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Application of slightly acidic electrolyzed water as a potential sanitizer in the food industry
No full textJournal ArticleTe food industry has extensively explored postharvest microbial control, seeking viable technologies to ensure food safety.
Although numerous chlorine-based commercial sanitizers serve this purpose, many are plagued by constraints such as instability
and diminished disinfectant efcacy. Tese issues arise from exposure to organic matter in wash water, light, or air. As an
innovative and promising alternative, slightly acidic electrolyzed water (SAEW) has emerged, captivating attention for its robust
sterilization potential and eco-friendliness in agricultural and food sectors. SAEW generated via electrolysis of a diluted
hydrochloric acid (HCl) solution with concentrations ranging from 2 to 6% or aqueous solution of sodium chloride (NaCl) in
a nonmembrane electrolytic chamber is reported to possess equivalent antimicrobial properties as strong acidic electrolyzed water
(StAEW). In contrast to traditional chlorine sanitizers, SAEW leaves less chlorine residue on sanitized foods such fresh-cut fruit
and vegetables, meat, poultry, and aquatic products due to its low available chlorine concentration (ACC). Its near neutral pH of 5
to 6.5 not only renders it environmentally benign but also mitigates the production of chlorine gas, a contrast to low pH conditions
seen in StAEW generation. Te bactericidal efect of SAEW against various strains of foodborne pathogens is widely believed and
accepted to be due to the combined action of high oxidation-reduction-potential (ORP) reactions and undissociated hypochlorite/
hypochlorous acid (HOCl). Consequently, a burgeoning interest surrounds the potential of SAEW for sanitation in the food
industry, ofering an alternative to address shortcomings in sodium hypochlorite solutions and even StAEW. It has been hy-
pothesized from a number of studies that SAEW treatment can increase the quality and nutritional value of harvested fruits, which
in turn may enhance their ability to be stored. Terefore, SAEW is not only a promising sanitizer in the food industry but also has
the potential to be an efcient strategy for encouraging the accumulation of bioactive chemicals in plants, especially if it is used
extensively. Tis review encapsulates the latest insights concerning SAEW, encompassing its antimicrobial efectiveness, san-
itization mechanism, advantages vis-à-vis other sanitizers, and plausible applications across the food industr
Analysis of diurnal and seasonal dynamics of water quality parameters and their implications on metabolism and physiology of nile tilapia (oreochromis niloticus) cultured in pond.
No full textPhD ThesisAquaculture production of Nile tilapia (Oreochromis niloticus) has
attracted considerable attention around the world because of their
fastest growth rate, good quality meat, and fascinating
physiological characteristic that allow them to adopt and strive in
a broad range of production systems. Because of
these
characteristics, Nile tilapia has been adopted as the key
aquaculture species in Tanzania. Nile tilapia production in
Tanzania takes place primarily in earthen ponds, mostly under a
semi-intensive system without the use of water treatment
technology. In Tanzania more than 80% of the aquaculture
produced fish comes from Nile tilapia raised ponds. The
production of Nile tilapia in ponds has for long time been
unsuccessful due to poor growth performance. This is because,
unlike in other production systems such as Recirculating
Aquaculture Systems (RAS), in small water bodies such as
earthen ponds water quality parameters vary considerably on a
daily basis, depending on the equilibrium reached with the regular
physical and chemical characteristics of the surrounding
environment. These variation are likely to considerablly effect
physiology and welfare of the cultured fish. Unfortunatly, the
extent of diurnal, and seasonal variation in water quality
parameters in the production ponds across the country are not
yet known. This makes it difficult for estimating the influence of
changes in fish ponds water quality influences on physiology and
performance of cultured Nile tilapia.
This study was carried out to determine the current status and
dynamics of the diurnal, and seasonal fishpond water quality
parameters in Tanzania. It was also carried out to assess the
effects of the observed water quality variation on the physiology,
metabolism and performance of the pond-cultured Nile tilapia. To
achieve the study objectives, a field survey of fish onds and three
laboratory experiments were performed. The diurnal and
seasonal trends in pond water quality parameters were
documented and the effect of changes of some selected water
quality parameters on the Nile tilapia physiological characteristics
and performances were reported.
