A study was conducted in Morogoro, Tanzania to assess the effect of treated wastewater as an alternative source of irrigation water and nutrients for rice. Wastewater was sourced from a local wastewater Stabilization Ponds and cleaned through a Constructed Wetland. Four treatments namely, (i) Waste water (WW) only (ii) WW + NPK (iii) Tap water only (iv) Tap water + NPK were tested in a Randomized Complete Block Design (RCBD) with 4 replicates. Rice, variety Saro 5 was planted in August 2013.Data was collected on physical-chemical and biological qualities of the WW, and soils, yield and yield components. Analysis of variance and Least Significant Difference (LSD) on yield were conducted (p≤0.05) using INSTAT software. WW had alkaline pH of 8.2 and acceptable levels of physical-chemical-biological components. WW only treated rice resulted in higher yields over non-treated rice. The combination of WW and NPK was not as effective especially for flowering, grain size and total yield indicative of nutrients overloading. Tap water only treated rice yielded 1.3 tons/ha while WW treated rice yielded 5.44 ton/ha mostly through promotion of higher number of fertile tillers while a combination of WW and NPK depressed yield potential to only 1.7 ton/ha. Effectiveness of WW for irrigation is acknowledged.

1. Effect of Treated Domestic Wastewater as Source of Irrigation Water and Nutrients on Rice Performance in Morogoro, Tanzania
JEWM
Effect of treated domestic wastewater as source of
irrigation water and nutrients on rice performance in
Morogoro, Tanzania
Agnes MS Nyomora
Department of Botany, University of Daressalaam, P.O. Box 35060, Tanzania.
Tel.: +255 222 410,764/255754478021; Email: agnesnyomora@gmail.com;nyomora@amu.udsm.ac.tz
A study was conducted in Morogoro, Tanzania to assess the effect of treated wastewater as an
alternative source of irrigation water and nutrients for rice. Wastewater was sourced from a
local wastewater Stabilization Ponds and cleaned through a Constructed Wetland. Four
treatments namely, (i) Waste water (WW) only (ii) WW + NPK (iii) Tap water only (iv) Tap water +
NPK were tested in a Randomized Complete Block Design (RCBD) with 4 replicates. Rice,
variety Saro 5 was planted in August 2013.Data was collected on physical-chemical and
biological qualities of the WW, and soils, yield and yield components. Analysis of variance and
Least Significant Difference (LSD) on yield were conducted (p≤0.05) using INSTAT software. WW
had alkaline pH of 8.2 and acceptable levels of physical-chemical-biological components. WW
only treated rice resulted in higher yields over non-treated rice. The combination of WW and
NPK was not as effective especially for flowering, grain size and total yield indicative of
nutrients overloading. Tap water only treated rice yielded 1.3 tons/ha while WW treated rice
yielded 5.44 ton/ha mostly through promotion of higher number of fertile tillers while a
combination of WW and NPK depressed yield potential to only 1.7 ton/ha. Effectiveness of WW
for irrigation is acknowledged.
Keywords: Constructed wetlands, saro 5 rice, irrigated rice, organic fertilizer, alternative irrigation, wastewater
INTRODUCTION
The increasing global population is creating a gap
between water supply and demand thus threatening
human consumptive use and therefore need for water
conserving measures. Fresh water is a finite and
vulnerable resource whose sustainability is threatened by
human induced activities including domestic
consumption, livestock feeding, irrigated agriculture,
hydropower generation industries and aquaculture.
Unreliable rainfall, multiplicity of competing uses,
degradation of water sources and catchment areas all
have exacerbated water use conflicts. One way of
remedying the situation is the reuse of domestic
wastewater for irrigation purposes. This could release
clean water for domestic use and drinking only as well as
availing other alternatives especially for irrigation
purpose. In developed countries where environmental
standards are adhered to, much of the wastewater is
treated prior to use for irrigation of pasture, parks, and
seed crops and, to a limited extent, for the irrigation of
orchards, vineyards, and other crops. Evidence for
extensive use in developing world including Tanzania is
limited (Balkema et al., 2010).
