Assessment of the contribution of microbial activities to tomato growth and yield under an organic production system

Abstract

Optimizing microbiological activities in an organic crop production system is crucial to the realization of optimum growth and yield of the crops. Field and pot experiments were conducted to assess soil microbial activities, growth and yield of tomato varieties in response to 4 rates of composted plant and animal residues. The trials were carried out in the Federal University of agriculture, Abeokuta Nigeria, between April 2014 and November 2015. The compost rates were 0, 5, 10 and 20 t ha−1, while the varieties used were Ibadan-improved and Ibadan-local. Fungi population, microbial biomass nitrogen and enzyme activities were significantly higher (P≤ 0.05) at the rhizosphere of the local variety than that of the improved variety. This led to a significantly higher number of branches, plant height, leaf area, number of fruits and less days to maturity in the local variety. Also, growth parameters and tissue N significantly increased in all compost treatments while dry matter yield and weight of fruits were significantly higher in soil amended with 20 t ha−1. Microbial activities correlated more significantly with growth and yield parameters at 6 weeks after transplanting. It was concluded that microbial activities could be optimized to improve the yield of tomato varieties in an organic production system, through the application of compost, particularly at 20 t ha−1.

Keywords

• compost rates
• tomato varieties
• microbial populations
• microbial biomass
• enzyme activities