Study 1. A field survey was conducted between June 2019 and
April 2021 in Tanzania. Four agroecological zones (Easter,
Southern Highland, Northern, and Lake Zones) were selected as
study sites. A total of 120 fish farmers were interviewed using a
well structured questionnaire to collect information on the current
general farm characteristics and farming practices. In addition, a
fish farm with identical ponds stocked with Nile tilapia was
selected in each agro-ecological zone, and an in-situ
measurement of the water parameters was carried out for one
year, covering two seasons (the cold: June to September and the
warm season November to January). Results revealed
significantly difference in mean pond water temperature between
the study zones (p <0.001) with the highest in the Eastern and
the lowest in the Southern Highland zones. Results show that the
temperature in the Northern zone and Southern highlands during
the cold season (June to September) was below the level
required for Nile tilapia growth. Other water quality parameters
(pH, DO, turbidity, and TDS) varied between seasons within
zones, but, were within the range suitable for Nile tilapia growth.
The annual fish yield was higher in the Lake zone (629 ±124
kg/ha/yr) suggesting a positive relationship between temperature
and fish yield. High net primary production during the warm
season in all zones indicates the need for good water quality
management to prevent algae blooms, which may result in acute
and prolonged stress from hypoxia and hypercapnia, which are
the primary physiological stressors for fish. The available data
from the survey study was used as a baseline in a series of
experiments conducted in the lab at Denmark Technical
University (DTU-aqua) to critically assess the effects of the
variation in water parameters on the physiology and performance
of the cultured Nile tilapia.
Experiment 1. High level s of dissolved carbon dioxide (CO 2 )
occurs nightly in earthen ponds characterized by high respiration
rates. Exposure to high CO 2 conditions (hypercapnia) leads to
acidosis in fish, which can be compensated by an accumulation
of HCO 3- to recover intra - and extracellular pH levels, with a
capacity that appears to be species-specific. For Nile tilapia, a
freshwater tropical teleost traditionally produced in earthen
ponds, little information is available on the tolerance to dissolved
levels of CO 2 and associated acid-base disturbances. Here, we
investigated first the effects of acute and progressively increasing
CO 2 , from normocapnic conditions to 60 mg CO 2 L -1 , on oxygen
uptake rates (MO 2 ). This was followed by exposure to three
concentrations of CO 2 ; 10, 30, and 60 mg L -1 (equivalent to pCO 2
of 5.4, 16.2, and 32.4 mmHg) against a normocapnic control
(pCO 2 0.3 mmHg), to investigate acute (1h) or prolonged (24h)
effects on standard (SMR) and maximum metabolic rate s
(MMR), haematology, and extra - and intracellular acid-base
status in adult Nile tilapia (mean BM 435 ± 16 g ±SE). Acute
exposure to hypercapnia led to concentration-dependent
decreases in both SMR and MMR. Fish were able to fully or
partially recover MMR and metabolic scope (MS) after 24h, while
depression of SMR persisted at all CO 2 levels. Acute exposure to
CO 2 caused intra-and extracellular pH levels to decrease by up to
0.5 units in a concentration-dependent manner. Only the lowest
hypercapnic treatment (pCO 2 5.4 mmHg) was able to fully
recover within 24h. Changes in haematological variables
appeared minor, being restricted to increasing haematocrit,
haemoglobin concentration, and mean cell volume in the highest
CO 2 treatments after 24h exposure. Although the Nile tilapia is
generally considered a species able to tolerate poor water quality,
the modest or slow acid-base regulation following hypercapnic
exposure suggests sensitivity to hypercapnia.
Experiment 2. Dissolved gases (carbon dioxide and oxygen) in
earthen ponds exert strong opposing effects due to
photosynthesis and respiration. This leads to daily conditions that
fluctuate between being hyperoxic and hypocapnic during the day
and becoming severely hypoxic and hypercapnic at night. The
interacting effects of hypoxia and hypercapnia and fluctuating
conditions on pond-farmed Nile tilapia have not received any
attention. This study evaluated the effects of daily variations in
dissolved O 2 and CO 2 on the appetite and feed utilization in Nile
tilapia using groups reared under normoxic - normocapnic
conditions (control, C), diurnal hypoxia (HO), diurnal hypercapnia
(HC), or combined diurnal hypoxia and hypercapnia (HO × HC) in
a digestibility system. Results show that hypoxia and hypercapnia
exerted strong individual effects on appetite, specific growth rate,
and feed conversion and that simultaneous hypoxia and
hypercapnia amplified these effects. Appetite depression induced
by nocturnal hypoxia or hypercapnia was restored at mid-day, but
simultaneous exposure resulted in a day-long loss of appetite.