Municipal treatment facilities including passage through
constructed wetlands are designed to treat raw
wastewater to produce a liquid effluent of suitable quality
Journal of Environment and Waste Management
Vol. 2(2), pp. 047-055, February, 2015. © www.premierpublishers.org, ISSN: 1936-8798x
Research Article

2. Effect of Treated Domestic Wastewater as Source of Irrigation Water and Nutrients on Rice Performance in Morogoro, Tanzania
Nyomora AMS 047
that can be disposed off to the natural surface waters
with minimum impact on human health or the
environment but this can be problematic for low income
countries with limited capacities for land based treatment
and disposal (Balkema et al., 2010).
Tanzania has insufficient water resources but has
tremendous irrigation potential with some 44 million
hectares (Mha) deemed suitable for irrigation; but only 10
Mha (23%) is actually cultivated and of that only 227,000
hectares (ha) is irrigated (Evans et al., 2014). This
irrigation potential is not being realized due to limited
financial resources capacities of the millions of
smallholder farmers who constitute the majority of the
agricultural sector in Tanzania. They are currently unable
to take advantage of improved irrigation techniques and
technologies.
Of the twenty major urban water utilities in Tanzania, 11
provide some access to sewer connections. In Moshi the
reported connection rate is 45%. In Morogoro the
reported rate is 15% and in Dodoma and Iringa it is 13%
while in Dar es Salaam the length of the sewer network is
estimated at 188 km, but only 4% of households have
access to it (Balkema et al., 2010; Kilobe et al., 2013).
The total population of Morogoro urban is 250,000
demanding 30,000 m
3
of water daily from all sources
(MORUWASA, 2010). Using waste water for irrigation
would remove the competition of water with urban
domestic usage. However, some degree of treatment
must normally be provided to raw wastewater before its
use for agricultural or landscape irrigation; this strategy
has received limited practice in Tanzania (Balkema et al.,
2010). On the other hand, farmers around Morogoro
waste stabilization ponds where the constructed wetlands
were constructed already grow lowland irrigated rice
using water from the Ngerengere River. The volume of
water in this river diminishes during the dry season thus
limiting acreage that can be cultivated otherwise due to
optimal high temperatures throughout the year; it would
be possible to plant and harvest rice 4 times in one year.
Significant investments in infrastructure, institutions and
human resources will be required to achieve the
government’s stated goal of increasing the irrigated area
to 7 Mha by 2015 and raising paddy yields from an
average of 2 t/ha to 8 t/ha as those realized in
experimental research sites (Evans et al, 2014).
Constructed wetlands are designed, man-made complex
of saturated substrate, with emergent and submerged
vegetation, animal life, and water that simulate natural
wetlands for human uses and benefits (EPA, 1993). They
are relatively cost effective to establish and operate,
provide effective and reliable wastewater treatment,
relatively tolerant of fluctuating hydrologic and
contaminant loading rates and finally provide indirect
benefits such as green space, wildlife habitats and
recreational and educational areas. Therefore,
wastewater that has been treated through a constructed
wetland is a resource that can be used for productive
uses in agriculture, aquaculture, and other activities
because it contains plant nutrients like N, P, K and S that
contributes to promotion of plant growth (Hussain et
al.,2001). Its reuse can deliver positive benefits to
farming communities, and municipalities (FAO, 2004).
This study intended to evaluate the effect of constructed
wetlands treated Waste Water on potential productivity of
rice as an alternative solution to supplying the needed
moisture and nutrients to increase rice yield productivity
in Morogoro region.
MATERIALS AND METHODS
Study site
The study was conducted in Mafisa Ward, Morogoro
Urban, Tanzania (Fig 1) where MORUWASA operates its
Waste Stabilization Ponds (WSP). MORUWASA-WSP
collects municipal sewage and household wastewater
which either flows in directly through the networked
central sewer system or is emptied by tankers. The
sewerage system area is situated in an undulating valley
having fertile alluvial clayey soils in the lowland and
farmers cultivate paddy using water from a stream that
feeds into Ngerengere River. The University of Dar es
Salaam-Waste Stabilization Ponds (UDSM-WSP)
research group has constructed an artificial wetland that
cleans wastewater intercepted from WSP No. 2 of the 6
waste water treatment ponds and delivers it to the
experimental fields through closed piping. An irrigation
pump with following specifications: model SE-50X;
Delivery volume- 600L/min; Total head- 30M and Power
speed- 2.0Kw (Fig 2) delivered waste water (WW) and
tap water into the experimental bunded plots from 2
temporary reservoirs, one for WW and the other for
freshwater that were dug close to the plots.
