Influence of poultry waste biochar on soil microbial biomass and yield of tomato ((lycopersicon esculentum l.)

Abstract

Tomato is a crop grown mainly for its fruits. The use of chemical fertilizers to enhance its yield negatively impacts the soil microbiota and decreases soil quality overtime. Hence, there is need to explore more sustainable ways of increasing tomato production. The aim of this study was to assess the effect of poultry waste biochar on soil microbial biomass and yield of tomato. A greenhouse experiment was conducted in 2018 and 2019 planting season at the Federal University of Agriculture Abeokuta, Nigeria. A composite soil used in the greenhouse were analysed and 5 kg soil were filled into the Planting pots. The poultry waste biochar was prepared at a temperature of 350°C using a two-barrel charcoal retort and was applied to the soil at the rates of 12.5 thaˉ1 (T1), 25 thaˉ1 (T2) and control (without biochar). The experiment was a complete randomised designed replicated five times. The following agronomic data; Plant height (cm), stem gith (mm), leaf area (cm2), number of leaves, number of fruits and fruits weight (g/plant), on tomato variety (NGB00730) were taken. Soil physical and chemical properties were determined using the Mid Infrared Reflectance Spectroscopy method. The effect of biochar on Microbial Biomass Carbon, nitrogen and phosphorus (MBC, MBN and MBP) were determined using the fumigation extraction method. Physicochemical properties of biochar amended soil showed a pH of 6.66, cation exchange capacity (CEC) of 17.2 cmol/kg and total carbon of 1.7 % for T2 and a pH of 6.50, CEC of 16.62cmol/kg and total carbon of 1.4% for T1 whereas control soil exhibited low properties with pH of 6.24, CEC of 9.9 cmol/kg and total carbon of 1.26%. There was a significant (P ≤ 0.05) increase in growth and yield of tomato in the biochar amended soils (T1 and T2) compared to the control soil. Highest MBC, MBN and MBP values were observed in T2 and ranged from 261.3-288.8 μg/g, 16.48-17.82 μg/g and 10.09-10.73 μg/g respectively. In contrast, T1 showed lower values of 244.10-274.07 μg/g, 17.33-17.54 μg/g and 10.11-10.63 μg/g for MBC, MBN and MBP respectively. Control soil sample exhibited the least MBC, MBN and MBP values of 240.0-242 μg/g, 14.37-15.08 μg/g and 9.37-10.08 μg/g respectively. The addition of biochar to soil improved overall soil physicochemical properties and enhanced the yield of tomato.