Journal of Agriculture and Rural Development in the Tropics and Subtropics (JARTS)
Not a member yet
469 research outputs found
Sort by
Growth performance and immunological response of African Catfish (Clarias gariepinus) juveniles reared in biofloc system
Get PDFThis study was conducted to examine the growth and immune performance of catfish (Clarias gariepinus) juveniles cultured in a biofloc fish farming system. To achieve this, 900 C. gariepinus juveniles (9.0 ± 0.23 g) were cultured in an intensive zero water exchange biofloc system for 72 days in 9 separate tanks (2 m3 each) aerated by an air blower, after which growth assessment of fish was conducted. The trial consisted of three treatments in triplicates, a control without carbon source addition, and two biofloc treatments with carbon source addition of rice bran or cassava flour. The two carbon sources added had a C/N rate of 15:1 to form the floc. The results showed no significant difference between dissolved oxygen (DO), pH, and temperature in all the treatments, however, conductivity, total dissolved solids, and salinity showed significant differences between the bioflocs and control treatments and the treatment group. Nevertheless, the obtained values for the water parameters were within the range required for culturing C. gariepinus. Survival rate of catfish was significantly higher in the biofloc culture with a cassava carbon source (98.3%) compared with the control experiment (64.3 %). Weight gain of the fish was highest in rice bran based biofloc (44.9 ± 3.00 g) and lowest (37.0 ± 4.15 g) in the control treatment. The non-specific immune assay revealed that monocytes, serum lysozyme, and myeloperoxidase were higher in the biofloc treated groups compared to the control group. In contrast, neutrophils' percentage was lower in the treated groups than in the control group. Therefore, this study demonstrated the suitability of biofloc as an aquaculture wastewater purifier, growth-promoting, and immune-enhancing technology for the small-scale culture of C. gariepinus
Forage diversity and fertiliser adoption in Napier grass production among smallholder dairy farmers in Kenya
Get PDFFeed scarcity is one of the major challenges affecting smallholder dairy production in Kenya. Forages are the foundation of livestock nutritional requirements; forage diversification and fertiliser are intensification options that can increase productivity. A sample of 316 and 313 smallholder farmers were surveyed in eastern midlands and central highlands of Kenya, respectively, to establish the types of forages cultivated and the factors that influence fertiliser adoption in Napier grass (Cenchrus purpureus Schumach.) production. Independent t-tests were applied to compare the effect of continuous variables on social economic and institutional characteristics between adopters and non-adopters on fertiliser and area allocated to different forages. Chi-square tests were used to compare nominal variables for the proportion of farmers growing different forages, criteria they consider in selection of suitable forages, and social economic and institutional characteristics of adopters and non-adopters of fertiliser. Binary logistic regression was used to determine factors that influence fertiliser adoption. The study revealed that forage diversification was low with Napier grass being the only forage cultivated by most farmers (~90%). Urochloa (Urochloa spp), Rhodes grass (Chloris gayana Kunth.) and Guinea grass (Megathyrsus maximus Jaq.) were cultivated by less than 11% of farmers. The fertiliser adoption rate was high (77%) and was influenced by gender of household head, membership of groups, access to extension services and labour. Future research should focus on promoting of forage diversification and investigate quantity and fertiliser application regimes in order to enable development of appropriate advisory services
Drivers of adaptation to climate change in vulnerable farming communities: a micro analysis of rice farmers in Ndop, Cameroon
Get PDFFarmers in developing economies often struggle to adapt to climate change and their decisions to adapt usually hinges on perception and prevailing socio-economic factors. This study examines factors controlling farmers’ decision to adapt to climate change and evaluate the impact of such decisions on farm output. Using primary data from 138 rice farming households in Ndop-Cameroon, we employ the probit model with endogenous switching regression to investigate the impact of the farmers’ adaptation decisions on output. The results indicate that access to credits, other incomes, farmers’ age, extension services and farmer groupings form key factors that significantly affects farmers’ decision to adapt to climate change. Strategic implementation of adaptive measures, significantly increased average output of adapters by 49%. Building resilience against climate change and ensuring food security, therefore requires stakeholders to take into account existing management strategies and the underlying factors influencing these. This study suggests the crucial need for institutional advancement and policy changes towards credit accessibility for rice farmers. More local farmers’ associations should be created and extension services improved to enhance effective adaptation and farmers’ vulnerability
Agroecological heuristics: Xi (Ξ) biomathematical models of alpha diversity and Lambda functional entropy index (λ) applied for macrofauna in diversified agroecosystems of Nicaragua
