Influence of Biochar Rates From two Temperature Regimes Integrated with Inorganic Fertilizers on Major Nutrient Uptake, AMF Colonization, Yield and Yield Component of Hot Pepper at Jimma Ethiopia

Abstract

Hot pepper production is an important activity in Southwestern Ethiopia as a means of income generation. Although it is one of the cash crops in the region, its production is constrained by many factors among which nutrient depletion and soil acidity can be mentioned. Biochar has been advocated to have a positive effect on crop yield improvements in acidic and highly weathered tropical soils via its effect on acidity amelioration. However, the dynamic use of biochar to a specific soil and crop type depends on how biochar is made, the amount applied and its interactions with soil-plant factors. Therefore, this experiment was conducted in a greenhouse to investigate the effect of biochar and inorganic fertilizers on N, P uptake, yield and root colonization by Arbuscular mychrohizal fungi (AMF). The experiment was laid out in 2×2×3 factorial arrangement with control consisting of two pyrolysis temperature (3500 C and 5000 C), tow biochar application rate (6 and 18 t ha-1 ) and three levels of the recommended inorganic fertilizer (N and P)as 0%, 60% and 100% in randomized complete block design with four replications. Analysis of variance (ANOVA) showed that interaction effect of pyrolysis temperature, biochar rate and inorganic fertilizer significantly (P<0.001) affected growth, yield, N & P uptake, AMF root colonization and chemical properties of the soil. Besides, plant height, number of branches and soil total N content were significantly (P<0.001) affected by the interaction of biochar rate and inorganic fertilizer. The earliest days to flowering was obtained from the interaction of 6 t ha-1 biochar prepared at 3500 C along with 100% inorganic fertilizer. Similarly, the highest N and P uptake by fruit, haulm and total plant was obtained from the combination of biochar prepared at 5000 C, 18 t ha-1 biochar along with 100% inorganic fertilizer. The Arbuscul, Vesicular and Hyphal root colonization were also significantly (P<0.001) affected by the interaction of 18 t ha-1 biochar at 5000 C along with 60% inorganic fertilizer. The application of 18 t ha-1 biochar prepared at 500 0 C pyrolysis temperature along with 100% or 60% inorganic fertilizer appeared to be a promising combination to optimize hot pepper yield, N and P uptake, AMF colonization and soil properties. However, to give strong conclusion and to determine the N and P use efficiency of hot pepper, this experiment need to be repeated on larger production field of hot pepper.