scholarly journals Effects of water and fertilizer coupling on the physiological characteristics and growth of rabbiteye blueberry

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254013
Author(s):  
Xiaolan Guo ◽  
Shuangshuang Li ◽  
Delu Wang ◽  
Zongsheng Huang ◽  
Naeem Sarwar ◽  
...  

Understanding the impact of irrigation and fertilizer on rabbiteye blueberry (Vaccinium virgatum) physiology is necessary for its precision planting. Here, we applied varied irrigation and fertilizer under completely randomized experimental design to see its impact on the physiological characteristics and bush growth of rabbiteye blueberries. A comprehensive evaluation of the membership function was used to establish the best water–fertilizer coupling regimes. Rabbiteye blueberry enhanced the net photosynthetic rate, stomatal conductance and transpiration rate of leaf and improved its photosynthetic capacity at maximum level of irrigation water and fertilizer application (F3W4). The high fertilizer–medium water treatment (F3W3) increased leaf-soluble protein contents. The medium fertilizer–medium water treatment (F2W3, F2W2) increased leaf- soluble sugar, superoxide dismutase, and chlorophyll contents; decreased the malondialdehyde content; and enhanced leaf resistance and metabolism. It also promoted the growth of flower buds and new shoots. Combined membership function and cluster analyses revealed that the optimal water and fertilizer conditions for promoting rabbiteye blueberry plant growth were the medium fertilizer–medium water [(NH4)2SO4:Ca(H2PO4)2:K2SO4 at 59:10:20 g plant-1; 2.5 L water plant-1], medium fertilizer–medium-high water [(NH4)2SO4:Ca(H2PO4)2:K2SO4 at 59:10:20 g plant-1; 3.75 L water plant-1], and high fertilizer–medium-high water [(NH4)2SO4:Ca(H2PO4)2:K2SO4 at 118:20:40 g plant-1; 3.75 L water plant-1] treatments. The findings of this study could be used in improving the precision and efficacy of rabbiteye blueberry planting in Guizhou, China. Such an approach can increase the productivity and profitability for local fruit farmers.

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1965 ◽  
Author(s):  
Skoczko ◽  
Szatyłowicz

The aim of the study was the assessment of corrosivity and aggressiveness for boiler feed water. The negative effects of water corrosivity and aggressiveness may include silting up of the steel water supply system and the destruction of boiler equipment touched or washed by such water. They may cause the whole industrial production system to fail or be destroyed. That is why it was important to reach a high water purification level, including the calculation of water aggressiveness and corrosivity indicators. The carried out test showed that the simple system used before the modernization of the industrial water treatment plant is not sufficient to reach clean and stable water. The authors proposed modernization, including additional processes to improve boiler water quality, and designed new devices for water treatment. As a result of the new idea, groundwater taken as raw water was treated in individual and complex processes, such as pre-aeration, filtration, ion exchange (cation and anion exchange resigns), extra aeration, and extra degassing. The conducted research included chemical analyses of raw and treated water. In the conducted studies, the indirect method of water aggressiveness and corrosivity assessment was applied using mathematical calculation of the Langelier Saturation Index (LSI), the Ryznar Stability Index (RI), the Larson–Skold Index (LI), and the Singley Index (SI). The results proved that the new proposed processes for the boiler feed water treatment station allow reaching a high water quality and low level of water aggressiveness and corrosion.


Agronomy ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 597 ◽  
Author(s):  
Misganaw Wassie ◽  
Weihong Zhang ◽  
Qiang Zhang ◽  
Kang Ji ◽  
Liang Chen

