The effect of land management practices on soil physical and chemical properties in Gojeb Sub-river Basin of Dedo District, Southwest Ethiopia

Abstract

This study was undertaken to evaluate the effect of cultivation, fallow and woody land with and without soil bund on soil physical and chemical properties in Gojeb river basin of Dedo district. Landscape of the basin was divided in to three slope positions as upper (25 to 35%), middle (15 to 25%) and lower (5 to 15%). From each slope position, purposely three land use types (cultivated, fallow and woody) lands conserved with and without soil bund were selected. Accordingly, a total of 54 composited soil samples, from 3 slope positions x 3 land use types x 3 replications x 2 conservation system (with and without soil bund) were considered to collect soil sample for soil physical and chemical properties analysis. For both composited and core sampled soil sample collection systematic random sampling techniques were conducted through considering similarity of slope gradient, soil types and land use cover. Analysis of variance (ANOVA) and mean separation was carried out by Turkey test using Rversion 3.2.2 (2015). Additionally, Pearson's correlation analysis was done by using Statistical Package for Social Sciences (SPSS version 20).The result showed that soil bulk density and sand fraction decreased from upper to lower slope position. In contrast, total soil porosity, gravimetric soil moisture content, fraction of clay and silt were increased from upper to lower slope position. With respect to land use soil porosity, gravimetric soil moisture content, clay and silt proportion of woody land >fallow land> cultivated land. However soil bulk density and sand fraction highest in the cultivated land than fallow and woody land. Similarly, for all land uses conserved with soil bund has highest gravimetric soil moisture content, soil porosity, clay and silt fraction than similar land uses not conserved with soil bund. Soil chemical parameters [pH, EC, Av.P, OM, OC, TN, CEC,[exchangeable cations (K, Ca and Mg), exchangeable sodium percentage (ESP) and percent base saturation (PBS)] were significantly increased from upper to lower slope position while exchangeable sodium was not significantly increased. All soil chemical parameters, mean value of woody and fallow land were highest than cultivated land. Similarly, land uses conserved with soil bund has highest mean value than land uses without soil bund. The result of Pearson's correlation matrix also confirmed that several soil phyisical and chemical parameters have a positive relationship, particularly soil organic matter/organic carbon was strongly correlated with cation exchangeable capacity and clay content. In conclusion, the result affirmed that soil physicochemical property of the study area was strongly influenced by land use and conservation difference in addition to topographic position variation. Therefore, to conserve soil resources it needs highest attention of policy makers as well as land use planners to concentrate their efforts on land management/conservation strategies based on land use system and slope variation.

Effects of Soil Conservation Practice and Crop Rotation on Selected Soil Physicochemical Properties: The Case of Dembecha District, Northwestern Ethiopia

“…e reason might be due to presence of slight increase in amount of clay mineral and OM under conserved farmlands as a result of some deposition. is result was in line with the study conducted by Behailu et al [57] who reported that cultivated lands conserved with soil bund showed higher value of CEC than unconserved under three slope positions.…”

“…is is because that cultivated lands with physical soil and water conservation practice might have reduced soil erosion and leaching of exchangeable cations. e result was in line with that of the study conducted by Behailu et al [57] who revealed that cultivated lands treated with soil bund showed higher value of exchangeable Ca 2+ than unconserved one under higher, middle, and lower slope classes.…”

Soil loss tolerance in calcareous soils of a semiarid region: evaluation, prediction, and influential parameters

“…The result of the silt content was in agreement with Mengistu et al (2016) who showed higher silt content in nonconserved areas than conserved lands. However, Bezabih, Aticho, and Mossisa (2016) reported higher mean silt content in forestland use compared with agricultural land use. As can be seen in Figure 9, rangelands have the lowest amount of fine particles compared to other land uses, especially to the dam shore, due to transporting the fine soil particles by runoff and rainfall from this area located in the upper catchments to the lower catchments (agricultural lands and dam shore).…”

Micromorphological features of soils formed on calcium carbonate–rich slope deposits in the Polish Carpathians

“…This seems to be the result of leaching of calcium carbonate in less stable soil conditions, causing a neutral or slightly acidic reaction of the soil (Gunal and Ransom 2006;Rubio and Escudero 2005;Scheatzl and Anderson 2005). However, in the case of heterogeneous soils located on slopes, the loss of carbonates from soil by leaching (decarbonation) is sometimes doubtful (Alijani and Sarmadian 2014;Badía et al 2013). Thus, different causes leading to carbonate removal should be emphasized.…”

“…Even if the soils had a high content of calcium carbonate in the entire profile at the beginning of their formation, slope processes (e.g. soil washing, mixing) could lead to depletion or loss of calcium carbonate from the soil material (Alijani and Sarmadian 2014). As the result, the calcium carbonate was preserved in horizons that were not under strong redeposition processes (Kowalska et al 2019).…”