Get PDFAgriculture causes chaos on the macrofauna associated with agroecosystems. The functions developed by macrofauna species in agroecological environments are harmful, beneficial and fundamental for food production. In order to design Xi (Ξ) biomathematical models of alpha diversity and to create a functional entropy index (λ), the taxonomic identification of macrofauna was carried out in 10 agroecosystems with conventional and agroecological production approach in five locations of Nicaragua: Boaco, Carazo, Chinandega, Estelí and Matagalpa. The capture of macrofauna was carried out in five surface sampling points of 3.1416 m2 each and subsequent subtraction of five soil monoliths per subsystem. Each monolith had dimensions of 0.25 m (length) 0.25 m (width) 0.30 m (depth) for atotal of 98 monoliths. The agroecosystems with a conventional approach presented 73 families and with an agroecological approach 124 families were observed. The dominant interaction of macrofauna families were between Scarabaeidae, Formicidae, Chrysomelidae, Elateridae and Noctuidae; especially the first two, influenced the final result of the model, generating a tendency to negativity due to its herd behaviour. The families Lumbricidae, Rhinotermitidaeand Acanthodrilidae, the three gregarious, pushed the model towards positivity together with Polydesmidae and Porcellionidae. The biomathematical model Xi () generated polynomial equations with an agroecological approach to simulate abundance, richness, dominance, uniformity, stability and functionality of the macrofauna species. The agroecosystems with an agroecological approach presented a range of between 41.36 to 127,095.41 much higher than the conventional approach with a range of -81.62 to 8,588.73 and a tendency to negativity
Optimisation of the seedball technology for sorghum production under nutrient limitations
Get PDFThe seedball technology is a simple and affordable seed-pelleting technique that uses locally available materials such as sand, loam, wood ash and seeds to enhance early crop establishment. It has been shown to be effective for pearl millet (Pennisetum glaucum (L.) R.Br.) subsistence production in Sahelian environments. The objective of this study was to optimise the seedball technology for sorghum (Sorghum bicolor (L.) Moench) under greenhouse conditions. Series of pot experiments were conducted in order to identify optimal size, seed number as well as nutrient content under low- and normal-soil phosphorus availability. The identified optimal seedball formula for sorghum is: 80 g sand + 50 g loam + 25 ml water + about 20 seeds. As maximum 1.5 g NPK mineral fertiliser can be added as nutrient compound. Compared to the control treatment, seedballs significantly improved root and shoot biomass variables as well as nutrient uptake of sorghum seedlings grown for 19 days. The lower the substrate P level, the better the biomass enhancement effect of seedballs, i.e. likely caused by nutrient availability. The next step is on-farm field testing under Sahelian conditions
Potassium iodide influence on iodine-leaf concentration and growth of amaranth (Amaranthus cruentus L.).
Get PDFLow iodine content in soils is a common feature in lowland and in mountainous regions far from oceans. The diets of the people living in these regions are often deficient in dietary iodine, resulting in chronic iodine deficiency syndrome, goiter, hearing loss and other debilitating diseases. A field experiment was conducted at the Teaching and Research Farm, University of Ilorin, Nigeria during the 2017 and 2018 cropping seasons, to evaluate the response of amaranths to iodine enrichment using an agronomic approach. The trial consisted of potassium iodide (KI) applied as foliar spray at 0, 3.5, 7, 10.5, 14 kg ha-1 and soil applied at the rates of 4, 8, 12 and 16 kg ha-1. These treatments were in four replicates laid out in a randomized complete block design. Data were collected on plant height, number of leaves, leaf area, crop growth rate, yield and iodine-leaf concentration. The data were subjected to analysis of variance (ANOVA) followed by mean separation using Duncan`s Multiple range test p 0.05. The results indicated that the use of KI improved the growth of amaranthus at the low level of application, but foliar application at 10.5 and 14 kg ha-1 yielded the highest iodine leaf concentration. Although application of iodine in amaranthus improved iodine leaf concentration, there was a colour change at higher rates of application which may affect the acceptability of the vegetable by consumers
Income diversification trough animal husbandry for smallholder vanilla farmers in Madagascar
Get PDFThe SAVA region in northeastern Madagascar is the largest vanilla producing area globally. Here, we investigated the role of animal husbandry (AH) for income diversification of small-scale vanilla farmers. To do this, 300 household heads were interviewed about livestock ownership, management and marketing. This information was complemented by data from 1800 households (HHs) on involvement in vanilla production (VP) and AH. Throughout the region, 83 % of HHs produced vanilla and 84 % kept livestock. Chicken-keeping (72 %) was most prominent, followed by keeping zebus (42 %), ducks (22 %) and pigs (13 %). A moderate correlation existed between VP and AH in general (r=0.356; p 0.01) and between VP and chicken-keeping (r=0.324; p 0.05), but none between VP and zebu or pig-keeping. Buying, fattening and reselling one zebu cattle yielded a price span of 9 % relative to the purchasing price, while a plus of 275 % was achieved for purchasing, fattening and reselling a pig. For chicken and ducks, the respective increase in monetary value amounted to 33 % and 49 %. Relating these price spans to the total annual income of a vanilla-producing HH revealed a potential income contribution of AH of up to 18.4 % in case of selling offspring from own cattle and 5 % or less for selling a pig or a chicken. Against the current high vanilla prices, small-scale AH is therefore an only moderately effective income diversification strategy for vanilla farmers in the SAVA region but might contribute to food security. However, in situations of low to intermediate vanilla prices AH most likely plays a more important role and might increase vanilla farmers´ resilience to income shocks
