Now showing items 49468-49487 of 49529

    • Xanthomonas Wilt of Banana Drives Changes in Land-Use and Ecosystem Services Across Infected Landscapes

      Walter Ocimati; Jeroen J. C. Groot; Pablo Tittonell; Godfrey Taulya; Jules Ntamwira; Serge Amato; Guy Blomme (MDPI AG, 2020-04-01)
      Changes in land-use have been observed in banana-based systems in the African Great Lakes region affected by Xanthomonas wilt disease (XW) of banana. Through focus group discussions (FGDs) and the 4-cell method (to map the area under production and the number of households involved), changes in land-use were assessed in 13 XW-affected landscapes/villages along a 230 km transect from Masisi (where XW arrived in 2001) to Bukavu (XW arrived around 2014) in the Eastern Democratic Republic of Congo. Farmers’ perceptions on the sustainability of new land uses were also documented. Soil nutrient content and erosion levels were measured for five major land-use options/trajectories on 147 fields across 55 farms in three landscapes along the transect. From banana being ranked the most important crop (92% of landscapes) before XW outbreaks, its importance had declined, with it grown on smaller farms by most households in 36% of the landscapes, while in 64% of cases by few households on smaller plots. Farmers uprooted entire banana mats or fields, expanding land under other crops. Species richness did not change at landscape level, although 21 crops were introduced at farm level. Banana is, however, still perceived as more sustainable due to its multi-functional roles. Soils under banana had better chemical attributes, while high erosion levels (Mg ha<sup>−1</sup> year<sup>−1</sup>) occurred under cassava (1.7–148.9) compared with banana (0.3–10.7) and trees (0.3–5.9). The shifts from banana could thus affect supply of key services and sustainability of the farming systems. This study offers a good basis for interventions in XW-affected landscapes.
    • XGBoost for Imbalanced Multiclass Classification-Based Industrial Internet of Things Intrusion Detection Systems

      Thi-Thu-Huong Le; Yustus Eko Oktian; Howon Kim (MDPI AG, 2022-07-01)
      The Industrial Internet of Things (IIoT) has advanced digital technology and the fastest interconnection, which creates opportunities to substantially grow industrial businesses today. Although IIoT provides promising opportunities for growth, the massive sensor IoT data collected are easily attacked by cyber criminals. Hence, IIoT requires different high security levels to protect the network. An Intrusion Detection System (IDS) is one of the crucial security solutions, which aims to detect the network’s abnormal behavior and monitor safe network traffic to avoid attacks. In particular, the effectiveness of the Machine Learning (ML)-based IDS approach to building a secure IDS application is attracting the security research community in both the general cyber network and the specific IIoT network. However, most available IIoT datasets contain multiclass output data with imbalanced distributions. This is the main reason for the reduction in the detection accuracy of attacks of the ML-based IDS model. This research proposes an IDS for IIoT imbalanced datasets by applying the eXtremely Gradient Boosting (XGBoost) model to overcome this issue. Two modern IIoT imbalanced datasets were used to assess our proposed method’s effectiveness and robustness, X-IIoTDS and TON_IoT. The XGBoost model achieved excellent attack detection with F1 scores of 99.9% and 99.87% on the two datasets. This result demonstrated that the proposed approach improved the detection attack performance in imbalanced multiclass IIoT datasets and was superior to existing IDS frameworks.
    • XGBoost-DNN Mixed Model for Predicting Driver’s Estimation on the Relative Motion States during Lane-Changing Decisions: A Real Driving Study on the Highway