Wastewater and soil samples analyses
Wastewater from MORUWASA–Waste Stabilization Pond
No. 2 was sampled in 1L capacity plastic containers each
of which were thoroughly washed with 1M HCL and
rinsed several times with deionized water prior to sample
collection according to Allen (1989). Sampling was
conducted using the grab method whereby WW was
scooped from the pond. Samples were kept in tight
bottles in an ice chest (temp =4 º
C) and immediately
taken to the laboratory for further processing. The
samples were then filtered and acidified to pH 2 using 6
M HNO3 and stored at 4º
C for subsequent analyses of
various physical-chemical parameters namely pH, EC,
C.E.C, organic matter content, available phosphorus,
total nitrogen, and soil texture according to APHA (1998).
Soil samples from the area were collected from two

3. Effect of Treated Domestic Wastewater as Source of Irrigation Water and Nutrients on Rice Performance in Morogoro, Tanzania
J. Environ. Waste Manag. 048
Figure 1. A Map of Morogoro showing the site of the study area
Figure 2. Irrigation water intake and water delivery pump
points along the center-line at a depth of 0 – 10cm, and
10 – 20cm. The samples were then homogenized into a
composite sample which was weighed separately, kept in
polythene bags, properly sealed to prevent contamination
and loss of moisture. Sub samples were derived from this
composite sample for measurements of presence or
absence of fecal coliform bacteria. The samples were
incubated in a water bath at 44.5ºC for 24 hours where
gas production in the fermentation tube after 24 hours
was considered a positive reaction, indicating presence
of fecal coliform. Based on which dilutions showed
positive for coliform and/or fecal coliform, a table of most
probable numbers was used to estimate the coliform
content of the sample plus other disease causing
organisms. The results were reported as most probable
number (MPN) of coliform per 100 ml (EPA, 1998).

4. Effect of Treated Domestic Wastewater as Source of Irrigation Water and Nutrients on Rice Performance in Morogoro, Tanzania
Nyomora AMS 049
Table 1. Physical Chemical Composition of Wastewater before passing through the constructed wetland
Parameter Source of Sample
Anaerobic Pond Inlet Anaerobic Outlet Pond Outlet of the Last
Maturation Pond
Threshold levels for
irrigation water
TSS (mg/L) 250 120 50 0-2000
Phosphorus (mg/L) 2.69 2.71 2.78 10-500
Nitrates (mg/L) 0.345 0.635 0.653 50
BOD5 (mg/L) 410 150 120 200
Ammonia (mg/L) 6.07 6.24 6.05 5-50
Faecal Coliforms
(MPN/100ml)
4.2 x 106
2.8 x 105
3.6 x 103
< 1000
Electric
conductivity(dS/m)
0. 866 0.7-3.0
Source: Baseline data collected by CW-WSP Team, 2012: FAO (2004) for the Threshold levels
Table 2. Levels of diseases causing organisms in waste water reuse environment (Most probable number (MPN)/100ml
effluent sample)
Component Total
Coliforms
Fecal
coliforms
Eschereia coli Salmonella Campylobacter spp.
Wastewater 1,100 210 9 ND 3
Leaf rinse water 90 3 ND ND ND
Experimental layout and design for paddy
A total of 16 plots measuring 9m
2
each (3m long x 3m
wide) were ploughed by hand and finely cultivated into
bunds. An improved rice variety [Oryzasativacv Saro 5
(TXD 306)] was used for this trial and it was sown in
furrows spaced 20cm apart on 23rd
August 2013. The
trial was irrigated using tap water to begin with and
seedlings were thinned to single plants at a spacing of 10
cm between plants. About 2 weeks after emergence on
5th
September, 2013 half of the plots received an
inorganic NPK fertilizer (15:9:20) at a rate of 400kg/ha
and the other half of the plots received waste water (WW)
treatments which were initiated on 19
th
September, 2013.
