Response of Olive Trees (<i>Olea europaea</i> L.) cv. Kalinioti to Nitrogen Fertilizer Application

Nitrogen is the most commonly managed mineral nutrient in olive groves because it is essential for plant growth. The precise management of N fertilization in olive cultivation is still not fully clarified, but it is essential for providing sustainable production. A nitrogen fertilizer experiment with olive trees (cv. Kalinioti) was carried out over a six-year period. Seven levels of nitrogen fertilizer given as ammonium nitrate (control, 1, 2, 3, 4, 5, and 6 kg/tree) were annually applied in order to determine the effect of nitrogen on vegetative growth, fruit set, fruit weight, yield, maturation index, and leaf N, P, and K concentrations. The results indicate that, under these conditions, application of up to 4 kg NH4NO3/tree significantly increased yield to 62.5 kg/tree compared to the control (37.09 kg/tree). The positive effect was attributed to the initial and final fruit set increases (7.63 and 3.73%, respectively at 4 kg NH4NO3/tree). However, the weight of 100 olives (W100 = 331 g) at 4 kg NH4NO3/tree obtained during harvest was considerably lower compared to the control (W100 = 384 g). Higher nitrogen rates decreased yield while increasing overall shoot growth. Nitrogen fertilization did not significantly influence the oil content of olive fruit. Fruit weight, maturation index, and concentration of oil reached maximum levels in the beginning of December, indicating a suitable start to olive harvesting. The concentration of N in olive leaves increased from 1.23% to 2.38% as fertilizer levels increased from 0 to 6 kg NH4NO3. Maximum yield was achieved at a level of 6 kg NH4NO3/tree, which corresponded to 2.01% N in leaves. The results suggest that application of 3 kg NH4NO3/tree can be recommended for table olive production, due to the fact that fruit weight was not decreased, while fertilization with 4 kg NH4NO3/tree was suitable for oil olives

Organic Fertilization and Tree Orchards

Organic fertilization has been proposed as an alternative approach to supply nutrients for crops, in the frame of organic and sustainable agriculture, with the aim to decrease high inorganic fertilization rates, protect the environment and decrease production costs for farmers. Since different types of organic fertilizers, such as manures, olive mill wastewater (OMW), sewage sludge (SS), crushed pruning wastes, composts and cover crops, exist as soil amendments to improve soil fertility, enhance plant nutrition and sustain the productivity of tree crops, their role as biofertilizers has been fully analyzed under the most important published papers. In addition, the benefits and drawbacks of organic fertilization, in a comparative approach with inorganic fertilization, are presented and discussed. Within the most important advantages of organic fertilizers, the enhancement of beneficial soil microorganisms and the improvement in soil physical properties and fertility should be included, while their most important disadvantage is their inability to directly satisfy the prompt N nutritional needs of tree crops, due to slow N mineralization rates. Finally, some novel aspects on the interrelation among innovative organic fertilizers for tree crops, sustainable field management, crop productivity and fruit quality are also included in this review, under the light of the most important and recent research data existing in the literature, with the aim to provide recommendations and future directions for organic fertilizers by tree growers

Long-Term Effects on Soil of the Disposal of Olive Mill Waste Waters (OMW)

<div><p>Disposal of untreated olive mill waste waters (OMW) is a serious environmental problem in many Mediterranean countries. The aim of this work was to assess whether changes in soil properties have occurred due to direct disposal of raw OMW on soil and in evaporation ponds, and to investigate the potential fate and transport of pollutants after olive oil production had ceased. The results clearly showed that uncontrolled OMW disposal is a significant source of pollution to surface soil and waters. Disposal of OMW on soil greatly increased electrical conductivity (EC), available phosphorous (P), exchangeable potassium (K) and magnesium (Mg), organic matter, polyphenols, total and inorganic nitrogen (N), and available micronutrients mainly in surface soil layers. The presence of a high content of clay and carbonates in soil act as barriers and prevent downward transport of pollutants. Residual levels of total carbon (C), polyphenols, total and inorganic N, exchangeable K⁺, available P, iron (Fe), and copper (Cu) were also elevated even 8 years after mill closure. The long term disposal of OMW highlights the need to establish soil quality standards for soil parameters in order to identify soils affected by the disposal of OMW.</p> </div

Sjuksköterskors och undersköterskors uppfattningar om omvårdnadens innehåll och arbete : En intervjustudie

