scholarly journals Management of the saltwater intrusion phenomenon in the alluvial aquifer of Katapola, Amorgos, Greece

2017 ◽  
Vol 18 (3) ◽  
pp. 936-949 ◽  
Author(s):  
M. Siaka ◽  
Z. Dokou ◽  
G. P. Karatzas

Abstract The purpose of this study is to investigate the saltwater intrusion phenomenon in the alluvial aquifer of Katapola, on Amorgos Island, under current and future climatic conditions and to provide groundwater management options for alleviating this problem. To this end, a groundwater flow model was developed and the sharp-interface approximation combined with the Ghyben–Herzberg equation was used. A correction factor that accounts for the hydrodynamic dispersion occurring at the brackish zone was also incorporated in the analysis. The model results show that under the current pumping strategy, the saltwater intrusion front extent is vast, posing a serious threat to the quality of groundwater used for drinking and irrigation in the area. The management goal is to find the alternative pumping scenarios for the existing well network that will prevent further spreading of saltwater intrusion. Several water management scenarios were developed, taking into account the effects of climate change, the increase in water supply demand and the expected population growth. The results indicate that controlling the propagation of seawater intrusion in Katapola necessitates the periodic deactivation of most of the pumping wells and the design of alternative plans in order to meet the increasing water demand.

2018 ◽  
Vol 12 (2) ◽  
pp. 1-7
Author(s):  
Sînziana Venera Morărița

Abstract Although relatively recent, peach culture has grown great in our country due to the special quality of the fruit, its very complex chemical composition and the large production that can be obtained without much effort. Peach is a species slightly adapted to our climatic conditions, suffers from winter frost, but can provide productive and long productions of 10-15 years.


2020 ◽  
pp. 26-28
Author(s):  
Н.Т. Чеботарев ◽  
Н.Н. Шергина

Пахотные угодья Республики Коми в основном представлены дерново-подзолистыми почвами с низким естественным плодородием, которые без применения удобрений быстро подвергаются деградационным процессам, что резко снижает их продуктивность. Цель исследований: оценка эффективности долговременного применения органических и минеральных удобрений при выращивании картофеля в кормовом севообороте в условиях Республики Коми. Методической основой выполнения работ были комплексные исследования дерново-подзолистых почв, клубней картофеля на участках многолетнего полевого эксперимента, заложенного на землях Института агробиотехнологий ФИЦ Коми НЦ УрО РАН в соответствии с «Методическими указаниями географической сети опытов с удобрениями». Длительный период исследований (более 40 лет) характеризовался различными климатическими условиями, которые отразились на количестве урожая и качестве клубней картофеля. Было проведено 7 ротаций (14 лет) с выращиванием картофеля. Вносили органические удобрения – торфонавозный компост (ТНК) в дозах 40 и 80 т/га (1 и 2 фон, соответственно) под картофель и минеральные удобрения – NPК в дозах 1/3; 1/2 и 1 для восполнения выноса растениями элементов питания. Установлено положительное влияние комплексного применения органических и минеральных удобрений на урожайность и качество картофеля, а также на плодородие дерново-подзолистой легкосуглинистой среднеокультуренной почвы в кормовом севообороте в почвенно-климатических условиях Республики Коми. В результате применения шестипольного севооборота и комплексного внесения удобрений с 1978 года к 2019 году в почвах снизилась обменная и гидролитическая кислотность; повысилось содержание гумуса на 0,5% (в контроле); на 0,2–0,5% (с тремя дозами минеральных удобрений); на 0,3–1,1% (с ТНК); на 0,2–1,6% (при совместном применении органических и минеральных удобрений). Наибольшие урожаи картофеля получены при совместном применении органических (80 т/га) и минеральных удобрений (1 NPК) и составили 37,1 т/га клубней (8,5 тыс/га кормовых единиц). При таком соотношении удобрений показано высокое качество клубней картофеля: содержание крахмала 15,5%, витамина С – 19,4 мг%, сырого протеина – 14,1%. Количество нитратного азота не превышало ПДК (ПДК 250 мг.с.м.). Экономические расчеты показали, что при внесении ТНК 40 т/га + 1 NPК в дерново-подзолистые почвы с.-х. использования в среднетаежной зоне Республики Коми при выращивании картофеля, условный чистый доход составит 68,4 тыс. р. с 1 га, себестоимость 1 т картофеля – 2,8 тыс. р., рентабельность 188,7%. The arable land of the Republic of Komi is mainly represented by dern-sub-ground soils with low natural fertility, which without the use of fertilizers are quickly subjected to degradation processes, which dramatically reduces their productivity. The aim of the research is to evaluate the efficiency of long-term use of organic and mineral fertilizers in the growing of potatoes in feed crop rotation in the conditions of the Komi Republic. The methodological basis for carrying out the works was comprehensive studies of dern-subhead soils, potato tubers on the sites of a multi-year field experiment laid on the lands of the Institute of Agrobiotechnology of the FRC Komi SC UB RAS in accordance with the «Methodological Instructions of the Geographical Network of Experiments with Fertilizers». A long period of research (more than 40 years) was characterized by different climatic conditions, which affected the number of crops and the quality of potato tubers. There were 7 rotations (14 years) with potato cultivation. Organic fertilizers – peat-avous compost (TNK) in doses of 40 and 80 t/ha (1 and 2 background, respectively) for potatoes and mineral fertilizers – NPK in doses of 1/3; 1/2 and 1 to replenish the carry-out of food elements by plants. The positive effect of the integrated use of organic and mineral fertilizers on the yield and quality of potatoes, as well as on the fertility of soddy-podzolic light loamy medium cultivated soil in fodder crop rotation in the soil and climatic conditions of the Komi Republic, has been established. As a result of the use of six-bed crop rotation and the integrated application of fertilizers, metabolic and hydrolytic acidity decreased in soils from 1978 to 2019; humus content increased by 0.5% (in control); 0.2–0.5% (with three doses of mineral fertilizers); 0.3–1.1% (with TNCs); 0.2–1.6% (with combined use of organic and mineral fertilizers). The largest potato yields were obtained from the combined use of organic (80 t/ha) and mineral fertilizers (1 NPK) and amounted to 37.1 t/ha tubers (8.5 thousand/ha feed units). The largest potato harvests were obtained with the combined use of organic (80 t/ha) and mineral fertilizers (1 NPK) and amounted to 37.1 t/ha of tubers (8.5 thousand/ha of feed units). With this ratio of fertilizers, the high quality of potato tubers was also determined: the starch content was 15.5%, vitamin C – 19.4 mg%, crude protein – 14.1%. The amount of nitrate nitrogen did not exceed the MPC (MPC 250 mg.s.m.). Economic calculations showed that if TNK is added 40 t/ha 1 NPK to the dern-sub-ground soils of agricultural use in the medium-sized zone of the Komi Republic when growing potatoes, the conditional net income will be 68.4 thousand rubles from 1 ha, the cost of 1 t of potatoes – 2.8 thousand rubles, profitability 188.7%.


