Exploring Factors Affecting Performance of Smallholder Tea Farmers in Tanzania

Tea sub-sector is a major driver of poverty reduction for Tanzanians, especially smallholder tea farmers, who depend mostly on tea farming as the source of employment and household earnings. However, their tea production has been experiencing a declining trend, and so far, the reasons behind this decline remains unclear. Therefore, the aim of this study was to explore factors affecting the performance of smallholder tea farmers in two Tanzanian tea producing districts; Muheza and Njombe. Questionnaires were administered to smallholder tea farmers (n = 320) and key informants (n = 80) to gather all the required information, which were then analysed using Statistical Package for Social Sciences (SPSS; Version 21.0) software. The level of education, number of household members who assist in tea farming activities, tea farming experience, age of the farmer, tea membership status, as well as access to extension and credit services were the significant (p < 0.05; in all cases) determinants on the performance of smallholder tea farmers. Strategies that aim at; encouraging the participation of young and energetic population in the tea sub-sector, prioritizing the provision of education and extension services, expanding access to credits, strengthening tea associations, building markets closer to smallholders’ tea farms, and improving the conditions of the roads that connect market centres and tea farms, are recommended. The findings from this study are crucial, and should be used by relevant stakeholders in addressing challenges that impede the performance of smallholder tea farmers across the country. Keywords: smallholder tea farmers, performance, Muheza, Njombe, Tanzania

Increasing importance of nitrate-nitrogen and organic nitrogen concentrations in bulk and throughfall precipitation across urban forests in southern China

Atmospheric nitrogen (N) deposition is an increasingly serious threat to forest ecosystems requiring urgent global actions. While it is well-known that developing countries are experiencing rapid urbanization, an understanding of its effects on N composition and sources in atmospheric deposition is only beginning to emerge. We measured dissolved inorganic N (DIN), dissolved organic N (DON) and total dissolved N (TDN) concentrations in bulk precipitation (BP) and throughfall precipitation (TP) across four seasons in forest ecosystems along the more urbanized river (Bailongjiang; BJR) and the less urbanized river (Wulongjiang; WJR) in Fuzhou coastal city. Concentrations of all N forms were greatly enhanced in BJR forests than in WJR forests, suggesting increased anthropogenic N pollution in forests along the BJR that, in turn, can cause serious N cycle perturbations. While precipitation N concentrations over the BJR forests were primarily influenced by pollutants from fossil fuel combustion activities (ammonium-nitrogen; NH4 +-N/nitrate-nitrogen; NO3 −-N = 0.77), those over the WJR forests were collectively influenced by pollutants from fossil fuel combustion and agricultural activities (NH4 +-N/NO3 −-N = 1.14). The DON contributed 22–38% of N to the TDN across seasons and rivers and was positively related to other N forms, indicating that DON is steadily becoming a vital component in atmospheric N deposition especially in anthropogenically N-polluted atmospheres. Summer was characterized by precipitation with lower N concentrations, highlighting increased dilution effect and decreased anthropogenic N emissions. Nitrogen concentrations were more elevated in TP than in BP, suggesting that tree canopies augment atmospheric N deposition to forest soils. Generally, soil and foliar TN and δ15N were positively related to precipitation TDN, indicating that increased atmospheric N deposition enhances forest ecosystem N availability. Our results demonstrate that urban areas particularly in developing countries are not only NHx but also NOx emission and deposition hotspots and emphasize the necessity of including them in future global N budgets and N pollution abatement initiatives

Arbuscular mycorrhizal fungi mitigate soil nitrogen and phosphorus losses: A meta-analysis