      Chen Zhao; Xia Zhao; Zhao Li; Qiong Zhang (MDPI AG, 2022-06-01)
      This study is conducted on a real live highway to investigate the driver’s performance in estimating the speed and distance of vehicles behind the target lane during lane changes. Data on the participants’ estimated and actual data on the rear car were collected in the experiment. Ridge regression is used to analyze the effects of both the driver’s features, as well as the relative and absolute motion characteristics between the target vehicle and the subject vehicle, on the driver’s estimation outcomes. Finally, a mixed algorithm of extreme gradient boosting (XGBoost) and deep neural network (DNN) was proposed in this paper for establishing driver’s speed estimation and distance prediction models. Compared with other machine learning models, the XGBoost-DNN prediction model performs more accurate prediction performance in both classification scenarios. It is worth mentioning that the XGBoost-DNN mixed model exhibits a prediction accuracy approximately two percentage points higher than that of the XGBoost model. In the two-classification scenarios, the accuracy estimations of XGBoost-DNN speed and distance prediction models are 91.03% and 92.46%, respectively. In the three-classification scenarios, the accuracy estimations of XGBoost-DNN speed and distance prediction models are 87.18% and 87.59%, respectively. This study can provide a theoretical basis for the development of warning rules for lane-change warning systems as well as insights for understanding lane-change decision failures.
    • Xylan Hemicellulose: A Renewable Material with Potential Properties for Food Packaging Applications

      Petronela Nechita; Roman Mirela; Florin Ciolacu (MDPI AG, 2021-12-01)
      Xylan hemicelluloses are considered the second most abundant class of polysaccharides after cellulose which has good natural barrier properties necessary for foods packaging papers and films. Xylan exists today as a natural polymer, but its utilisation in packaging applications is limited and not sufficiently analysed. In this study, the performances of hardwood xylan hemicellulose in forming uniform films and as biopolymer for paper coatings were analysed. The xylan-coated paper and film samples were tested regarding their water, air, and water vapour permeability, water solubility, mechanical strength, and antimicrobial activity against pathogenic bacteria. Structural analyses of xylan hemicelluloses emphasised a high number of hydroxyl groups with high water affinity. This affects the functional properties of xylan-coated papers but can facilitate the chemical modification of xylan in order to improve their hydrophobic properties and extend their areas of application. The obtained results unveil a promising starting point for using this material in food packaging applications as a competitive and sustainable alternative to petroleum-based polymers.
    • Yard Operations and Management in Automated Container Terminals: A Review

      Hang Yu; Yiyun Deng; Leijie Zhang; Xin Xiao; Caimao Tan (MDPI AG, 2022-03-01)
      With the increasing volume of global moving containers and the application of automation technologies, it is important for container terminals to improve handling efficiency. This paper provides a comprehensive literature review on yard management issues in automated container terminals, which is proven to be the key to improve container handling efficiency. This paper analyzes the hotspots in the current yard management research based on the VOSviewer for the last 20 years. More than 600 papers are recorded, and we further discuss 75 papers closely related to the research aiming to identify main features in current research. The research is divided into several clusters based on the 75 papers by VOSviewer. After reviewing and analyzing the literature on these clusters, this paper demonstrates the contribution and gap in the current research and puts forward emerging pressing research topics on yard management in automated container terminals for future research.
    • Yield and Cost Effects of Plot-Level Wheat Seed Rates and Seed Recycling Practices in the East Gojam Zone, Amhara Region, Ethiopia: Application of the Dose–Response Model

      Yirgalem Eshete; Bamlaku Alamirew; Zewdie Bishaw (MDPI AG, 2021-03-01)
      Previous studies investigated the effects of seed rates and seed recycling practices on the yield and yield-related variables. However, higher yield does not always guarantee cost-efficiency. This study aimed to investigate the yield effects of plot-level seed rate and the cost–benefit analysis of seed recycling practices. This study has introduced the dose–response model to the existing analytical methods used in analyzing the effect of different agrochemicals on crop yield. A multi-stage stratified sampling technique was used to select a total of 450 sample respondents. Data were gathered using a mix of data collection tools. Descriptive statistics along with the dose–response model were applied for data analysis. Farmers of the study were found to be dissimilar in terms of their seed rate application. A dose–response analysis indicated that the highest average wheat yield was associated with a seed rate of 50 kg ha<sup>−1</sup> above what is recommended. The yield effect of seed recycling was also assessed, and a one-time seed recycling has caused a yield decline of 665 kg ha<sup>−1</sup> compared to the non-recycled seeds. The cost reduced using recycled seed is by far lower than the economic gains associated with using unrecycled and fresh seeds. The cost–benefit analysis made clear that farmers can reduce their seed costs through seed recycling, but their yields and net income can be best improved by using unrecycled certified bread wheat seed (CBWS). Thus, farmers must be encouraged to use unrecycled seed by establishing agricultural credit schemes geared towards seed procurement and seed price subsidy as key strategies to reduce economically wasteful seed recycling practices.
    • Yield and Milk Composition at Different Stages of Lactation from a Small Herd of Nguni, Boer, and Non-Descript Goats Raised in an Extensive Production System

