SOIL FERTILITY STATUS AND NUTRIENTS CONTENT IN MAIZE (ZEA MAYS L.) TISSUE AT MIGNA KURA IN WAYU TUKA DISTRICT, EAST WOLLEGA, ETHIOPIA

Abstract

Declined soil fertility is one of the main constraints to improve food production in Ethiopia and inadequate information about soil fertility in the study area. To replenish impoverished soils, site and crop-specific studies of soil fertility parameters are required to devise appropriate suggestions for site-specific balanced fertilizer recommendation and soil fertility management in the study area. With this milieu, this study was initiated to assess soil fertility, quantify nutrients content in maize tissue, and mapping selective soil parameters of Migna Kura Kebele, Wayu Tuka District, east Wollega, Ethiopia in 2019. A total of 32 surface soils and leaf samples were randomly collected for nutrients concentration quantify. Soil physicochemical properties and maize leaf nutrients of 32 samples were analyzed using standard laboratory procedures. The data obtained were analyzed by Microsoft Excel and SPSS software version 20. Soil fertility status maps were prepared using the ordinary kriging interpolation technique and employed with ArcGIS10.4.1 and rated as very low to very high following the criteria nutrient rating guidelines for pH, OC, TN, P, K, S, Ca, Mg, CEC, PBS, B, Fe, Mn, Cu, and Zn. The Laboratory analysis results revealed that textural classes of soils are clay loam and clay. Soil bulk density and total porosity varied from 1.13 to 1.46 g cm-3 and 42.57 to 55.15 %, respectively. Soil reaction varies from slightly acidic (pH=6.7) to strongly acidic (pH=4.91). Soil exchangeable acidity values ranged from 0 to 2.46 cmol (+) kg-l . Soil OC values ranged from the medium (1.79 %) to the high (3.51 %) range. Soil total N and available P values were between very low to low (0.19 to 1.11 % and 6.71 to 13.44 mgkg-l , respectively). Available K and S values ranged from very low to medium (27.57 to 290.78 mg/kg) and (1.34 to 13.76 mg/kg), respectively. Exchangeable Ca, Mg, K, and Na of the soil values varied from 6.93 to 51.15, 2.85 to 23.63, 0.21 to 1.76, and 0.05 to 0.71 cmol (+) kg−1, respectively, while medium to a very high level of CEC (22.19 to 77.42 cmol (+) kg−1 was registered. Soil PBS varied from 42.13 to 98.30 % within a rating of moderate to very high. Soil DTPA extractable Fe, Mn, Cu, Zn and B values varied from 12.07-33.51, 16.02-48.26, 0.18-0.62, 1.09-3.68 and 0.19-0.62 mg kg-1 , respectively. Based on the Maize leaf macronutrients concentration analysis of N, P, K, S, Ca and Mg concentration values varied between 1.90- 3.20, 0.07-0.21, 0.69-2.89, 0.05-0.48, 0.2-0.91, and 0.38-0.90 %, respectively. Ca, Mg, S, and K nutrients concentrations were at sufficient levels whereas 81.25% and 100 % of the total leaf samples were deficient in N and P nutrients content, respectively. The levels of micronutrients concentration in maize leaves tissue values ranged from 2.43-8.02 mg/kg for B, 96.36-190.38 mg/kg for Fe, 32.43-226.01 mg/kg for Mn, 18.70- 44.38 mg/kg for Cu, and 15.87-45.40 mg/kg for Zn. Fe, Mn, and Cu nutrients concentrations were sufficient, while in 37.5 and 56.25 % of the total leaf samples, Zn and B were below the critical level. Soil micro and macronutrient results revealed highly significant at (P≤ 0.01) and positive correlations with maize leaf macro and micronutrient concentrations. These results of the present study indicated that the soils affected by soil acidity and deficiencies of six yield limiting nutrients N, P, K, S, B, and Zn were identified in soils of the study area. Organic matter, N, P, S, K, B, and Zn containing fertilizers and lime should be applied to soils for sustainable crop production in the study area