Hypoxia and hypercapnia reduced specific growth rates by up to
40% and increased feed conversion ratio by up to 80%, while
combined exposure to hypoxia and hypercapnia reduced specific
growth rates by >60%. Surprisingly, the digestibility of dry matter,
protein, and lipid was improved in groups exposed to single or
combined diurnal variation in dissolved oxygen and carbon
dioxide. This study concludes that nocturnal exposure to hypoxia
or hypercapnia has adverse effects on the growth performance of
Nile tilapia driven by a combination of reductions in appetite and
poor feed utilization. The results emphasize that there is a need
for careful management of dissolved gases in pond culture.
Application of aeration technology, combined with management
of the nutrient status of the pond and sludge accumulation to
control oxygen consuming and CO 2 liberating processes, is likely
able to greatly improve production performance.
Experiment 3. Temperature plays a significant role in controlling
oxygen solubility in water and its availability to aquatic breathing
species including fish. In fish ponds, the water temperature can
increase gradually during the day resulting in elevated
temperature and an extended period of low dissolved oxygen. In
this study, the response of Nile tilapia (Oreochromis niloticus)
interms of thermal tolerance limit (CTmax), metabolic rate (SMR),
Cardiac performance (ƒ H ), and ventilation frequency (ƒv) to the
acute increase in temperature upon changing dissolved oxygenv
saturation was investigated. Nile tilapia were experimentally
exposed to an increased temperature of 0.1 °C min -1 at 100% DO
saturation (Normoxia), 70% (hypoxia), and 130% (hyperoxia)
from 26 °C (Optimum) until the onset of loss of equilibrium (LOE).
Oxygen consumption rate (MO 2 ), heartbeat, and opercula activity
were averaged at each temperature increase for three DO
saturation levels. Results show that high DO saturation (130%)
increased Nile tilapia’s Critical Thermal Maximum (CTmax) by
10%. The Nile tilapia metabolic rate (SMR) varied significantly
with the changing DO saturation at acute increased temperature
levels (One-way ANOVA; F(2,44) = 4.596, P = 0.016).
Temperature-DO-limited
metabolic
relationship
affected
cardiorespiratory activities and maximum thermal tolerance
(CTmax) in Nile tilapia (one-way ANOVA; F (2,44) = 0.34, P =
0.713). Different levels of DO saturation were found to
significantly affect Nile tilapia’s respiration ability (Opercula beats
min -1 ) (P < 0.001).
This study is concluding that diurnal and seasonal pond water
quality varies significantly between zones and between seasons
within the investigated zones and affectsthe production
performance of the pond-cultured Nile tilapia. Nile tilapia might
only be stocked in the warm season in the Northern and southern
highland zone if farmers are to achieve the best growth of Nile
tilapia. Although the Nile tilapia is generally considered a species
able to adapt to and tolerate poor water quality, the modest or
slow acid-base regulation following hypercapnic exposure
suggests that it is quite sensitive to CO 2 exposure. Although Nile
tilapia is considered resilient to environmental stress, feeding and
feed utilization, oxygen uptake, and Critical thermal maximum are
strongly influenced by daily fluctuations in dissolved CO 2 , O 2 and
Temperature.Danish International Development Agency (DANIDA
Serological survey of leptospira spp. in livestock and rodents from different settlements in the kilombero wetland, Tanzania
No full textJournal ArticleBackground: The circulation of Leptospira has been linked to various occupational activities
globally. This study investigated the seroprevalence of Leptospira spp. in rodents and livestock
(cattle and goats) in three settlements/villages involved in agriculture, livestock keeping, and mixed
agriculture and livestock in the Kilombero district, Tanzania. Methods: Data were collected dur-
ing the wet and dry seasons. A total of 179 rodents were live-captured from selected habitats.
