SOIL PHYSICOCHEMICAL PROPERTIES, GROWTH AND YIELD OF BEETROOT (Beta vulgaris .L) AS AFFECTED BY BIOCHAR SOURCE AND RATE IN MESKAN DISTRICT, EASTERN GURAGE ZONE, CENTRAL ETHIOPIA

Abstract

Biochar application has been widely suggested as a highly improving soil property and fertility replenishment option to promote sustainable agriculture. The biochar amendment in the soil has received more study in recent times to reclaim soil property and improve productivity. This study aimed to investigate the interaction effects of different sources (coffee husk, maize cob, and Enset leaf) and rates (0, 5, 7.5 and 10 t ha-1 ) of biochar on soil chemical properties (pH, electrical conductivity (EC), organic carbon (OC), total nitrogen (TN), and available phosphorus (Av. P) cation exchange capacity (CEC), growth (plant height, leaf (number, length and area), and yield (beet diameter, weight per (plant and pot) of beetroot at Meskan District. A factorial pot experiment was conducted at the greenhouse, and the experiment was set up using a completely randomized design (CRD) with four levels of biochar and three types of biochar sources and replicated three. The ANOVA result indicates that a significant variation was observed at P<0.05 among the interaction effects of source and rate of biochar on soil chemical properties like (pH, EC, OC, TN, and Av. P and CEC). The result of the analysis of variance specifies that pH and EC show a significant difference at p<0.05 among the interactions of source and rate of biochar. The highest values of soil pH and EC were 7.69±0.075 and 0.25±0.008 μm cm -1 ) respectively and the lowest was recorded in the control (6.46±0.075, 0.06±0.008μm cm-1) respectively. The ANOVA results also state that a significantly varied value was recorded within the interaction effect of different sources and rates of biochar on OC, OM, TN, Av.p., and CEC, and the highest value of OC, OM, TN, Av.p., and CEC was (7.93±0.15%, 13.68±0.29%, 0.76±0.01%, 21.5±0.49cmol. Kg-1and40.36±0.48mgkg 1 ) respectively and the lowest value (2.29±0.15%, 3.92±0.29%, 0.17±0.01%, 13.84±0.49mg kg-1 and 28.68±0.48 cmol.Kg-1 ) respectively was recorded as untreated treatment. The ANOVA result also indicates that a significant variation was observed (P<0.05) among the interaction effects of source and rate of biochar on growth and yield of beetroot, like plant height, number of leaves per plant, leaf area and length, beet diameter, and beet weight per plant and per pot. The result of analysis of variance table shows a significant variation in height. The highest value of plant height at the three growth stages was (25day, 50day and harvest) (18.56±0.67, 34.58±0.3and36.97±0.91 cm) respectively and the lowest value of plant height was (14.85±0.67, 25.88±0.3 and 35.43±0.91 cm), respectively, were recorded in control. Similarly, ANOVA showed that a significant difference value (P<0.001) resulted in a leaf (number, length and area) within the interaction effect of source and rate of biochar. The highest values were (19.66±0.48, 34.14± 0.26cm and 826.83±16cm-2 ), respectively, and the lowest value (17.66±0.48, 29.04±0.26cm and 327.87±16cm2 ) resulted in untreated soil. Likewise, a significant variation was obtained (P<0.001) on beet (diameter, weight per plant and pot) within the interaction of the source and the rate of biochar. The maximum value of (beet (diameter, weight per plant and pot)) was (6.61±0.013cm, 482.67±3.05g and 1458.33±10.91g) respectively, and the minimum value was (5.78±0.013cm, 343±3.05g, and 1062±10.91g) was recorded within the control. The economic analysis result shows the highest net benefit was 1012,725,480 ETB ha-1 obtained at soil treated with 7.5 t ha-1 Enset leaf biochar with an additional gain of, 21596% from every Birr invested .Finally, the study concludes that the interaction effects of different sources and the rate of biochar show a significant variation among soil chemical properties, growth and yield of beetroot in a pot experiment. Future studies should articulate the study's need for additional biochar sources by increasing the rate over a long period on research stations and farmers' fields in locations with diverse management practices