Nutrient loss from terrestrial ecosystems via leaching and gaseous emissions is increasingly threatening global environmental and human health. Although arbuscular mycorrhizal fungi (AMF) have been shown to regulate soil N and P losses, a comprehensive quantitative overviewof their influences on the losses of these soil nutrients across global scales is currently lacking. This study used a meta-analysis of 322 observations from 36 studies to assess the effect of AMF inoculum on 11 variables related to the loss of soil N and P.We found that the presence of AMF significantly reduced soil N and P losses, with the most pronounced reduction occurring in soil NO3 –N (−32%), followed by total P (−21%), available P (−16%) and N2O (−10%). However, the mitigation effects of AMF on soil N and P loss were dependent on the identity of AMF inoculum, plant type and soil biotic and abiotic factors. Generally, the mitigation effects of AMF increased with increasing AMF root colonization rate, microbial diversity of inoculants, soil organic carbon (SOC) content and experimental duration as well as with decreasing soil sand contents and soil N and P availability. Overall, this meta-analysis highlights the importance of AMF inoculation inmitigating N and P nutrient loss and environmental pollution for terrestrial ecosystem sustainability

Distinct Growth and Nutrient Status Responses to Fertilization Regimes in Two Generations of Chinese Fir Seedlings

Exponential fertilization is well-known for improving the growth and nutritional status of seedlings during nursery culture. However, less is known about how genetic variability among seedling species influences the effects of fertilization regimes on the growth of seedlings and their nutritional status under varying fertilization levels. Here, we conducted a greenhouse experiment to compare the growth, as well as the nitrogen (N) and phosphorus (P) nutrient concentration responses, of 2- and 3-generation Chinese fir (Cunninghamia lanceolata (Lambert) Hooker) seedlings to the impacts of varying exponential and conventional constant-rate fertilization levels (50, 100, and 200 mg P seedling−1). Seedling size and shoot:root ratios were lower in exponential fertilization than in conventional fertilization. Exponentially fertilized seedlings had higher concentrations of N and P nutrients compared to conventionally fertilized seedlings during low-level fertilization. Conversely, an elevated P concentration was observed in seedlings subjected to conventional fertilization compared to those exposed to exponential fertilization during high-level fertilization. However, there were no significant differences in seedling N and P concentrations between the two fertilization regimes during medium-level fertilization. Furthermore, 2- and 3-generation Chinese fir seedlings differed greatly in their growth and nutritional status. Additionally, there were significant fertilization regime × seedling generation interaction effects on the seedling shoot:root ratio and N concentration. Our findings suggest that exponential fertilization can improve the nutritional status, survival, and growth of Chinese fir seedlings, especially on competitive sites, and that information on both intra-species genetic variability and appropriate fertilizer levels is necessary for the successful fertilization of Chinese fir seedlings, regardless of fertilization regimes

Habitat utilisation and nesting behaviour of two sympatric weavers in Mbalmayo District, Cameroon

Avian ecology and behaviour data provides crucial information for bird conservation and management, but are still missing for many species, particularly in developing countries. This study examines habitat utilisation, nesting behaviour, anthropogenic disturbances and impacts on agricultural crops of Village Weaver Ploceus cucullatus and Vieillot’s Black Weaver Ploceus nigerrimus in Mbalmayo District, Cameroon. Abundance was estimated by nest counts and point counts of birds at 40 previously located colonies, where also tree metrics and anthropogenic disturbances were measured. In total, more than 1 700 birds of the two species were estimated within a 9 km2 study area, divided into two blocks and five different habitat types. Village Weavers were generally more abundant, especially in the urban habitat, whereas Vieillot’s Black Weavers were most numerous in the rural habitat. Among the tree species used for nesting, mango Mangifera indica and African border tree Newbouldia laevis had the highest nest counts, which also was positively related to canopy cover diameter. Traffic noise disturbance was associated with lower bird and nest counts, whereas the opposite was observed on farming disturbance. The relative impacts on agricultural crops were estimated for African oil palm Elaeis guineensis (38%), maize Zea mays (36%), Musa spp. (18%) and Mangifera indica (8%). The implications for long-term coexistence between farmland birds and humans are discussed, and the challenge is to minimise both kinds of bird–human interactions, i.e. anthropogenic disturbances and agricultural crop damage

Effects of land use change from natural forest to plantation on C, N and natural abundance of 13C and 15N along a climate gradient in eastern China