Livestock samples were collected from 80 cattle in a livestock settlement and 120 goats from both
livestock and mixed agricultural–livestock settlements. The microscopic agglutination test was
utilized to identify Leptospira serovars. Results: The seroprevalence of Leptospira spp. was 17.3%
in rodents (21.7% in Mastomys natalensis and 3.9% in Rattus rattus) and 8.3% in livestock (13.5% in
cattle and 12.6% in goats). The prevalence among rodents and livestock differed between settlements
(p = 0.01). A higher prevalence was observed among rodents in the agricultural settlement relative
to the other settlements. A higher prevalence of antibodies in livestock was observed in the live-
stock settlement compared with the mixed agricultural–livestock settlement. The Leptospira serovars
Sokoine (serogroup Icterohaemorrhagiae) and Hebdomadis (serogroup Hebdomadis) were detected
in both rodents and livestock. The serovars Hardjo (serogroup Sejroe) and Gripothyphosa (serogroup
Gripothyphosa) were found exclusively in cattle, whereas the serovars Pomona (serogroup Pomona)
and Lora (serogroup Australis) were identified in rodents. Leptospira antibodies were found to be
elevated during the rainy season compared with the dry season (p = 0.05) in all settlements, with the
exception of rodents in the mixed agricultural–livestock settlement. Conclusions: This study demon-
strates the presence of anti-Leptospira antibodies in rodents and livestock related to occupational
activities in human settlements. It further demonstrates that wild animals (rodents) and livestock are
reservoirs of Leptospira and are important in the epidemiology of leptospirosis. Management and
control strategies should target both rodents and livestock
Assessment of community perception on proper solid waste management at household-level in Morogoro municipality, Tanzania
No full textJournal ArticleEffective solid waste management is integral to environmental sustainability and public health. The success of waste management initiatives is intricately linked to community perceptions, as their awareness and attitudes significantly influence outcomes. This study, conducted in Morogoro Municipality, Tanzania, aimed to assess the community's perception of proper solid waste management at the household level. Employing a descriptive cross-sectional design, data were gathered from 70 respondents across three randomly chosen wards: Mazimbu (26), Mji Mkuu (22), and Mji Mpya (22). These wards were pivotal in capturing a comprehensive view of solid waste management practices, accounting for variations across different areas within Morogoro Municipality. Data were also collected from five key informants using the Kobo Collect survey tool. Inferential statistics, specifically Pearson chi-square tests, were applied to analyze the data. Descriptive statistics, including frequencies and percentages, were used to explore the types of solid waste generated at the household level. The findings revealed that 38.6% of respondents produced vegetable waste, 28.6% generated leaves/grass, 20% produced plastic waste, and 12.9% generated other types of solid waste. The chi-square tests showed no significant differences in community awareness regarding the importance of proper solid waste management across wards, except for a significant difference in relation to disease outbreak reduction. Descriptive statistics were employed to analyze the community's perception of obstacles hindering proper solid waste management. To evaluate the community's perception of solid waste management, a composite mean score was calculated; a mean score above 2.00 indicated a positive perception, while a score below 2.00 suggested a negative perception. In conclusion, while the community generally holds a positive perception of solid waste management, factors such as collection fees and inadequate infrastructure hinder its effectiveness and efficiency at the household level. It is recommended that municipal authorities enhance solid waste management strategies and implement educational campaigns to raise awareness within the communit
Modeling the electrical conductivity relationship between saturated paste extract and 1:2.5 dilution in different soil textural classes
No full textdoi: 10.3389/fsoil.2024.1-10Regression models were developed to estimate the electrical conductivity of
saturated paste extract (ECe) from the electrical conductivity of soil-water ratio
(EC1:2.5) for different soil textural classes. ECe is a crucial parameter used to
indicate the presence, type, and distribution of salinity in soils. However,
determining ECe is demanding, time-consuming, requires considerable skill to
accurately identify the correct soil saturation point, and is not routinely
performed by soil testing laboratories. Many laboratories, instead, commonly
measure the electrical conductivity of soil-water extracts at various dilutions,
such as EC1:1, EC1:2.5, or EC1:5. In this study, 706 soil samples were collected from
depths of 0 - 30 cm across three rice irrigation schemes to determine EC1:2.5,
with 50% analyzed for ECe. ECe values were grouped based on soil textural
classes. The results showed a strong linear relationship between EC1:2.5 and ECe
values, with a high coefficient of determination (R² > 0.95). The Root Mean