Scaling up community-based goat breeding programmes via multi-stakeholder collaboration
Get PDFCommunity-based livestock breeding programmes (CBBPs) have emerged as a potential approach to implement sustainable livestock breeding in smallholder systems. In Malawi and Uganda, goat CBBPs were introduced to improve production and productivity of indigenous goats through selective breeding. Scaling up CBBPs have recently received support due to evidence-based results from current implementation and results of CBBPs implemented in other regions of the world. This paper explores strategies for scaling up goat CBBPs in Malawi and Uganda, and documents experiences and lessons learned during implementation of the programme. A number of stakeholders supporting goat-based interventions for improving smallholders’ livelihoods exists. This offers an opportunity for different actors to work together by pooling financial resources and technical expertise for establishment and sustainability of goat CBBPs. Scaling up strategies should be an integral part of the pilot design hence dissemination partners need to be engaged during the design and inception stages of the pilot CBBPs. Creation of self-sustaining CBBPs requires early collaborative programme planning, meaningful investment and long-term concerted and coordinated efforts by collaborating partners. Permanently established actors, like government agencies and research and training institutions, are better placed to coordinate such efforts. The overall goal of the scaling up programme should be creation of a financially sustainable system, in which smallholders are able, on their own, to transact and sustain operations of their local breeding institutions using locally generated revenue/ resources. Since CBBP scaling up is a ‘learning by doing process’, an effective monitoring and evaluation system should be an integral part of the process
Variation in baobab (Adansonia digitata L.) root tuber development and leaf number among different growth conditions for five provenances in Malawi
Get PDFThe baobab tree is an underutilised indigenous fruit tree in sub-Saharan Africa which, at the same time is vulnerable to overexploitation in areas close to centres of demand, as currently baobab use is limited to wild, baobab trees. Baobab seedlings are known to form root tubers, but little is known about their growth characteristics and its yield potential. This study aims to investigate the root tuber and leaf development of baobab seedlings grown from seeds of five provenances, sown at three different planting distances in two nursery trials at climatically distinct locations in Malawi, namely Mzuzu and Mangochi. The observed yield data was fed into preliminary farm-gate profitability analyses for three different scenarios that differed by planting distance. Results indicate increased growth rates for root dry mass and number of developed leaves with increasing planting distance. However, we did not find a significant effect of seedling provenance on any of the measured plant growth parameters. Seedlings invested mainly into root development during the growth period, with root tubers reaching an average fresh weight of 41 ± 39 g and an average length of 24 ± 11.9 cm at 138 days after sowing. Profitability analyses showed a potential total net benefit of 12.78 USD per harvest cycle of 16 weeks and per 100 m² of land cultivated with baobab root tubers, which was better than an alternative scenario of maize cropping on the same area that showed a negative total net benefit when cost of family labour was included. However, the heterogeneity of root tuber development as affected by abiotic and biotic factors like soil fertility and water availability, as well as genetic origin warrant further investigation
Are there gender differences in access to and demand for East Coast fever vaccine? Empirical evidence from rural smallholder dairy farmers in Kenya
Get PDFWomen lag in the adoption of agricultural innovations compared to men, mainly due to gender inequalities in access to complementary inputs, capital, and knowledge/information. The Infection-and-Treatment-Method (ITM) is considered a safe and effective method of controlling East Coast fever. However, since its commercialisation in Kenya differences in demand for this vaccine among smallholder men and women dairy cattle keepers have not been assessed. Using a sample of 448 respondents, we used an Average-Treatment-Effect framework to estimate ITM adoption rates under awareness constraints and the determinants of adoption among smallholder male-headed (MHHs) and female-headed (FHHs) households. We found some difference in ITM awareness between MHHs (57 per cent) and FHHs (46 per cent). However, gender adoption gaps in the actual and potential adoption rates were considerable, with actual adoption rates of 41 per cent and potential adoption rate of 62 per cent among MHHs, compared to 19 per cent actual and 31 per cent potential adoption for FHHs. The smaller adoption gap for FHHs indicates that only increasing awareness amongst FHHs will not reduce inequities. ITM adoption in both household headships was mainly determined by education, extension interventions, access to financial services, and social capital. In addition to this, ITM adoption in FHHs was positively influenced by age, land-size, and group membership. To realise adoption beyond the current potential and to reduce inequities at the scale-up stage, gender-specific interventions targeting resource-poor women cattle keepers would be effective, in addition to ensuring that women have access to extension and financial services