Letteratura scientifica selezionata sul tema "Nutrients"
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Articoli di riviste sul tema "Nutrients"
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Roopa Jammula e Syeda Nishat Fathima. "Balancing act: Understanding nutrient interactions". World Journal of Biology Pharmacy and Health Sciences 18, n. 3 (30 giugno 2024): 243–47. http://dx.doi.org/10.30574/wjbphs.2024.18.3.0346.
Testo completoAbstract (sommario):
Nutrient interactions refer to the dynamic relationship between various nutrients, including minerals, vitamins, amino acids, and fatty acids, for proper functioning. An excess or deficiency of one nutrient can affect the requirements for many others, and increasing or decreasing a deficient nutrient may require an increase in other nutrients. Many nutrients require other nutrients to convert into other forms, and chemical combinations or reactions between nutrients can change their biological availability. Direct metabolic requirements of one nutrient can change the biological activity of another. Structurally similar nutrients can compete for absorption and utilization, and one nutrient can replace another with a different action. This review deals with different types of interaction observed in between dietary carbohydrates, dietary proteins and dietary fats.
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Mattson, Neil S., e Marc W. van Iersel. "Application of the “4R” Nutrient Stewardship Concept to Horticultural Crops: Applying Nutrients at the “Right Time”". HortTechnology 21, n. 6 (dicembre 2011): 667–73. http://dx.doi.org/10.21273/horttech.21.6.667.
Testo completoAbstract (sommario):
The 4R nutrient stewardship framework presents four concepts to consider when applying fertilizers in a responsible matter; the “right source” of nutrients should be applied at the “right rate” during the “right time” and supplied to the “right place” to ensure their uptake. In this article, we provide ideas to consider when attempting to provide nutrients at the right time. When nutrients are applied at a time when they are not required by the plant, the result can be economic and environmental losses. Oversupply relative to plant demand can result in losses of applied nutrients because of leaching or volatilization. Undersupply relative to demand, especially in the case of phloem-immobile nutrients, may limit plant growth and yield. Several factors interact to affect plant nutrient demand such as growth stage, life history (annual vs. perennial), environmental conditions, and plant health. Techniques such as soil and tissue testing, isotopic labeling, and spectral reflectance have been used with varying degrees of success and expense to measure plant nutrient demand and guide fertilizer decisions. Besides knowledge of plant nutrient demand, efficient nutrient supply also depends on systems that allow precise spatial and temporal delivery of nutrients. Future improvements to the timing of nutrient delivery will depend on improvement in knowledge of plant nutrient demands. For example, targeted gene expression chips show promise for use in rapidly assessing plant status for a broad suite of nutrients. Future developments that allow more precise nutrient delivery or more robust agroecosystems that scavenge available nutrients before they are lost to the environment will also help producers use nutrients more efficiently.
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Meirinawati, Hanny, e A'an Johan Wahyudi. "Deepening Knowledge of Nutrient Dynamics in Coastal Waters". ASEAN Journal on Science and Technology for Development 39, n. 1 (28 aprile 2022): 23–33. http://dx.doi.org/10.29037/ajstd.747.
Testo completoAbstract (sommario):
Nutrients are important compounds in waterbodies that regulate primary productivity and phytoplankton growth, the basis of food webs. Increased nutrient concentration has become a serious concern because it causes eutrophication and threatens the sustainability of ecosystems. Eutrophication is the process of nutrient enrichment in water bodies that affects their productivity and decreases water quality. Although information about nutrient distribution, limiting nutrients, and nutrient budgets is important for coastal water management, studies of wide-scale nutrient dynamics in Indonesian waters remain limited. To provide comprehensive data on nutrients, this review summarized the concentrations and compositions of nutrients in coastal waters, compared the limiting nutrients in various coastal waters based on the Redfield ratio, and described the factors affecting nutrient budgets using the database in ScienceDirect and Google Scholar. Curation was performed to summarize the nutrient dynamics in coastal waters. Results showed that nutrient concentration differed in each region due to many factors. Anthropogenic inputs greatly affected nutrients in tropical areas, such as Jakarta Bay (Indonesia). Understanding the quality and characteristics of water can help in managing waterbodies. This study provided knowledge related to nutrient dynamics in Indonesian waters and global biogeochemistry.
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Bugbee, Bruce. "284 Towards Efficient Nutrient Management in Recirculating Hydroponic Culture". HortScience 34, n. 3 (giugno 1999): 491C—491. http://dx.doi.org/10.21273/hortsci.34.3.491c.
Testo completoAbstract (sommario):
There is an increasing need to recirculate and reuse nutrient solutions to reduce environmental and economic costs. However, one of the weakest points in hydroponics is the lack of information on managing the nutrient solution. Many growers and research scientists dump out nutrient solutions and refill at weekly intervals. Some authors have recommended measuring the concentrations of individual nutrients in solution as a key to nutrient control and maintenance. Dumping and replacing solution is unnecessary. Monitoring ions in solution is unnecessary; in fact the rapid depletion of some nutrients often causes people to add toxic amounts of nutrients to the solution. Monitoring ions in solution is interesting, but it is not the key to effective maintenance. During the past 18 years, we have managed nutrients in closed hydroponic systems according to the principle of “mass balance,” which means that the mass of nutrients is either in solution or in the plants. We add nutrients to the solution depending on what we want the plant to take up. Plants quickly remove their daily ration of some nutrients while other nutrients accumulate in the solution. This means that the concentrations of nitrogen, phosphorous, and potassium can be at low levels in the solution (<0.1 mM) because these nutrients are in the plant where we want them. Maintaining a high concentrations of some nutrients in the solution (especially P, K, and Mn) can result in excessive uptake that can lead to nutrient imbalances.
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Bagale, Suman. "Nutrient Management for Soybean Crops". International Journal of Agronomy 2021 (6 settembre 2021): 1–10. http://dx.doi.org/10.1155/2021/3304634.
Testo completoAbstract (sommario):
Soybean is one of the most important pulse crops in the world which supplies most of the protein and oil requirements. The efficient production of soybean crops is a constraint, with several biotic factors, abiotic factors, and crop management practices. Nutrient management is one of the important aspects for achieving higher production of crops. Effective nutrient management helps to assure the required nutrients needed for the plant without causing a significant decrease in the yield of crops. In addition to this, managing the nutrient efficiently helps the crop to cope with several types of biotic and abiotic stress. For soybean crop, altogether fifteen nutrients are needed, which comprises six macronutrients, namely, nitrogen, phosphorous, potassium, calcium, magnesium, and sulfur, which are required relatively in large amounts, and nine micronutrients which include iron, boron, zinc, cobalt, copper, manganese, molybdenum, nickel, and chlorine. These nutrients can be supplied to the plants through soil incorporation or foliar spray of commercially available fertilizers. Nutrient requirements for soybean crops vary in concentration, and deviations can cause nutrient deficiency or toxicity in soybean crops. Nutrient availability to soybean crops depends on the available nutrients in the soil solution, the form of available soil nutrients, mode of uptake of nutrients, its interaction with other soil nutrients, soil chemistry, and method of fertilizer application. This review article explores essential nutrients for sustainable soybean production in relation to the role and functions of nutrients, required concentration, and visual syndrome shown during deficiency, including findings from several researches. The review article is aimed to guide soybean farmers for effective nutrient management and academicians in reviewing the literature in soybean nutrient management.
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Nabilla, Sarah, Retno Hartati e Ria Azizah Tri Nuraini. "Hubungan Nutrien Pada Sedimen dan Penutupan Lamun Di Perairan Jepara". Jurnal Kelautan Tropis 22, n. 1 (13 aprile 2019): 42. http://dx.doi.org/10.14710/jkt.v22i1.4252.
Testo completoAbstract (sommario):
The availability of nutrients in seagrass beds can act as growth limiting factors. Absorption of nutrients in the water column is carried out by the leaves while the absorption of nutrients from the sediment is carried out by the roots but does not rule out the transport of nutrients by the roots will also arrive at the leaves of the seagrass. If the nutrient requirement is not met properly, then the growth will be disrupted. Like the difference in distribution and density of seagrass itself. Nutrient concentrations in waters vary. Nitrate and phosphate levels in the waters are strongly influenced by sources of organic material from outside/land (allochthonous) or from the water itself (autocthonous). This research was conducted with the aim of nothing: to determine the relationship between nutrient content (nitrate and phosphate) in sediment to seagrass cover in Teluk Awur and Pantai Blebak, JeparaData collection of seagrass and sediment was carried out on March 2018 in the waters of Teluk Awur and Blebak Beach, Kabupaten Jepara. Type identification, density, and coverage are carried out at the research location. Nitrate and phosphate analysis in sediments is carried out in Laboratorium Pengujian dan Peralatan. Based on the results of research that has been carried out, it can be concluded that there is a very strong positive relationship between nutrients and seagrass closure in the two research locations, each of which is 0.955 (91.1%) in Teluk Awur waters and 0.962 (92.6%) in Blebak Beach.Ketersediaan nutrien di perairan padang lamun dapat berperan sebagai faktor pembatas pertumbuhan. Penyerapan nutrien pada lamun pada kolom air dilakukan oleh daun sedangkan penyerapan nutrien dari sedimen dilakukan oleh akar namun tidak menutup kemungkinan pengangkutan nutrien oleh akar juga akan sampai pada bagian daun. Jika kebutuhan nutrien tidak terpenuhi dengan baik, maka pertumbuhannya mengalami gangguan. Seperti perbedaan sebaran dan kepadatan lamun itu sendiri. Konsentrasi nutrien di perairan bervariasi. Kadar nitrat dan fosfat di perairan sangat dipengaruhi oleh sumber bahan organik yang berasal dari luar/ daratan (allochthonous) maupun dari dalam perairan itu sendiri (autocthonous). Penelitian ini dilakukan dengan tujuan: untuk mengetahui hubungan antara kandungan nutrien (nitrat dan fosfat) pada sedimen terhadap tutupan lamun di Teluk Awur dan Pantai Blebak, Jepara. Identifikasi jenis, kepadatan dan penutupan dilakukan pada lokasi penelitian. Analisa nitrat dan fosfat dalam sedimen dilakukan di Laboratorium Pengujian dan Peralatan. Berdasarkan hasil penelitian yang telah dilakukan dapat di ambil kesimpulan bahwa terdapat hubungan sangat kuat positif antara nutrien dengan penutupan lamun pada dua lokasi penelitian, nilainya masing-masing sebesar 0,955 (91,1%) di Perairan Teluk Awur dan 0,962 (92,6%) di Pantai Blebak.