Soil C and N turnover rates and contents are strongly influenced by climates (e.g., mean annual temperature MAT, and mean annual precipitation MAP) as well as human activities. However, the effects of converting natural forests to intensively human-managed plantations on soil carbon (C), nitrogen (N) dynamics across various climatic zones are not well known. In this study, we evaluated C, N pool and natural abundances of δ13C and δ15N in forest floor layer and 1-meter depth mineral soils under natural forests (NF) and plantation forest (PF) at six sites in eastern China. Our results showed that forest floor had higher C contents and lower N contents in PF compared to NF, resulting in high forest floor C/N ratios and a decrease in the quality of organic materials in forest floor under plantations. In general, soil C, N contents and their isotope changed significantly in the forest floor and mineral soil after land use change (LUC). Soil δ13C was significantly enriched in forest floor after LUC while both δ13C and δ15N values were enriched in mineral soils. Linear and non-linear regressions were observed for MAP and MAT in soil C/N ratios and soil δ13C, in their changes with NF conversion to PF while soil δ15N values were positively correlated with MAT. Our findings implied that LUC alters soil C turnover and contents and MAP drive soil δ13C dynamic

Chemical Composition and Deposition Characteristics of Precipitation into a Typical Temperate Forest in Northeastern China

The chemical compositions and deposition characteristics of atmospheric precipitation affect the structure and function of forest ecosystems and reflect regional air quality. Although northeastern China constitutes a vital forested area, few relevant studies reveal the chemical composition and the nitrogen (N) and sulphur (S) deposition characteristics within precipitation. In this study, we monitor precipitation chemistry during 2018–2020 at a rural forested site in northeastern China (the Qingyuan site) and compare it with those from background sites (Mondy in Russia and Ochiishi in Japan) and highly anthropogenically influenced areas (Beijing). The precipitation pH range was 4.7–8.0 (volume-weighted average 6.2). The average concentration of total ions in precipitation was 459 μmol L−1, representing a moderate pollution level. Nitrate (NO3−, 73 μmol L−1) and ammonium (NH4+, 133 μmol L−1) were the major anions and cations in the precipitation. Total inorganic nitrogen (TIN) deposition was 12.3–15.9 kg N ha−1 year−1 (NH4+-N deposition accounted for 54–67%), lower than the average level in China (19.4 kg N ha−1 year−1). Annual precipitation sulphate (SO42−) deposition was 4.9–6.7 kg S ha−1 year−1. Seventy-two percent of the precipitation ions at our site originated from human activities. This work has revealed that N and S deposition is an important ion deposition component in atmospheric precipitation in the study of temperate forests in northeastern China. Nitrogen deposition, as a source of vital nutrients in the forest ecosystem, may promote forest growth and, thereby, forest carbon sequestration

Chemical Composition and Deposition Characteristics of Precipitation into a Typical Temperate Forest in Northeastern China

The chemical compositions and deposition characteristics of atmospheric precipitation affect the structure and function of forest ecosystems and reflect regional air quality. Although northeastern China constitutes a vital forested area, few relevant studies reveal the chemical composition and the nitrogen (N) and sulphur (S) deposition characteristics within precipitation. In this study, we monitor precipitation chemistry during 2018–2020 at a rural forested site in northeastern China (the Qingyuan site) and compare it with those from background sites (Mondy in Russia and Ochiishi in Japan) and highly anthropogenically influenced areas (Beijing). The precipitation pH range was 4.7–8.0 (volume-weighted average 6.2). The average concentration of total ions in precipitation was 459 μmol L−1, representing a moderate pollution level. Nitrate (NO3−, 73 μmol L−1) and ammonium (NH4+, 133 μmol L−1) were the major anions and cations in the precipitation. Total inorganic nitrogen (TIN) deposition was 12.3–15.9 kg N ha−1 year−1 (NH4+-N deposition accounted for 54–67%), lower than the average level in China (19.4 kg N ha−1 year−1). Annual precipitation sulphate (SO42−) deposition was 4.9–6.7 kg S ha−1 year−1. Seventy-two percent of the precipitation ions at our site originated from human activities. This work has revealed that N and S deposition is an important ion deposition component in atmospheric precipitation in the study of temperate forests in northeastern China. Nitrogen deposition, as a source of vital nutrients in the forest ecosystem, may promote forest growth and, thereby, forest carbon sequestration