The 4 treatment combination were as follows: (i) Waste
water (WW) only (ii) WW + NPK (iii) Tap water only (iv)
Tap water + NPK and all the treatments were replicated 4
times in a Completely Randomized Block (RCBD)
Design. WW and Tap water treatments were applied
every time there was a need for irrigation, while NPK was
applied only once at planting.
Yield and yield components recorded and data
analyses
Data on yield and yield components i.e. the number of
tillers, flag leaf area, flowering (%), number and length of
panicle/plant, proportion of fertile and sterile grains and
yield per plot were collected at appropriate times during
plant growth using the SES standard procedures
(Choudhary, 1996).
Analysis of variance (ANOVA) was conducted (p≤0.05)
as RCBD using INSTAT software and Least Significant
Difference (LSD) was computed to test for the differences
between treatment means (p≤0.05) according to Gomez
and Gomez (1994).
RESULTS
Physical-chemical-biological properties of
wastewater and soils
The results of the physical chemical properties of
wastewater used as source of irrigation water for the
experiments and soils at the experimental field are as
shown in Tables 1, 2 and 3. The Initial waste water came
from the 2
nd
maturation pond which was closest to the
outlet of the anaerobic pond shown in Table 1. The
values for TSS, P, Nitrates, BOC and Ammonia were
similar to the typical values reported by FAO (2004).
Table 3a shows the Physical-chemical properties of the
soil samples collected at the experimental site i.e. pH
8.2±0.04,0.71±0.023 total nitrogen, while P was
0.5±0.03.mg/100g. The organic matter was2.3±0.08%
and CEC measured to 57.9± 0.57meq/100g. The soil
texture was categorized as silt loam.

5. Effect of Treated Domestic Wastewater as Source of Irrigation Water and Nutrients on Rice Performance in Morogoro, Tanzania
J. Environ. Waste Manag. 050
Table 3a. Physical –Chemical properties of
the soil from the experimental site
Properties Mean values
pH 8.2 ±0.04
Total N(mg/1) 0.71 ±0.023
Organic matter (%) 2.3 ±0.08
P (mg/100g) 0.5 ±0.03
C.E.C (meq./100g) 57.9 ±0.57
Sand (%) 7.7 ±3.84
Silt (%) 75.7 ±17.84
Clay (%) 23.3 ±11.67
Table 3b. Heavy metalcontent in soils sampled from experimental field at Mafisa
Heavy metals Values (µg/100g) Acceptable limits(mg/kg) References
Pb bdl 20 McKeague and Wolynetz (1980)
Cr 0.05±0.01 150 Adriano (1986)
Cu 55.6±1.14 1500 McKeague(1980)
Zn 146.86±4.42 450 Adriano (1986)
Table 4. Heavy metal content of wastewater (WW) samples from MORUWASA
Constructed wetland
Heavy metals Values(µg/100g) Acceptable limits(µg/l) Reference
Pb 0.01±0.003 10 (WHO-2008)
Cr 0.14±0.009 150 (WHO-2008)
Cu 6.423±0.03 2000 (WHO-2008)
Zn 59.4±0.12 3000 (WHO-2008)
Figure 3. Influence of WW and inorganic fertilizer NPK on number of tillers of rice: (a) Averaged over dates (b)
Averaged over treatments
Results of heavy metals in the soil samples were as
shown in Table 3b which indicated that Pb was below
detection limit while Cr (0.05), Cu (55.6) and Zn
(146.86)µg/100gwere below the acceptable minimum
threshold limits. Similar values were found in wastewater
destined for irrigating paddy.
