Soil Sciences

EFFECTS OF DIFFERENT LAND-USE LAND-COVER TYPES AND SLOPE POSITION ON SELECTED PHYSICO-CHEMICAL SOIL PROPERTIES AND SOIL QUALITY IN MAYA-GUDDOO SUBWATERSHED OF MAYA-CITY, EASTERN ETHIOPIA

2026-05-20T07:06:50Z

EFFECTS OF DIFFERENT LAND-USE LAND-COVER TYPES AND SLOPE POSITION ON SELECTED PHYSICO-CHEMICAL SOIL PROPERTIES AND SOIL QUALITY IN MAYA-GUDDOO SUBWATERSHED OF MAYA-CITY, EASTERN ETHIOPIA Deribe Dawit Regassa; Samuel Feyissa (PhD); Lemma Wogi (PhD) Soil is a vital resource for agricultural production and environmental sustainability. Soils in SSA suffer from nutrient depletion, leading to low agricultural productivity. The soils in Hararghe are highly degraded due to intensive and continuous cultivation. Gathering fundamental information about soil properties under different LULC types is so vital to guide management techniques and address the problems of declining soil fertility and quality. This study assessed the influence of LULC types and slope position on selected physico-chemical soil properties and soil quality in Maya-Guddoo subwatershed of Maya-City, Eastern Ethiopia. To achieve this, a total of 27 surface composite soil samples (0-20 cm depth) were collected from cultivated, Khat and grazing LULC types across slope positions. For each composite sample, 8-10 sub-samples were randomly collected using the quadrant method. Key soil properties were analyzed by following the standard laboratory procedures. The soil quality was assessed using a SQI from the selected indicators in the MDS. A linear scoring approach was utilized, being categorized as more is better, less is better, or optimal is better for each indicator. Data were analyzed using a two-way factorial ANOVA in R software to assess the main and interaction effects on soil properties. Tukey's HSD test (p<0.05) was used to further analyze significant effects in pairwise comparisons. The findings indicate significant differences for most soil parameters. However, the PBS showed non-significant variation. Additionally, silt and AWHC among LULC types and TN across slope positions showed nonsignificant difference. Grazing LC type on lower slopes, exhibited the highest values of clay content (40.33%), TP (57.09%), FC (38.00%), AWHC (17.54%), OM (4.91%), TN (0.24%), and most exchangeable bases and micronutrients. In contrast, cultivated LU types at upper slope displayed the lowest values of clay content (21.33%), OM (1.95%) and TN (0.09%). Khat LU types presented mixed results, with higher AV.P (23.41mg/kg) and MC (28.57%) at lower and middle slopes but variable values for other indicators depending on slope positions. The soil under Khat and grazing LULC types exhibited comparable SQI values of 0.65 and 0.64, respectively, while the soil under cultivated LU type showed the lowest SQI of 0.62. Among the slope positions, the highest SQI (0.67) was recorded at middle slope followed by the lower slope (0.65), whereas the upper slope had the lowest SQI (0.59). Notably, the middle slope of Khat LU type exhibited the highest soil quality. The study concludes that the LULC types and slope position significantly influence the soil fertility and quality. To lessen soil degradation, especially on upper slopes and intensively farmed areas, sustainable land management techniques like contour-based strip cropping and biochar-compost blends, reduced tillage and organic matter incorporation are recommended. These results offer vital information for improving agricultural productivity in the area and conserving soil. Mandatory residue retention and nitrogen-fixing hedgerows should be implemented in Khat fields to improve soil fertility and quality. In pasturelands, rotational grazing can greatly enhance soil structure and water retention. 81p.

