Environmental Impacts, Human Health, and Energy Consumption of Nitrogen Management for Maize Production in Subtropical Region

Over-application of fertilizers could not improve crop yield and agronomic efficiency, but result in increasing nitrogen (N) surplus and adverse effects on the ecosystem sustainability. Although some previous studies have addressed one or a few environmental aspects in crop production, an integrated assessment for the effects of N fertilizer on multiple environmental impacts, and the optional steps of normalization and weighting is required. A consecutive 2-yr plot-based field experiment was conducted with five N fertilizer levels (0, 90, 180, 270, and 360 kg N ha-1) in maize production at three sites in Southwest China, to evaluate the environmental performance and sustainability through joint use of life cycle assessment (LCA) and energy consumption analysis. Results demonstrated that the optimal N rate (180 kg N ha-1) showed greater potential for maintaining high yield (achieved 86% of the yield potential) and reducing the global warming (-31%), acidification (-47%), eutrophication (-44%) compared to farmers’ practice, and energy depletion potentials, by reducing pollutants emission during the production and transportation of N fertilizer and Nr losses at farm stage. Optimal N treatment indirectly reduced the land use, life-cycle human toxicity, aquatic eco-toxicity, and terrestrial eco-toxicity potentials by improving grain yield and agronomic efficiency. In addition, the optimal N treatment reduced the energy consumption by enhancing the energy use efficiency (EUE) (+74%) and reducing non-renewable energy form (-45%) than the farmer’s practice. This study will provide comprehensive information for both scientists and farmers involved in maize production and N management in subtropical region.

Fruit Physiology and Sugar-Acid Profile of 24 Pomelo (Citrus grandis (L.) Osbeck) Cultivars Grown in Subtropical Region of China

In the present study, the fruit physiology and sugar-acid ratio of 24 pomelo cultivars grown in ten different locations of the subtropical region of China were measured. The contents of soluble sugars and organic acids were quantified using high-performance (HPLC-MS) and ultra-performance liquid chromatography-mass spectrometry (UPLC-MS), respectively. The results revealed that the physiological and basic quality attributes of 24 pomelo cultivars, including fruit weight, fruit width, fruit length, peel thickness, number of segments, pulp weight, pulp color, soluble solids, and Vitamin C, ranged between 264.63–1945.85 g, 8.60–19.56 g, 7.40–20.70 g, 0.46–3.33 mm, 11–18.66, 210.25–1351.66 g, 8.59–15.14 Brix°, and 34.79–84.58 mg/100 g, respectively. Soluble sugars, i.e., fructose, glucose, and sucrose, ranged between 16.25–24.25, 16.17–24.22, and 19.90–55.28 mg/g, respectively. Similarly, Organic acids, i.e., pyruvate, fumaric acids, succinic acid, tartaric acid, quinic acid, citric acid, malic acid, and cis-aconitic acid, in 24 pomelo cultivars ranged between 0.48–1.84, 0.02–0.45, 0–0.05, 0.01–0.1, 0–0.14, 3.01–11.85, 0.18–1.42, and 0.01–0.16 mg/g, respectively. The pomelo cultivars ‘Hongzuanmi’, ‘Minihong’, and ‘Hangwanmi’ exhibited maximum contents of citric acid and pyruvate and showed ultimately excessive organic acids. Overall, the ‘Guanximi’ and its budding cultivars, i.e., ‘Hongroumi’, ‘Huangjinmi’, and ‘Sanhongmi’, had the best quality fruits having maximum sugar-acid ratio. Correlation analysis showed that total soluble sugars had a significantly positive correlation with sucrose contents, while citric acids, malic acid, and pyruvate were positively correlated with total organic acids. The determined sugar-acid profile of pomelo cultivars provides the basis for future elucidation of key mechanisms regulating sugars and acids biosynthesis in pomelo.

Correlation study between sunspot and rainfall in Udaipur subregion

ABSTRACT. The cross correlation among 102 years rainfall data in Udaipur subtropical region and sunspots show tpe influence of solar activity on the climatic conditions of Udaipur. The periodicity obtained using rainfall and other data sets. such as. water storage of Jaisamand lake and gauge measurements of two rivers. Jakham and Karmoi, are similar to the periodicity of sunspots, which indicates a relationship between rainfall and sunspot activity. A period of about 27% is found to deviate from normal rains in the form of flood. excess and deficit of rains in Udaipur sub-tropical region. The possible physical mechanisms to explain sun-weather relationship in astro-physical context are discussed.

Variability of Fruit Quality among 103 Acerola (Malpighia emarginata D. C.) Phenotypes from the Subtropical Region of Brazil

Acerola fruit is one of the richest natural sources of ascorbic acid. As a consequence, acerola fruit and its products are in demand worldwide for the production of health supplements and for the development of functional products. Acerola phenotypes (103) were screened in Western Paraná State, in the Southern region of Brazil, and evaluated to obtain information on fruit quality characteristics with the aim of using them in future breeding programs. Principal Component and Hierarchical Cluster analysis were performed on all datasets to explore the variability among samples and to identify the main clusters. A great variability among phenotypes was observed, with potential for use in breeding programs. Seven phenotypes were selected as candidates in the next breeding program, characterized by high vitamin C content and yield, or higher values of fruit size and color parameters. Four belong to cluster 1 and three to cluster 2. Specifically, two phenotypes, belonging to cluster 2, showed the best performance in terms of vitamin C (2150 mg 100 g−1 pulp and 2625 mg 100 g−1 pulp respectively) and pulp yield (74.8% and 82.3% respectively), and one phenotype, belonging to cluster 1, for high pulp yield, fruit size and vitamin C content (80.3% 6.43 g and 2490 mg 100 g−1 pulp).