      Emrobowansan M. Idamokoro; Voster Muchenje; Patrick J. Masika (MDPI AG, 2017-06-01)
      This study was conducted to evaluate the yield and composition of milk from 30 indigenous South African goats of different genotypes, namely Nguni, Boer, and non-descript, reared under a free-ranging system. Milk yield and composition (milk fat, protein, lactose, solid non-fat, and minerals) from Nguni (10), Boer (10) and non-descript (10) goats were measured and analysed per week at each stage of lactation. Results showed that Nguni goats produced (1.2 ± 0.09, 1.3 ± 0.11 and 1.2 ± 0.07 litres per day) more milk (p < 0.05) at early, mid-, and late stages of lactation than Boer (0.6 ± 0.10, 1.0 ± 0.17, and 0.6 ± 0.09 litres per day) and non-descript (0.3 ± 0.10, 0.3 ± 0.12, and 0.3 ± 0.09 litres per day) goats, respectively. The mean value of milk fat, protein, and lactose content from Nguni goats was 3.98, 3.54, and 5.31; Boer goats, 2.9, 3.59, and 5.04 and non-descript goats, 4.05, 3.39, and 5.02, respectively. There was a significant effect (p < 0.05) of genotypes on milk fat, milk magnesium, and sodium contents of Nguni, Boer, and non-descript goats. It could be concluded that Nguni goats produced more milk than Boer and non-descript goats, but the non-descript goat had a higher mean percentage of milk fat compared to Nguni and Boer goats.
    • Yield and Quality Performance of Traditional and Improved Bread and Durum Wheat Varieties under Two Conservation Tillage Systems

      Magdalena Ruiz; Encarna Zambrana; Rosario Fite; Aida Sole; Jose Luis Tenorio; Elena Benavente (MDPI AG, 2019-08-01)
      The increasing spread of conservation agriculture demands that the next generation of wheat varieties includes cultivars capable of maintaining satisfactory yields with lower inputs and under uncertain climate scenarios. On the basis of the genetic gains achieved during decades of selection oriented to yield improvements under conventional crop management, it is important that novel breeding targets are defined and addressed. Grain yield, yield-related traits, and phenological and morphological characteristics, as well as functional quality parameters have been analyzed for six varieties each of bread and durum wheat, under minimum tillage and no-tillage. During the three-year experiment, the climatic conditions at the field trial site were characterized by low rainfall, although different degrees of aridity—from moderate to severe—were experienced. Differences were found between these two soil management practices in regard to the varieties’ yield stability. A positive influence of no-tillage on traits related to grain and biomass yield was also evidenced, and some traits among the examined seemed involved in varietal adaptation to a particular non-conventional tillage system. The study also confirmed some breeding targets for improved performance of wheat genotypes in conservation agroecosystems. These traits were represented in the small set of traditional varieties analysed.
    • Yield and Yield Criteria of Flax Fiber (Linum usititassimum L.) as Influenced by Different Plant Densities