Square Error values were low (1.4 < RMSE), and the Mean Absolute Error values
were similarly low (0.85 < MAE). Therefore, the regression models developed
provide a practical means of estimating ECe for various soil textural classes,
thereby enhancing soil salinity assessment and management strategiesDANID
Influences of different types of fertilizers on the agronomic characteristics of chloris gayana forage in a selected area of Tanzania
No full textJournal ArticleA study was undertaken from January to April 2021 in a commercial dairy farm in Iringa,
Tanzania, to determine the effects of applying different types of fertilizers on the agronomic
characteristics of Chloris gayana (Rhodes grass). Four types of fertilizers, namely cattle farm
yard manure (CFYM), blended Nitrogen, Phosphorus, Sulphur, and Zinc (NPSZn), Sulphate of
Ammonium (SA), and Urea, were applied in experimental plots using six different combinations
in a Completely Randomized Design (CRD). The combinations were control (T1) with no
fertilizer, CFYM alone (T2), CFYM and NPSZn (T3), NPSZn alone (T4), NPSZn with SA (T5),
as well as NPSZn with Urea (T6) allocated in four replications per treatment. The physical and
chemical properties of the soil in the experimental plots and the CFYM were also determined. The
application of the fertilizers followed the protocols of the manufacturers. The seeds of C. gayana
were broadcasted in all the experimental plots at a rate of 20 kg/ha. On the 90th day, forages
in their respective sub-plots were clipped to obtain representative samples for the determination
of the agronomic characteristics. Parameters considered were plant population (PP), number of
tillers per plant (NTPP), stem height (SH), number of leaves per plant (NLPP), leaf length per
plant (LLPP), leaf width per plant (LWPP) and stem diameter (SD). Results showed that the soil
texture was primarily sandy clay loam. The soil and manure contained total N (%) of 0.15 and
1.76 respectively. The amounts of extractable P (mg/kg) in soil and manure were 3.38 and 40.35,
respectively. The study showed that the plots fertilized by a combination of NPSZn and Urea (T6)
produced the highest (p<0.05) mean values of PP (85.7 plants/m2), NTPP (24.5), SH (136.6 cm),
NLPP (6.9), LLPP (40.9 cm), LWPP (1.5) and SD (3.1 mm) compared with other fertilizers. The
control treatment (T1) with no fertilizer application had the least (p>0.05) mean values of PP
(27.6 plants/m2), NTPP (5.3), SH (53.9 cm), NLPP (3.7), LLPP (23.4 cm) LWPP (0.5) and SD (1.5
mm). It is concluded that a mixture of blended NPSZn and Urea could improve the soil fertility and
hence promote the growth parameters of C. gayana. Further studies to determine biomass yield
and quality of the forage fertilized with different fertilizers under similar soil and environmental
conditions are recommended
Power relations and knowledge linkages among actors in the groundnuts seed value chain in Central Tanzania
No full textTanzania Journal of Agricultural Sciences (2024) Vol. 23 No. 1, 95-108Interdependence among actors enhances value chain functioning as it not only closely links them, but also enables them to engage with each other across the chain to form a network. The network created through these actors’ involvement and interdependence creates a necessary condition for adoption and diffusion of incentives for the value chain development and stability.In the groundnut seed value chain, less is known like in other crops’ value chain less is known on issues related to power relations and dynamics that can be assessed in levels and dimesnions of knowledge, material and income. This study aimed to assess the power relations and knowledge linkages among the actors in the groundnut seed value chain in central Tanzania. The specific objectives of the study were to identify the actors involved, their roles, and the influence and importance of power relations in the knowledge aspect. The study used a qualitative approach and a cross-sectional design. The primary data were collected through focus group discussions and key informant interviews, while the secondary data were obtained from records related to the groundnut crop and its value chain from the sampled districts covered by the Tropical Legumes III project. The UCINET software statistical package for network analysis was used to analyze the data collected. The study reveales that there is a number of actors at the village and district levels, some of whom were found in both levels.Further, power relations among these actors are revelead through centrality measures, emphasizing the significance of ties and linkages in shaping knowledge exchange dynamics. The findings speak volume on the role of influential actors at both levels, with implications for information flow, decision-making, and the overall success of the groundnuts seed value chain. The study also found that the number of ties that the actors had in the groundnut seed value chain affected their knowledge linkages, as well as their influence and power over others. The study identified that NGOs, CBOs, local government, researchers, and traders had higher influence and importance in knowledge linkages than other actors at both levels. The study recommended prioritizing the inclusion of less powerful and influential actors and involving important stakeholders in interventions targeting power relations through innovation platforms