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De Souza, Juliana Sobreira, Deborah Guerra Barroso, Mirian Peixoto Soares da Silva e Daniele De Alvarenga Ferreira. "PRODUTIVIDADE DE MINICEPAS DE CEDRO-AUSTRALIANO EM FUNÇÃO DO TEOR INICIAL DE NUTRIENTES". FLORESTA 45, n. 3 (24 aprile 2015): 617. http://dx.doi.org/10.5380/rf.v45i3.36529.
Testo completoAbstract (sommario):
O objetivo do presente estudo foi avaliar a produtividade de minicepas de cedro-australiano em função do teor inicial de nutrientes em dois sistemas de minijardim multiclonal, conduzidos em canaletão e tubetes. Foi determinada a produtividade de miniestacas em 186 minicepas em cada sistema de manejo e os teores de nutrientes nas brotações emitidas por 20 minicepas selecionadas ao acaso em cada sistema. Foram realizadas cinco coletas de brotações em intervalos médios de 32 dias no sistema canaletão, enquanto no sistema tubete foram realizadas três coletas de brotações em intervalos médios de 31 dias. O número de miniestacas produzidas por minicepa foi correlacionado com o teor inicial de nutrientes da parte apical das mudas. A produtividade de minicepas de cedro-australiano manejadas em sistema canaletão e em tubetes está relacionada à nutrição mineral. Assim, níveis elevados de nutrientes nas minicepas favorecem o ganho em produtividade. Dessa forma, a reposição dos nutrientes conforme a exportação descrita favorecerá o aumento da produtividade das minicepas nos dois sistemas de produção.AbstractProductivity of cedar Australian ministumps in function of the initial nutrient. The aim of this research was to evaluate the productivity of Australian cedar ministumps in function of the initial content of nutrients in two systems of multiclonal minigarden; the experiment was conducted in tray and tubes. We determined the yield of minicuttings in 186 ministumps in each management system and the nutrient contents in shoots issued for 20 ministumps randomly selected in each system. We made a total of five collections of shoots in intervals of 32 days in the tray system, while in the cartridges system we made three collections of shoots in intervals of 31 days. The number of minicuttings produced by mini-stump was correlated with the initial content of nutrients in the apical part of seedlings. The productivity of australian cedar ministumps managed under tray and tubes is related to mineral nutrition. Thus, high levels of nutrients work in favor of ministumps gain in productivity. As result, the recovery of export nutrients, as described, work in favor of increased productivity of ministumps in both systems.Keywords: Vegetative propagation; Toona ciliata; multiclonal minigarden; mineral nutriton.
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Nyambaka, Hudson. "Impact of Processing on Nutrients and anti-Nutrients in Tubers and Leaves of Cassava (Manihot Esculenta Crantz)". Nutrition and Food Processing 7, n. 1 (30 gennaio 2024): 01–08. http://dx.doi.org/10.31579/2637-8914/185.
Testo completoAbstract (sommario):
Purpose The study investigated the effect of boiling and deep-frying on the levels of selected nutrients and anti-nutrients in tubers and leaves of new Migyera and MM96/2480 varieties planted in Busia County. Although cassava contains high levels of nutrients (elements and vitamins) that meet nutrient requirements when consumed as the main diet, it requires thorough cooking to reduce high levels of phytochemicals, anti-nutrients affecting nutrient bio-accessibility, and carcinogenic compounds; procedures which also affect the nutrient levels. Methods Tubers and leaves from the tips of the plant were harvested after 8 months. A portion of the tubers was boiled in water (100 ºC, 20 minutes), while another deep-fried in vegetable cooking oil until it turned brown (5 minutes). Leaves were pounded until uniformly macerated and boiled in water (100 ºC, 45 minutes). Levels of nutrients and antinutrients were determined by standard methods. Results The levels of nutrients and anti-nutrients were significantly higher in leaves than in tubers, and also differed significantly in different cassava varieties. Boiling of tubers significantly reduced the nutrients and anti-nutrients levels more compared to frying (P<0.001), ranging from 13.7 to 97.7%. Deep frying of Migyera variety had higher nutrient reduction than in MM96/2480 variety. Essential elements and antinutrients molar ratios indicated that the elements were not bio-accessible. Conclusion Boiling and deep-frying of cassava tubers and leaves results in significant reduction of nutrient and anti-nutrient levels, implying that cassava cannot be used as the main diet; explaining the high level of child malnutrition in such communities.
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Oriolowo, O. B., O. J. John, D. S. Abubakar, T. M. Jonah e D. Ismaila. "Anti-nutritional Composition of Honey Samples from Four Northern States of Nigeria". Nigerian Journal of Basic and Applied Sciences 27, n. 2 (27 maggio 2020): 32–38. http://dx.doi.org/10.4314/njbas.v27i2.5.
Testo completoAbstract (sommario):
Honey is sought globally for nutritional and therapeutic purposes because of the several chemical constituents that are abound in it. Some of these chemicals such as the anti-nutrients are defensive metabolic byproducts of plants from which bees obtained the nectars for honey production. This study was undertaken to determine the cyanide, oxalate, phytate, tannin and saponin compositions of honey samples from four North Central States of Nigeria. Anti-nutrients were analyzed following the Standards of Association of Official Analytical Chemists protocol for anti-nutrient compositions. Data obtained were compared using One-Way Analysis of Variance (ANOVA) and the means were separated using Fischer’s Least Significance Difference (LSD). The results showed that cyanide, phytate and tannin were present in all the four honey samples while oxalate and saponin were only present in two of the honey samples, though at varying concentrations each of them. All anti-nutrient except cyanide are within tolerable limit for human consumption. There were significant differences (p<0.05) in each of the anti-nutrient’s concentrations across the honey samples. The study showed that location and geographical region significantly influence honey’s anti-nutrient compositions as well as their concentrations.
Keywords: Honey, Anti-nutrients, Tannin, Saponin, Cyanide, Oxalate, Phytate.
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Anderson, Wendy B., e William G. Eickmeier. "Nutrient resorption in Claytonia virginica L.: implications for deciduous forest nutrient cycling". Canadian Journal of Botany 78, n. 6 (1 giugno 2000): 832–39. http://dx.doi.org/10.1139/b00-056.
Testo completoAbstract (sommario):
According to the vernal dam hypothesis, spring ephemeral herbs temporarily sequester large nutrient pools in deciduous forests prior to canopy closure and return the nutrients to the soil following senescence of aboveground tissues. However, many species resorb nutrients from their leaves back to belowground tissues during senescence, and the degree of resorption is often associated with soil nutrient availability. Species that store large proportions of their absorbed nutrients between years are not participating in the temporary sequestering and rapid recycling of nutrients implied by the vernal dam. We investigated the extent to which Claytonia virginica L. sequestered and returned nutrients to the soil in response to nitrogen (N) and phosphorus (P) availability. We tested the effect of nutrient availability on nutrient use efficiency, resorption efficiency, and resorption proficiency (% nutrient in senescent leaves) of Claytonia. Nutrient additions significantly decreased N but not P use efficiency of Claytonia, particularly as the growing season progressed. Nutrient additions also significantly reduced N resorption efficiency from 80 to 47% and decreased P resorption efficiency from 86 to 56%. N and P resorption proficiencies were also significantly lower in senesced leaves of fertilized plants: N concentrations were 2.33% when unfertilized and 4.13% when fertilized, while P concentrations were 0.43% when unfertilized versus 0.57% when fertilized. When unfertilized, Claytonia was more efficient at resorption compared with other spring herbs, but similar to other species when fertilized. However, Claytonia was much less proficient in resorbing nutrients than other reported plants, because senescent tissues maintained substantially higher concentrations of N and P, particularly when fertilized. In conclusion, Claytonia, an important spring ephemeral species, exhibits physiological responses that emphasize its role in the vernal dam by its temporary sequestration and substantial, rapid return of nutrients in deciduous forests. Adding nutrients to the site increases the total mass and the relative proportion of nutrients that Claytonia returns to the soil rather than sequestering between seasons, which ultimately increases nutrient recycling rates within the entire system.Key words: Claytonia virginica, nutrient response, resorption efficiency, nutrient cycling, spring ephemerals, vernal dam.
Tesi sul tema "Nutrients"
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Cromwell, Diane. "Pancreatic beta-cell actions of nutrients and metabolizable nutrient ester derivatives". Thesis, University of Ulster, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.494335.
Testo completo
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Silva, Maicon Gonçalves. "Biorremediação do solo contaminado por petróleo por diferentes técnicas de bioestimulação". reponame:Repositório Institucional da FURG, 2007. http://repositorio.furg.br/handle/1/3642.
Testo completoAbstract (sommario):
Dissertação(mestrado) - Universidade Federal do Rio Grande, Programa de Pós-Graduação em Oceanografia Física, Química e Geológica, Instituto de Oceanografia, 2007.Submitted by Cristiane Silva (cristiane_gomides@hotmail.com) on 2013-02-18T17:58:25Z No. of bitstreams: 1 2007_maicon_silva.pdf: 2073944 bytes, checksum: af385f9e57b56b200b854bc3856fc5a5 (MD5)
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Áreas contaminadas com hidrocarbonetos tem sido um problema cada vez mais constante, uma vez que existe um grande crescimento na produção, distribuição e consumo de petróleo, principalmente nos últimos anos. Desta forma, é cada vez mais importante o conhecimento de técnicas que sejam eficientes na limpeza destas áreas. Com isso, o presente trabalho através da técnica de biorremediação buscou estabelecer qual o melhor tratamento para a remoção de contaminantes de um petróleo leve em solo arenoso. Para tanto, foram realizados dois experimentos (I e II), em que no primeiro se estudou a eficiência de remoção dos contaminantes pela utilização de três tratamentos distintos de bioestimulação (adição de nutrientes (C), adição de biossurfactante (D), adição de nutriente mais biossurfactante (E)), os quais foram comparados a dois controles, um de solo (A) e outro de atenuação natural de petróleo (B). O outro experimento serviu para verificar a eficiência da esterilização no biossurfactante utilizado, sendo utilizados um controle de solo (F), um controle de atenuação natural de petróleo (G), um tratamento com biossurfactante/nutrientes (H) e outro com biossurfactante estéril/nutrientes (I). Ao final de seis meses de estudo verificou-se que os tratamentos C e E apresentaram as melhores taxas de remoção de óleos e graxas (OG), respectivamente, 90,4 e 78%, e os melhores índices de remoção de hidrocarbonetos alifáticos: 96,82 e 98,35% e de HPAs: 83,58 e 72,3% respectivamente. Já em relação ao experimento II, concluiu-se que não houve diferenças quanto ao uso do biossurfactante estéril ou não estéril, recomendando-se no entanto, a utilização do biossurfactante estéril uma vez que desta forma não há a introdução de microorganismos estranhos ao ambiente.