      Şahane Funda Arslanoglu; Soner Sert; Hasan Alp Şahin; Selim Aytaç; Ayman El Sabagh (MDPI AG, 2022-04-01)
      Flax (Linum usitatissimum L.) is mostly grown in temperate climate conditions. The rising demand for natural fibres other than cotton has re-introduced flax cultivation in to the agenda. This situation has necessitated the acceleration of flax production research in Turkey. The purpose of this research is to discover the best seeding density for flax fibre cultivation. The trials were carried out with the Rolin flax variety at the coordinates 41°21′53″ N and 36°11′17″ E, during the winter seasons of 2018–2019 and 2019–2020, at densities of 500, 750, 1000, 1250, 1500, 1750, and 2000 plant m−2, by using a random block design. According to the results obtained from analysis of variance, where all these charectors examined viz, years, densities, year and density interaction were found statistically significant (p < 0.01). The highest straw, fiber and seed yields per decare were measured at 2000 plant m−2 density, while as the lowest values were determined at 500 plant m−2 density. However In the interaction of year and density, the highest plant height and technical length were measured in the first year at 1750 plant m−2 density at 102.7 cm and 80.2 cm, respectively. Similarly the highest straw yield (764 kg da−1), fiber yield (198.6 kg da−1) and seed yield (133.9 kg da−1) were measured in the first year at 2000 plant m−2 density. Adequate rainfall during the rapid development stage of winter flax in April-May boosted plant height, technical length, straw, seed, and fibre yield. Although the yields were low during the second year, which was dry. While the positive significant correlation (**; p < 0.01) was found between plant density and plant height (r = 0.907 **), straw yield per decare (r = 0.981 **), seed yield per decare (r = 0.973 **), fiber yield per decare (0.978 **), technical length (r = 0.828; * p < 0.05), negative significant correlation (p < 0.01) was found between plant density and the number of secondary branches (r = −0.955 **), stem diameter (−0.955 **) and plant seed weight (r = −0.923 **). According to the data recorded in two-years. It was observed that for high straw, fiber and seed yield, 2000 plant m−2 density was appropriate for cultivating flax fiber during the winter growing period in mild climate conditions.
    • Yield of Leafy Greens and Microclimate in Deep Winter Greenhouse Production in Minnesota

      Claire Flavin Hodge; Mary Rogers; Dan Handeen; Greg Schweser (MDPI AG, 2018-12-01)
      The Deep Winter Greenhouse (DWG) uses passive solar technology to create an environment where cold tolerant crops like leafy greens can be grown during the winter to satisfy consumer demand for fresh local produce year-round and increase revenue for farmers. A cultivar trial consisting of 12 different salad greens was conducted in partnership with three farmers in order to determine suitable cultivars for these unique systems. Yield and days to maturity were recorded, and microclimate conditions such as light, temperature, and relative humidity were tracked throughout the season. This study included three sites from three distinct locations within Minnesota. Environmental differences among the DWG sites and within site replicates were observed. Yield also varied with micro-climate. The trials demonstrate that lettuces and greens such as &amp;lsquo;Florence&amp;rsquo; (Lactuca sativa L.), &amp;lsquo;Salanova&amp;rsquo; (Lactuca sativa L.), and &amp;lsquo;Vitamin Green&amp;rsquo; (Brassica rapa L.) generally grow well. These cultivar trials, coupled with other horticultural trials and economic analyses, will better inform recommendations for farmers growing in these unique environments.
    • Yield Perceptions, Determinants and Adoption Impact of on Farm Varietal Mixtures for Common Bean and Banana in Uganda

      Rose Nankya; John W. Mulumba; Francesco Caracciolo; Maria Raimondo; Francesca Schiavello; Elisabetta Gotor; Enoch Kikulwe; Devra I. Jarvis (MDPI AG, 2017-07-01)
      Crop variety mixtures (different varieties of a crop grown together in a single plot) have been successfully deployed in pathogen and pest management for several crops including wheat, common bean and rice. Despite the available evidence, promotion of this approach has remained limited in many countries, including Uganda. The factors that influence farmers’ adoption of varietal mixtures for common bean and banana were assessed, as well as the perceptions of farmers on the effects of mixtures on yields, through household surveys and statistical modelling. A three-year yield increase in both common bean and banana varietal mixtures in farmer fields, of 5.2% and 28.6%, respectively, is realized using robust OLS estimates. The study reveals that accessing knowledge on the importance of crop varietal mixtures and the skills relating to the approach are crucial for their adoption. Location of the farm significantly determined the perceived yield change, which calls for more research into mixtures’ suitability under particular contexts in respect to compatibility of genotypes, management practices and appropriate acreage for maximum impact. The positive effects of mixtures on yields make it an effective bioeconomy strategy. Policies that minimize the adoption barriers could improve the adoption of crop varietal mixtures on a wider scale.
    • Yield Performance and Physiological Response of a Maize Early Hybrid Grown in Tunnel and Open Air under Different Water Regimes

