Table 18.4 Summary of research done evaluating the potential of organic nutrient sources in
hydroponic vegetable production (Source: Mupambwa et al. 2019)
Organic nutrient
sources
Method of
organic nutrient
solution
preparation
Nutrient content
of solution
Observations and
research gaps
Reference
Chicken manure,
goat manure, cow
manure, goat
manure compost,
and conventional
hydroponic
fertilizer
A 58.8 g of
manure was
immersed in 1 L
of water whilst
enclosed in a filter
bag and left to
brew for 7 days.
The goat manure
compost was prepared by thermophilic composting
for 6 months,
after which the
compost was
treated as in
above.
Not determined.
The control with
conventional
hydroponic fertilizer yielded the
highest results
across all parameters measured.
However, it was
observed that
composted goat
manure yielded
the highest
among all other
organic nutrient
sources. This
study points to
the need for optimized mineralization of organic
nutrient sources
before they can be
used in preparation of hydroponic nutrient
solutions.
Mowa (2015)
Biogas digestate
from a biogas
digester treating
food and vegetable waste; whilst
a control of commercial hydroponic solution
was also
included.
Concentrated biogas digestate was
diluted with
de-ionized water
to achieve a dilution factor of
5, 10, 15, 20,
30, and 50.
The diluted biogas digestate
contained the following nutrient
concentrations
(mg/L): NH 4 —
475; NO 3 —68.2;
total P—28.1;
total K—558;
total Ca—171;
total Mg—256;
total Na—319.
The results
clearly showed
that growth of
silverbeet was
significantly
higher in the control compared to
all other treatments. Within the
organic nutrient
sources, the treatment with a dilution of 20 resulted
in the highest
growth and yield
parameters,
higher than even
the 50% treatment. At 20%
dilution, the
nitrate and P
Krishnasamy
et al. (2012)
(continued)
322
H. A. Mupambwa et al.
hydroponic vegetable production (Source: Mupambwa et al. 2019)
Organic nutrient
sources
Method of
organic nutrient
solution
preparation
Nutrient content
of solution
Observations and
research gaps
Reference
Chicken manure,
goat manure, cow
manure, goat
manure compost,
and conventional
hydroponic
fertilizer
A 58.8 g of
manure was
immersed in 1 L
of water whilst
enclosed in a filter
bag and left to
brew for 7 days.
The goat manure
compost was prepared by thermophilic composting
for 6 months,
after which the
compost was
treated as in
above.
Not determined.
The control with
conventional
hydroponic fertilizer yielded the
highest results
across all parameters measured.
However, it was
observed that
composted goat
manure yielded
the highest
among all other
organic nutrient
sources. This
study points to
the need for optimized mineralization of organic
nutrient sources
before they can be
used in preparation of hydroponic nutrient
solutions.
Mowa (2015)
Biogas digestate
from a biogas
digester treating
food and vegetable waste; whilst
a control of commercial hydroponic solution
was also
included.
Concentrated biogas digestate was
diluted with
de-ionized water
to achieve a dilution factor of
5, 10, 15, 20,
30, and 50.
The diluted biogas digestate
contained the following nutrient
concentrations
(mg/L): NH 4 —
475; NO 3 —68.2;
total P—28.1;
total K—558;
total Ca—171;
total Mg—256;
total Na—319.
The results
clearly showed
that growth of
silverbeet was
significantly
higher in the control compared to
all other treatments. Within the
organic nutrient
sources, the treatment with a dilution of 20 resulted
in the highest
growth and yield
parameters,
higher than even
the 50% treatment. At 20%
dilution, the
nitrate and P
Krishnasamy
et al. (2012)
(continued)
322
H. A. Mupambwa et al.