  
Vol 10 (6) ◽  
pp. 366
Author(s):  
Ping Yan ◽  
Kairong Lin ◽  
Yiren Wang ◽  
Xinjun Tu ◽  
Chunmei Bai ◽  
...  

Understanding the spatial variability of soil organic matter (SOM) is crucial for implementing precise land degradation control and fertilization to improve crop productivity. Studying spatial variability provides a scientific basis for precision fertilization and land degradation control. In this study, geostatistics and classical statistical methods were used to analyze the spatial variability of SOM and its influencing factors under various degrees of land degradation in the red bed area of southern China. The results demonstrate a declining trend for SOM content with increasing land degradation. The SOM content differs profoundly under different land degradation degrees. The coefficient of variation ranges from 13.61% for extreme land degradation to 8.98% for mild land degradation, 7.96% for moderate land degradation, and 5.64% for severe land degradation. A significant positive correlation is displayed between the altitude and the SOM (p < 0.01) under mild and moderate land degradation conditions. Bulk density and pH value have a significant negative correlation with SOM (p < 0.01). It can be observed that terrain factors, as well as physical and chemical soil parameters, have a great influence on SOM.

Author(s):  
Pushkin Kumar

Abstract: Land degradation is seen as a development or additional that reduces current and/or potential soil capability to produce products and goods. This implies a decline from a higher to a lower state due to a decline in land capacity, productivity, and biodiversity loss. This can be both natural and human-induced. Natural causes embody earthquakes, tsunamis, droughts, avalanches, landslides, volcanic eruptions, floods, tornadoes, and wildfires. Whereas human-induced soil degradation results from land clearing and deforestation, inappropriate agricultural practices, improper management of industrial effluents and wastes, over-grazing, careless management of forests, surface mining, urban sprawl, and commercial/industrial development. Inappropriate agricultural practices embody excessive tillage and use of heavy machineries, excessive and unbalanced use of inorganic fertilizers, poor irrigation and water management techniques, chemical or pesticide overuse, inadequate crop residue and organic carbon inputs, and poor crop cycle planning. Some underlying social causes of soil degradation in Asian nation square measure land shortage, decline in per capita land handiness, economic pressure onto land, land occupancy, poverty, and population increase.. The aim of the current study is to prepare baseline data to combat land degradation and conserve land resources in an economical and efficient manner. To assess land degradation with the help of Remote Sensing (RS) and Geographical Information System (GIS) – in Rasulabad Block of Kanpur Dehat district, Uttar Pradesh, different levels of analysis were performed to estimate the extent of land. Degradation to assess saline or salt-free soils and calcareous or sodium soils and to match this data with satellite studies. The spatial variability of these soil parameters was shown in soil maps created in a GIS environment. A temporary study of the 2017 and 2021 Sentinel satellite datasets was done to find the parameters that are responsible for land degradation. The severity of land degradation was calculable quantitatively by analyzing the physico-chemical parameters within the laboratory to see salinity and sodicity of soils and further correlating them with satellite-based studies. The pH varied between 7.1 and 8.2, electrical conductivity (EC) between 0.23 and 0.6 miliSiemens/m and the methyl orange or total alkalinity between 0.095 and 0.225 (HCO3 ) gL-1 as CaCO3. The spatial variability in these soil parameters was pictured through soil maps generated in a GIS environment with the help of IDW Interpolation. The results revealed that the soil in the study area was exposed to salt intrusion, most of the soil samples of the study area were slightly or moderately saline with a few salt-free sites. Moreover, the majority of the soil samples were calcareous and a few samples were alkaline or sodic in nature. Keyword: Land degradation, Sodic land, Saline land, GIS, IDW Interpolation.


