• Rural Digital Europe
• Publications close
• ZW close
• BJ close

Due to the need to continuously monitor and understand the thermal environment and its socioeconomic implications, this study used remotely sensed data to analyze thermal comfort variation in LCZs, including along the rural to urban gradient of the eThekwini Municipality in KwaZulu-Natal province of South Africa. LCZs were mapped using multi-temporal and multi-spectral Landsat 8 and Landsat 9 data using the approach by World Urban Database and Access Portal Tools (WUDAPT), while thermal data were used to retrieve land surface temperatures (LSTs). Data for training classification of LCZs and accuracy assessment were digitized from GoogleEarth guided by knowledge gained and data collected during a field survey in March 2022 as well as pre-existing maps. LCZs were mapped using the random forest classifier in SAGA GIS software while a single channel algorithm based on band 10 was used to compute LST for different scenes. The LSTs were adjusted and further used to derive thermal comfort based on the Universal Thermal Comfort Index (UTCI) categories as an indicator for outdoor thermal comfort on the extremely low- and extremely high-temperature periods in the cool and hot seasons, respectively. LCZs were mapped with high accuracy (overall accuracy of 90.1% and kappa of 0.88) while inter-class separability was high (>1.5) for all LCZ pairs. Built-up LCZs dominate the eastern parts of the municipality, signifying the influence of the sea on development within the area. Average LST was coolest in the dense forest, open low-rise and water LCZs in the cool and hot seasons, respectively. The compact high-rise LCZ was the warmest in both the hot (36 °C) and the cool (23 °C) seasons. The sea sands were among coolest regions in both seasons due to their high water content, attributed to their high water table and close proximity to the ocean. There was no thermal stress during the cool season, while most areas recorded moderate to strong heat stress in the hot season. Some areas in the densely built-up LCZs recorded very strong heat stress in the hot season. The findings suggest that policies and strategies should enhance heat mitigation capacities in strong-heat-stress areas during the hot season. Municipal authorities and citizens must work together to build strategies to minimize temperature extremes and associated socioeconomic pressures. Urban development policies, plans and strategies should consider implications on the thermal environment as well as the value of conservation of LCZs with high-heat mitigation value such as dense forests and expansion of built-up LCZs with low-heat absorption levels such as open low-rise. The study was based mainly on remotely sensed temperatures with some ground data used to validate results, which may limit the assessment. Overall, the study provides insights towards achievement of global sustainable and climate-smart development targets.

In Benin, synthetic insecticides are the main pest control option used by farmers to protect and enhance their production. However, failures to control the target pests are often observed after application and may be related to agricultural practices or insecticide quality. The present work was designed to assess a rapid, simple, and reliable analytical method for detecting and quantifying the most commonly used insecticides (λ-cyhalothrin and acetamiprid) in Benin. The analytical standard technical grade separation was performed by gradient reversed-phase high-performance liquid chromatography on a C18 stationary-phase column. The mobile phase consisted of a mixture of acetonitrile/water using a gradient flow. The flow rates were 1 and 1.4 mL·min−1 for λ-cyhalothrin and acetamiprid, respectively. The analysis times were 15 and 20 min, with retention times of 2.35 and 7.94 min for λ-cyhalothrin and acetamiprid, respectively. Results reveal that most of the surveyed farmers were not educated (70% < Primary School Certificate) and were men (95%). Of the main insecticides applied by farmers, λ-cyhalothrin and acetamiprid were found to be the most technical-grade ones. Furthermore, the analysis of insecticides showed that the concentrations obtained in our study often differed from the ones mentioned on insecticide labels. The proposed method is useful for quantifying insecticides in various technical and commercial formulations with little interference from additives.

