scholarly journals Spatial Distribution of Soil Bulk Density, Organic Carbon and pH under Different Land Use Systems along Umuahia South Local Government Area of Abia State in South Eastern Nigeria

2019 ◽  
Vol 11 (2) ◽  
pp. 298-303
Author(s):  
Brown Mang ONWUKA ◽  
Emmanuel Adeboye ADESEMUYI

Information about spatial distribution of soil qualities in a given area is a fundamental piece of land surface prerequisites for ecological purposes, agriculture and other land use systems. The utilization of numerical methods to portray soil properties and upgrade objectivity in soil-related decision making, was applied to soil samples collected from soil under the land use systems; excavation site (EX), refuse dump site (RD), forest land (FL), continuously cultivated land (CC) and 4-year bush fallow (4-BF) along Umuahia South LGA of Abia State in south eastern Nigeria. Geostatistical technique was applied to estimate the spatial distribution and produce soil maps for each selected soil properties. Results revealed that excavation site (1.70 Mg m-3) recorded a high bulk density, while the other land use systems had a moderate bulk density. The results showed that refuse dump site had a neutral soil reaction (7.02), slightly acidic reaction was recorded under 4-year bush fallow (6.00) and forest land (5.71). Continuously cultivated land had a moderately acidic soil reaction (5.41) and organic carbon content (1.48%). The result also revealed that forestland (2.97%) and refuse dump site (3.20%) had very high organic carbon content, while excavation site (0.38%) had very low organic carbon content. This study will help land owners/users in terms of choice and adoption of land for different uses in the area.  

2020 ◽  
Author(s):  
Gülay Karahan ◽  
Seongyun Kim ◽  
Yakov Pachepsky

<p>Infiltration is strongly affected by soil structure. The measurement technique and the land use are two soil structure-related attributes that are typically available in descriptions of infiltration experiments. We hypothesized that these attributes may be good predictors of the performance of different infiltration models, and of the parameter values in those models. The international soil infiltration database SWIG assembled in the Institute of Agrosphere in Jülich, Germany, was used as the data source. The database encompasses about 5000 experiments all over the world, Texture, measurement method and land use were known for all experiments, availability of organic carbon content, bulk density, saturated hydraulic conductivity (Ksat), pH, the electrical conductivity of saturated paste, and initial water content varied. Comparison of the performance of eight infiltration models showed that Horton and Mezencev models outperformed all others and that one of these two models could be preferred based on the infiltration measurement method. The machine learning method – regression trees – was applied to find the most influential predictors of parameters of Horton and Mezencev models. The measurement method, the textural class, and the land use were the most influential predictors in 80% of cases for both models. The measurement method was the most influential input in 40% of cases. The accuracy of parameter estimates increased when only the subset of measurements with the same method was used to estimate infiltration parameters. Land use, textural class, and organic carbon content dominated as the most influential predictors for the parameters of the Mezencev model, whereas land use, textural class, Ksat, and bulk density became most important in the case of the Horton model. Overall, estimates of the infiltration equation parameters can be more accurate if they have been developed for the same measurement method as in the task in hand. Land use category and the infiltration measurement method provide useful surrogate information about the soil structure effect on infiltration. </p>


2021 ◽  
Vol 13 (15) ◽  
pp. 8332
Author(s):  
Snežana Jakšić ◽  
Jordana Ninkov ◽  
Stanko Milić ◽  
Jovica Vasin ◽  
Milorad Živanov ◽  
...  