Alfalfa (Medicago sativa L.) is a valuable forage legume, but its production is largely affected by high temperature. In this study, we investigated the effect of heat stress on 15 alfalfa cultivars to identify heat-tolerant and -sensitive cultivars. Seedlings were exposed to 38/35 °C day/night temperature for 7 days and various parameters were measured. Heat stress significantly reduced the biomass, relative water content (RWC), chlorophyll content, and increased the electrolyte leakage (EL) and malondialdehyde (MDA) content of heat-sensitive alfalfa cultivars. However, heat-tolerant cultivars showed higher soluble sugar (SS) and soluble protein (SP) content. The heat tolerance of each cultivar was comprehensively evaluated based on membership function value. Cultivars with higher mean membership function value of 0.86 (Bara310SC) and 0.80 (Magna995) were heat tolerant, and Gibraltar and WL712 with lower membership function value (0.24) were heat sensitive. The heat tolerance of the above four cultivars were further evaluated by chlorophyll a fluorescence analysis. Heat stress significantly affected the photosynthetic activity of heat-sensitive cultivars. The overall results indicate that Bara310SC and WL712 are heat-tolerant and heat-sensitive cultivars, respectively. This study provides basic information for understanding the effect of heat stress on growth and productivity of alfalfa.


2020 ◽  
Vol 35 (12) ◽  
pp. 2154-2160 ◽  
Author(s):  
Georges Bendine ◽  
Fabien Autin ◽  
Bruno Fabre ◽  
Olivier Bardin ◽  
François Rabasco ◽  
...  

Abstract Introduction Sustainable growth and environmental issues are currently a topic for all human activities, and dialysis represents a real challenge in this field because of high water and power consumption and the production of large amounts of care-related waste. In this article we describe data collection implemented in the NephroCare centres in France and the changes observed during a 13-year period regarding environmental parameters. Methods Monthly data collection (eco-reporting) was implemented in NephroCare centres in France in 2005. It covers three topics designed as key performance indicators (KPIs): electricity and water consumption and care-related waste production expressed, respectively, as kilowatt-hour (kWh), litres (L) and kilograms per session. We report on the three action plans (2005–10, 2011–14 and 2015–18) and changes observed during this 13-year period. Results During the period, power and water consumption declined by 29.6% (from 23.1 to 16.26 kWh/session) and 52% (from 801 to 382 L/session), respectively. At the same time, the yearly number of dialysis sessions has increased from 169 335 to 399 336. The sources of savings came both from improvements in the dialysis technology (dialysis machines and water treatment systems) and from updating and remodelling of the dialysis unit equipment and buildings. The care-related waste decreased from 1.8 to 1.1 kg because of regular staff training and the retrofiltration system, allowing the voiding of the remaining saline solution after dialysis. These savings have been estimated as equivalent to 102 440 tons of carbon dioxide. Discussion Implementation of KPIs and their regular monitoring by trained staff to evaluate water and power consumption and the reduction of care-related water production are essential to implement actions to reduce the impact of dialysis on the environment. These data show the importance of water treatment and dialysis technology to decrease water and power consumption and the production of care-related waste as well as upgrading or remodelling of buildings housing dialysis units. Other measures are discussed, including the reuse of rejected water by reverse osmosis, as well as behavioural changes that are needed to reach sustainable development of dialysis. Conclusion The first step to reach ‘green’ dialysis is to collect precise information from defined KPIs. This is the only way to design action plans to reduce the impact of dialysis therapy on the environment. Beyond this, the nephrology community must be sensitized to this challenge to be proactive and to anticipate future regulations.


1992 ◽  
Vol 26 (5-6) ◽  
pp. 1255-1264
Author(s):  
K. L. Martins

During treatment of groundwater, radon is often coincidentally removed by processes typically used to remove volatile organic compounds (VOCs)-for example, processes such as liquid-phase granular activated carbon (LGAC) adsorption and air stripping with vapor-phase carbon (VGAC). The removal of radon from drinking water is a positive benefit for the water user; however, the accumulation of radon on activated carbon may cause radiologic hazards for the water treatment plant operators and the spent carbon may be considered a low-level radioactive waste. To date, most literature on radon removal by water treatment processes was based on bench- or residential-scale systems. This paper addresses the impact of radon on municipal and industrial-scale applications. Available data have been used todevelop graphical methods of estimating the radioactivity exposure rates to facility operators and determine the fate of spent carbon. This paper will allow the reader to determine the potential for impact of radon on the system design and operation as follows.Estimate the percent removal of radon from water by LGAC adsorbers and packed tower air strippers. Also, a method to estimate the percent removal of radon by VGAC used for air stripper off-gas will be provided.Estimate if your local radon levels are such that the safety guidelines, suggested by USEPA (United States Environmental Protection Agency), of 25 mR/yr (0.1 mR/day) for radioactivity exposure may or may not be exceeded.Estimate the disposal requirements of the waste carbon for LGAC systems and VGAC for air stripper “Off-Gas” systems. Options for dealing with high radon levels are presented.