Bakgrund: Omvårdnad är ett ord som kan ha flera olika betydelser, det kan vara ett verb som något man utövar eller en synonym med kunskap som något som erhålls. Syfte: Syftet med studien var att beskriva vad sjuksköterskor och undersköterskor ansåg inbegripas av begreppet omvårdnad och “god omvårdnad” samt vad för arbetsuppgifter de olika yrkeskategorierna utförde inom ramen för omvårdnad. Metod:Individuella intervjuer av tre sjuksköterskor och fyra undersköterskor. Innehållet analyserades med hjälp av kvalitativ innehållsanalys. Fem teman och 21 kategorier framkom. Resultat: Respondenterna uttryckte att den basala omvårdnaden hade en central roll inom begreppet omvårdnad. Vid diskussion om vad god omvårdnad innebar framhävde de flesta att ett gott bemötande var avgörande, att utföra arbetsuppgifter med omtanke och respekt. Att bedriva personcentrerad vård ansågs även ge god omvårdnad. Förutom basal omvårdnad och bemötande framkom det att medicinsk teknik var en stor del av arbetet inom omvårdnaden och att samarbete var en viktig del. Det rådde få meningsskiljaktigheter angående sjuksköterskans respektive undersköterskans arbetsuppgifter. Slutsats: Sjuksköterskorna och undersköterskorna som intervjuats har till stor del en samlad bild utav vad begreppet omvårdnad innebär. Det fokuserades mest på basal omvårdnad och gott bemötande vilket båda är två viktiga och centrala delar inom omvårdnaden. Att det inte fanns många meningsskiljaktigheter mellan undersköterskorna och sjuksköterskan kan ses som ett resultat av en tydlig arbetsfördelning. Background: Nursing is a word that can have several meanings, it can be a verb or be synonymous with knowledge. Aim: The aim with this study was to describe what registered nurses (RN) and certified nursing assistant (CNA) perceived by the expressions nursing  and “qualitative nursing ” and what tasks at work these two different professions performed within the limits of nursing. Method: Qualitative interview study with individual interviews with three RN's and four CNA's. The content was analyzed through qualitative content analysis. Five themes and 21 categories arose. Results: The respondents expressed that the basal nursing care had a central role within the concept; nursing. At discussions about what good nursing meant, it was brought forth that a good interaction was decisive, to perform work related tasks with consideration and respect. To exercise person centered care was also considered to be good nursing. Besides basal nursing care and interactions it became apparent that medical technique is a big part of the job within nursing and that cooperation is an important part as well. There were few differences in opinions concerning RN respectively CNA job tasks. Conclusion: RN's and CNA's that were interviewed have the same general idea about what the concept nursing implies. It mainly focused on basal nursing care and good interactions, which were both considered as important parts within nursing. It can be seen that the lack of differences in opinion between CNA's and RN's is brought forth by a clear division of work between the two

Nitrogen Application Can Be Reduced without Affecting Carotenoid Content, Maturation, Shelf Life and Yield of Greenhouse Tomatoes

Tomatoes (Solanum lycopersicum L.) of the variety Elpida were grown under standard Mediterranean greenhouse conditions during the spring season at three different nitrogen levels (low 6.4, standard 12.8, high 25.9 mM/plant), which were replicated during two consecutive years. Application of high nitrogen significantly increased the colour index a* (p p ≤ 0.001) or by super-optimal temperatures in the second year of experimentation (10 days, p ≤ 0.001). The colour indices L* and a* and the hue angle (a/b*) were positively correlated with the sum of total carotenoids, while differences in b* depended on the year of cultivation. The sustainability of this type of tomato production can be improved by reducing the nitrogen supply to less than the current standard practice, with minimal risk or negative effects on yield and quality of tomatoes

Influence of Pulsed Electromagnetic Field on Plant Growth, Nutrient Absorption and Yield of Durum Wheat

<p>Researchers have adopted the use of magnetic field as a new pre-sowing, environmental friendly technique. Enhancements on plant characteristics with economic impact on producer’s income could be the future of a modern, organic and sustainable agriculture. A field experiment was established at Soil Science Institute of Athens, Lycovrissi, Greece, in the winter of 2014. Two durum wheat cultivars were used. It was a pot experiment with 6 treatments (2 cultivars with 3 magnetic field time exposure). The seeds were treated using a PAPIMI electromagnetic field generator for 0, 30 and 45 minutes one day before planting. The experiment followed a completely randomized design with six treatments and 30 replications. The aim of this study was to evaluate the positive effect of magnetic field pre-sowing treatment in a wide range of plant measurements, including yield. The influence of pulsed electromagnetic field on two varieties of durum wheat seeds showed some statistically significant differences at the 0.05 level in growth measurements, physiological measurements and root growth measurements. Plant tissue analysis showed that magnetic field treatments had higher values than control in total nitrogen, phosphorus, potassium, magnesium, copper (only MF-45), zinc (only MF-30) and boron content, although values showed statistically significant differences only in total nitrogen. The results indicate that this innovative technique can increase the yield of durum wheat, through enhanced absorption of nutrients. Pre-sowing treatment of the seeds leads to vigorous plant growth that are more productive.</p

Influence of Pulsed Electromagnetic Field on Plant Growth, Nutrient Absorption and Yield of Durum Wheat