      Lucia Ottaiano; Ida Di Mola; Chiara Cirillo; Eugenio Cozzolino; Mauro Mori (MDPI AG, 2021-10-01)
      Climate change is one of the most important and studied phenomena of our age and it can have a deep impact on agriculture. Mediterranean countries are and will continue to be strongly affected by changing environmental factors, including lack of precipitation and prolonged heatwaves. The current study aimed to assess the adaptability of an early maize hybrid grown in two temperature conditions and subjected to different irrigation water regimes. The experimental design was a randomized complete-block design with two different temperature conditions: (i) ordinary temperature in open field (OF) and (ii) high temperature (about 3 °C higher than the current condition) under a poly-ethylene tunnel (PE). In both environments, five irrigation level treatments were applied: 100% (DI100), 75% (DI75), 50% (DI50), 25% (DI25), and 0% restoration of water lost by evapotranspiration (DI0). The responses of maize plants were assessed in terms of yield, nitrogen content determination, nitrogen use efficiency, leaf gas exchanges, and leaf water potential measurements. In both conditions, yield and its components linearly decreased as the irrigation water amount reduced, and even the DI0 plants did not produce. Notably, the PE-DI100 treatment had a significantly higher yield than the corresponding treatment in the open air (9.9 vs. 8.5 t ha&lt;sup&gt;−1&lt;/sup&gt;), due mainly to the increased number of ears per square meter (13 vs. 11 m&lt;sup&gt;2&lt;/sup&gt;, respectively). Though, as far as it concerns physiological parameters, a significant effect of environmental conditions was found, with values significantly lower under the protected environment, compared to the plants in the open field. Considering our results, it can be assumed that correct management of amount and time intervals of irrigation could adapt the maize to future climate change.
    • Yield Response, Nutritional Quality and Water Productivity of Tomato (&lt;i&gt;Solanum lycopersicum&lt;/i&gt; L.) are Influenced by Drip Irrigation and Straw Mulch in the Coastal Saline Ecosystem of Ganges Delta, India

      Indranil Samui; Milan Skalicky; Sukamal Sarkar; Koushik Brahmachari; Sayan Sau; Krishnendu Ray; Akbar Hossain; Argha Ghosh; Manoj Kumar Nanda; Richard W. Bell (MDPI AG, 2020-08-01)
      In the coastal zone of the Ganges Delta, water shortages due to soil salinity limit the yield of dry season crops. To alleviate water shortage as a consequence of salinity stress in the coastal saline ecosystem, the effect of different water-saving (WS) and water-conserving options was assessed on growth, yield and water use of tomato; two field experiments were carried out at Gosaba, West Bengal, India in consecutive seasons during the winter of 2016–17 and 2017–18. The experiment was laid out in a randomized block design with five treatments viz., surface irrigation, surface irrigation + straw mulching, drip irrigation at 100% reference evapotranspiration (ET&lt;sub&gt;0&lt;/sub&gt;), drip irrigation at 80% ET&lt;sub&gt;0&lt;/sub&gt;, drip irrigation at 80% ET&lt;sub&gt;0&lt;/sub&gt; + straw mulching. Application of drip irrigation at 80% ET&lt;sub&gt;0&lt;/sub&gt; + straw mulching brought about significantly the highest fruit as well as the marketable yield of tomato (&lt;i&gt;Solanum lycopersicum&lt;/i&gt; L.). The soil reaction (pH), post-harvest organic carbon, nitrogen, phosphorus and potassium (N, P and K) status and soil microbial population along with the biochemical quality parameters of tomato (juice pH, ascorbic acid, total soluble solids and sugar content of fruits) were significantly influenced by combined application of drip irrigation and straw mulching. Surface irrigation significantly increased the salinity level in surface and sub-surface soil layers while the least salinity development was observed in surface mulched plots receiving irrigation water through drip irrigation. The highest water productivity was also improved from drip irrigation at 80% ET&lt;sub&gt;0&lt;/sub&gt; + straw mulched plots irrespective of the year of experimentation. Such intervention also helped in reducing salinity stress for the tomato crop. Thus, straw mulching along with drip irrigation at 80% ET&lt;sub&gt;0&lt;/sub&gt; can be recommended as the most suitable irrigation option for tomato crop in the study area as well as coastal saline regions of South Asia. Finally, it can be concluded that the judicious application of irrigation water not only increased growth, yield and quality tomatoes but also minimized the negative impact of soil salinity on tomatoes grown in the coastal saline ecosystem of Ganges Delta.
    • Yield Spread and Economic Policy Uncertainty: Evidence from Japan