Sites contaminated with hydrocarbons have been a problem more and more constant, a time that exist a great growth in the production, distribution and consumption of oil, mainly in the last years. Of this way the knowledge of techniques efficient in the cleanness of these sites is more and more important. With this, the present work through the bioremediation technique searched to establish which the best treatment for the removal of contaminantes of light oil in sandy ground. For in such a way, two experiments had been carried through (I and II), where in the first one if it studied the efficiency of removal of the contaminantes for the use of three distinct treatments of biostimulation (addition of nutrients (C), biosurfactant addition (D), addition of biosurfactant and nutrient (E)), which the two controls had been compared, one of soil (a) and another one of natural attenuation of oil (B). The other experiment served to verify the efficiency of the used biosurfactant, being used a control of soil (F), a control of natural attenuation of oil (G), a treatment with biosurfactant/nutrients (H) and another with biosurfactant sterile/nutrients (I). To the end of six months of study it can be verified that treatments C and E had presented the best ones resulted for OG, with rates of removal of 90,4 and 78% respectively. How much the Aliphatics and HPAs these had also been the best treatments with rates of removal of 96,82 and 98,35% for aliphatics and 83,58 and 72.3% for HPAs respectively. Already in relation to experiment II, it can be concluded that it doesn’t have differences how much to the use of the sterile or not sterile biosurfactant, however sends regards use to it of the biosurfactant sterile a time that of this form doesn’t have the introduction of strange microorganisms to the environment.
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Thornton, R. C. "Sediment-associated nutrients and their contribution to the nutrient loads of Devon catchments". Thesis, University of Exeter, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.354030.
Testo completo
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Ferreira, Francisco Jardelson. "Fertilization rose bushes based on nutrient balance in the soil - plant system". Universidade Federal do CearÃ, 2016. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=17134.
Testo completoAbstract (sommario):
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgicoRose is an economically important crop for the national and the international market and due to this fact generates income to the Ceara State. Rose is a demanding crop in relation to fertilizers, requiring knowledge of soil fertility, nutritional plant requirements and nutrients use efficiency to obtain adequate fertilization. Based on the nutritional balance through the use of mechanistic and empirical models, it is possible to develop a system to quantify the plant nutrients demands to achieve a given productivity. This paper aims to establish parameters of a fertilizer and lime recommendation system to rose crop, based on the plant nutritional balance. The experiment was conducted at the company Cearosa in SÃo Benedito - CE. Plants will be collected during five months and once a month, five rose plants from four varieties (Top Secret, Avalanche, Attache and Ambience) As contradictory Airlines plants Were grinded. Samples will be ground and nutrients content will be determined: N, P, K, Ca, Mg, S, B, Fe, Mn, e Zn. Every sampling plant time, were also soil samples collected at two depths (0-20 and 20-40 cm) In which they underwent fertility analysis. To estimate the fertilizer recommendation, the system was be subdivided into requirement subsystem (REQ), which includes the plant nutrients demands, considering the recovery efficiency of the nutrients to be applied and a rate to achieve the "sustainability" criteria and the supply subsystem (SUP) that comprises the soil nutrient supply. After determining the total REQ and SUP, held -if the nutritional balance, and if the result is positive (REQ> SUP), fertilizers application is recommended and if the result negative or zero (REQ ≤ SUP), fertilizers application is not recommended. The system estimated that there is excess nitrogen and phosphorus fertilization for all cultivars , however , there needs to be supplemental potassium fertilizer . The system estimated that the soil is able to meet the demand of plants for P and Fe for all cultivars , however , there must be supplementary nitrogen fertilizer , potassium . As for micronutrients , the system estimated that there is need for additional fertilizer for Zn in all rosebushes and Mn for the rosebushes "Top Secret " and " Avalnche " , however with very close recommendation the optimal dose , ie equal to zero
A roseira à uma cultura de grande valor no mercado interno e externo, devido a esse fato, as rosas geram benefÃcios para o estado do CearÃ. à uma cultura muito exigente em relaÃÃo à adubaÃÃo, sendo necessÃrios conhecimentos da fertilidade do solo, exigÃncias nutricionais da planta e eficiÃncia na utilizaÃÃo de nutrientes, para obtenÃÃo de uma adubaÃÃo adequada. Partindo a hipÃtese de que conhecendo-se o balanÃo nutricional da cultura, levando-se em consideraÃÃo a demanda de nutrientes pela cultura para alcanÃar uma dada produtividade e o suprimento de nutrientes pelo solo, à possÃvel determinar a quantidade de nutrientes a ser adicionada na fertilizaÃÃo do solo. O presente trabalho tem como objetivo determinar com base no balanÃo de nutrientes solo-planta a quantidade de nutrientes a ser adicionada no solo para cultura da roseira. O experimento foi conduzido na empresa Cearosa, em SÃo Benedito - CE, as plantas foram coletadas durante cinco meses, sendo uma vez por mÃs, amostrando cinco plantas aleatÃrias, de quatro cultivares de rosas: (Top Secret, Avalanche, Attache e Ambience). As partes aÃreas das plantas foram moÃdas e mineralizadas para determinaÃÃo dos teores dos nutrientes: N, P, K, Ca, Mg, S, B, Fe, Mn e Zn. Simultaneamente a coleta de plantas, tambÃm foram coletadas amostras de solo em duas profundidades, camada de 0 a 20 e de 20 a 40cm. Na qual foram submetidas à anÃlise de fertilidade. Para estimar a recomendaÃÃo de adubaÃÃo o sistema foi subdividido em: subsistema requerimento (REQ), que contempla a demanda de nutrientes pela planta, considerando a eficiÃncia de recuperaÃÃo dos nutrientes a serem aplicados, alÃm de uma dose que atende ao critÃrio de âsustentabilidadeâ e o subsistema suprimento (SUP), que corresponde à oferta de nutrientes pelo solo. ApÃs a determinaÃÃo do REQ total e SUP total, realizou -se o balanÃo nutricional, no qual se apresentar resultado positivo (REQ > SUP), recomenda-se a aplicaÃÃo de fertilizantes, e negativo ou nulo (REQ ≤ SUP), nÃo serà recomendado aplicar fertilizantes. O sistema estimou que o solo à capaz de suprir a demanda das plantas para P e Fe para todas as cultivares, no entanto, à necessÃrio que haja complementaÃÃo de adubaÃÃo nitrogenada, potÃssica. Assim como para os micronutrientes, o sistema estimou que hà necessidade de complementaÃÃo de adubaÃÃo, para Zn em todas as roseiras e Mn para as roseiras âTop secretâ e âAvalncheâ, no entanto com a recomendaÃÃo bem prÃximos a dose ideal, ou seja, igual a zero
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Viera, Márcio. "DINÂMICA NUTRICIONAL EM UM POVOAMENTO HÍBRIDO DE Eucalyptus urophylla x Eucalyptus globulus EM ELDORADO DO SUL-RS, BRASIL". Universidade Federal de Santa Maria, 2012. http://repositorio.ufsm.br/handle/1/3743.
Testo completoAbstract (sommario):
Conselho Nacional de Desenvolvimento Científico e TecnológicoUnderstanding of the involved issues in nutritional dynamics process in eucalyptus stands is the base to sustainable management. Objective this study was to determine the nutritional dynamic in Eucalyptus urophylla x Eucalyptus globulus stand, Eldorado do Sul - RS. For this, was available: a) litter production (leaves, twigs diameter ≤ 1.0 cm, miscellaneous and thick branches diameter > 1.0cm) and nutrients uptake, from 6.5 to 9.5 years-old stand (2007 at 2010); b) leaf litter decomposition and nutrients release by litterbags method (adding 12g of dried leaves in nylon bags), for three years (2007 to 2009); c) aboveground biomass and nutrients amount in the eucalyptus (wood, bark, branches and leaves) and underground (wood and leaves) to ten-year-old stand (June 2010); d) interfere of different intensities of biomass removal (all aboveground biomass removal eucalyptus + underground; eucalyptus removal; wood with bark removal and only wood removal) in relation nutrients stock and; - silvicultural alternative for sustainable forestry management. Litter production was increasing with stand age increasing, showing seasonal behavior with deposition increasing with the air temperature increasing and being mainly composed by leaves fraction that also is main fraction nutrients return through litter. Accumulated litter showed decomposition coefficient of 0.54 with 1.86 years how time average renewal and 1.29 and 5.59 years to disappear 50 and 95% of the litter. Mass loss leaf showed positive correlation with nutrients concentration, indicating that the higher mass loss, higher the nutrients concentration in litter remaining. Litter leaf decay initially showed P, Fe, Mn and Zn immobilization and release of the others, in the second year occurred P release and in the third year occurred Mn and Zn release, with Fe exception. Eucalyptus biomass was allocated predominantly to stem (Wood + bark) with 93.7% and with the largest nutrients stock. Biomass components had different chemical composition, being generally higher in leaves and bark and smaller in wood and branches biomass. With the harvest of wood with the bark all the nutrients removal would suffer more than 45% of the total amount accumulated in aboveground biomass. However, removed just the wood, which has the highest nutrients utilization rate, the nutrients removed percentage, except by Cu and Zn, will be less than 50% and up to 10% in the case of Ca in relation the total biomass contained. Phosphorus and calcium can be the main nutrients became limiting in next rotation productivity, because the potential rotation estimates are close to one, when in the harvest of wood with the bark. Nutrients output through forestry harvest must be take account by companies during the planning of activities. Avoiding productivity decreasing with the next rotations, and also contributing sustainable management, because the nutrients exportation, Ca mainly, is high due to wood with bark harvest.
