Soil Sciences

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

SOIL PROPERTIES AND NUTRIENT UPTAKE OF MAIZE (Zea mays L.) AS INFLUENCED BY INTEGRATED NUTRIENT MANAGEMENT ON VERTISOLS OF HARAMAYA DISTRICT, EASTERN ETHIOPIA

2024-12-19T07:05:38Z

SOIL PROPERTIES AND NUTRIENT UPTAKE OF MAIZE (Zea mays L.) AS INFLUENCED BY INTEGRATED NUTRIENT MANAGEMENT ON VERTISOLS OF HARAMAYA DISTRICT, EASTERN ETHIOPIA DEJENE TERESSA GUTEMA; Dr.Kibebew Kibret (PhD); Prof. Nigussie Dechassa (PhD); Dr.Lemma Wogi (PhD) The declining state of soil fertility and productivity in Ethiopia can be attributed to the inadequate attention given to the biological, chemical, and physical properties of soil. Additionally, the high phosphorus fixing characteristics of Vertisols have posed a significant challenge to agriculture in the country, leading to phosphorus deficiency, and rendering inorganic fertilizers less effective. Greenhouse and field experiments were conducted at Haramaya University, eastern Ethiopia, to investigate the effect of mixed manure rates (0, 5, 10, and 15 t ha-1 ), blended nitrogen, phosphorus, sulfur, and boron (NPSB) fertilizer rates (0, 50, 100, and 150 kg ha-1 ), and cropping systems (maize monocropping and maize faba bean intercropping) when used alone or in combination on selected soil chemical properties, phosphorus adsorption and desorption characteristics, and performance and nutrient uptake of maize (Zea mays L.) in Vertisols. Five experiments were conducted. Relevant soil and crop data were collected from all the experiments and subjected to statistical analysis. The results of the first experiment revealed that the application of mixed manure significantly decreased the soil pH, calcium carbonate content, the amount and efficiency of adsorbed phosphorus, and the Freundlich adsorption coefficient and constant while increasing available P and percentage of desorbed P. The highest changes in these parameters were observed in the treatment that received 15 t ha–1 of mixed manure. The findings of the second and third experiments demonstrated a significant reduction in soil pH, phosphorus adsorption efficiency, Freundlich adsorption coefficient and constant (p ≤ 0.001), and also an increase in organic carbon, total nitrogen, and available phosphorus. Moreover, significant improvements were observed in the growth parameters of maize plants, including height and diameter, tissue nitrogen and phosphorus content and uptake, and total above-ground biomass. The highest improvement in the majority of these parameters was observed for the combined use of 15 t ha–1 of mixed manure and 100 kg ha–1 of blended NPSB fertilizer compared to the control as well as their sole application. The findings of the fourth experiment also showed that the quantities of adsorbed phosphorus in all treatments revealed an increasing trend with an increased rate of added P concentration from 100 to 500 mg kg−1 . However, the efficiency of adsorbed P decreased significantly as added P concentration rates increased from 100 to 400 mg kg−1 in all the treatments, and then decreased as the added phosphorus concentration advanced to 500 mg kg−1. Moreover, all treatments that received mixed manure and blended NPSB combined applications showed a significant increase in both quantity and percentage of desorbed P compared to the control. The Freundlich adsorption coefficient and constant were also significantly reduced because of the combined application of mixed manure and blended NPSB. Overall, the soil treated with a combined application of 15 t ha−1 of MM with 100 kg ha−1 of blended NPSB showed the highest reduction in both quantity and efficiency of adsorbed phosphorus, as well as Freundlich adsorption coefficient and constant while increasing the quantity and percentage of desorbed P. The findings of the fifth experiment indicated that intercropping maize with faba bean led xxii to a noteworthy reduction in soil pH, but significantly increased soil organic carbon. Similarly, the interaction of the cropping system and blended NPSB also revealed the highest value of soil total nitrogen in maize-faba bean intercropping with 150 kg ha−1 NPSB suggesting its ability to augment belowground biomass. However, available phosphorus was higher in maize monocropping with 150 kg ha−1 NPSB. The cropping system and blended NPSB were found to have a significant influence on maize plant height, diameter, above ground biomass, total nitrogen, and phosphorus uptake. The interaction effects of the cropping system and blended NPSB revealed higher total nitrogen and phosphorus uptake of maize including nitrogen content in monocropped maize with 150 kg ha−1 NPSB. In conclusion, intercropping maize and faba bean, along with blended NPSB fertilizer, could be a promising approach to improving soil fertility. However, for enhanced crop productivity, maize growth parameters and nutrient uptake require further investigation, particularly in reducing competition for light, water, and other nutrients. Therefore, it is recommended that further research be conducted to evaluate the long-term effects of combined application of mixed manure, blended NPSB, and cropping system on soil fertility and nutrient uptake of different maize varieties. 236