AbstractA review of available literature shows that small grains are widely used across the globe for human and livestock feed. Sustainable chicken production can significantly contribute to dietary needs and resolve food insecurity in the smallholder sector. It is estimated that local chickens constitute 80% of poultry production in sub-Saharan countries, 28% in America, 15% in Europe, and 60% in Asia. The success of production of small grains such as sorghum (Sorghum bicolor), finger millet (Eleusine coracana), and pearl millet (Pennisetum glaucum) has been attributed to their drought resilience and adaptability to climate change. Sorghum, in particular, is the fifth most important global cereal crop after maize. Chicken producers use local small grains as major components for inclusion in poultry diets in order to decrease the cost of production and increase the profits. The potential use of small grain as a major source of native chicken is attributed to their richness in the composition of diverse nutrients. Small grains contain diverse amino acids and energy levels. Millets, in particular, are high in minerals such as calcium, iron, and pyridoxine (vitamin B6). Sorghum has metabolizable energy, calcium, and phosphorus for supporting chicken growth and production. Studies reviewed on on the performance of broilers on varying degrees of small grain inclusion have been made using broiler chickens fed on varying degrees of small grain inclusion in various diets. Studies showed that a diet containing 12.34 MJ ME/kg dry matter (DM) to 12.91 MJ ME/kg DM is recommended for growth performance during the starter and grower phases of Venda spotted breed chicks. Furthermore, indigenous naked neck chickens aged between 1 and 6 weeks were reported to require a diet containing an energy level of 14 MJ ME/kg DM for optimal growth and carcass quality. Chicken feed formulation through least cost feed formulation recommended small grain inclusion at 13.9 ME (MJ/kg) to obtain diets with 11.8% crude protein. Physical (such as grain germination, soaking, and grinding) and chemical (such as fermentation, urea treatment, and use of alkali substance) strategies can enhance the utilization of small grains by chickens. There is a greater scope for improving small grain utilization by chickens by establishing convenient and accurate levels of inclusion in the diets and adding their value through biofortification interventions.

Globally, Miombo woodlands store important quantities of carbon, with tree cover and carbon stocks strongly determined by human use. We assessed woodland cover and aboveground carbon (AGC) stocks of miombo along a utilisation gradient on three different land use types, that is, a national park, a buffer zone and a communal area. Woodland cover and carbon stock changes were assessed through mapping of AGC between 2007 and 2017 using Phased Array L-Band Synthetic Aperture Radar observations (ALOS-PALSAR 1 and 2). Woodland cover was higher in the national park and the buffer zone than in the communal area for both 2007 and 2017. In 2007, mean AGC stock was not significantly different (p = 0.005) across all three land use types. However, in 2017, mean AGC was significantly lower (p < 0.001) in the buffer zone and communal area than in the national park. In all three land use types, Miombo woodland cover and mean AGC gains outweighed losses over the 10-year period. AGC gains were significantly higher (p < 0.001) in the national park than in both the buffer zone and the communal area. Results of the study indicate that woodland cover and aboveground carbon increased in all three land use types despite the observed human disturbance over the study period. Both variables recorded a lower increase with elevated utilisation. The study concluded that sustainable resource utilisation is possible without loss of such ecosystem services as carbon sequestration and climate change mitigation.

AbstractMany international policy and academic circles have explored the effects of climate change on household livelihood outcomes, such as food and nutrition security, household income, and household resilience. Yet, little attention has been paid to understanding how literature has framed adoption drivers of agroecological intensification practices, an area addressed in this study. This review consolidates available literature on how adoption impacts crop yields, food and nutrition security, household incomes, and poverty reduction in Southern Africa. We systematically reviewed 45 empirical studies on adoption drivers and the associated impacts on household livelihood outcomes. Variables affecting adoption of agroecological intensification practices are rainfall distribution and temperature, non-farm economic activities, status of soil fertility, market access, ownership of communication equipment, livestock ownership, age of household head, gender of the household head, household size, factors of production and wealth status. Majority of the reviewed publications found a positive correlation between the use of agroecological intensification practices and crop yield, food and nutrition security, household incomes, and poverty reduction. Thus, it is recommended that agricultural interventions are designed in a way that farmers have a sense of ownership to ensure continuity of adoption, and practices are tailored to the needs of the target population, taking into account both the mix of technologies and existing farmer resource constraints.

