The role of “effective microorganisms” in the composting of banana (Musa ssp.) residues

Abstract

Effective microorganisms" (EM) are a poorly defined mixture of supposedly beneficial microorganisms that are claimed to enhance microbial turnover in compost and soil. In Costa Rica, EM are used to produce organic compost (bokashi) from banana residues (Musa ssp.). Given the scarcity of scientific data about the effects of EM on the mineralization of plant residues, this study aimed at investigating the effects of EM addition on the decomposition of banana residues during Bokashi production. To this end, the following non-EM treatments were compared to EM Bokashi: Bokashi produced with water (W), with molasses (M) as an EM additive, and with sterilized EM (EMst). Subsequently, the effects of the resulting Bokashi treatments on the growth of young banana plants were evaluated. Compared with non-EM controls, the effect of EM on the mineralization of banana material was negligible. Dry-matter losses of the composts with different EM treatments were similar, with about 78% over 5 weeks. Ergosterol concentration was highest in EM Bokashi (77 lg (g dry soil) -1 ) and lowest in EMst Bokashi (29 lg (g dry soil) -1 ). Microbial biomass carbon (C mic ) and microbial biomass nitrogen (N mic ) were both lowest in EM (C mic = 3121 lg g -1 ; N mic = 449 lg g -1 ), while C mic was highest in Bokashi produced with molasses (3892 lg g -1 ) and N mic was highest in EMst (615 lg g -1 ). Treatment effects on adenylate concentrations and adenylate energy charge were negligible. Application of all Bokashi variants to young banana plants significantly increased shoot growth under greenhouse conditions compared to plants grown in a control soil without amendments. However, these effects were similar for all Bokashi treatments, even if EM Bokashi increased the K concentrations in banana leaves significantly compared to Bokashi produced with EMst and the control. Bokashi produced with only molasses and EM Bokashi decreased the number of root nematodes under greenhouse conditions compared to the control. Overall, the results confirmed the expected influence of composting on the degradation of organic material and the effect of compost application on plant growth. Hower, under the conditions of this study, EM showed no special effects in this, except for increasing the K concentrations in the leaves of young banana plants.

Effects of Biofertilizers Combined with Different Soil Amendments on Potted Rice Plants

“…1A). Earlier studies depicted variable effects of EM application on crop growth and yield; some researchers have shown positive effects of EM (Javaid, 2006;Khaliq et al, 2006;Javaid and Bajwa, 2010) while others reported negative or no effects (Bajwa et al, 1999;Formowitz et al, 2007;Daiss et al, 2008). According to Kinjo et al (2000), the lack of consistency in experimental results when applying EM may be due to variable cultural conditions employed in previous studies.…”

Effect of Effective Microorganisms (EM) and Potassium Sulphate on Productivity and Fruit Quality of "Hayany" Date Palm Grown Under Salinity Stress

“…The beneficial effect of EM application on alleviating the adverse effect of salinity on leaf total chlorophyll content might be attributed to their effect on enhancing organic matter, lowering soil pH as well as increased the uptake of water and nutrients (Higa, 1991;Higa and Wididana, 1991), enhancing soil fertility (Formowitz et al, 2007 andIbrahim, 2012). Also, EM is restoration of healthy ecosystem in soil (Higa, 1991).…”

“…The enhancement effect of EM on alleviating the adverse effect of salinity on yield and bunch weight may be attributed to the increase of leaf total chlorophyll content which leads to more carbohydrates production through photosynthesis process and increasing vegetative growth and consequently improved fruit set percentage, retained fruit percentage and finally improved yield and bunch weight. Also, EM have beneficial effect on enhancing organic matter, lowering soil pH as well as increased the uptake of water and nutrients (Higa, 1991;Higa and Wididana, 1991), and enhanced soil fertility (Formowitz et al, 2007 andIbrahim, 2012).EM is restoration of healthy ecosystem in soil (Higa, 1991). Moreover, EM application increased number of the soil microflora i.e.…”

Effective microorganisms and compost favor nematodes in wheat crops

“…According to Higa and Parr (1994), effective microorganisms include about 80 species, such as photosynthetic bacteria, lactic acid bacteria, yeasts, actinomycetes, and fermenting fungi such as Aspergillus and Penicillium. Some studies reported that effective microorganisms improved crop growth and yield by increasing photosynthesis, producing bioactive substances, such as hormones and enzymes, controlling soil diseases, and accelerating decomposition of lignin materials in the soil (Daly and Stewart 1999;Formowitz et al 2007;Javaid et al 2008). Khaliq et al (2006) and Javaid and Bajwa (2011) reported that the application of effective microorganisms increased the efficiency with which organic nutrients were used.…”