      Mei-Chih Wang; Pao-Lan Kuo; Chan-Sheng Chen; Chien-Liang Chiu; Tsangyao Chang (MDPI AG, 2020-05-01)
      In this paper, we adopt the nonlinear autoregressive distributed lags (NARDL) model extended by Shin et al. (2014) to investigate the relationship between the treasury yield spread and economic policy uncertainty (EPU) in Japan. This model helps us to explore the short- and long-run asymmetric reactions of explained variables through positive and negative partial sum decompositions of changes in the explanatory variable(s). In our research, the testing of the NARDL specification reveals the existence of a significant long-run asymmetric equilibrium between the yield spread and EPU in Japan. On the other hand, we find a significant positive nexus between the treasury yield spread and EPU reduction in the long run. We speculate that because of low inflation, a poor economic outlook and the low interest rate environment since 1990, financial agents are markedly sensitive to negative shocks resulting from EPU. This means that when facing a good economy, bond agents are quick to sell, especially with higher-risk long-term interest rate bonds. Meanwhile, because the Bank of Japan announced the Stock Purchasing Plan in October 2002 and from the point view of portfolio management, while the influence of a positive economic outlook dominates the negative outlook, flight from quality has no role in asset portfolio adjustment. The empirical implications are that the long history of unconventional monetary policy supports the demand for both bonds and stock markets. When taking the stock market into consideration, the correlations between the yield spread, EPU and stock market capture the full wealth effects of the low interest rate environment in Japan.
    • Yield Variability in Oil Palm Plantations in Tropical India Is Influenced by Surface and Sub-Surface Soil Fertility and Leaf Mineral Nutrient Contents

      Sanjib Kumar Behera; Arvind Kumar Shukla; Kancherla Suresh; Kamireddy Manorama; Ravi Kumar Mathur; Kaushik Majumdar (MDPI AG, 2022-02-01)
      Oil palm (&lt;i&gt;Elaeis guineensis&lt;/i&gt; Jacq.), an industrial oilseed crop, is the most prominent oil-producing crop in the world and one of the highest dry matter producers among C&lt;sub&gt;3&lt;/sub&gt; plants. It removes large amounts of soil nutrients to support its substantial biomass and oil production. Thus, maintaining adequate levels of limiting nutrients at favorable ratios in the soil is crucial to sustain the required palm nutritional status and oil production over extended periods. We evaluated the levels and ratios of the available soil and leaf nutrients in high-yielding (HYOPP) and low-yielding (LYOPP) oil palm plantations from two locations in southern India and assessed their relations to develop effective nutrient management for sustaining fresh fruit bunch (FFB) production. The FFB yield varied from 2.00 to 31.0 t ha&lt;sup&gt;−1&lt;/sup&gt; (location 1) and 6.84 to 30.9 t ha&lt;sup&gt;−1&lt;/sup&gt; (location 2), and the FFB yields of the high- and low-yield population at each location differed significantly. Wide ranges of soil properties, available nutrients, and leaf nutrients concentrations were observed at 0–20- and 20–40-cm soil depths at both locations. The soil nutrient ratios at both sampling depths of the HYOPP were significantly different than the LYOPP at location 1. The mean leaf N (2.09%) and K (0.68%) concentrations at location 2 were significantly higher than those in location 1 (1.85% and 0.54, respectively). The mean leaf concentrations at both locations followed the order N (1.85%, 2.09%) &gt; Ca (1.65%, 1.36%) &gt; K (0.54%, 0.68%) &gt; Mg (0.49%, 0.47%) &gt; S (0.16%, 0.18) &gt; P (0.11%, 0.12%) &gt; B (35.8 mg kg&lt;sup&gt;−1&lt;/sup&gt;, 27.5 mg kg&lt;sup&gt;−1&lt;/sup&gt;). We observed positive and significant correlations between the available N and P at 0–20 cm and between the available N and K as well as Ca and S at both soil depths for HYOPPs. In LYOPPs, the available N was significantly correlated with the available P, K, Ca, and Mg at both soil depths and with the available S at 0–20 cm. The FFB yield of LYOPPs was positively and significantly correlated with the available P and S at the 0–20-cm soil depth and with the available N and P at the 20–40-cm soil depth. Except for a negative correlation (&lt;i&gt;p&lt;/i&gt; &lt; 0.05) with exchangeable Ca at the 20–40-cm soil depth, the FFB yield in HYOPPs had no significant correlation with the available soil nutrients at both depths. The FFB yield of LYOPPs had a positive significant (&lt;i&gt;p&lt;/i&gt; &lt; 0.01) correlation with the leaf P and K concentrations, while the yield of HYOPPs had a negative correlation (&lt;i&gt;p&lt;/i&gt; &lt; 0.01) with the leaf P. Fertilizer accounts for a large part of the on-farm cost in oil palm plantations, and an evidenced approach for fertilizer management based on nutrient contents and ratios in the soil and in the plant is useful for sustainable and profitable production of palm oil.
    • Yields of the Major Food Crops: Implications to Food Security and Policy in Tanzania’s Semi-Arid Agro-Ecological Zone

