Epsilon Archive for Student Projects

Abstract

The leachate obtained from bokashi fermentation household
vessels, are among proponents of the bokashi method believed
to be useful as a biofertilizer. The bokashi fermentation
method does not lead to foul odours as it is anaerobically
fermented in air-­tight bins with lactic acid bacteria, among
other groups of microorganisms, and is therefore interesting
in the light of an increasing interest of urban farming and
unexploited resources of plant mineral nutrients within the
urban area.

To examine the potential use of bokashi fermentation leachate as a biofertilizer in an urban farming context,
leachate obtained from fermentation of food waste from four
different sources in Malmö and Lund, Sweden, was tested on
pak choi. The leachate was tested in a sand substrate, a
garden waste compost substrate and a peat substrate, in
order to give a general idea on how the leachate could be
applied in actual situations in urban farming projects,
with varying use and availability of substrates and soil.

The plant mineral content of the leachates varied depending
on food source, although the leachates were generally low
in nitrogen, supposedly as a result of denitrification
during the fermentation process.

Thus, substrates low in nitrogen gave poor growth for all
leachate treatments, although significant difference
between different leachate treatments, were found in all
substrates.

All leachates were relatively high in potassium and phosphorous. The plants were fertilized with two concentrations of leachates diluted in water. Treatments with higher concentration of leachate gave different shoot
weight depending on the food waste source of the leachate.
The content of sodium and chloride in the leachates
varied remarkably depending on food waste source, and it
was concluded that avoidable food waste contained higher
amounts than unavoidable food waste, making unavoidable
food waste a more appropriate source for production of
bokashi leachate fertilizer.