Impact of agricultural global value chains trade policies on livelihood and : the case of coffee and sugar in Tanzania
No full textPhD ThesisAgricultural global value chains (GVCs) are “organizational systems
that operate across multiple nations and are always integrated”. The
GVCs commodities link producers to consumers worldwide through
a global network of multinational enterprises (MNEs). GVCs trade is
managed using trade policies both in producing and importing
countries. GVCs trade policies in developing countries, including
Tanzania, must optimally deliver social, economic, and
environmental benefits to trade participants. The socio, economic
and environmental benefits realized sometimes are offset by socio
and environmental costs. This happens to all trade policies, whether
in trade agreements, trade rules, regulations, or global standards
such as certifications. It is thus essential to assess the impact of
GVCs trade policies to suggest appropriate policy levers that can
optimise social, economic, and environmental benefits. Thus, this
study uses coffee and sugar GVCs in Tanzania to assess the impact
of certification policy, which is one of the GVC‟s trade policies, the
trade policies landscape of the country (trade governance), and the
role played by GVCs in ensuring delivery of social, economic, and
environmental benefits. Specifically, the study evaluates how
governance affects the sugar trade, determines the impact of coffee
certification policy on livelihood and environmental conservation and
finally analyzes the contribution of the coffee trade to livelihood
improvement and gender equity. The study hypothesizes that trade
governance does not affect Tanzania's sugar trade and trade policy
landscape; coffee certification does not improve household incomes
and environmental conservation. Coffee production and trade do not
contribute positively to livelihood improvement and gender equity.
The study uses data collected from randomly sampled 400 coffee
farmers and 375 randomly selected sugar supply chain actors in
Tanzania. The study used a mixed method of data analysis. The
endogenous switching regression (ESR) model is used to ascertain
the impact of the coffee certification policy. Exploratory (factor
analysis) and confirmatory (weighted least square regression)
models are applied to evaluate the level of trade governance in
Tanzania and ascertain its effects on the sugar trade. The Oaxaca–
Blinder decomposition and Gini coefficient models evaluate coffee
income distribution and how general coffee production and trade
contribute to gender equity and livelihood improvement. The major
findings are that trade governance is essential in ensuring the
delivery of benefits to all participants in trade. The study confirms
that governance affects the sugar trade, with the magnitude of its
effects being felt differently between farmers and traders. The
findings show further that abrupt trade policy change significantly
(p<0.05) reduces sugar trade by almost half (47.7%) and lowers the
overall level of efforts to invest within the sugar supply chain. The
study shows further that the evaluated GVCs certification trade
policy does not offer socio-economic benefits but contributes
significantly to environmental conservation. This is because the
study rejects the hypothesis of certification to improve household
income but accepts its contribution to improved awareness and
environmental conservation practices among coffee farmers.
Additionally, GVCs trade contributes positively to livelihood
improvement and gender equity since the study found coffee to have
income inequality-reducing effects. Therefore, using sugar and
coffee GVCs and one of the GVC policies, certification, the study
has confirmed that certification does not optimally deliver social,
economic, and environmental benefits to trade participants.
However, participation in trade is essential for inclusive
socioeconomic benefits. The study confirms further that good sugar
trade governance is a panacea for Tanzania to achieve optimal
trade policies in the sugar sector. Predictability of the trade policies
in the sector is a major factor for allowing forward contracting of
imports and/or exports and investments. Thus, the study has
provided the importance of trade governance in shaping how
countries should implement trade policies. The study recommends
ensuring trade policies are stable and predictable for increasing
trade and allowing forward contracting and investments. It is also
essential to create awareness of institutions and organizations
managing the GVCs by encouraging transparency in trade policy
administration and practices. The certification policy should be
implemented by easing the transmission of price premiums to coffee
farmers for an increased supply of sustainably grown coffee,
improving coffee farmers‟ livelihood and helping attain environmental
sustainability goals within the coffee supply chain. This must be
supported with awareness creation and making certification services
accessible and cost-effective to coffee farmers. In striking a balance
between people and nature, participation in the GVCs trade is
encouraged. This is because coffee is an essential crop with an
inequality-reducing effect, contributing to livelihood improvement.
