Bokashi compost and biofertilizer increase lettuce agronomic variables in protected cultivation and indicates substrate microbiological changes

Abstract

The aim of the study was to evaluate agronomic productive variables of iceberg lettuce and soil microbiological variables for two crop cycles by using organic inputs. The treatments were as follows: control (no fertilization); Bokashi compost (20 g per plant); Penergetic-k plus Penergetic-p bio-activators (both at 1.5 g per litre of water, applied to the substrate and plant, respectively); and biofertilizer at different concentrations (2.5, 5.0, 7.5, and 10% dilutions in water). Biofertilizer concentrations were applied during five fertigation times per day in the first crop experiment and in single daily fertigation in the second crop experiment. Agronomic productive variables evaluated were: total mass, commercial mass, discarded leaves mass, stem diameter, commercial head diameter and plant height. Soil microbial biomass carbon, basal soil respiration and metabolic quotient were evaluated for substrate microbial quality measurement. In the first cycle, plants treated with Bokashi or Penergetic presented superior total mass, commercial mass and commercial head diameter of lettuce, while plants treated with biofertilizer did not exhibit improvement and presented tipburn in some plants, when compared to control. In the second cycle, the use of Bokashi and biofertilizers improved the total mass and commercial head diameter, compared to control. Higher than control microbial biomass was achieved with biofertilizer concentrations and Bokashi. Lower metabolic quotient (qCO2) was observed for all the treatments, when compared to control. Soil microbial quality data corresponded to better lettuce yields.

Use of reduced Bokashi doses is similar to NPK fertilization in iceberg lettuce production

“…Treatments with Bokashi show 50% to 216% higher microbial carbon biomass than the control (water only) in microcosms experiments and lettuce production (Scotton et al, 2017;Hata et al, 2020). This indicates higher microorganism's activity that may be reflected in a mean of 53% increase in the lettuce production experiments (Hata et al, 2020). The Bokashi microorganism community depends on its raw materials and the inoculum used.…”

“…Besides the relative richness in nutrients, the microorganisms supplied by inoculum enable higher mineralization and availability of nutrients from the organic matter (Quiroz & Céspedes, 2019). Treatments with Bokashi show 50% to 216% higher microbial carbon biomass than the control (water only) in microcosms experiments and lettuce production (Scotton et al, 2017;Hata et al, 2020). This indicates higher microorganism's activity that may be reflected in a mean of 53% increase in the lettuce production experiments (Hata et al, 2020).…”

“…Bokashi compost is a soil amendment that provides organic matter rich in microorganisms and mineral nutrients (Scotton et al, 2017;Hata et al, 2020). The use of Bokashi together with other amendments in organic agriculture should be tested to verify possible additive and even synergetic effects (Quiroz & Céspedes, 2019).…”

Role of Organic Manure Bokashi Improving Plant Growth and Nutrition: A Review

“…The bulb yield of shallot improved 145 % from 4.79 t ha -1 (Lasmini et al, 2018). Bokashi triggered the lettuce development, which improved total mass, commercial (after eliminating the damaged leaves), and commercial head diameter for two cycles (Hata et al, 2020). Bokashi and 10% boiled manure showed a significant increase of the first three trusses of one plant in tomato fruiting for two growing cycles (Hata et al, 2021).…”

“…The application of Bokashi improved crop yields such as coffee (Gómez-Velasco et al, 2014), head lettuce (Lactuca sativa) (Hata et al, 2020), peanut (Arachis hypogaea) (Karimuna et al, 2016), and tomato (Hata et al, 2021). The bulb yield of shallot improved 145 % from 4.79 t ha -1 (Lasmini et al, 2018).…”