2003 ◽  
Vol 48 (4) ◽  
pp. 139-146 ◽  
Author(s):  
B. Wett ◽  
J. Alex

A separate rejection water treatment appears as a high-tech unit process which might be recommendable only for specific cases of an upgrading of an existing wastewater treatment plant. It is not the issue of this paper to consider a specific separate treatment process itself but to investigate the influence of such a process on the overall plant performance. A plant-wide model has been applied as an innovative tool to evaluate effects of the implemented sidestream strategy on the mainstream treatment. The model has been developed in the SIMBA environment and combines acknowledged mathematical descriptions of the activated sludge process (ASM1) and the anaerobic mesophilic digestion (Siegrist model). The model's calibration and validation was based on data from 5 years of operating experience of a full-scale rejection water treatment. The impact on the total N-elimination efficiency is demonstrated by detailed nitrogen mass flow schemes including the interactions between the wastewater and the sludge lane. Additionally limiting conditions due to dynamic N-return loads are displayed by the model's state variables.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Yahya Albalawi ◽  
Jim Buckley ◽  
Nikola S. Nikolov

AbstractThis paper presents a comprehensive evaluation of data pre-processing and word embedding techniques in the context of Arabic document classification in the domain of health-related communication on social media. We evaluate 26 text pre-processings applied to Arabic tweets within the process of training a classifier to identify health-related tweets. For this task we use the (traditional) machine learning classifiers KNN, SVM, Multinomial NB and Logistic Regression. Furthermore, we report experimental results with the deep learning architectures BLSTM and CNN for the same text classification problem. Since word embeddings are more typically used as the input layer in deep networks, in the deep learning experiments we evaluate several state-of-the-art pre-trained word embeddings with the same text pre-processing applied. To achieve these goals, we use two data sets: one for both training and testing, and another for testing the generality of our models only. Our results point to the conclusion that only four out of the 26 pre-processings improve the classification accuracy significantly. For the first data set of Arabic tweets, we found that Mazajak CBOW pre-trained word embeddings as the input to a BLSTM deep network led to the most accurate classifier with F1 score of 89.7%. For the second data set, Mazajak Skip-Gram pre-trained word embeddings as the input to BLSTM led to the most accurate model with F1 score of 75.2% and accuracy of 90.7% compared to F1 score of 90.8% achieved by Mazajak CBOW for the same architecture but with lower accuracy of 70.89%. Our results also show that the performance of the best of the traditional classifier we trained is comparable to the deep learning methods on the first dataset, but significantly worse on the second dataset.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lawan Gana Ali ◽  
Rosimah Nulit ◽  
Mohd Hafiz Ibrahim ◽  
Christina Yong Seok Yien

AbstractRice is an important staple crop produced and consumed worldwide. However, poor seed emergence is one of the main impediments to obtaining higher yield of rice especially in hot and dry ecosystems of the world that are ravaged by drought. Therefore, this study was carried out to evaluate the effects of potassium nitrate (KNO3), salicylic acid (SA) and silicon dioxide (SiO2) priming in improving emergence, seedling growth, biochemical attributes and antioxidant activities of FARO44 rice under drought conditions. Rice seedlings primed with 2.5% and 5% KNO3, 3% and 3.5% SiO2, and 1 mM and 2.5 mM SA were subjected to three drought levels of low, moderate and severe under the greenhouse. Seed emergence, seedling growth, biochemical attributes and antioxidant activities were thereafter evaluated. Seed priming experiments were laid in a completely randomized design with five replicates per treatment. The results found that rice seedlings responded differently to different priming treatments. However, all primed rice seedlings had significantly (P ≤ 0.05) improved emergence percentage (72–92%), seedling growth, seedling vigor, seedling fresh and dry biomass and shorter emergence time compared with controls. Likewise, total soluble protein content, activities of catalase, ascorbate peroxidase and superoxide dismutase, carbohydrate, soluble sugar and total chlorophyll contents of rice seedlings were increased by more than two-folds by seed priming compared with control. Salicylic acid showed less effect in increasing emergence, seedling growth, antioxidant activities and biochemical attributes of rice. Thus, this study established that seed priming with KNO3 (2.5% and 5%) and SiO2 (3% and 3.5%) were more effective in improving emergence, seedling growth, biochemical attributes and antioxidant activities of FARO44. Thus, priming of FARO44 rice with this chemical is recommended for fast emergence, seedling growth and drought resistance in dry ecosystems.