Vegetative growth and Tillering
Tillering or shooting from the stem bases started in late
September, optimized in October about two months after
planting, and peaked in November when the effect of
treatments was evident (Fig 3a). Plants in WW treated
0
20
40
60
80
Numberof
WW
WW+NP
Tap
Tap
Key
a

6. Effect of Treated Domestic Wastewater as Source of Irrigation Water and Nutrients on Rice Performance in Morogoro, Tanzania
Nyomora AMS 051
Figure 4. Influence of WW and inorganic fertilizer NPK on rice biomass (a) flag leaf area and (b) Wt. of Stover
Figure 5. Influence of WW and inorganic fertilizer NPK on
yield components (a) Flowering %age/plant, (b) Length of
inflorescence (cm) and (c) No. of spikelets/inflorescence
plots produced insignificantly higher total number of tillers
per plant (48) than the Tap water irrigated plots (44) and
NPK treated plots (38) while plants which received both
WW and NPK produced the least number of tillers (36)
(Figure 3b). Likewise the flag leaf area was insignificantly
higher in WW treated (37.6 cm
2
) than NPK treated (34.3
cm2
) and non- treated plots which were irrigated with tap
water only (29.1 cm
2
) (Fig 4). Figure 4b reveals that WW
treated plots resulted in significantly higher biomass
(straw) weight than the rest of the treatments. Biomass
left over after harvest was highest in WW treated plots
i.e. 2.6 ton/ha and lowest in tap water treated plots (0.8
t/ha) while in NPK treated plots it ranged between 1.1
and 1.2 ton/ha.
a
a

7. Effect of Treated Domestic Wastewater as Source of Irrigation Water and Nutrients on Rice Performance in Morogoro, Tanzania
J. Environ. Waste Manag. 052
Figure 6. Influence of WW and inorganic fertilizer NPK on yield components (a) No. of fertile grains/inflorescence (b) Wt.
of fertile grains/inflorescence and (c) No. of sterile grains and (d) Wt of sterile grain/inflorescence
Yield components
WW resulted in significantly higher flowering than other
treatments. The proportion of fertile or flowering
tillers/plant was significantly higher in WW treated
(21.5%) than in non-treated plots (5.3%) or where WW
was combined with NPK (9%) (Figure 5a). The length of
flower panicles did not show any significant differences
between treatments (Figure 5b) and so was the number
of spikelets/inflorescence which averaged to ten (10) and
the length of inflorescences which averaged 23cm
(Figure 5b). The number of fertile grain/inflorescence was
least in plots irrigated with tap water but was significantly
higher in WW and NPK treated plots (Figure 6a). The
weight of fertile grains/inflorescence followed similar
trend to the numbers of fertile grains and ranged between
2.4 to 3.5g. Plots which received tap water only
produced the least number of fertile grains/inflorescence
(94) weighing 2.4gm while WW treated plots averaged
135 grains/inflorescence weighing 3.5gm; similarly the
number and weight of sterile grains (Figure 6c and 6d).
Yield
Very highly significant differences in total yield between
WW treated plants and non-treated treatments were
observedin this study (Figure 7). Plots which received
WW only as source of irrigation water and nutrients
produced 5.44 ton/ha while plots which were treated with
a combination of WW and NPK produced only 1.7ton/ha.
On the other hand, tap water irrigated plots but which
received inorganic NPK fertilizers yielded 1.6 ton/ha
while plots which were irrigated using tap water only
produced only 1.3 ton/ha.
a b
c

8. Effect of Treated Domestic Wastewater as Source of Irrigation Water and Nutrients on Rice Performance in Morogoro, Tanzania
Nyomora AMS 053
Figure 7. Paddy grain yield under the two sources of
nutrients and irrigation water
DISCUSSION
Physical chemical biological properties of
wastewater and soil
The soil pH averaged to 8.2± 0.04 was considered
slightly alkaline. A pH between 5 and 8.5 is generally
acceptable for use in irrigation; very acidic (pH less than
5), or very alkaline (pH greater than 8.5), may need to be
neutralized before application as soil pH affects the
availability of nutrients and other elements to plants
(FAO, 2004). If pH exceeds 7.3, phosphorus is
increasingly made unavailable by fixation in phosphates
especially Calcium (Islam, 2013). The key nutrients in the
soil N and P in the form of nitrates and phosphates were
considered generally low. The organic matter content of
2.3±0.08% was considered fairly adequate and CEC
which measured 57.9±was high indicating that the soil
had a high capacity for holding cations.