EFFECTS OF NITROGEN AND PHOSPHORUS FERTILIZER RATES ON WHEAT (Tiriticum aestivum L.) YIELD AND SELECTED SOIL PROPERTIES IN KERSA DISTRICT, EAST HARARGHE ZONE, ETHIOPIA

2025-02-12T06:13:01Z

EFFECTS OF NITROGEN AND PHOSPHORUS FERTILIZER RATES ON WHEAT (Tiriticum aestivum L.) YIELD AND SELECTED SOIL PROPERTIES IN KERSA DISTRICT, EAST HARARGHE ZONE, ETHIOPIA Robe Elema Wako; (PhD) Lemma Wogi; (PhD) Tamasgen Desalegn Low soil fertility resulting from land degradation, crop residue removal, low soil OM content and poor management practices is major constraint to crop production. Nitrogen (N) and phosphorus (P) are the most deficient nutrients of Ethiopia soil that limit the yield potential of cereal crops, particularly wheat. Determining the optimum rates of fertilizers, especially that of N and P, is the key to maximize the economic yield and maintain soil health in a sustainable way. The present study was conducted during the 2024 cropping season in Kersa district of east Hararghe zone, with the main objective to evaluate effects of nitrogen and phosphorus fertilizer rates on wheat yield, yield components and selected soil physical and chemical properties and thereby identifying the economically feasible nitrogen and phosphorus fertilizer rates. The experiment encompassed factorial treatment combinations of four levels of N (urea) and P(TSP) fertilizers plus control (0:0) laid out in randomized complete block design (RCBD). Composite and core soil samples were collected from the experimental site and experimental plots, and analyzed following standard laboratory procedures. Genstat 18th edition software version was used for the data analysis. Mean comparisons were done by Duncan’s multiple range test at the 5% level of significance. Results indicated that total nitrogen was in the low range; whereas available P was very low in the study site. The pH of the soil decreased as the level of nitrogen increased; which may be attributed to the acidifying ability of nitrogen fertilizer. Phenological and growth parameters like days to heading, days to maturity, plant height and spike length were highly significantly (p<0.001) influenced by the main effects of N and P. Number of productive tillers, number of seed per spike, thousand seed weight, above ground biomass and grain yield were significantly (p<0.05) affected by the interaction effects of N and P. The highest gran yield (4563 kg/ha) was obtained from the interaction of N and P at the rates of 184 kg/ha N and 92 kg/ha of P2O5. Agronomic efficiencies of applied fertilizers increased as the N and P rates became more balanced with the highest agronomic efficiency (5.51) was observed at the combination of 46 kg/ha N and 46 kg/ha P2O5. The economic analysis revealed that, the highest marginal rate of return (1595%) was obtained from the application of 184 kg/ha N and 46 kg/ha P2O5, followed by 92 kg/ha N and 92 kg/ha P2O5 (1129.79%) and 46 kg/ha N and 46 kg/ha P2O5 (980 %).It could be concluded that, low and middle income farmers may benefit from the 46:46 and 92:92 N and P combinations respectively; while high income farmers or investors could opt for184:46 combinations. However further research over several seasons and across wider production site is essential for more sound recommendations. 68p.

EFFECTS OF LIME AND PHOSPHORUS FERTILIZER RATES ON SELECTED PHYSICOCHEMICAL PROPERTIES OF ACID SOIL AND YIELD OF BARLEY (Hordeum vulgare L.) AT HULBAREG WOREDA, SILTE ZONE, SOUTHERN ETHIOPIA

2025-02-11T07:03:47Z

EFFECTS OF LIME AND PHOSPHORUS FERTILIZER RATES ON SELECTED PHYSICOCHEMICAL PROPERTIES OF ACID SOIL AND YIELD OF BARLEY (Hordeum vulgare L.) AT HULBAREG WOREDA, SILTE ZONE, SOUTHERN ETHIOPIA Jemal Mohammed Beshir; (PhD) Samuel Feyisa; (PhD) Abay Ayalew Acid soils are among the major constraints to agricultural productivity in many parts of sub- Saharan Africa, including Ethiopia. Soil acidity problem is among soil degradation constraints to crop production and productivity in high rainfall areas of Ethiopia in general and in the present study area in particular. A field experiment was undertaken in 2022/23 main cropping season at Hulbareg Woreda Silte Zone Southern Ethiopia to evaluate the effects of lime and phosphorus fertilizer rates on selected physicochemicala properties of acid soil and yield of barley. The study was conducted in a completely randomized block design with three replications, employing a 4x4 factorial combination of lime and phosphorus at four levels each, using food barley variety-HB-1307 as a test crop. The lime treatments included 0, 2.1, 4.2, and 6.3 t ha-1 , while the phosphorus treatments consisted of 0, 10, 20, and 30 kg P ha-1 . The interaction between lime and phosphorus had a significant effect (P≤0.01) on plant height, grain yield, and biomass yield. However, combined application of lime and phosphorus had no significant interaction effect (P≤0.05) on spike length and number of tillers. The highest grain yield of barley was obtained from the application of 6.3 t ha-1 lime with 30 kg P ha-1 which is at par with the application of 4.2 t ha-1 lime with 20 kg P ha-1 treatment. The partial budget analysis also indicated that 2.1 t lime ha-1 along with 30 kg P ha-1 gives highest (2298.42) MRR%. The interaction effect of lime and phosphorus also had a significant effect on acid soil properties. For instance, 6.3/4.2 t lime ha-1 with 20 kg P ha-1 increased soil pH and available P from 4.93/1.4 to 6.5/13.31 respectively while it decreases exchangeable acidity from 2.74 to 0.01. Therefore, the management of P-deficient acid soils of Albazer area requires combined applications of 2.1 t lime ha-1 with 30 kg P ha-1 . 94p.