RSC Advances ◽  
2021 ◽  
Vol 11 (32) ◽  
pp. 19788-19796
Author(s):  
Bramha Gupta ◽  
Rushikesh S. Ambekar ◽  
Raphael M. Tromer ◽  
Partha Sarathi Ghosal ◽  
Rupal Sinha ◽  
...  

The impact of micro and nanoplastic debris on our aquatic ecosystem is among the most prominent environmental challenges we face today.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hongyi Zhao ◽  
Juelan Guan ◽  
Qing Liang ◽  
Xueyuan Zhang ◽  
Hongling Hu ◽  
...  

AbstractThe effects of cadmium stress on the growth and physiological characteristics of Sassafras tzumu Hemsl. were studied in pot experiments. Five Cd levels were tested [CT(Control Treatment) : 0 mg/kg, Cd5: 5 mg/kg, Cd20: 20 mg/kg, Cd50: 50 mg/kg, and Cd100: 100 mg/kg]. The growth and physiological characteristics of the sassafras seedlings in each level were measured. The results showed that soil Cd had negative influences on sassafras growth and reduced the net growth of plant height and the biomass of leaf, branch and root. Significant reductions were recorded in root biomass by 18.18%(Cd5), 27.35%(Cd20), 27.57%(Cd50) and 28.95%(Cd100). The contents of hydrogen peroxide decreased first then increased while malondialdehyde showed the opposite trend with increasing cadmium concentration. Decreases were found in hydrogen peroxide contents by 10.96%(Cd5), 11.82%(Cd20) and 7.02%(Cd50); increases were found in malondialdehyde contents by 15.47%(Cd5), 16.07%(Cd20) and 7.85%(Cd50), indicating that cadmium stress had a certain effect on the peroxidation of the inner cell membranes in the seedlings that resulted in damage to the cell membrane structure. Superoxide dismutase activity decreased among treatments by 17.05%(Cd5), 10,68%(Cd20), 20.85%(Cd50) and 8.91%(Cd100), while peroxidase activity increased steadily with increasing cadmium concentration; these results suggest that peroxidase is likely the main protective enzyme involved in the reactive oxygen removal system in sassafras seedlings. Upward trends were observed in proline content by 90.76%(Cd5), 74.36%(Cd20), 99.73%(Cd50) and 126.01%(Cd100). The increase in proline content with increasing cadmium concentration indicated that cadmium stress induced proline synthesis to resist osmotic stress in the seedlings. Compared to that in CT, the soluble sugar content declined under the different treatments by 32.84%(Cd5), 5.85%(Cd20), 25.55%(Cd50) and 38.69%(Cd100). Increases were observed in the soluble protein content by 2.34%(Cd5), 21.36%(Cd20), 53.15%(Cd50) and 24.22%(Cd100). At different levels of cadmium stress, the chlorophyll content in the seedlings first increased and then decreased, and it was higher in the Cd5 and Cd20 treatments than that in the CT treatment. These results reflected that cadmium had photosynthesis-promoting effects at low concentrations and photosynthesis-suppressing effects at high concentrations. The photosynthetic gas exchange parameters and photosynthetic light-response parameters showed downward trends with increasing cadmium concentration compared with those in CT; these results reflected the negative effects of cadmium stress on photosynthesis in sassafras seedlings.


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