Recommended levels of Total soluble solids(TSS) for
agricultural irrigation water quality standard is 0-700mg/l
(FAO, 2004) which indicates that the 120mg/l soluble
solids which was found in the WW from MORUWASA
and used for irrigating paddy was within the acceptable
concentration.
The values for fecal coliforms were higher than the
threshold values recommended of less than
1000MPN/100ml WW. After passing the wastewater
through the constructed wetland, table 2 shows the
disease causing organisms in waste water and plant
parts as an indicator for the health concerns of
stakeholders (operators, farmers and consumers). The
total coliforms were slightly higher than the acceptable
values while the fecal coliforms were not.
Vegetative Growth and Yield
There was a trend for greener and more luxurious plant
growth in all plots that were irrigated using WW followed
by plots that were irrigated with tap water but which also
received inorganic fertilizers. WW only treated plots also
flowered slightly later than plots that were irrigated using
tap water only.
Waste water previously treated in a constructed
wasteland promoted vegetative growth, tillering, and
biomass production of this rice variety much more than
non-treated plots or those treated with NPK or their
combination in that order indicating the effectiveness of
WW in realization of the yield potential of rice- variety
Saro 5. Tillering is an essential yield component used to
determine the overall architecture of cereal crops and
therefore is an important agronomic trait for rice grain
production. It is a specialized grain bearing branch that is
formed on un-elongated basal internode and grows
independently of the mother stem or culm by means of its
own adventitious roots. The inflorescence are born on
fertile tillers so by promoting these inflorescence bearing
tillers using WW in the current study, it was evident that
WW potentially effected paddy productivity. There was a
tendency of increased production of sterile grains in WW
treated plots in comparison to other treatments but this
was masked by the higher production of fertile grains.
Response of other paddy yield components including the
flag leaf area, flowering %, the number and length of
spikelets were similar to that of tillering confirming the
effectiveness of WW as a good source of irrigation water
and nutrients for high productivity. In rice, the flag leaf
area is the most metabolically active organ that supplies
photosynthates to the developing grain and therefore it
plays a big role in grain yield as also suggested by
Prakash (2012). This was highly promoted by WW
treatment alone while the combination of WW and NPK
was not as effective especially for flowering, grain size
and total yield indicative of nutrients overload.

9. Effect of Treated Domestic Wastewater as Source of Irrigation Water and Nutrients on Rice Performance in Morogoro, Tanzania
J. Environ. Waste Manag. 054
Effectiveness of Constructed wetland in supplying
nutrient rich WW
Irrigating using municipal treated wastewater can
conserve water and fertilize crops economically by
capturing nutrients that would normally be wasted. This
irrigation method is also an effective way to prevent
contamination of nearby waterways with the disease
organisms that wastewater contains, hence a
considerable health benefit. However, reuse of
wastewater for agricultural irrigation, industrial reuse and
ground water recharge can become a risky endeavor if
prior evaluation of residual contamination of nutrients
(high N and P), organics, toxic, trace elements and some
enteric bacteria and virus and monitoring is not regularly
done (Kivaisi, 2001); as well as converting harmful
substances to harmless components or to acceptable
concentration that can be assimilated into the receiving
waters without environmental damage. In studies utilizing
several Municipal and agriculture wastewater discharge
have been found to contain elevated nutrient
concentrations (N and P) that may stimulate excessive or
nuisance algal growth in downstream receiving waters
(Kivaisi, 2001). On the other hand, chemicals (organic,
inorganic and heavy metals) in wastewater that passes
through a wetland ecosystem is rapidly inter-converted
from organic to inorganic forms and forms of chemical
complexes that in turn maybe adsorbed or precipitated
within the wetland (Musiwa, 2001).