SOIL CHARACTERIZATION, LAND USE TYPES AND EFFECTS OF LIMING AND PHOSPHORUS ON SELECTED SOIL PROPERTIES AND MAIZE (Zea mays L.) YIELD IN TIRO AFETA DISTRICT OF JIMMA ZONE, SOUTH-WEST ETHIOPIA

2025-01-01T07:16:18Z

SOIL CHARACTERIZATION, LAND USE TYPES AND EFFECTS OF LIMING AND PHOSPHORUS ON SELECTED SOIL PROPERTIES AND MAIZE (Zea mays L.) YIELD IN TIRO AFETA DISTRICT OF JIMMA ZONE, SOUTH-WEST ETHIOPIA GEBRU GEBRETSADIK AMDEMICHAEL; Dr. Kibebew Kibret (PhD); Prof. Abi Tadesse (PhD) Sustainable agricultural production to meet the increasing demands forfood, fiber and fuel requires understanding of soil characteristics, distribution over an area and effects of land use types and management on soil properties for efficient utilization of limited land resources. A field study was conducted in Tiro Afeta District of Jimma Zone, Southwest Ethiopia, to characterize and classify soils along a toposequence; assess the effects of land use types on selected soil properties; and investigate the effects of liming and phosphorus fertilizer application on soil properties and performance of maize. Five representative pedons were opened for the first objective; soil samples were collected from the 0-20 cm depth of five adjacent land use types (forest, grazing, cultivated, degraded and coffee lands) for the second objective; and five levels of lime (0, 0.5, 1.0, 1.5 and 2 tones h-1 ) and P fertilizer (0, 46, 92, 138 and 184 kg P2O5 ha-1 ) were used for achieving the third objective. Soils of the study area showed spatial variability in their properties within and across pedons. The soils have a clay texture, with bulk density values ranged from 1.11 to 1.33 g cm-3 . The pH-H2O values varied from 5.6-5.8 at the surface layers and 5.74 to 6.30 in sub-surface layers. The soils had 0.50-1.50% organic carbon, 10.50-13.95 mg kg-1 available P, and 20.05-26.40 cmolc kg-1 soil cation exchange capacity. The Reference Soil Groups identified are Haplic Nitisols (Orthodystric), Gleyic Vertisols (Mesotrophic), Stagnic Vertisols (Eutric), Haplic Nitisols (Orthoeutric) and Vermic Phaeozems (Chromic). The results of study on effects of land use types on soil properties revealed the negative impact of cultivation on most of the soil parameters as compared to the forestland. The field experiment results indicated that phosphorus fertilization did not significantly increase maize production as compared to the control treatments due probably to the rates were not high enough to bring about statistically significant changes. However, there were improvements of different levels in the measured plant parameters as compared to the control treatment. The results further demonstrated that soil properties, such as pH, available P, exchangeable Ca2+ , cation exchange capacity, and percent base saturation were increased with combined application of lime and P fertilizer at optimum rates. From the results obtained, it can be concluded that, as a result of differences in soil properties along the toposequence, different soil types were developed with different potentials and constraints and application of lime and P fertilizer could improve productivity of maize in the study area. 139