O entendimento dos aspectos envolvidos no processo da dinâmica nutricional em povoamentos de eucaliptos é a base para um manejo sustentável. O objetivo deste estudo foi determinar a dinâmica nutricional em um povoamento híbrido de Eucalyptus urophylla x Eucalyptus globulus em Eldorado do Sul RS, com dez anos de idade. Para isso, foi avaliado: a) a produção de serapilheira (folhas, galhos finos diâmetro ≤ 1,0 cm, miscelânea e galhos grossos diâmetro > 1,0 cm) e o aporte de nutrientes, dos 6,5 aos 9,5 anos de idade do povoamento (2007 a 2010); b) a decomposição da serapilheira foliar e liberação de nutrientes pelo método de litterbags (adição de 12g de folhas secas recém caídas em bolsas de naylon), durante três anos (2007 a 2009); c) o estoque de biomassa e nutrientes no eucalipto (madeira, casca, galhos e folhas) e sub-bosque (lenho e folhas) aos dez anos de idade do povoamento (junho de 2011); d) a influência de diferentes intensidades de remoção da biomassa (retirada de toda a biomassa eucalipto + sub-bosque; retirada de toda a biomassa de eucalipto; retirada da madeira com a casca e retirada apenas da madeira) sobre o estoque de nutrientes e; e) alternativas silviculturais para um manejo florestal sustentável. A produção de serapilheira foi crescente com o aumento da idade do povoamento, apresentando comportamento sazonal com maior deposição no período de aumento da temperatura do ar e sendo composta predominantemente pela fração folhas, que também é a responsável por maior parte do retorno de nutrientes via serapilheira. A serapilheira acumulada apresentou coeficiente de decomposição de 0,54 com tempo médio para a renovação de 1,86 anos e tempo médio para decomposição de 50 e 95% da serapilheira em 1,29 e 5,59 anos, respectivamente. A perda de massa foliar apresentou correlação positiva com a concentração de nutrientes, indicando que quanto maior a perda de massa, maior a concentração dos elementos no folhedo remanescente. A decomposição da serapilheira foliar apresentou inicialmente imobilização do P, Fe, Mn e Zn e disponibilização dos demais, a partir do segundo ano o P tornou-se disponível e a partir do terceiro ano o Mn e Zn também se tornaram disponíveis, com exceção do Fe. A biomassa do eucalipto encontra-se predominantemente alocada no fuste (madeira + casca) com 93,7% e com os maiores estoques de nutrientes. Os componentes da biomassa apresentaram composições químicas distintas, sendo geralmente maiores nas folhas e casca e menores nos componentes madeira e galhos. Com a colheita da madeira com casca todos os nutrientes sofreriam remoção superior a 45% de sua quantidade acumulada na biomassa total acima do solo. Entretanto, removendo apenas a madeira comercial, que apresenta o maior coeficiente de utilização de nutrientes, a porcentagem de remoção para os nutrientes, com exceção ao Cu e Zn, seria inferior a 50% e chegando até 10% no caso do Ca em relação ao total contido na biomassa. O fósforo e o cálcio poderão ser os principais nutrientes a tornarem-se limitantes na produtividade nas próximas rotações, pois as estimativas de rotações estão próximas a um, quando da colheita da madeira com casca. A saída de nutrientes do sítio via colheita florestal deve ser um componente levado em consideração por parte das empresas, durante o planejamento das atividades, e assim evitando que haja diminuição de produtividade nas próximas rotações e contribuindo para o manejo sustentável, pois a exportação de nutrientes, principalmente do Ca, é elevado devido à colheita da madeira com casca.
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Smiyanov, Nikita. "Nutrients spreading with cloudburst modeling". Thesis, KTH, Hållbar utveckling, miljövetenskap och teknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-287367.
Testo completoAbstract (sommario):
Climate change and environmental disasters are strongly dependent. Humanity is facing considerable changes in environmental adaptions and remediation of contaminated sites. Water is a valuable resource that should be protected and prevented from hazardous influences. One of the main water quality problems is the excess of nutrients causing algae blooming. Many surface-and groundwaters have lost the ability to be used as anthropogenic water sources and other purposes (recreation, water supply, irrigation, etc.). Both nutrients and other substances impact water quality and climate change, making it challenging for modern society to maintain good water quality. Moreover, extreme rainfalls become more common, temporarily increasing surface runoff and exceeding infiltration capacity during high-intensity rainfall events. Water that is not capable of infiltration in the soil will run on the watershed into depressions and be infiltrated or spread to downstream catchments. This water might contain hazardous substances, e.g., nutrients, thereby enhancing water contamination in nearby waters. The investigation is made in how nutrients (P – phosphorus and N – nitrogen) spread depending on surface runoff from cloudburst in Hörby municipality in southern Sweden, Skåne-region. The land-use of the site is investigated, where pervious-and impervious areas are defined and further classified in more specific sub-groups. Different rain returns periods used to provide clear explanation of how the nutrient spreading is taking place and how rain intensity is impacting spreading of N and P. Furthermore, the sources of nutrient load are detected and investigated with a hydraulic model. The results show that the hydrodynamic model can be used to visualize the spread and determine the accumulated concentration in the flood area. Furthermore, rainfall mapping has been carried out to identify vulnerable areas in the landscape and determine critical parameters such as distribution and maximum water depth. The method's application area has been discussed in the industry's interest in studying cloudburst more simply and cost- effectively in parallel with nutritional load problems.Klimatförändringar och miljökatastrofer är starkt beroende händelser. Mänskligheten står inför betydande förändringar i miljöanpassningar och sanering av förorenade platser. Vatten är en värdefull resurs som bör skyddas och förhindras från farlig påverkan. Ett av de viktigaste vattenkvalitetsproblemen är överflödet av näringsämnen som orsakar alger som blommar. Många yt- och grundvattenkällor har förlorat förmågan att nyttjas som dricksvattenkällor samt källor för andra ändamål (rekreation, vattenförsörjning, bevattning etc.). Både näringsämnena och andra kemikalietyper påverkar vattenkvaliteten och klimatförändringarna, vilket gör det utmanande för det moderna samhället att upprätthålla god vattenkvalitet. Dessutom blir extrema regn i form av skyfall vanligare och ökning i avrinning från ytor som överstiger infiltrationskapaciteten under högintensiva regnhändelser. Vatten som inte kan infiltrera i marken kommer att rinna längst avrinningsområdet till låga punkter och infiltreras eller spridas till nedströms avrinningsområden. Den rinnande vatten kan innehålla farliga ämnen, t.ex. näringsämnen, vilket kan bidra till ökade föroreningar i närliggande vattendrag. Undersökningen görs i hur näringsämnen (P - fosfor och N - kväve) sprids beroende på ytavrinning från skyfall i Hörby kommun, Skåne, i södra Sverige. Områdets markanvändning undersöks, där genomträngliga och ogenomträngliga ytor definieras och klassificeras ytterligare i mer specifika undergrupper. Olika återkomsttider på regn används för att ge en förklaring på hur närsaltsspridningen sker och hur regnintensiteten påverkar spridningen av fosfor och kväve. Vidare upptäcks och undersöks källorna för näringsbelastning med en hydraulisk modell. Resultaten visar att den hydrodynamiska modellen kan användas för att visualisera spridningen och bestämma den ackumulerade näringsbelastningen i översvämningsområdet. Dessutom har skyfallskartering genomförts för att identifiera utsatta områden i landskapet och bestämma kritiska parametrar som fördelning och maximalt vattendjup. Metodens applikationsområde har diskuterats av kommersiellt intresse i att studera skyfall på ett enkelt och kostnadseffektivt sätt parallellt med närsaltsbelastningen.
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Muskolus, Andreas. "Anthropogenic plant nutrients as fertiliser". Doctoral thesis, Humboldt-Universität zu Berlin, Landwirtschaftlich-Gärtnerische Fakultät, 2008. http://dx.doi.org/10.18452/15774.
Testo completoAbstract (sommario):
Nachhaltige Landbewirtschaftung impliziert ausgeglichene Pflanzennährstoffflüsse ohne die Abhängigkeit von Düngern aus nicht erneuerbaren Quellen. Stickstoff, Phosphor und Kalium aus der menschlichen Nahrung werden in Mitteleuropa im Allgemeinen in Schwemmkanalisationen gesammelt und dabei mit Schadstoffen vermengt. Neuartige stoffstromtrennende Sanitärsysteme ermöglichen die Bereitstellung von Humanurin und Fäkalien zur Verwendung als Düngemittel. In der vorliegenden Arbeit wurden praxisrelevante Aspekte der Verwendung von Düngemitteln anthropogener Herkunft untersucht. Die in Gefäß- und Feldversuchen in Berlin Dahlem ermittelte Ertragswirkung zeigte, dass Urin in dieser Hinsicht äquivalenten Mineraldüngern grundsätzlich gleichwertig ist. Bei sehr hohen Konzentrationen kam es abhängig von der Pflanzenart zu Depressionseffekten, welche vermutlich auf den Salz- und Ammoniumgehalt von Urin zurückzuführen sind. Unter Freilandbedingungen traten diese Effekte nicht auf. Bodenbiologische Auswirkungen von Düngerapplikationen sind entscheidend für die Abschätzung ihrer langfristigen Bodenfruchtbarkeitserhaltung. Sowohl in Labor-versuchen als auch im Freiland zeigten sich Regenwürmer durch menschlichen Urin aus Trenntoiletten deutlich beeinträchtigt. Die Ursache der Schädigung konnte nicht geklärt werden. Von einer langfristigen bodenfruchtbarkeitsreduzierenden Beein-trächtigung wird jedoch nicht ausgegangen. Mikrobielle Enzymaktivitäten im Boden wurden im Freiland durch Urinapplikation nicht beeinflusst. Für die Praxis wird empfohlen Urin während der Ausbringung einzuarbeiten, da die Tiere dann weniger mit der Flüssigkeit in Kontakt kommen. Da es ein umweltpolitisches Ziel ist, die Ammoniakemissionen der Landwirtschaft zu minimieren, wurden diese nach der Urinausbringung im Freiland gemessen. Auf Grund der sehr geringen Trockensubstanzgehalte von Humanurin emittierte deutlich weniger NH3 als üblicherweise nach Ausbringung von Schweine- oder Rindergülle. Verbraucherumfragen bestätigten eine hohe Bereitschaft pflanzliche Nahrung, welche mit Urin als Dünger erzeugt wurde, zu kaufen und zu verzehren. Praktizierende Landwirte reagierten dagegen deutlich reservierter. Die Ausbringung von Urin aus Trenntoiletten kann im Sinne einer nachhaltigen Landwirtschaft grundsätzlich empfohlen werden. Es besteht aber weiterer Forschungsbedarf.Sustainable agriculture implies balanced nutrient flows and independence from fertiliser made from non renewable resources. In Europe, plant nutrients excreted by humans are commonly collected in water borne sewage systems and thus mixed with potentially harmful substances. Novel segregating sanitation techniques can collect separated urine and faeces in a form which enables their use as fertiliser. In the presented thesis selected aspects concerning the use of anthropogenic plant nutrients relevant to farming were investigated. Pot and field experiments indicated that equal yields can be gained if urine instead of mineral fertiliser is applied. Very high concentrations of urine led to reduced growth, presumably caused by the presence of ammonium or salt. However, this was not found under field conditions. Soil biological effects caused by the application of a fertiliser must be considered when assessing its long term contribution to soil fertility. Laboratory experiments as well as field investigations showed that human urine application severely affects earthworms, however, the harmful components were not identified. The results suggest that the effect is of short term only. Soil microbial enzyme activities were not influenced by urine fertiliser. For farming practice it is recommended to inject or incorporate urine to prevent earthworms from coming into direct contact with the infiltrating fertiliser. Gaseous ammonia loss was measured after urine application on fields as reducing harmful emissions from agriculture is a goal of European environmental policy. Because of the very low Dry Matter contents of urine, far less ammonia was emitted to the atmosphere than usually occurs after application of cattle or pig slurry. A consumer acceptance study showed a general high public willingness to accept urine as fertiliser even if used on crops for food production. The reaction of farmers was mainly reserved as a result of the present legal regulations in Germany. Within the context of sustainable agriculture the use of human urine as fertiliser can be recommended. Further research is necessary, especially concerning any effects resulting from residues of pharmaceutical substances contained in human excreta.
