scholarly journals Effects of Agricultural Reclamation on Soil Physicochemical Properties in the Mid-Eastern Coastal Area of China

Land ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 142 ◽  
Author(s):  
Yan Xu ◽  
Lijie Pu ◽  
Runsen Zhang ◽  
Ming Zhu ◽  
Meng Zhang ◽  
...  
Keyword(s):  
Land Use ◽  
Particle Size ◽  
Physicochemical Properties ◽  
Size Ratio ◽  
Soil Particle ◽  
Population Pressure ◽  
Available Phosphorus ◽  
Soil Physicochemical Properties ◽  
Soil Particle Size ◽  
Particle Size Ratio

Agricultural reclamation in coastal zones is effective for mitigating population pressure on the food supply. Soil properties are important factors influencing crop production in reclaimed coastal lands. This study aims to investigate the impacts of time and land use trajectories on soil physicochemical properties after reclamation. We sampled soils in areas that were reclaimed in 1999, 1998, 1991, 1989, 1986, 1981, and 1979 and determined some soil physicochemical properties such as electrical conductivity with a 1:5 soil:water ratio (EC1:5), exchange sodium percentage (ESP), sodium adsorption ratio (SAR), pH, organic matter (OM), total nitrogen (TN), alkaline hydrolyzable nitrogen (AN), cation exchange capacity (CEC), total phosphorus (TP), available phosphorus (TP) and soil particle size ratio. We analyzed their correlation with land use and the time since reclamation using one-way analysis of variance (ANOVA) and principal component analysis (PCA). The results showed that soil physicochemical properties changed significantly after agricultural reclamation. Soil EC1:5, ESP, and SAR declined rapidly, and OM, TN, and AN increased rapidly during the 29 years after reclamation. The soil particle size ratio was not significantly correlated with reclamation time. The land-use trajectories identified after reclamation had obvious effects on soil physicochemical properties. Aquaculture ponds were superior to cultivated land in terms of decreasing soil salinity but were inferior in terms of soil nutrient accumulation. In the future, more attention should be given to the environmental effects of agricultural reclaimed soils.

scholarly journals Effects of Land Use, Soil Depth and Topography on Soil Physicochemical Properties along the Toposequence at the Wadla Delanta Massif, Northcentral Highlands of Ethiopia

2016 ◽  
Vol 5 (2) ◽  
pp. 57 ◽  
Author(s):  
Nahusenay Abate ◽  
Kibebew Kibret
Keyword(s):  
Land Use ◽  
Physicochemical Properties ◽  
Soil Depth ◽  
Bottom Layer ◽  
Exchange Capacity ◽  
Available Phosphorus ◽  
Soil Physicochemical Properties ◽  
Cultivated Land ◽  
Topographic Positions ◽  
Effects Of Land Use

The study was conducted to investigate the effects of land use, depth and topography on soil physicochemical properties at the Wadla Delanta Massif, northcentral Ethiopia. Four land uses (natural forest, shrub, grazing and cultivated land), three soil depths (0-20, 20-40, 40-60 cm) and three topographic positions (upper, middle and lower) in three replications were considered for this study. A total of 108 composite samples were collected for laboratory analysis. The results show that particle size distribution was affected by the main effects of land use and soil depth; bulk and particle densities, total porosity, organic matter and total nitrogen contents, C:N ratio and available phosphorus were significantly affected by the interaction of land use by soil depth only, whereas, soil pH, electrical conductivity, exchangeable bases, cation exchange capacity, percent base saturation and extractable micronutrients were affected by the interaction effects of the three factors. Highest clay and bulk density were recorded at the bottom layer of the cultivated land soils, while the utmost porosity, organic matter and nitrogen contents, and available phosphorus were recorded at the surface layers of the natural forest land soils. Highest pH was at the bottom layer of the cultivated land at the three topographic positions. Highest exchangeable bases and cation exchange capacity were observed in the bottom layers of soils under the four land use types at the lower topographic position, whilst extractable micronutrients were recorded at the surface layers of the forest land soils at the upper topographic position. In general, most of the measured soil properties were measured better in forest than in other land use soils and the lower topographic positions than the upper and middle ones. Interaction of land use with topography showed negative effects especially on cultivated and grazing land soils in all topographic positions. Therefore, integrated soil fertility management and soil conservation measures are required in all topographic positions to maintain soil physicochemical properties.