Researchers have adopted the use of magnetic field as a new pre-sowing, environmental friendly technique. Enhancements on plant characteristics with economic impact on producer’s income could be the future of a modern, organic and sustainable agriculture. A field experiment was established at Soil Science Institute of Athens, Lycovrissi, Greece, in the winter of 2014. Two durum wheat cultivars were used. It was a pot experiment with 6 treatments (2 cultivars with 3 magnetic field time exposure). The seeds were treated using a PAPIMI electromagnetic field generator for 0, 30 and 45 minutes one day before planting. The experiment followed a completely randomized design with six treatments and 30 replications. The aim of this study was to evaluate the positive effect of magnetic field pre-sowing treatment in a wide range of plant measurements, including yield. The influence of pulsed electromagnetic field on two varieties of durum wheat seeds showed some statistically significant differences at the 0.05 level in growth measurements, physiological measurements and root growth measurements. Plant tissue analysis showed that magnetic field treatments had higher values than control in total nitrogen, phosphorus, potassium, magnesium, copper (only MF-45), zinc (only MF-30) and boron content, although values showed statistically significant differences only in total nitrogen. The results indicate that this innovative technique can increase the yield of durum wheat, through enhanced absorption of nutrients. Pre-sowing treatment of the seeds leads to vigorous plant growth that are more productive

Enhancing the Yield of Mature Olive Trees via Comparative Fertilization Strategies, including a Foliar Application with Fulvic and Humic Acids, in Non-Irrigated Orchards with Calcareous and Non-Calcareous Soils

This study investigated the impact of fertilization treatments on mature, forty-year-old, fully productive olive trees (Olea europaea L. cv. Koroneiki) in two non-irrigated orchards featuring contrasting soil types: non-calcareous–acidic and calcareous–alkaline. Over three years (2019–2021), seven distinct treatments were applied, involving inorganic soil fertilizers (traditional strategy) and foliar applications of a liquid organic product containing fulvic and humic acids. Fertilization significantly influenced physiological parameters, such as mineral nutrition, photosynthetic pigments of olive leaves, fruit yield, and oil production per tree, revealing noteworthy effects influenced by soil types and their interactions with treatments. Statistical analysis highlighted specific treatments, indicating that the foliar application of the organic product once a year in alkaline soil or biannually in acidic soil resulted in the highest observed fruit yield and oil production per tree. Indeed, contrary to the control–unfertilized trees, specific fertilization strategies resulted in an average increase of up to 47% and 73% in fruit yield per tree and up to 96% and 100% in oil production per tree in acidic and alkaline soil, respectively. Furthermore, consistently high yields were correlated with constant high values of the chlorophyll a/chlorophyll b ratio (2.3–3.3 in August for acidic soil) and leaf chlorophyll a concentration (55–66 mg/100 g f.w. in August for alkaline soil). This novel finding underscores the crucial role of these factors as prerequisites for achieving superior fruit production. Our results emphasize the potential of integrating foliar organic fertilization as a complementary strategy to traditional soil-based approaches. This is particularly relevant under non-irrigated/rainfed cultural conditions, emphasizing the significance of considering alternative fertilization practices for optimized olive orchard management

Origin of recalcitrant heavy metals present in olive mill wastewater evaporation ponds and nearby agricultural soils

Δημοσίευση σε επιστημονικό περιοδικόSummarization: The present study attempts to elucidate the origin of recalcitrant heavy metals, namely Cr, Ni, and Mo, present in olive mill wastewater (OMW) evaporation ponds and nearby agricultural soils. Steel corrosion tests were carried out using several types of alloys (316L, 316, 304, and St 37-2) while sludge and soil samples were collected from the walls of active and inactive OMW evaporation ponds as well as from nearby soils and analyzed in order to elucidate the presence of heavy metals of interest. Experimental results prove that corrosion of high quality steels is extremely limited and is mainly caused in solutions characterized by high chloride concentration. It is therefore assumed that the presence of recalcitrant heavy metals in soils is the result of past (between 1970 and 2000) olive oil milling activities when inferior quality steel equipment was used.Παρουσιάστηκε στο: Environmental Forensic

Geostatistical estimation of risk for soil and water in the vicinity of olive mill wastewater disposal sites

Δημοσίευση σε επιστημονικό περιοδικόSummarization: Olive mill wastewater (OMW) is often disposed of in poorly engineered evaporation ponds or various environmental receptors in most Mediterranean countries causing contamination of soils and water bodies. The aim of this work is to estimate the risk for soils and waters as a result of OMW disposal in an area of 15 km2 at Rethymnon, island of Crete, Greece. Soil, surface, and groundwater samples were collected over a period of five years and geostatistics using the kriging approach was considered for the assessment of risk. Risk maps for several pollutants, namely phenols, Ni, Cr, and available P, in soil and water were produced. The results of the study indicate the presence of hot spots in the area under investigation, mainly in the vicinity of OMW disposal sites. Finally, the fate of contaminants in affected media is discussed and a framework for monitoring of soils and water bodies in areas affected by OMW disposal is proposed.Παρουσιάστηκε στο: Desalination and Water Treatmen