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Rose, Christopher. "Developing a nutrient recovery process for recovering nutrients in anaerobic digestate in low income countries". Thesis, Cranfield University, 2015. http://dspace.lib.cranfield.ac.uk/handle/1826/9984.
Testo completoAbstract (sommario):
It is estimated that 2.7 billion people worldwide are served by on-site sanitation facilities that require faecal sludge management. Anaerobic digestion is a treatment mechanism that can provide faecal sludge management, methane production and an effluent digestate rich in nutrients. However, there is a paucity of information regarding the composition of the input faecal sludge which hinders the advancement of anaerobic digestion treatment and downstream nutrient recovery together with a lack of knowledge as to how best to recover these output nutrients in a simple process. Following an initial review to collate composition data for fresh faeces and urine, practical studies examined the physical, biological and chemical composition and variation of four different types of faecal sludge from on-site sanitation facilities. Faecal sludge storage strongly influenced the biodegradability and methane production potential in subsequent anaerobic digestion. However, the high concentrations of ammonium observed in faecal sludge (520-1853 mg NH4-N L- 1 ) were highlighted as a key goal for nutrient recovery and the ability of biochar and clinoptilolite as natural adsorbents for ammonium recovery in a drying bed application were investigated through batch and dynamic studies using synthetic and real digestate. Batch tests observed ammonium uptake of 5 and 12.2 mg NH4-N/g for biochar and clinoptilolite respectively whilst under dynamic experimental conditions the most efficient operation for ammonium recovery was at the longest empty bed contact times (354 minutes), ensuring the maximum fertiliser value was obtained (60g NH4-N/kg clinoptilolite). Nevertheless, clogging occurred rapidly at the surface of the media bed (0.04 – 0.5 kg TS/m2 ), consequently a sacrificial sand layer (0.05 m) was included to increase the longevity of the nutrient recovery system (15 fold increase in TS application rates). It has been demonstrated that clinoptilolite can effectively be used as part of a sludge drying bed configuration to recover nutrients from digestate and the saturated media can be used directly as a fertiliser product or blended with the dried sludge to create a balanced nitrogen, phosphorus and potassium fertiliser product (5.9% NH4-N/ 4.2% P/ ≥6.0% K+ ).
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Giménez, Grau Pau. "Nutrients and algal growth in the oligotrophy: a field experimental approach in mountain lakes = Nutrients i creixement algal en la oligotròfia: una aproximació experimental de camp en estanys de muntanya". Doctoral thesis, Universitat de Barcelona, 2016. http://hdl.handle.net/10803/402582.
Testo completoAbstract (sommario):
The main objectives of this dissertation were (a) to determine the effects of nitrogen (N) and phosphorus (P) fertilization on the growth of microalgal groups of periphyton and phytoplankton, and (b) to evaluate some indicators of the regulatory processes (e.g. N:P content, chlorophyll content per biovolume) involved in such growth responses. To do so, we followed a field experimental approach of short-term nutrient enrichments (21-25 days), using nutrient-diffusing substrates in the case of epilithic periphyton (Chapter 1), and mesocosms in the case of phytoplankton (Chapter 2 and 3). These experiments were performed in lakes of the Pyrenees, a region of particular interest because the average conditions are just on the threshold between the N and P limitation of algal growth. Moreover, most of these lakes are oligotrophic, and the nutrient availability is highly conditioned by N and P inputs of atmospheric origin, which appears to be changing due to human activities and global change.
In the first chapter, we evaluated the influence of the main factors controlling the algal colonization of epilithic periphyton, and compared the differences between the two major algal groups (i.e. diatoms and chlorophytes). We selected nine lakes and two streams to account for environmental gradients of trophic status and water renewal, while the influence of N and P availability was evaluated in each location using nutrient-diffusing substrata. Water renewal had a significant positive effect on the algal colonization of epilithic periphyton, although this influence was only significant for diatoms. Lake trophic status (i.e. dissolved organic carbon) was the second most influential factor in the algal colonization, and similarly affected diatoms and chlorophytes. High N:P availability tended to favour chlorophytes over diatoms. The nutrient enrichments inhibited the growth of diatoms -particularly the N enrichments-, but this adverse effects were mitigated by high water currents. Chlorophytes better tolerated high nutrient levels than diatoms.
The second chapter aimed to assess the influence of nutrient availability on the productivity, the composition of major phytoplankton groups, and the C:N:P proportions in seston, and evaluate the interrelationships among them. We noticed that the response of productivity, community structure, and seston C:N:P to increasing P availability was not strictly coherent. Productivity was especially sensitive to low and intermediate P additions, while seston C:N:P was only markedly changed under high P supply. The highest P-enrichment lead the seston C:N:P toward Redfield proportions in a non-linear way. N excess conditions reduced the growth of phytoplankton and enhanced the differentiation of autotrophic community, but did not affect seston C:N:P. High ammonium availability tended to increase seston C:P and N:P ratios, as well as to stimulate productivity and alter phytoplankton structure when P stress diminished.
Finally, we evaluated the relationships among nutrient availability, growth, and chlorophyll content per biovolume in phytoplankton. Specifically, we evaluated to what extent intense growth is associated with high chlorophyll content or with a major plasticity of that content. Pigments content and their plasticity were determined for all algal groups estimating power-law based models. We observed that diatoms and chlorophytes were the two groups that showed the highest growth capacity, what could be associated with their ability to increase the chlorophyll content per biovolume when nutrient supply increases. Chrysophyceans and dinoflagellates achieved their maximum growth rates at relatively low P supply, and may be better adapted to cope with low P availability.Els principals objectius d’aquesta tesi han estat els de (a) determinar els efectes de la fertilització de nitrogen (N) i fòsfor (P) sobre el creixement dels grups algals del perífiton i del fitoplàncton, i (b) avaluar la influència d’alguns processos reguladors (p.ex. contingut de N:P, contingut de clorofil·la per biovolum) involucrats en les respostes del creixement. S’ha seguit una aproximació experimental de camp basada en la utilització de substrats difusors de nutrients en el cas del perífiton (Capítol 1), i en l’addició de nutrients a mesocosms en el cas del fitoplàncton (Capítol 2 i 3). En el primer capítol es va avaluar la influència dels factors que controlen la colonització del perífiton per part de les diatomees i dels cloròfits. La renovació de l’aigua i l’estat tròfic (DOC) van tenir un efecte positiu en la colonització algal. L’alta disponibilitat de N en relació a P va tendir a afavorir els cloròfits per sobre de les diatomees. Les addicions de nutrients (sobretot de N) van resultar perjudicials pel creixement de les diatomees en molts casos, mentre que els cloròfits van tolerar millor aquestes altes concentracions. En el segon capítol es van observar diferents pautes de resposta de la producció, l’estructura de la comunitat i la composició C:N:P del seston a diferents enriquiments amb P. La producció primària va augmentar considerablement a addicions baixes i mitjanes de P, mentre que les proporcions C:N:P del seston només van canviar de forma marcada -dirigint-se cap a “Redfield”- a altes addicions de P. Les condicions d’excés de N van reduir el creixement del fitoplàncton però no van afectar les proporcions C:N:P. Finalment es van avaluar les relacions entre disponibilitat de nutrients, creixement i contingut de clorofil·la per biovolum en el fitoplàncton. Les diatomees i els cloròfits van demostrar tenir les capacitats de creixement més altes, i això podria estar associat amb la seva habilitat d’incrementar el contingut de clorofil·la quan la disponibilitat de nutrients augmenta. Les crisofícies i les dinofícies van assolir les màximes taxes de creixement a concentracions de P comparativament baixes, indicant que estarien més ben adaptades a baixes disponibilitats de nutrients.
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Pistori, Raquel Eduarda Trevisan. "Crescimento das macrófitas aquáticas flutuantes Eichhornia crassipes (Mart.) Solms, Pistia stratiotes L. e Salvinia molesta (Mitchell) em diferentes concentrações de nutrientes /". Jaboticabal : [s.n.], 2009. http://hdl.handle.net/11449/100244.