Fractal Characteristics of Soil Particle-Size Distributions under Different Landform and Land-Use Types

2011 ◽  
Vol 201-203 ◽  
pp. 2679-2684 ◽  
Author(s):  
Xiao Yu Song ◽  
Huai You Li
Keyword(s):  
Land Use ◽  
Particle Size ◽  
Fractal Dimension ◽  
Soil Particle ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Soil Particle Size ◽  
Mass Fractal ◽  
Land Use Types ◽  
Mass Fractal Dimension

It can provide theoretical guidance for the prevention of soil erosion and planting structure adjustment to study on fractal characteristics of soil particle-size distributions under different landform and land-use types. Soil particle-size distribution (PSD) is one of the most important physical attributes due to its strong influence on soil properties related to water movement, productivity and soil erosion. The fractal and multifractal measures were useful tools in identifying soil PSD with different taxonomy. Land-use type, as one of important factors to affect soil PSD was paid little attention in the previous research. In this paper, the theory of soil particle-size fractal was applied to characterize PSD in soils with the same taxonomy and different land-use types. Then the effects of land use on the fractal and multifractal parameters were analyzed. The study was conducted on the loess hilly areas of the Loess Plateau in Nanxiaohegou basin of Gansu. Soil was sampled from 18 land use types. The soil PSDs were obtained by sieving and pipette methods. The result showed that: (1) the mass fractal dimension of soil particles was significant correlated with the soil mass clay content; （2）both the soil mass clay content and the mass fractal dimension of soil particles showed the same tendency of increasing with the soil layer， and the mass fractal dimension relates to the land uses and topographic feature. Thus they could be potential parameters to reflect soil physical properties influenced by land use. More significant result is required in the future study to test the applicability of fractal parameters in characterizing land use effect on soil particle-size distributions.

Simulation on Extrusion Comminution Model of Roller Press

2010 ◽  
Vol 156-157 ◽  
pp. 1702-1707
Author(s):  
Xiang Wen Cheng ◽  
Jinchao Liu ◽  
Qi Zhi Ding ◽  
Li Ming Song ◽  
Zhan Lin Wang
Keyword(s):  
Experimental Data ◽  
Particle Size ◽  
Field Experiments ◽  
Size Ratio ◽  
Optimum Operating ◽  
Extrusion Force ◽  
Particle Size Ratio ◽  
Small Constant ◽  
Working Parameters ◽  
The Relationship

How to predict the relationship among particle size and among product size, to establish the relationship between the granularity and working parameters in the process of grinding and to determine the optimum operating parameters. With proposing BS squeeze crush model by L. Bass and the idea of roll surface division as the material uneven extrusion force are adopted. Based on field experiments the experimental data is analyzed, the select function and the breakage functions are fitted with MATLAB software, and obtaining their model. The comminution model is determined by the roller division. We obtain the model parameter through the experimental data. Through model analysis shows: the relationship between particle breakage and energy absorption, namely the smaller size of the same power, the lower broken; the breakage diminishes with the decrease of particle size ratio and it will be tending to a small constant when the smaller particle size ratio. The breakage functions rapidly decrease within ratio of between 0.2-0.7. This shows: the energy consumption will rapidly increase when the particle size of less than 0.2 in broken; the selection diminish with the decrease of particle size. Pressure (8-9MPa) should be the most appropriate value.

Particle size ratio and distribution effects on packing behaviour of crushed GMZ bentonite pellets

2019 ◽  
Vol 351 ◽  
pp. 92-101 ◽  
Author(s):  
Zhang-Rong Liu ◽  
Wei-Min Ye ◽  
Zhao Zhang ◽  
Qiong Wang ◽  
Yong-Gui Chen ◽  
...  
Keyword(s):  
Particle Size ◽  
Size Ratio ◽  
Gmz Bentonite ◽  
Particle Size Ratio
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