Topography-induced microclimate differences determine the local spatial variation of soil characteristics as topographic factors may play the most essential role in changing the climatic pattern. The aim of this study was to investigate the spatial distribution of soil organic carbon (SOC) with respect to the slope gradient and aspect, and to quantify their influence on SOC within different land use/cover classes. The study area is the Region of Niš in Serbia, which is characterized by complex topography with large variability in the spatial distribution of SOC. Soil samples at 0–30 cm and 30–60 cm were collected from different slope gradients and aspects in each of the three land use/cover classes. The results showed that the slope aspect significantly influenced the spatial distribution of SOC in the forest and vineyard soils, where N- and NW-facing soils had the highest level of organic carbon in the topsoil. There were no similar patterns in the uncultivated land. No significant differences were found in the subsoil. Organic carbon content was higher in the topsoil, regardless of the slope of the terrain. The mean SOC content in forest land decreased with increasing slope, but the difference was not statistically significant. In vineyards and uncultivated land, the SOC content was not predominantly determined by the slope gradient. No significant variations across slope gradients were found for all observed soil properties, except for available phosphorus and potassium. A positive correlation was observed between SOC and total nitrogen, clay, silt, and available phosphorus and potassium, while a negative correlation with coarse sand was detected. The slope aspect in relation to different land use/cover classes could provide an important reference for land management strategies in light of sustainable development.


1986 ◽  
Vol 96 (2) ◽  
pp. 185-196 ◽  
Author(s):  
Ariel E. Lugo ◽  
Mary Jeane Sanchez ◽  
Sandra Brown

Author(s):  
Hamza Haruna ◽  
Galal H.G. Hussein ◽  
Mohammed B

Soil is a living and dynamic natural reservoir and source of plant nutrients that play numerous key roles in terrestrial ecosystems. This study investigated the impact of three adjacent land use systems (Acacia senegalensis plantation (ACP), pilostigma raticulatum plantation (PRP) and Ground nut field (GNF) on selected soil physical quality indicators in a Northern Nigeria semi- arid Savanna. Minimum data set for assessing soil quality (Prime quality agricultural land) in this study include bulk density, organic carbon content, total nitrogen, carbon stock, available phosphorus and pH values obtained from DRMCC research field. Mean values of the data set were arranged and scored to obtain totals among the minimum data set (MDS). Soil quality is considered a key element for evaluating the sustainability of land management practices. Data generated were analyzed using ANOVA and significant means were determined using Duncan multiple range test (DMRT). ACP had significantly higher organic carbon content (9.37 gkg-1) and lower bulk density (2.16 gkg-1) than pilostigma and GNF respectively. The lower bulk density (ρb) and high organic carbon in ACP might be due to high leaf shading by acacia while the lower bulk density in ground nut field aided by trampling induced compaction resulted in its high relative field capacity (RFC), permanent wilting point (PWP) and micro-p ore spaces (PMIC) tillage in ground nut field created loose soil in the plough layer (<20 cm) which turn out to its low bulk density (ρb). Acacia plantation contained highest total nitrogen value (1.23 gkg-1); perhaps resulting Acacia leaf litter is known to have a high decomposition rate. Pilostigma plantation contained (1.22 gkg-1) nitrogen, while the least nitrogen content was obtained under ground nut field. On scoring the land use types and depth against the minimum data set, the least total was that under acacia plantation, followed by pilostigma plantation then ground nut field. Therefore, soils under acacia plantation were ranked best quality (SQ1) for cultivation purposes at 0-10 cm, followed by pilostigma land use type that were ranked SQ2. Ground nut field soils were ranked least (SQ6) in quality for use in crop production at depth of 10-20 cm.


Soil Research ◽  
2002 ◽  
Vol 40 (5) ◽  
pp. 847 ◽  
Author(s):  
Ravinder Kaur ◽  
Sanjeev Kumar ◽  
H. P. Gurung