Testo completoAbstract (sommario):
Resumo: Esta tese esta organizada em dois capítulos. O capítulo I testou a hipótese de que o crescimento de Eichhornia crassipes, Pistia stratiotes e Salvinia molesta esta relacionado com a absorção de fosfato e de nitrogênio. Foi avaliado o efeito de diferentes concentrações de nutrientes sobre a taxa de crescimento e de absorção de ortofosfato (PPO4) e nitrogênio inorgânico total (NIT) em E. crassipes, P. stratiotes e S. molesta. As três espécies, quando cultivadas em baixa concentração de nutrientes apresentaram as maiores taxas de absorção tanto de P-PO4 quanto de NIT no período entre 0-5 dias, diferente do que ocorreu quando cultivadas em alta concentração, na qual as maiores taxas de absorção do P-PO4 ocorreram no período entre 0-5 dias e as maiores taxas de absorção de NIT para P. stratiotes ocorreram no período entre 5-10 dias e para E. crassipes e S. molesta no período entre 10-15 dias. Em baixa concentração, S. molesta obteve um ganho de massa 12,8 vezes menor que E. crassipes e 1,3 vezes menor que P. stratiotes e sua taxa de absorção de PPO4 no mesmo período foi semelhante a de E. crassipes e P. stratiotes. Padrão semelhante também foi observado em alta concentração, entretanto, apesar de apresentar maior taxa de absorção, S. molesta foi a espécie menos eficiente na remoção de nutrientes e a que menos estocou N e P, devido ao menor ganho de biomassa. E. crassipes e P. stratiotes apresentam crescimento vertical, o que favorece o maior ganho de biomassa e conseqüentemente maior taxa de remoção de nutrientes e estoque de N e P em sua biomassa. Os resultados permitem concluir que na aplicação para tratamento em wetlands, S. molesta, apesar de apresentar maior taxa de absorção pode ser menos eficiente. O capítulo II teve como objetivo testar o efeito de diferentes concentrações de fosfato na água sobre o crescimento e a composição química... (Resumo completo, clicar acesso eletrônico abaixo)Abstract: The thesis is organized in two chapters. The first chapter tested the hypothesis that the growth of Eichhornia crassipes, Pistia stratiotes and Salvinia molesta is related with the absorption of phosphate and nitrogen. It was studied the effect of different nutrient concentrations on the growth rate and orthophosphate (P-PO4) and total inorganic nitrogen (NIT) absorption rate in E. crassipes, P. stratiotes and S. molesta. The three species cultivated in low nutrient concentrations showed the highest absorption rate of P-PO4 and NIT between 0- 5 days. In high nutrient concentrations the highest absorption rate of P-PO4 for all species occurred between 0-5 days and the highest rate of absorption of NIT for P. stratiotes occurred between 5-10 days and for E. crassipes and S. molesta occurred between 10-15 days. The gain of mass of S. molesta in low concentration was 12.8 times minor than E. crassipes and 1.3 times minor then P. stratiotes and absorption rate in the same period were similar for the tree species. A similar pattern was observed in high concentration of nutrients. However, S. molesta have lower efficiency to absorb nutrients and have lower stock of N and P, due to the minor gain of biomass. E. crassipes and P. stratiotes showed vertical growth that provided high gain of biomass and consequently high uptake of nutrients and stock of N and P in the biomass. We concluded that S. molesta have lower efficiency in wetlands to treat effluents. In the chapter II we investigate the effect of different concentrations of phosphate in the water on the growth and the chemical composition of E. crassipes, P. stratiotes and S. molesta. The fully randomized experiment (4 treatment and 3 replicates) was conducted in the laboratory. The PPO4 concentration was different on the 4 treatment (< 0.005; 0.031; 0.31; 3.1 mg.L-1). The constant derivates from Michaelis Menten model that defined... (Complete abstract click electronic access below)
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Libri sul tema "Nutrients"
1
Miransari, Mohammad. Soil nutrients. Hauppauge, N.Y: Nova Science Publishers, 2011.
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Naeem, M., Abid A. Ansari e Sarvajeet Singh Gill, a cura di. Essential Plant Nutrients. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-58841-4.
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Maathuis, Frans J. M., a cura di. Plant Mineral Nutrients. Totowa, NJ: Humana Press, 2013. http://dx.doi.org/10.1007/978-1-62703-152-3.
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Neves, Delminda, a cura di. Anti-ageing nutrients. Chichester, UK: John Wiley & Sons, Ltd, 2015. http://dx.doi.org/10.1002/9781118823408.
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Clouatre, Dallas. Anti-fat nutrients. 2a ed. San Francisco, CA: Pax Pub., 1993.
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6
Greer, Rita. The nutrients guide. London: Dent, 1985.
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Sang-Woon, Choi, e Friso Simonetta, a cura di. Nutrients and epigenetics. Boca Raton: Taylor & Francis, 2009.
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Koch, Marguerite S. Soil and surface water nutrients in the Everglades nutrient removal project. West Palm Beach: Environmental Sciences Division, Research and Evaluation Dept., South Florida Water Management District, 1991.
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Prasad, Kedar N., e Frank L. Meyskens, a cura di. Nutrients and Cancer Prevention. Totowa, NJ: Humana Press, 1990. http://dx.doi.org/10.1007/978-1-4612-4516-2.
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Poirier, Lionel A., Paul M. Newberne e Michael W. Pariza, a cura di. Essential Nutrients in Carcinogenesis. Boston, MA: Springer US, 1987. http://dx.doi.org/10.1007/978-1-4613-1835-4.
Testo completoCapitoli di libri sul tema "Nutrients"
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Collinson, A. S. "Nutrients and nutrient cycles". In Introduction to World Vegetation, 84–110. Dordrecht: Springer Netherlands, 1988. http://dx.doi.org/10.1007/978-94-015-3935-7_4.
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Ronco, Alvaro Luis, e Eduardo De Stéfani. "Nutrients". In Nutritional Epidemiology of Breast Cancer, 35–51. Dordrecht: Springer Netherlands, 2011. http://dx.doi.org/10.1007/978-94-007-2397-9_4.
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Brandes, J. A. "Nutrients". In Encyclopedia of Earth Sciences Series, 1–3. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-39193-9_151-1.
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Brandes, J. A. "Nutrients". In Encyclopedia of Earth Sciences Series, 1019–21. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-39312-4_151.
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Rocha, Carlos, e Malcolm Woodward. "Nutrients". In Chemical Marine Monitoring, 197–221. Chichester, UK: John Wiley & Sons, Ltd, 2012. http://dx.doi.org/10.1002/9781119990826.ch7.
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Montes, Manuel Flores. "Nutrients". In Encyclopedia of Estuaries, 464–66. Dordrecht: Springer Netherlands, 2015. http://dx.doi.org/10.1007/978-94-017-8801-4_168.
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Bala, Renu. "Nutrients". In Encyclopedia of Animal Cognition and Behavior, 1–4. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-319-47829-6_1099-1.
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Bala, Renu. "Nutrients". In Encyclopedia of Animal Cognition and Behavior, 4707–10. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-319-55065-7_1099.
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Schwarz, Meier. "Nutrients". In Advanced Series in Agricultural Sciences, 7–32. Berlin, Heidelberg: Springer Berlin Heidelberg, 1995. http://dx.doi.org/10.1007/978-3-642-79093-5_3.
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Boyd, Claude E. "Soil Nutrients". In Bottom Soils, Sediment, and Pond Aquaculture, 69–112. Boston, MA: Springer US, 1995. http://dx.doi.org/10.1007/978-1-4615-1785-6_3.
Testo completoAtti di convegni sul tema "Nutrients"
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"Performance analysis of chicken manure coated slow-release urea fertilizer (CM-CSRUF)". In Sustainable Processes and Clean Energy Transition. Materials Research Forum LLC, 2023. http://dx.doi.org/10.21741/9781644902516-11.
Testo completoAbstract (sommario):
Abstract. Slow-release fertilizers (SRFs) are developed, to halt the nutrient loss to the environment, either by coating the urea or by infusing the urea in a hydrophobic material. SRFs reduces the nutrient release to that point where a single application of fertilizer can meet the nutrient demand of the plants. Diverse range of materials have already been utilized to produce SRFs, however several disadvantages such hydrophilicity, non-biodegradability and crystallinity limit their scale up. Herein, we reported the production of coating of urea using chicken manure with paraffin wax as a binder. Nitrogen release test of the coated urea revealed that only 11.8% of total nutrients were released in first 12 h whereas uncoated urea released ≥99.9 % nutrients. Ritger-Peppas model was found to best fit the nutrient release kinetic data with an R2 value of 0.97.
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Huang, Chun-Yuh, e Wei Yong Gu. "Effects of Compression on Distributions of Oxygen and Lactate in Intervertebral Disc". In ASME 2007 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2007. http://dx.doi.org/10.1115/sbc2007-176025.
Testo completoAbstract (sommario):
Since the intervertebral disc (IVD) is the largest avascular cartilaginous structure in the human body, poor nutrient supply has been suggested as a potential mechanism for disc degeneration. The previous theoretical studies have shown that the distributions of nutrients and metabolites (e.g., oxygen, glucose, and lactate) within the IVD depended on tissue diffusivities, nutrient supply, cellular metabolic rates, and coupling effects between nutrient and metabolite [1,2]. Our recent theoretical study suggested that dynamic compression can promote transport of neutral solute in the anisotropic cartilaginous tissue by enhancing both diffusive and convective solute fluxes [3]. However, the effect of compression on distributions of nutrients and metabolites in the IVD has not been studied. The objective of this study was to examine the effects of compression on distributions of oxygen and lactate in the IVD under static and dynamic unconfined compression using a new formulation of the triphasic theory.
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Birch, David G., Eileen E. Birch e Ricardo D. Uauy. "ERGs and VEPs in Very Low Birth Weight (VLBW) Infants". In Noninvasive Assessment of the Visual System. Washington, D.C.: Optica Publishing Group, 1988. http://dx.doi.org/10.1364/navs.1988.wb2.
Testo completoAbstract (sommario):
The survival rate for very low birth weight (VLBW) infants has risen dramatically over recent years. With increased viability has come increased attention to the role of specific nutrients as causative factors for complex multifactorial syndromes such as cerebral palsy. In certain cases, the role of specific nutrients in brain development has been established. Taurine, for example, is an essential nutrient necessary for normal visual development in VLBW infants (1,2). Based on this knowledge, nutritional practices have been modified to assure an adequate taurine intake for formula-fed infants (3).
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Asahi, Toshimasa, Toshimasa Asahi, Kazuhiko Ichimi, Kazuhiko Ichimi, Kuninao Tada e Kuninao Tada. "NUTRIENT DYNAMICS IN EELGRASS (ZOSTERA MARINA) MEADOW AND THE VARIATION OF NUTRIENT CONTENTS OF EELGRASS". In Managing risks to coastal regions and communities in a changing world. Academus Publishing, 2017. http://dx.doi.org/10.31519/conferencearticle_5b1b938251aa95.85691438.