Wastewater treatment cost studies show that marginal
costs are very high at higher levels of treatment (Schleich
et al., 1996). However, these higher marginal treatment
costs may sometimes be justifiable in view of the value of
the crop, degree of water scarcity, and public concern. In
the current study, tap water only irrigated plots produced
1.3 ton/ha which was far below the yield potential of
Saro5 rice variety of 8-10 ton/ha. WW only treated plots
promoted yields which was within the yield potential of
Saro 5 while a combination of WW and NPK depressed
yield potential of Saro 5 to only 1.7 ton/ha. Other
research studies (Kanyeka, 2013) had shown that Saro 5
is an open pollinated rice variety grown both in lowland
rainfed and irrigated systems in Tanzania. It has a
high tillering ability with a range of 30 to 50 tillers/pl
ant with a high yielding potential of 8‐ 10 ton/ha at r
esearch station and 4‐ 6.5 ton/ha in farmer’s field. M
ost local varieties in Tanzania produce
10 ‐15 tillers that give total yield of 1.8 ton/ ha due to
their low yielding abilities (Kanyeka, 2013). The current
study results on the number of tillers and yield/ha
especially in the WW treated plots were within the yield
potential of this variety.
NPK applied once at planting at a rate of 400kg/ha added
yields of only 0.4ton/ha in excess to that realized under
tap water. At the current price of 54,000TShs/50 kg bag
of NPK fertilizer, this translates into 432,000 Tanzanian
shillings/ha. Therefore, based on the extra price tag of
the inorganic fertilizer, it pays to irrigate rice fields using
WW from CW when it is available. This is in addition to
getting an extra source of irrigation water. FAO (2004)
had estimated that a city with a population of 500,000
and water consumption of 200 l/day per person would
produce approximately 85,000 m
3
/dayor 30 m³/year of
wastewater, assuming 85% inflow to the public sewerage
system. If treated wastewater effluent is used in carefully
controlled irrigation at an application rate of 5000
m
3
/ha/year, an area of some 6,000 ha could be irrigated.
In addition to this economic benefit of the water, the
fertilizer value of the effluent in the range of 50 mg/l
Nitrogen, 10 mg/l Phosphorus and 30mg/l Potassium
would be supplied. Assuming the application rate of
5,000 m3
/ha/year the fertilizer contribution of theeffluent
would be: 250 kg/ha N, 50 kg/ha P and150 kg/ha K per
year which is quite substantial.
Constructed wetlands systems are technically a good
option to realize hygienic sanitation as the reduction of
faecal coliform is high. Faecal coliform removal in
constructed wetlands in Tanzania has been determined
and found to be greater than 99% during 5 case studies
(de Ruijter 2009). In practice, most developing countries
use untreated wastewater for agriculture for a variety of
reasons, least of which is the cost of treatment and the
loss of precious nutrients. However, treatment of
wastewater prior to agricultural use is believed to be
essential: first, from the point of view of public health
protection, and second, to respect local social and
religious beliefs (Mara 2000). In view of these
requirements, water scarcity, dry land farming, hot
climatic conditions, and the high economic value of fresh
water resources, a great deal of research and
development efforts needs to be undertaken, for the
reuse of wastewater. More studied are needed to
concretize the health status of farmers handling irrigation
using WW as well as consumers of rice grown in the
study area under this system.
ACKNOWLEDGEMENT
The author acknowledges the financial support offered by
the Centre for Science and Technology, Tanzania
(COSTECH) and logistical contributions of other
researchers in the team
REFERENCES
Adriano DC (1986).Trace elements in the terrestrial
environment. Springer- Verlag, Berlin,
Heidelberg, New York.
Allen SE (ed.). (1989). Chemical Analysis of Ecological

10. Effect of Treated Domestic Wastewater as Source of Irrigation Water and Nutrients on Rice Performance in Morogoro, Tanzania
Nyomora AMS 055
Materials 2nd
ed. Blackwell Scientific Publishing,
Oxford, London.
APHA (1998). Standard methods for the analysis of water
and wastewater,18
th
edition, American Public Health
Association, Washington, D.C.
Balkema, Njau KN, Romijna H, de Ruijter R. (2010).
Socio-economic analysis of constructed wetlands
systems for hygienic sanitation in Tanzania Water
Practice and Technology 5 (1) @ IWA
Publishing.doi:10.2166/WPT2010.022
Chaudhary RC (1996). Standard Evaluation System
(SES) for rice. Inger Genetic Resources Center, IRRI
Phillipines, 52pp.