1993 ◽  
Vol 58 ◽  
Author(s):  
D. Maddelein ◽  
J. Neirynck ◽  
G. Sioen

Mature  Scots pine (Pinus sylvestris  L.) stands are dominating large parts of the Flemish forest area. Broadleaved  species regenerate spontaneously under this pine canopy. This study studied  the growth and development of two planted pine stands with an older natural  regeneration, dominated by pedunculate oak (Quercus  robur L.), and discussed management options for  similar stands.     The results indicated a rather good growth of the stands, with current  annual increments of 5 m3.ha-1.yr-1. The pine overstorey is growing into valuable sawwood  dimensions, while the broadleaved understorey slowly grows into the  upperstorey. The quality of the regeneration is moderate but can be improved  by silvicultural measurements (pruning, early selection).     In both stands, an interesting (timber production, nature conservation)  admixture of secondary tree species is present in the regeneration. Stand  management is evolving from the classical clearcut system towards a  combination of a type of selection and group selection system.


Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1427
Author(s):  
Gulen Ozyazici

Environmental contamination and the excessive use of inorganic fertilizers resulting in stagnant yields of field crops which necessitate the utilization of combined fertilization approach under changing climatic conditions. Current study was aimed to clarify the influence of several fertilizer sources (chemical, organic, organomineral fertilizers) on yield and quality of coriander (Coriandrum sativum L.). The results revealed that the fertilizer sources significantly affected the yield of coriander cultivars. The absence of “Year x Variety x Fertilizer Type” interactions for any of the noted parameters signaled that the detected “Variety x Fertilizer Type” interactions were constant regardless of the year factor. The recorded values of traits according to fertilizer sources different for the plant height from 61.85 to 69.67 cm, number of branches from 5.98 to 7.71 (piece/plant), number of umbels per the main umbel from 5.62 to 7.18 pieces, seed yield from 1.06 to 1.66 t/ha, the biological yield from 4.29 to 5.70 t ha−1, harvest index from 25.29 to 29.41%, essential oil ratio from 0.29 to 0.33%, and essential oil yield from 3.1 to 5.6 L ha−1. Erbaa variety was observed to be superior over the rest of the varieties producing the maximum values of 6.5 L ha−1 of essential oil, 0.36% essential oil content, 30.9% harvest index, 1.81 t/ha seed yield, and 5.9 t ha−1 biological yield with the treatment of chemical fertilizers.


Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2009
Author(s):  
Caroline Ednah Mwebaze ◽  
Jackson-Gilbert Mwanjalolo Majaliwa ◽  
Joshua Wanyama ◽  
Geoffrey Gabiri

Limited studies in East Africa and particularly in Uganda have been carried out to determine and map water use and demands. This study aimed at assessing the impact of management options on sustainable water allocation in environmentally sensitive catchments of Mubuku and Sebwe of Lake Edward-George basin in Western Uganda. We used hydro-meteorological data analysis techniques to quantify the available water. We applied Mike Hydro model to allocate water to the different ongoing developments in the catchment based on 2015 and 2040 water demand management scenarios. We used the Nile Basin Decision Support System to assess the sustainability of the different water management scenarios for sustainable water resources use. Reliability computation did not consider hydropower in this study. Results show that water available in 2015 was 60 MCM/YR and 365 MCM/YR for Sebwe and Mubuku, respectively and is projected to decrease by 15% and 11% by the year 2040 under climate scenario RCP8.5. We project water demand to rise by 64% for domestic, 44% for livestock, 400% for industry, 45% for hydro power and 66% for irrigation by 2040. Mubuku water demand is projected to increase from 5.2 MCM in 2015 to 10.7 MCM in 2040. Mubuku available water is projected to fall from 364.8 to 329.8 MCM per annum. Sebwe water demand is projected to increase from 9.7 MCM in 2015 to 22.2 MCM in 2040 and its available water is projected to fall from 60 to 52 MCM per annum by the year 2040 from 2015. Water managers ought to allocate water based on the reliable water allocation which prioritizes domestic and environmental water demands, allocates 90% of industrial demand, 70% of irrigation and 60% of livestock demand. We recommend institutionalizing this model to guide water allocation in the Mubuku-Sebwe sub catchments. Water users should employ more efficient water use techniques to achieve high reliability and sustainable water resources management.


Toxins ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 214
Author(s):  
Agathe Roucou ◽  
Christophe Bergez ◽  
Benoît Méléard ◽  
Béatrice Orlando

The levels of fumonisins (FUMO)—mycotoxins produced by Fusarium verticillioides—in maize for food and feed are subject to European Union regulations. Compliance with the regulations requires the targeting of, among others, the agroclimatic factors influencing fungal contamination and FUMO production. Arvalis-Institut du végétal has created a national, multiyear database for maize, based on field survey data collected since 2003. This database contains information about agricultural practices, climatic conditions and FUMO concentrations at harvest for 738 maize fields distributed throughout French maize-growing regions. A linear mixed model approach highlights the presence of borers and the use of a late variety, high temperatures in July and October, and a water deficit during the maize cycle as creating conditions favoring maize contamination with Fusarium verticillioides. It is thus possible to target a combination of risk factors, consisting of this climatic sequence associated with agricultural practices of interest. The effects of the various possible agroclimatic combinations can be compared, grouped and classified as promoting very low to high FUMO concentrations, possibly exceeding the regulatory threshold. These findings should facilitate the creation of a national, informative and easy-to-use prevention tool for producers and agricultural cooperatives to manage the sanitary quality of their harvest.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Fabrizio Luppi ◽  
Meena Kalluri ◽  
Paola Faverio ◽  
Michael Kreuter ◽  
Giovanni Ferrara

AbstractIdiopathic pulmonary fibrosis (IPF) is a chronic and progressive disorder with an estimated median survival time of 3–5 years after diagnosis. This condition occurs primarily in elderly subjects, and epidemiological studies suggest that the main risk factors, ageing and exposure to cigarette smoke, are associated with both pulmonary and extrapulmonary comorbidities (defined as the occurrence of two or more disorders in a single individual). Ageing and senescence, through interactions with environmental factors, may contribute to the pathogenesis of IPF by various mechanisms, causing lung epithelium damage and increasing the resistance of myofibroblasts to apoptosis, eventually resulting in extracellular matrix accumulation and pulmonary fibrosis. As a paradigm, syndromes featuring short telomeres represent archetypal premature ageing syndromes and are often associated with pulmonary fibrosis. The pathophysiological features induced by ageing and senescence in patients with IPF may translate to pulmonary and extrapulmonary features, including emphysema, pulmonary hypertension, lung cancer, coronary artery disease, gastro-oesophageal reflux, diabetes mellitus and many other chronic diseases, which may lead to substantial negative consequences in terms of various outcome parameters in IPF. Therefore, the careful diagnosis and treatment of comorbidities may represent an outstanding chance to improve quality of life and survival, and it is necessary to contemplate all possible management options for IPF, including early identification and treatment of comorbidities.


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