Agriculture in free spaces within urban areas sustains residents as they grow crops to ensure food availability while at the same time selling other produce to fund other needs. Due to the value of urban agricultural production, the main focus of this study was to investigate the implications of urban growth on maize yield in Harare metropolitan city. In order to achieve this, Landsat multispectral and multi-temporal data were used to establish the responses of the estimated maize yield to city growth from 1984 to 2018. Initially, Land Use and Land Cover map for each period were produced using multispectral images and field observation in Support Vector Machine (SVM)-based supervised image classification. The maps were reclassified using a binary scheme of croplands and non-croplands, which was used to quantify cropland area in each period and hence change over time. The maize yield for each period was estimated from data obtained from a study of maize yields obtained at the University of Zimbabwe Farm (UZ) farm for maize grown under variable agricultural practices. Results showed that cropland area was reduced from 11,120 ha in 1984 down to 2631 ha in 2018. The estimated average maize yield decreased from 52,264 tons in 1984 to 12,366 tons in 2018. In addition to showing the value of urban agriculture, the findings of this study are important in informing the government, municipalities, and other stakeholders about how urban growth has the potential to compromise food security and livelihoods, especially for the urban poor.

AbstractCassava is one of the most common food crops grown and consumed in many parts of Africa, and boiled cassava is especially popular in West Africa. However, its quality characteristics and attributes are not well documented. This study aimed at generating data to produce useful information on cassava trait preferences for boiling. To understand end-users’ trait-preferences for raw and boiled cassava, the study used a mix of approaches including a qualitative survey, process diagnosis and consumer testing. Gender-disaggregated data on cassava varieties were clustered into three categories: “common varieties with similar rank”, “common varieties but differently ranked” and “varieties exclusively cited by women or men”. Raw cassava root for making high-quality boiled cassava should have cracked peel, a sweet taste, and white flesh. Irrespective of cassava varieties, the three descriptors: “hard to break in the hand”, “not crumbly in the mouth” and “too bitter tasting” greatly penalized the overall liking, lowering values by a range of 2.2 to 2.6 on a nine-point scale (i.e. by about a quarter). Accordingly, high-quality boiled cassava should be attractive with white, homogenous flesh, a sweet taste, easy to break in the hand, crumbly in the mouth, and fiber-free.

AbstractSoil fertility degradation is one of the major constraints in smallholder farming environments especially in the semi-arid region of Sub-Saharan Africa. This has been worsened by poor farming methods, lack of technical knowledge and inadequate application of nutrient sources by farmers. The use of mineral fertiliser alone has been cost ineffective and causes land degradation. Although several soil fertility management (SFM) practices have been put forward, knowledge about their benefits, access and adoption by smallholder farmers is still limited. Synthetic review of published articles obtained from Web of Science, Google Scholar and Scopus which cover semi-arid regions across Africa were retrieved and synthesied. Farmers have been applying low organic manure (<5 t ha−1) against the recommended rate of 20–40 t ha−1 depending on soil texture and this caused low crop yields. This call for farmers to adopt integrated soil fertility management (ISFM) practices to improve nutrient availability and crop yields. The use of ISFM has been reported to increase maize yields by 15–145% in semi-arid areas. Maize yields varies from 4200 to 5500 kg ha−1 and sorghum from 690 to 3500 kg ha−1 under ISFM. Yield increment for various crops with the use of cattle manure integrated with other nutrient sources was reported but there are still few studies where effects compost, farmyard manure and poultry manure were combined with inorganic fertiliser were evaluated. Therefore, this review paper seeks to synthesise the effects of ISFM practices available for smallholder farming systems in semi-arid areas of sub-Saharan Africa to improve crop production.