Testo completoAbstract (sommario):
Nutrient dynamics in seagrass beds and nutrient demands of seagrass biomass are not clear, although nutrient uptake of seagrass has been experimentally studied in the laboratory. We conducted the field observations and the bottom sediment core incubations to estimate nutrient fluxes in the seagrass, Zostera marina meadow. DIN (nitrate, nitrite and ammonium) concentrations were always low particularly during the Z. marina growing season (from spring to summer), and water exchanges caused by tidal currents hardly supplied nutrient demand for Z. marina. Sediment pore water also supplied insufficient nutrients to Z. marina, because pore water had less volume than the water column, although DIN concentrations of pore water were 10-100 fold higher than those of the water column. Nutrient flux from sediment to water column estimated by the sediment core incubation experiments showed a similar rate with tidal water exchange. Thus, our results suggested that Z. marina adapted for low nutrient concentrations and each nutrient source in the Z. marina meadow slightly contributed but could not support Z. marina growth. We found that another nutrient source, for example, precipitation, supplied high DIN to the Z. marina meadow. After rainfall, the DIN concentration of seawater in the Z. marina meadow increased 2-5 times higher. Moreover, nitrogen content of eelgrass also increased 2-3 times higher during several days. Those results suggested that Z. marina was usually exposed to a low nutrient concentration but could uptake abundant nutrients from temporary nutrient supplies such as precipitation.
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Asahi, Toshimasa, Toshimasa Asahi, Kazuhiko Ichimi, Kazuhiko Ichimi, Kuninao Tada e Kuninao Tada. "NUTRIENT DYNAMICS IN EELGRASS (ZOSTERA MARINA) MEADOW AND THE VARIATION OF NUTRIENT CONTENTS OF EELGRASS". In Managing risks to coastal regions and communities in a changing world. Academus Publishing, 2017. http://dx.doi.org/10.21610/conferencearticle_58b4316623b72.
Testo completoAbstract (sommario):
Nutrient dynamics in seagrass beds and nutrient demands of seagrass biomass are not clear, although nutrient uptake of seagrass has been experimentally studied in the laboratory. We conducted the field observations and the bottom sediment core incubations to estimate nutrient fluxes in the seagrass, Zostera marina meadow. DIN (nitrate, nitrite and ammonium) concentrations were always low particularly during the Z. marina growing season (from spring to summer), and water exchanges caused by tidal currents hardly supplied nutrient demand for Z. marina. Sediment pore water also supplied insufficient nutrients to Z. marina, because pore water had less volume than the water column, although DIN concentrations of pore water were 10-100 fold higher than those of the water column. Nutrient flux from sediment to water column estimated by the sediment core incubation experiments showed a similar rate with tidal water exchange. Thus, our results suggested that Z. marina adapted for low nutrient concentrations and each nutrient source in the Z. marina meadow slightly contributed but could not support Z. marina growth. We found that another nutrient source, for example, precipitation, supplied high DIN to the Z. marina meadow. After rainfall, the DIN concentration of seawater in the Z. marina meadow increased 2-5 times higher. Moreover, nitrogen content of eelgrass also increased 2-3 times higher during several days. Those results suggested that Z. marina was usually exposed to a low nutrient concentration but could uptake abundant nutrients from temporary nutrient supplies such as precipitation.
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Domnin, Dmitry, Dmitry Domnin, Boris Chubarenko, Boris Chubarenko, Rene Capell e Rene Capell. "MATHEMATICAL MODELING OF NUTRIENT LOADING FROM SMALL CATCHMENTS OF THE VISTULA LAGOON". In Managing risks to coastal regions and communities in a changing world. Academus Publishing, 2017. http://dx.doi.org/10.31519/conferencearticle_5b1b93dfde6248.02952871.
Testo completoAbstract (sommario):
Vistula Lagoon as a part of the coastal zone translates nutrient load from catchment to the Baltic Sea. Catchments of the Primorskaya River (small settlements, mostly agricultural area, 120 km2) and Banówka-Mamonovka River (transboundary catchment between Russia and Poland, relatively big settlements, food production enterprises, agricultural activity, 490 km2) were selected as test ones for the Vistula Lagoon catchment (23 870 km2). Assessment of the retention of total nitrogen and phosphorus in the catchment and the transformation of nutrient load from anthropogenic sources while passing the catchment were studied by using open source numerical modeling tools. Initial data comprises the geomorphic characteristics, river net data, information on land use and nutrient point sources, time series of temperature, precipitation. Runoff was simulated by hydrological model HYPE considering the evaporation and infiltration into the soil. Retention and transport of nutrients were accessed using the model FyrisNP. Source apportionment was made for the nutrient load discharging from both catchments to the Vistula Lagoon. The greatest amount of nutrients in final discharge is coming from the arable land (50-80%), point sources constitute a smaller proportion (5-30%). The results will be used to obtain the first order approximation of the nutrient load from other small rivers of the Vistula Lagoon catchment and from the biggest river in the area, the Pregolya River (15 300 km2) by analogy.
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Domnin, Dmitry, Dmitry Domnin, Boris Chubarenko, Boris Chubarenko, Rene Capell e Rene Capell. "MATHEMATICAL MODELING OF NUTRIENT LOADING FROM SMALL CATCHMENTS OF THE VISTULA LAGOON". In Managing risks to coastal regions and communities in a changing world. Academus Publishing, 2017. http://dx.doi.org/10.21610/conferencearticle_58b431754b7a5.
Testo completoAbstract (sommario):
Vistula Lagoon as a part of the coastal zone translates nutrient load from catchment to the Baltic Sea. Catchments of the Primorskaya River (small settlements, mostly agricultural area, 120 km2) and Banówka-Mamonovka River (transboundary catchment between Russia and Poland, relatively big settlements, food production enterprises, agricultural activity, 490 km2) were selected as test ones for the Vistula Lagoon catchment (23 870 km2). Assessment of the retention of total nitrogen and phosphorus in the catchment and the transformation of nutrient load from anthropogenic sources while passing the catchment were studied by using open source numerical modeling tools. Initial data comprises the geomorphic characteristics, river net data, information on land use and nutrient point sources, time series of temperature, precipitation. Runoff was simulated by hydrological model HYPE considering the evaporation and infiltration into the soil. Retention and transport of nutrients were accessed using the model FyrisNP. Source apportionment was made for the nutrient load discharging from both catchments to the Vistula Lagoon. The greatest amount of nutrients in final discharge is coming from the arable land (50-80%), point sources constitute a smaller proportion (5-30%). The results will be used to obtain the first order approximation of the nutrient load from other small rivers of the Vistula Lagoon catchment and from the biggest river in the area, the Pregolya River (15 300 km2) by analogy.
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Fernandez, Maria Luz, M. Luisa Bonet, Francisco J. Pérez Cano e Egeria Scoditi. "Preface: The 3rd International Electronic Conference on Nutrients". In The 3rd International Electronic Conference on Nutrients. Basel Switzerland: MDPI, 2024. http://dx.doi.org/10.3390/blsf2023029028.
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Prasetyo, Vincentius Riandaru, Yudhistira Anggara Jayadinata e Naufal Muflih Ramadhan. "Implementation of Three Types of Sensors for Monitoring Plant Development in Hydroponic Media". In The 4th International Conference on Science and Technology Applications. Switzerland: Trans Tech Publications Ltd, 2023. http://dx.doi.org/10.4028/p-tsb27g.
Testo completoAbstract (sommario):
Hydroponics is an agricultural cultivation system without using soil media. Hydroponics is an agricultural activity carried out using water as a medium to replace soil. Hydroponics emphasizes meeting the nutritional needs of plants through the flow of water. If nutrients are given through fertilizer in soil media, then in hydroponics, the nutrients are dissolved and flow through water. The concentration of nutrients that dissolve in water will affect the high and low pH of the water. The pH level in the water will affect the development and growth of plants. In addition, air humidity can also affect plant growth, especially for plants grown in a greenhouse. Therefore, special attention is needed to maintain the pH level in the water. The particular concern is when is the right time to replace the water or add nutrients to the water. However, the large land area and the limited number of workers owned by the partners make it difficult for them to monitor the development and growth of existing plants. Therefore, a sensor will be installed in the hydroponic system to monitor the plant's development and growth. Based on the results of the tests and evaluations, the three hydroponic monitoring sensors, which include the pH sensor, nutrient solution concentration sensor, and air humidity sensor, may be properly programmed on the Arduino. The measurements between sensors and manual measurements showed an error value of 0.36% for pH measurements, 0.56% for EC measurements, and 0.42% for humidity measurements.
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Crista, Laura, Isidora Radulov, Adina Berbecea e Florin Crista. "THE ENHANCING IMPACT OF FOLIAR FERTILISERS ON QUALITY INDICES OF WHEAT". In 23rd SGEM International Multidisciplinary Scientific GeoConference 2023. STEF92 Technology, 2023. http://dx.doi.org/10.5593/sgem2023v/6.2/s25.51.
Testo completoAbstract (sommario):
Achieving profitable crop production milestones hinges on the establishment of a robust soil fertility program. Such programs demand foresight and meticulous planning. To ensure the profitability and efficiency of wheat cultivation, it is imperative to provide the right amount of essential plant nutrients precisely when and where the crop requires them. The application rates of fertilizers hold little significance if these vital nutrients are not distributed at the appropriate locations and times. Wheat, in particular, exhibits a heightened sensitivity to fertilization, responding favorably to the application of fertilizers. This is due to the fact that grains consume relatively modest quantities of nutrients, primarily because their roots explore a smaller volume of soil. Additionally, they possess a limited capacity for solubilizing and absorbing nutrients in highly soluble forms when compared to other crops. The influence of foliar fertilizers on various plant species is diverse and contingent upon the specific plant type and even its variety. Foliar application can offer the advantage of improved nutrient accessibility for crops, ultimately leading to higher yields. The judicious fertilization of wheat crops, contingent upon soil fertility, significantly contributes to the quality of grain production. The presence and balance of both macro and microelements play a pivotal role in crop nutrition, ultimately leading to higher yields. The primary objective of this study was to assess variations in several wheat quality indicators under conditions of varying nitrogen (N) levels.
