Organic Treatment effects on Ferritic soil quality and Tomato (Lycopersicon esculentum Mill.) Yield

Abstract

The impact of the combination of plant (Tithonia diversifolia) (Td) plus cow dung (Cd) as biofertilizer and aqueous extract of Callistemon citrinus (CAL) leaves as biofungicide on physicochemical properties, and the microbial biomass in carbon (MBC) and nitrogen (MBN) of soil and on tomato yield were assessed under field condition. The experimental design was a complete block design with 2 factors (soil amendment and plant sprays) and 3 repetitions. The soil treatment included organic amendment (OA): Td + Cd at the ratio of 3:4 (w/w)/plant; inorganic amendment (IA): 21:8:8 NPK (26.2g/plant) and potassium sulfate (4g/plant); and control (unamended soil). The field treatments were plants sprayed with: 5% (w/v) CAL; 5% (w/v) Mancozeb (M); and water (W). All amendments except IA did not significantly modify the soil organic matter (˂2.4mg.kg-1) and organic carbon content. An increase of 23.15% and 30.60% of calcium concentration and cation exchangeable capacity (CEC) respectively, was recorded in OA soil compared to the soil before cultivation (SBC) (P˂0.05). Copper and zinc contents in OA soil were reduced respectively by 49% and 48.5% compared to SBC. The highest concentration of MBC was recorded in OA.M plot. The different combine treatments (OA.CAL, IA.M, and OA.M) increased tomato yield by 3.4; 3; and 5.3 fold, respectively compared to their controls. This study provided new information about the organic amendment on soil and plant sprayed with C. citrinus extract as a green alternative to conventional input that might improve soil quality and crop yield.