2013 ◽  
Vol 21 (8) ◽  
pp. 992-997
Author(s):  
Kun MA ◽  
Cheng LI ◽  
Fan XIAO ◽  
Sheng-Dong FENG ◽  
Zhi-Xin YANG

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1180
Author(s):  
Jan Skála ◽  
Radim Vácha ◽  
Jarmila Čechmánková

The paired Fluvisol and cereal samples in both the field screening and controlled experiments are reported to elucidate the soil–crop relationship for As, Cd, and Pb in relation to changing contamination levels. Significant varietal differences in plant uptake were observed for crop type (barley, triticale) and the harvested part of the crop (oat shoots and grain). When parametrizing the stepwise regression models, the inclusion of soil properties often improved the performance of soil–crop models but diverse critical soil parameters were retained in the model for individual metal(loid)s. The pH value was often a statistically significant variable for Cd uptake. For As and Pb, the more successful model fit was achieved using the indicators of quantity or quality of soil organic matter, but always with lower inherent model reliability compared to Cd. Further, a single correlation analysis was used to investigate the relationship between extractable metal concentrations in soil solution and their crop accumulation. For Cd, there were strong intercorrelations among single extractions, the NH4NO3 extraction stood out with perfect correlation with plant uptake in both experiments. For As and Pb, the CaCl2 and Na2EDTA solutions outperformed other single extractions and were the better choice for the assessment of depositional fluvial substrates.


2011 ◽  
Vol 130-134 ◽  
pp. 856-859
Author(s):  
Chun Sheng Ding ◽  
Yang Ping Fu ◽  
Qian Fen Zhu ◽  
Jing Fu

In this experiment quartz sand was chosen as a carrier to be coated by aluminous salt under alkaline condition, and then the specific surface area was tested, and the adsorption capability and Cd2+ removal influencing factors of modified sand were studied. The investigation results showed that the specific surface area of modified sand was 75.244m2/g which was 9.38 times of that of original sand; the removal efficiency of Cd2+ by aluminous salt modified sand reached 59% contrast to 39% of original sand with pH 7.00. It was also found that the removal efficiency of Cd2+ by the aluminous salt modified sand was reduced with the increase of initial concentration of Cd2+ solution, and was enhanced with the increase of pH value, the Cd2+ removal efficiency was almost 71% with pH 9.0.


Solid Earth ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 75-90 ◽  
Author(s):  
Naseer Ahmad ◽  
Puneeta Pandey

Abstract. Land degradation leads to alteration of ecological and economic functions due to a decrease in productivity and quality of the land. The aim of the present study was to assess land degradation with the help of geospatial technology – remote sensing (RS) and geographical information system (GIS) – in Bathinda district, Punjab. The severity of land degradation was estimated quantitatively by analyzing the physico-chemical parameters in the laboratory to determine saline or salt-free soils and calcareous or sodic soils and further correlating them with satellite-based studies. The pH varied between 7.37 and 8.59, electrical conductivity (EC) between 1.97 and 8.78 dS m−1 and the methyl orange or total alkalinity between 0.070 and 0.223 (HCO3−) g L−1 as CaCO3. The spatial variability in these soil parameters was depicted through soil maps generated in a GIS environment. The results revealed that the soil in the study area was exposed to salt intrusion, which could be mainly attributed to irrigation practices in the state of Punjab. Most of the soil samples of the study area were slightly or moderately saline with a few salt-free sites. Furthermore, the majority of the soil samples were calcareous and a few samples were alkaline or sodic in nature. A comparative analysis of temporal satellite datasets of Landsat 7 ETM+ and Landsat 8 OLI_TIRS of 2000 and 2014, respectively, revealed that the water body showed a slight decreasing trend from 2.46 km2 in 2000 to 1.87 km2 in 2014, while the human settlements and other built-up areas expanded from 586.25 to 891.09 km2 in a span of 14 years. The results also showed a decrease in area under barren land from 68.9847 km2 in 2000 to 15.26 km2 in 2014. A significant correlation was observed between the digital number (DN) of the near-infrared band and pH and EC. Therefore, it is suggested that the present study can be applied to projects with special relevance to soil scientists, environmental scientists and planning agencies that can use the present study as baseline data to combat land degradation and conserve land resources in an efficient manner.


2008 ◽  
Author(s):  
Thayla Morandi Ridolfi de Carvalho ◽  
Daniella Jorge Moura ◽  
Irenilza Alencar Nääs

2002 ◽  
Vol 42 (3) ◽  
pp. 45-61 ◽  
Author(s):  
Shin-ichi Nishimura ◽  
Kiyoshi Shimada ◽  
Hiroaki Fujii

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