      Msafiri Y. Mkonda; Xinhua He (MDPI AG, 2017-08-01)
      While Tanzania has been facing food shortage for some decades, little efforts have been made to elicit optimal crop yields. To limit this problem, there is a need for a robust agricultural policy that aims at stabilizing agricultural production and socio-economic entitlement among the farmers. The present study analyses the production trend of maize, sorghum and millet (i.e., staple food crops) under rain fed agriculture in Kongwa District, the semi-arid agro-ecological zone of Central Tanzania, and envisage their implications to food security and policy. We collected a set of crop data (1980–2015) from the Ministry of Agriculture, Livestock and Fisheries. In addition, 400 respondents were sampled randomly in the study area during household survey while a series of interviews and discussions were conducted mostly basing on the expertise. The Mann-Kendall Test and Microsoft excel (window 13) and theme content methods were employed for data analyses. The results showed that the production trends for maize, sorghum and millet yields have been decreasing at R2 = 0.40, 0.35 and 0.11 respectively and this trend was supported by 80% of the respondents. This decrease was greatly influenced by the temporal decrease in the mean annual rainfall (R2 = 0.21). The diminishing production trend has already decreased food security for 30% in the area. Since agricultural policy can be among the main sources of this poor yields, an explicit and sound agricultural policy should be the central aspect in planning and implementing agricultural activities.
    • You Are What You Eat: The Relationship between Values and Organic Food Consumption

      Manuela Vega-Zamora; Manuel Parras-Rosa; Francisco José Torres-Ruiz (MDPI AG, 2020-05-01)
      In current times, the man-made problems affecting our planet (climate change, loss of biodiversity, etc.) are making an urgent case for shifting towards a more sustainable kind of consumption. One of the ways these problems can be addressed is to promote organic agriculture, which means boosting levels of organic food consumption. This study examines the relationship between the number of organic foods consumed and the specific values that consumers look for in foods, in order to deepen the current knowledge regarding the behaviour of the organic food consumer. To this end, data was analysed from a face-to-face survey of 776 people in Spain through bivariate analysis techniques. Results show that organic food consumers have a different pattern of values from non-consumers and a greater level of involvement with food in general. Moreover, within the group of organic consumers, the effect of values on the quantity or variety of foods consumed is not as marked, although there are differences in favour of those that consume more frequently. Lastly, the main implication of the results obtained is that, in order to increase consumption, selfish values should be connected with altruistic ones. For this reason, instilling a specific value based on the term or concept “life” is proposed.
    • You Can’t See the Woods for the Trees: Invasive &lt;i&gt;Acer negundo&lt;/i&gt; L. in Urban Riparian Forests Harms Biodiversity and Limits Recreation Activity