Collection of non-destructive soil core samples for determination of bulk densities is costly, difficult, time- consuming, and often impractical. To overcome this difficulty, several attempts have been made in the past to estimate soil bulk densities through pedo-transfer functions (PTFs), requiring soil texture and organic carbon (OC) content data. Although many studies have shown that both organic carbon and texture predominantly determine soil bulk density, a majority of the PTFs developed so far are a function only of organic matter (OM)/OC. In addition, no attempts have been made to test and compare the applicability of these PTFs on an independent soil data set. Thus, through this study efforts have been made not only to develop a robust soil bulk density estimating PTF, based on both soil texture and organic carbon content data, but also to compare its predictive potential with the existing PTFs on an independent soil data set from 4 ecologically diverse micro-watersheds in Almora district of Uttaranchal State in India. Effects of varying levels of soil particle size distributions and/or OC/OM contents on the absolute relative errors associated with these PTFs were also analysed for assessing their applicability to the independent soil data set. Amongst the existing PTFs, Curtis and Post, Adams, Federer, and Huntington-A methods were found to be associated with positive bias or mean errors (ME) and root mean square prediction differences (RMSPD) ranging between 0.10 and 0.38, and between 0.23 and 0.45, respectively, whereas Alexander-A, Alexander-B, Manrique and Jones-A, Manrique and Jones-B, and Rawls methods were found to be associated with negative ME and RMSPD values ranging between -0.08 and -0.15, and 0.18 and 0.23, respectively. In contrast, Bernoux, Huntington-B, and Tomasella and Hodnett-PTFs, with RMSPD values ranging between 0.18 and 0.20, were the only methods associated with little or no bias. However, on comparing the predictive potential of the existing PTFs, in terms of their 1 : 1 relationships between the observed and predicted soil bulk densities and ME and RMSPD values, only Manrique and Jones-B (ME: -0.08; RMSPD: 0.18), Alexander-A (ME: -0.08; RMSPD: 0.19), and Rawls (ME: -0.11; RMSPD: 0.22) methods were observed to give somewhat more realistic soil bulk density estimations. The study revealed very limited predictive potential of the existing PTFs, due to their development on specific soils and/or ecosystems, use of an indirectly computed organic matter (instead of directly measured organic carbon) content as a predictor variable, poor predictive potential of developed regression model(s), and/or subjective errors. In contrast to this, the new soil bulk density estimating PTF was found to be associated with far better 1 : 1 relationship between the observed and predicted soil bulk densities and zero ME (or bias) and lowest (0.15 g/cm3) RMSPD values. The absolute relative errors associated with both the new and the existing soil OC/OM and texture-dependent PTFs were observed to be almost insensitive to the varying levels of silt and clay. However, compared with the existing PTFs, these errors associated with the new PTF were observed to be much more insensitive to the varying levels of OC/OM, thereby indicating the applicability of the new PTF to a wide range of soil types.


Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2550
Author(s):  
Andrej Hrabovský ◽  
Pavel Dlapa ◽  
Artemi Cerdà ◽  
Jozef Kollár

Vineyards are a 7000-year-old land-use tradition and both management and abandonment have result in altered soil properties. These have a great effect on water resources and soil services, and this inspired our investigation into the effects of land-use and land-use change on soils in the Modra wine-growing region in South-western Slovakia. Ten topsoil samples were taken at each of the seven research sites (n = 70) on granite parent material in cultivated and afforested vineyards and original forest soils. Laboratory analyses included determination of soil texture, organic carbon content, soil pH, and water repellency. This was supplemented by infiltration measurements under near-saturated conditions at the vineyard and afforested study sites. Studied soils have a low clay content and a high proportion of sand. The vineyard soils have significantly higher pH than the forest and afforested soils because the naturally acidic soils have been limed. The forest and afforested soils have similar properties, with higher organic carbon content. This makes them strongly to extremely water repellent and contrasts sharply with the wettability of cultivated vineyard soils. One afforested site, however, was less acidic and therefore was considered transitional between forest and vineyard soils. Our infiltration measurements established the influence of soil water repellency on the infiltration process, and our results highlighted that the infiltration rate in the vineyard soils was significantly higher than in afforested soils. The infiltration rate also gradually increased over time in afforested soils due to decreasing water repellency. Physically impossible negative sorptivity values in afforested soils were noted because of changes in water repellency during the infiltration process. Finally, we conclude that soil afforestation results in increased soil water repellency and a subsequent reduction in the infiltration rate at the matrix scale.


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