Investing in supporting the coffee supply chain impacts poverty
reduction, as the income earned from coffee favours people
experiencing poverty more than other income sources. Participation
should be supported through empowerment for equal access to land
and credit. Production and trade policies should also be gender responsive by providing opportunities to offer trade facilitation
services to increase the participation of women in coffee supply
chain activities and control their participation benefit
Land-use–land cover changes in the Urban River’s Buffer Zone and variability of discharge, water, and sediment quality— a case of urban catchment of the Ngerengere River in Tanzania
No full textResearch ArticleThe physical integrity of the Ngerengere River and its three tributaries drains within
Morogoro Municipality were evaluated by assessing the variations in land-use–land cover (LULC)
in the river’s buffer zone, the discharge, and the contamination of river water and sediment from
nutrients and heavy metals. Integrated geospatial techniques were used to classify the LULC
in the river’s buffer zone. In contrast, the velocity area method and monitoring data from the
Wami-Ruvu Basin were used for the discharge measurements. Furthermore, atomic absorption
spectrophotometry was used during the laboratory analysis to determine the level of nutrients and
heavy metals in the water and river sediment across the 13 sampling locations. The LULC assessment
in the river’s buffer during the sampling year of 2023 showed that bare land and built-up areas
dominate the river’s buffer, with a coverage of 28% and 38% of the area distribution. The higher
discharge across the sampling stations was in the upstream reaches at 3.73 m3/s and 2.36 m3/s at the
confluences. The highest concentrations of heavy metals in the water for the dry and wet seasons
were 0.09 ± 0.01, 0.25 ± 0.01, 0.03 ± 0.02, 0.73 ± 0.04, 4.07 ± 0.08, and 3.07 ± 0.04 mg/L, respectively,
for Pb, Cr, Cd, Cu, Zn, and Ni. The order of magnitude of the heavy metal concentration in the
sediments was Zn > Ni > Cr > Cu > Cd > Pb, while the highest NO2−, NO3−, NH3, and PO43− in
the water and sediment were 2.05 ± 0.01, 0.394 ± 0.527, 0.66 ± 0.05, and 0.63 ± 0.01 mg/L, and
2.64 ± 0.03, 0.63 ± 0.01, 2.36 ± 0.01, and 48.16 ± 0.01 mg/kg, respectively, across all sampling seasons.
This study highlights the significant impact of urbanization on river integrity, revealing elevated
levels of heavy metal contamination in both water and sediment, the variability of discharge, and
alterations in the LULC in the rivers’ buffer. This study recommends the continuous monitoring of
the river water quality and quantity of the urban rivers, and the overall land-use plans for conserving
river ecosystems.Sokoine University of Agriculture
Farmers' knowledge and traditional processing practices of pigeon peas (cajanus cajan) in rural areas in Lindi region Tanzania: a quantitative and qualitative mixed study
No full textJournal ArticlePigeon peas (Cajanus cajan) are an important protein source in many parts of tropical and
sub-tropical regions of the world. However, their quality and availability may be affected by post-
harvest handling and processing practices in use. In the present study, knowledge and practices
of pigeon pea growers (PPG) in Lindi Region were evaluated with respect to harvesting, storage,
processing and cooking preparation. A sample of 597 randomly selected PPG from two villages,
were interviewed and 60 farmers participated in focus group discussions. Majority PPG (83.6%)
harvested pigeon peas (PPs) by cutting and putting them in polyethylene sacks while 86.6% had
knowledge on only one storage method. Also, majority of PPG (77%) lacked any processing
knowledge on mentioned methods such as hulling and solar drying. Results also indicated
75.7% of PPG having no knowledge on cooking preparation methods out of which 94.5% had
no knowledge on soaking, 89.6% on use of bicarbonate and 89.9% on methods to increase shelf
life of PPs. Overall, 49.4% had little/limited knowledge on harvesting, storage, processing, and
cooking preparation practices, with no significant gender difference. All PPG prepared stew using
green or dry PPs. A sizeable proportion (45%) of PPG used dry PPs for stew preparation, after
traditional hulling. The threshing of peas from pods was carried out manually. Traditional methods
in the Lindi Region are laborious and time-consuming; resulting in poorly prepared products thus
affecting the appearance of processed PPs. Training farmers on proper postharvest handling and
processing can improve food security and market appeal