Linking litter decomposition to soil physicochemical properties, gas transport and land use

Author(s):  
Yuting Fu ◽  
Lis W. Jonge ◽  
Mogens H. Greve ◽  
Emmanuel Arthur ◽  
Per Moldrup ◽  
...  
2016 ◽  
Vol 5 (2) ◽  
pp. 57 ◽  
Author(s):  
Nahusenay Abate ◽  
Kibebew Kibret

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.


2020 ◽  
Vol 2020 ◽  
pp. 1-20
Author(s):  
Weldemariam Seifu ◽  
Eyasu Elias ◽  
Girmay Gebresamuel

Understanding topography effects and assessing the soil properties in different land use is an essential first step for sustainable soil management. Hence, land use type and altitudinal gradient on selected soil parameters were studied in Ayiba watershed, northern Ethiopia. Thirty composite soil samples were collected from 0 to 30 cm of soil depth under four land use types across three altitudinal gradients and were analyzed for selected soil parameters following the standard procedures. A significant main effect of land use and altitudinal gradient on the content of the soil particles was noted. Results also indicated that the bulk density (BD), total porosity (TP), and Pav of the soil are significantly different ( p  < 0.05) in the watershed because of land use type and altitudinal gradient. Barren land and higher altitude landscapes have the highest BD, and the lowest TP, and grassland and lower altitude landscapes have the lowest BD and high TP. Intensive cultivation accompanied by natural land conversion and erosion due to the rugged landscape nature caused high BD and low TP. Analysis of variance results also shows the significant interaction effect of land use type and altitudinal gradient on EC, SOM, SOC ( p  < 0.001), and pH-water (1:2.5), and TN ( p  < 0.01). The Pearson correlation of SOM with TP, TN, MC, and clay content showed a strong positive relationship. But, SOC, TN, and clay content were negatively correlated with BD. Soils of the study watershed are found in low to optimum rating levels in their selected physicochemical properties. Overall, the results show that land use and topography gradient significantly affected soil physicochemical properties in the study watershed. Therefore, soil management options should focus on scenarios that could improve the soil conditions to enhance crop production on a sustainable basis.


2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Gebretsadik Melak Tamene ◽  
Hailu Kindie Adiss ◽  
Melese Yigzaw Alemu

Recent research findings imply that the slope aspect has a great impact on soil genesis and soil microclimate. The microclimate has a significant effect on the soil geobiochemical processes taking place in the soil. However, the slope aspect impact on soil properties has not been yet studied well in Ethiopia, particularly in the northern highlands. This research was initiated to link selected soil physicochemical properties with slope aspects under different land use practices. The research was conducted in Gumara-Maksegnit watershed located at the upper Lake Tana basin, Ethiopia. Four slope aspects, eastward (Ew), northward (Nw), southward (Sw), and westward (Ww), and three land use types at each slope aspect, cropland (Cl), forest land (Fl), and grazing land (Gl), were considered. In total, 36 undisturbed soil samples for bulk density and 36 disturbed soil samples for selected soil properties were collected. Soil particle size (texture), bulk density, electrical conductivity (EC), soil pH, available phosphorus (av. P), available potassium (av. K), total nitrogen (TN), and soil organic carbon (SOC) were analyzed. The resulting analyses showed no significant variation (p<0.05) across both slope aspects and/or land use types for soil pH and EC, whereas the slope aspect showed a significant effect (p<0.05) on SOC, TN, av. K, and av. P. The highest significant (p<0.05) mean value of SOC was observed in the Ww (3.04%) followed by Nw (2.52%) but SOC was not significant (p<0.05) between Sw and Ew. While the highest av. K (1233.2 centimole/kilogram) and av. phosphorus (35.76 ppm) were observed in Nw slope aspect, the highest TN was in the Ww slope aspect (0.24%). The significant effect (p<0.05) of land uses can be summarized as Fl > Gl > Cl for SOC and TN. A strong positive correlation was observed between SOC and TN (R2 = 0.997) and av. K and av. P (R2 = 0.58) at p<0.05. Generally, the slope aspect, land use types, and their interaction had a significant effect on soil physicochemical properties.


2020 ◽  
Vol 12 (21) ◽  
pp. 9226
Author(s):  
Runxia Zhang ◽  
Xueyong Zhao ◽  
Chencheng Zhang ◽  
Jing Li

Land use/land cover (LULC) change widely occurs during urbanization and can affect the functionality of soil ecosystems by altering soil physicochemical properties. However, few studies have evaluated the impacts of LULC change on soils in arid regions. This study investigates LULC change patterns during 2010–2017 in Lanzhou New Area, China based on remotely sensed data (Chinese GaoFen-1 and Advanced Land Observing Satellite). We identified five main land use change types and reference native grassland and farmland to determine soil properties at different depths. Principal component analysis and scatter matrix were employed to evaluate the effect of LULC change on soil properties. The results showed that LULC changes that occurred in Lanzhou New Area were characterized by the rapid growth of construction and bare land (increased by 13.06% and 5.97%, respectively) at the expense of farmland (decreased by 25.38%). The conversion of native grassland to artificial grassland and bare land, and farmland to bare land had similar effects on soil properties; i.e., a significant decline and a lower level in total nitrogen and soil organic carbon. The farmland to construction land transition deteriorated soil nutrients and increased soil compaction by both increasing bulk density (BD, mean = 1.63 g cm−3) and enhancing sand content by 69.21%. All land use change types increased BD and decreased soil water content and saturated soil water content when compared to the reference areas. These results indicate that changes in LULC have significant impacts on soil physicochemical properties. Thus, it is essential to optimize land planning and improve soil quality in arid ecosystems to ensure sustainable resource management and ecosystem conservation.


2020 ◽  
Vol 13 ◽  
pp. 117862212093958 ◽  
Author(s):  
Fikru Assefa ◽  
Eyasu Elias ◽  
Teshome Soromessa ◽  
Gebiaw T Ayele

Change in land-use management practices such as cultivation of steep slopes, overgrazing, and no or limited fallow periods, and slope position affects the quality of soils. As a result, assessing soil physicochemical properties and subsequent implications on soil fertility is essential for understanding the influence of agro-ecosystem revolution on agricultural soil quality and efficiency. In this research, we assessed the effect of land-use management practices on selected soil properties under varying terrain slopes and with and without soil conservation measures in a highly disturbed landscape in the northern part of Ethiopia in 2016. Based on the result, for all slope positions considered—namely, lower (1%-15%), middle (15%-30%), and upper (30%-45% and above)—with and without soil conservation, soil moisture content, porosity, silt, and clay proportions were lower in the cultivated land compared with grazing and forestland-use units. Conversely, soil bulk density and the sand fraction were higher in the cultivated land than grazing and forestland units, relatively. Observing changes in a terrain slope position, sand content of forest, grazing, and cultivated land units increased from lower to upper slope position whereas silt and clay fraction generally showed a decreasing trend from lower to an upper slope positions. In all slope positions with and without conservation practice, cation exchange capacity, exchangeable K+, Ca2+, and Mg2+ showed a significant increase from cultivated land to grazing and then forestland. The mean value of pH and electrical conductivity of cultivated lands with and without soil conservation were significantly low in all slope categories. Summarizing the analysis of variance for selected soil chemical properties with different slope positions, except available phosphorous, all chemical properties considered in this study are statistically significant ( P < .05). In summary, the result confirmed that soil properties were strongly influenced by terrain slope, land use, and changes in management practice. Consequently, to conserve soil resources, policymakers need to implement appropriate land conservation strategies based on land-use structure and slope variation.


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