Collaizzi PD, Gowda PH, Marek TH, Porter O (2008).
Irrigation in Texas High Plains: A brief History and
Potential Reductions in Demand.
www.interscience.wiley.com doi 10.1002/ ird 418
de Ruijter R (2009). Dissemination of Constructed
Wetlands technology for improved sanitation in
Tanzania, Strategic Niche Management, MSc thesis
Technology and Policy, Eindhoven University of
Technology incorporation with the University of Dar es
Salaam,
EPA (1993). Constructed wetlands for wastewater
treatment and wildlife habitat.17 Case studies.EPA,
832-R-93-005.
Evans AEV, Giordano M, Clayton T (2014).Investing in
agricultural water management to benefit smallholder
farmers in Tanzania: Ag Water Solutions Project
country synthesis report. Colombo, Sri Lanka:
International Water Management Institute (IWMI
Working Paper 146). 34p. doi: 10.5337/2012.208
FAO (2004). Wastewater treatment and use in Agriculture
In: Prescod. MB. Study on reuse technology of
discharge water from municipal wastewater treatment
plants Environmental Management Corporation
Irrigation and Drainage pp. 11 Paper No.47. ISBN 92-5-
103135-5.
Gomez KA, Gomez AA (1994). Statistical procedure for
Agricultual research.2nd
edition.IRRI. John Wiley and
Sons, New York, pp. 340.
Hussain I, Raschid L, Hanjra MA, Marikar F, Wim van der
Hoek (2001).Wastewater Use in Agriculture: Review of
Impacts and Methodological Issues in Valuing Impacts.
Working Paper No. 37. IWMI. ISBN 92-9090-472-0
Islam RMD (2013). Assessing soil quality and yield
performance of rice under conventional and non-
conventional irrigation waters in Western fringe of
Khulna City, Bangladesh, BSc.Thesis, Khulna
University.
Kanyeka ZL (2013). New rice in Tanzania to boost
production. http://irri.org/news/39-media-releases/120-
new-rice-in-tanzania-to-boost-production accessed
23/04/2013.
Kilobe MB, Mgegela RH, Mtambo MMA (2013).
Acceptability of wastewater resource and its impact on
crop production in Tanzania:The case of Dodoma,
Morogoro and Mvomero wastewater Stabilization
Ponds. Kivukoni J. 1(2), 94-103.
Kivaisi AK (2001). The potential for constructed wetlands
for wastewater treatment and reuse in developing
countries: a review. Ecological Engineering 16, 545-
560.
Mara, DD (1976). Sewage treatment in hot climates.John
Wiley.London
McKeague JM (1980). Background levels of minor
elements in some Canadian soils. Geoderma,24 :299-
307.
MORUWASA (2010). Environmental and Social Impact
Assessment of the Proposed Improvements to the
Morogoro Water Supply System, Tanzania.
Musiwa JS (2001)The uptake of Copper, Lead and Zinc
by Cyperus papyrus in dozing experiments.
In:Mbwette.TSA, KatimaJHYand Jorgesensen SE
(eds). Proceedings of the Regional conference on
application of wetland systems and waste stabilization
ponds in water pollution control held on 24-30 August,
2001at the University of Dar es Salaam
Prakash M (2012). Variatal variation in flag leaf area and
yield in mutant lines of PY 5 rice. Karnataka J. Agric.
Sci. 24(4), 525-526
Schleich J, White D, Stephenson K (1996). Cost
implications in achieving alternative water quality
targets. Water Resources Research. 32(9),2879-
2884.15.
WHO (2006). Guidelines for drinking water quality.
Incorporating 1
st
and 2
nd
Addendum 1, 296-
460.Recommendations-3rd
ed. Geneva
Accepted 19 January, 2015.
Citation: Nyomora AMS (2015). Effect of treated
domestic wastewater as source of irrigation water and
nutrients on rice performance in Morogoro, Tanzania.
Journal of Environment and Waste Management 2(2):
047-055.
Copyright: © 2014 Nyomora AMS. This is an open-
access article distributed under the terms of the Creative
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