      Daria Sikorska; Piotr Sikorski; Piotr Archiciński; Jarosław Chormański; Richard J. Hopkins (MDPI AG, 2019-10-01)
      Public access to high quality green environments has become a key issue for city managers and a matter of environmental justice. Urban pressures on ecosystem remnants may act to favor the expansion of some invasive species in cities. Whilst the negative impacts of invasive species on ecosystem function is well documented, little is known about how invasive species influence the use of green space by people. Here, we examined one of the few remnants of urban riparian forests in Europe, the Vistula river valley in Warsaw, which has recently become an attractive recreation site. Despite their high ecological value, the poplar and willow forests have been increasingly taken over by the invasive tree species &lt;i&gt;Acer negundo.&lt;/i&gt; We examined the status of the invasion process and the relationship between recreational ecosystem services and the characteristics of the tree stands&amp;#8212;tree species, tree density, and age and NDVI values. We found the willow forest to be more susceptible to invasion by &lt;i&gt;A. negundo&lt;/i&gt; than the poplar forest, which was revealed in significantly higher share of the maple individuals and their greater volume per unit area. Ash-leaved maples also prevailed in numbers in younger stands (&amp;lt;10 years) than in older ones. The presence of &lt;i&gt;A. negundo&lt;/i&gt; affected biodiversity, resulting in decreased undergrowth density and biodiversity expressed in number of species. The use intensity by the public, assessed on the basis of soil compaction of existing informal tracks, as revealed by GLM analysis, was related to volume of invasive maple and distance from the main track. This study highlights the need to integrate invasive species management into green infrastructure planning and management.
    • “You Need a Month’s Holiday Just to Get over It!” Exploring Young People’s Lived Experiences of the UN Climate Change Negotiations

      Harriet Thew; Lucie Middlemiss; Jouni Paavola (MDPI AG, 2022-04-01)
      Despite youth organisations having participated as a recognised constituency (YOUNGO) in the United Nations Framework Convention on Climate Change (UNFCCC) for over a decade, few studies have explored their lived experiences of participation. Drawing upon deep ethnographic engagement with a member organisation of YOUNGO conducted between 2015 and 2018, this paper applies the “7P” model from the Youth Studies literature to explore youth participation in the UNFCCC from seven intersecting lenses: Purpose, Positioning, Perspectives, Power Relations, Protection, Place, and Process. This yields many insights into how youth participants negotiate sustainability in this context, including the Purposes or drivers motivating their participation, the ways in which youth are Positioned within the UNFCCC, the asymmetrical Power Relations they have to navigate, as well as the logistical challenges relating to their Protection, including their physical safety and psychological wellbeing. Based on rich empirical findings, we amend the 7P model of youth participation, replacing Process, which we argue is more of a methodological than an analytical concern, with Psychological Factors, which we propose is a key factor in shaping youth participation in negotiations of sustainability.
    • “Young and Green” a Study of Consumers’ Perceptions and Reported Purchasing Behaviour towards Organic Food in Poland and the United Kingdom

      Aleksandra Kowalska; Monika Ratajczyk; Louise Manning; Milena Bieniek; Radosław Mącik (MDPI AG, 2021-11-01)
      Globally, the organic food market is the most successful green market. Young consumers, the decision-makers of the future, are perceived as being more environmentally concerned than older cohorts. The aim of this study was to consider young consumers’ attitudes and behaviours concerning organic food, where the organic food market in the UK is more mature than in Poland. Empirical research was conducted using a web-based survey questionnaire (CAWI) with consumers (&lt;i&gt;n&lt;/i&gt; = 973) in both countries. The associations between four constructs (general pro-social attitudes, green consumption values, receptivity to green communication, and buying behaviour) were considered using CB-SEM. We extended the model with two new constructs to explain young consumers’ purchases of organic food. UK respondents are significantly more conscious green consumers with higher environmental attitude intensity than Polish residents. Intensity of pro-environmental attitude components influences directly and indirectly the choice of organic food. People with a higher intensity of pro-environmental attitudes are significantly more likely to choose organic food. Perception of organic food influences purchases only in Poland. The components of pro-environmental attitudes and perception of organic food alone do not explain the variability in behaviour, despite a good fit of the model. This suggests that other independent variables may be of influence.