Rapporti di organizzazioni sul tema "Nutrients"
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Theiling, Charles. A review of algal phytoremediation potential to sequester nutrients from eutrophic surface water. Engineer Research and Development Center (U.S.), ottobre 2023. http://dx.doi.org/10.21079/11681/47720.
Testo completoAbstract (sommario):
Harmful algal blooms (HABs) and coastal hypoxic zones are evidence of cultural nutrient enrichment affecting public health and water supplies, aquatic ecosystem health, and economic well-being in the United States. Recognition of the far-reaching impacts of Midwest agriculture has led to establishing nutrient reduction objectives for surface waters feeding the Gulf of Mexico, Lake Erie, and many smaller water bodies. Municipal nutrient enrichment impacts have been addressed by increasing levels of sewage treatment and waste management through the Clean Water Act era, but HABs rebounded in the 1990s because of non-point source nutrient enrichment. HAB control and treatment includes watershed and waterbody treatments to reduce loading and address outbreaks. Systems to remove nutrients from impaired waters are expensive to build and operate. This review of algal production systems summarizes emerging algal water treatment technologies and considers their potential to effectively sequester nutrients and atmospheric carbon from hundreds of eutrophic reservoirs and DoD wastewater treatment facilities while producing useful biomass feedstock using solar energy. Algal water treatment systems including open ponds, photobioreactors, and algal turf scrubbers® can be used to grow biomass for biofuel, wastewater treatment, and commercial products. This review recommends continuing research on surface water nutrient reduction potential with algal turf scrubber productivity pilot studies, preliminary site design, and biomass utilization investigations.
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Skone, Timothy J. NPK Nutrients Replacement, Operation. Office of Scientific and Technical Information (OSTI), febbraio 2010. http://dx.doi.org/10.2172/1509108.
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Guan, Kun-Liang. Regulation of mTOR by Nutrients. Fort Belvoir, VA: Defense Technical Information Center, luglio 2012. http://dx.doi.org/10.21236/ada569533.
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Guan, Kun-Liang. Regulation of mTOR by Nutrients. Fort Belvoir, VA: Defense Technical Information Center, luglio 2010. http://dx.doi.org/10.21236/ada602038.
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Larsson, Madeleine, Karin Tonderski, Genevieve Metson e Nils-Hassan Quttineh. Towards a more circular biobased economy and nutrient use on Gotland: finding suitable locations for biogas plants. Linköping University Electronic Press, luglio 2023. http://dx.doi.org/10.3384/report.diva-194234.
Testo completoAbstract (sommario):
In this study we have investigated the role of biogas solutions to support increased resource efficiency on the island Gotland, including recovery and redistribution of nitrogen (N) and phosphorus (P) within the agricultural sector. First, we analyzed the potential for expanding energy and nutrient recovery from organic residues using biogas solutions. Our findings suggest that the biogas production could expand to 165 GWh, from the current 36 GWh (2020), with manure accounting for a potential 110 GWh biogas annually if all were digested. Comparing the nutrients contained in organic feedstock with the crop nutrient demand on Gotland showed that for N the demand is 2.4 times higher than the supply. In contrast, the calculations showed a 137 tonnes P surplus, with distinct excess areas in the center and southern part of the island. We then compared scenarios with different numbers (3 - 15) of biogas plants with respect to efficient nutrient redistribution and transport costs. Spatial constraints for new plants, e.g. need for roads with a certain capacity and permit issues, were accounted for by adding local information to a national data set. We identified 104 potential locations (1 km$^2$ grid cells) and used an optimization model to identify the most suitable locations for minimized transport costs. Optimal (meeting the crop demand with no excess) redistribution of all nutrients contained in the feedstock, as raw digestate from biogas plants, would result in an export of 127 tonnes of P from the island. The model results indicated that if all potential feedstock would be digested in three additional biogas plants and nutrients redistributed for optimal reuse, the total transport cost would be 2.6 million SEK annually, excluding the costs for nutrient export from the island (3.7 million SEK). If instead 10 or 15 smaller plants would be built, the transport cost would drop to 1.8 million SEK, with the same amount of P being exported. Comparing the scenarios with different number of biogas plants (3 - 15), showed that some locations are more suitable than others in terms of distance to feedstock and to fields with fertilizer demands. Finally, a preliminary analysis of the amount of crop residues indicated that this type of feedstock could add a substantial amount of biogas production, but more extensive analyses are needed to assess the feasibility to realize part of that potential.
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Benefield, John. Assessing Soil Nutrients Using Rapid Electrical Conductivity Measurements. Ames (Iowa): Iowa State University, gennaio 2021. http://dx.doi.org/10.31274/cc-20240624-247.
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Wong, E. A., e Z. Uni. Modulating intestinal cellular maturation and differentiation in broilers by in ovo feeding. Israel: United States-Israel Binational Agricultural Research and Development Fund, 2018. http://dx.doi.org/10.32747/2018.8134161.bard.
Testo completoAbstract (sommario):
Mortality in a broiler flock will typically range from 4-5% of the population over the course of 6- 7 weeks in the U.S. and 7-8% of the population in Israel. Suboptimal intestinal maturation and functionality are one of the major factors that contribute to early age mortality and hinder flock body weight uniformity. The development of absorptive and secretory functions is orchestrated by differentiation of cells that arise from stem cells. Supplying compounds by in ovo feeding (IOF) during late embryogenesis provides nutrients that may change the dynamics of stem cell differentiation. We hypothesize that the introduction of specific nutrients or probiotics to the late embryonic chick via IOF will result in an acceleration of the maturation of the small intestine as measured by villus/crypt morphology and the number and distribution of absorptive and secretory cells. A chick that can absorb nutrients more efficiently by increasing the number of cells expressing nutrient transporters and resist enteric pathogens by increasing the number of cells expressing mucin and host defense peptides will be healthier at hatch. This chick may have less need for antibiotics and may show reduced early mortality. The objectives of this proposal are to: 1) develop a model for the development of putative stem cells and absorptive/secretory cells in the small intestine of the late embryonic and early post hatch broiler. 2) determine the ability of IOF of nutrients to modulate the population of differentiated cells in the intestine. 3) determine the ability of IOF of probiotics to modulate the population of differentiated cells in the intestine. 4) reduce early mortality and increase body weight uniformity by IOF of selected nutrients or probiotics. This proposal combines the IOF expertise of Zehava Uni (Hebrew University) with the RNAscope in situ hybridization technique of Eric Wong (Virginia Tech). Previous studies using quantitative PCR to examine expression of genes in the intestine were unable to identify specific cells expressing these genes. RNAscope allows the ability to identify putative stem, absorptive and secretory cells in the small intestine. Thus, we will be able to investigate the effect of IOF on the presence of intestinal absorptive and secretory cells at the cellular level. Understanding the mechanisms for intestinal development and function are key to maintaining peak growth and health of chickens and thus would be of great economic benefit to the poultry industry.
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Uni, Zehava, e Peter Ferket. Enhancement of development of broilers and poults by in ovo feeding. United States Department of Agriculture, maggio 2006. http://dx.doi.org/10.32747/2006.7695878.bard.
Testo completoAbstract (sommario):
The specific objectives of this research were the study of the physical and nutritional properties of the In Ovo Feeding (IOF) solution (i.e. theosmostic properties and the carbohydrate: protein ratio composition). Then, using the optimal solution for determining its effect on hatchability, early nutritional status and intestinal development of broilers and turkey during the last quarter of incubation through to 7 days post-hatch (i.e. pre-post hatch period) by using molecular, biochemical and histological tools. The objective for the last research phase was the determination of the effect of in ovo feeding on growth performance and economically valuable production traits of broiler and turkey flocks reared under practical commercial conditions. The few days before- and- after hatch is a critical period for the development and survival of commercial broilers and turkeys. During this period chicks make the metabolic and physiological transition from egg nutriture (i.e. yolk) to exogenous feed. Late-term embryos and hatchlings may suffer a low glycogen status, especially when oxygen availability to the embryo is limited by low egg conductance or poor incubator ventilation. Much of the glycogen reserve in the late-term chicken embryo is utilized for hatching. Subsequently, the chick must rebuild that glycogen reserve by gluconeogenesis from body protein (mostly from the breast muscle) to support post-hatch thermoregulation and survival until the chicks are able to consume and utilize dietary nutrients. Immediately post-hatch, the chick draws from its limited body reserves and undergoes rapid physical and functional development of the gastrointestinal tract (GIT) in order to digest feed and assimilate nutrients. Because the intestine is the nutrient primary supply organ, the sooner it achieves this functional capacity, the sooner the young bird can utilize dietary nutrients and efficiently grow at its genetic potential and resist infectious and metabolic disease. Feeding the embryo when they consume the amniotic fluid (IOF idea and method) showed accelerated enteric development and elevated capacity to digest nutrients. By injecting a feeding solution into the embryonic amnion, the embryo naturally consume supplemental nutrients orally before hatching. This stimulates intestinal development to start earlier as was exhibited by elevated gene expression of several functional genes (brush border enzymes an transporters , elvated surface area, elevated mucin production . Moreover, supplying supplemental nutrients at a critical developmental stage by this in ovo feeding technology improves the hatchling’s nutritional status. In comparison to controls, administration of 1 ml of in ovo feeding solution, containing dextrin, maltose, sucrose and amino acids, into the amnion of the broiler embryo increased dramatically total liver glycogen in broilers and in turkeys in the pre-hatch period. In addition, an elevated relative breast muscle size (% of broiler BW) was observed in IOF chicks to be 6.5% greater at hatch and 7 days post-hatch in comparison to controls. Experiment have shown that IOF broilers and turkeys increased hatchling weights by 3% to 7% (P<0.05) over non injected controls. These responses depend upon the strain, the breeder hen age and in ovo feed composition. The weight advantage observed during the first week after hatch was found to be sustained at least through 35 days of age. Currently, research is done in order to adopt the knowledge for commercial practice.
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Hochella, M. F. Microbial Community Acquisition of Nutrients from Mineral Surfaces. Final Report. Office of Scientific and Technical Information (OSTI), giugno 2003. http://dx.doi.org/10.2172/824025.
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Abbott, Mark R. Lagrangian Observations of Nutrients and Phytoplankton in the California Current. Fort Belvoir, VA: Defense Technical Information Center, settembre 1997. http://dx.doi.org/10.21236/ada627907.
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