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1
Comerford, N. B., W. P. Cropper, Jr., Hua Li, P. J. Smethurst, K. C. J. Van Rees, E. J. Jokela, H. Adégbidi e N. F. Barros. "Soil supply and nutrient demand (SSAND): A general nutrient uptake model and an example of its application to forest management". Canadian Journal of Soil Science 86, n. 4 (1 agosto 2006): 655–73. http://dx.doi.org/10.4141/s05-112.
Testo completoAbstract (sommario):
Models of soil nutrient bioavailability and uptake assist in nutrient management and lead to a better understanding of nutrient dynamics in the soil-plant system. SSAND (Soil Supply and Nutrient Demand) is a steady state, mechanistic nutrient uptake simulation model based on mass flow and diffusive supply of nutrients to roots. It requires user inputs for soil and plant parameters to calculate a nutrient’s concentration at the root surface and the subsequent uptake by a plant root and/or extrametrical mycorrhizal hyphae. It can be considered a sub-model linked to hydrological or plant growth models. SSAND provides a basis for simulating nutrient uptake under different soil-plant scenarios, including multiple soil compartments, net mineralization inputs, changing root growth, changing mycorrhizal hyphae growth, changing soil water content and multiple fertilizer events. It incorporates uptake from roots and mycorrhizal hyphae, including the potential competition between these entities. It should be useful for simulating the effects of climate change on soil nutrient bioavailability. It should also be a useful tool for managers in evaluating fertilizer regime options. Key words: Nutrient bioavailability, nutrient uptake modeling, phosphorus uptake, mycorrhizae, Spodosols, climate change
2
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.
3
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.
4
Turner, John, e Marcia J. Lambert. "Analysis of nutrient use efficiency (NUE) in Eucalyptus pilularis forests". Australian Journal of Botany 62, n. 7 (2014): 558. http://dx.doi.org/10.1071/bt14162.
Testo completoAbstract (sommario):
Alternative indices to use for nutrient use efficiency (NUE) were analysed for nitrogen, phosphorus, potassium, calcium, magnesium and sulfur, using 17 Eucalyptus pilularis forest sites to test the hypothesis that NUE increases with decreasing nutrient availability. Reported indices represent different measures of nutrient use, including (1) efficiency of acquisition from soil, (2) quantities required for organic matter production, (3) organic matter production related to uptake, (4) ability to internally retranslocate nutrients and (5) physiological requirement of nutrients. Some indices are highly correlated but the highest correlations were according to age. Phosphorus, the main growth-limiting nutrient, on average, produced 6.5 and 10.9 t of organic matter per kilogram of phosphorus required and taken up from soil, respectively. Comparable estimates were made for other nutrients. NUEs of mobile nutrients increased with decreases in nutrient availability and this supported the hypotheses when age was taken into account. The NUEs of one nutrient are not independent of other nutrients. The inverse of foliage nutrient concentration is a valuable low-cost index of nutrient utilisation and correlates with net primary production/nutrient requirement, and is related to age. Resorption of nutrients, comparing new and abscised tissue, was of low value, but abscised-tissue nutrient correlations are related to a lower benchmark and are of value. The use of selected NUE indices for species comparison was discussed.
5
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.
6
Yan, Jing, Nathaniel A. Bogie e Teamrat A. Ghezzehei. "Root uptake under mismatched distributions of water and nutrients in the root zone". Biogeosciences 17, n. 24 (17 dicembre 2020): 6377–92. http://dx.doi.org/10.5194/bg-17-6377-2020.
Testo completoAbstract (sommario):
Abstract. Most plants derive their water and nutrient needs from soils where the resources are often scarce, patchy, and ephemeral. It is not uncommon for plant roots to encounter mismatched patches of water-rich and nutrient-rich regions in natural environments. Such an uneven distribution of resources necessitates plant reliance on strategies for exploring and acquiring nutrients from relatively dry patches. We conducted a laboratory study that elucidates the biophysical mechanisms that enable this adaptation. The roots of tomato (Solanum lycopersicum) seedlings were laterally split and grown in two adjacent, hydraulically disconnected pots, which permitted precise control of water and nutrient applications to each compartment. We observed that the physical separation of water-rich and nutrient-rich compartments (one received 90 % water and 0 % nutrients and the other received 10 % water and 100 % nutrients) does not significantly stunt plant growth and productivity compared to two control treatments (control 1: 90 % water and 100 % nutrients versus 10 % water and 0 % nutrients; control 2: 50 % water and 50 % nutrients in each compartment). Specifically, we showed that soil dryness does not reduce nutrient uptake, vegetative growth, flowering, and fruiting compared to control treatments. We identified localized root proliferation in nutrient-rich dry soil patches as a critical strategy that enabled nutrient capture. We observed nocturnal rewetting of the nutrient-rich but dry soil zone (10 % water and 100 % nutrients) but not in the nutrient-free and dry zone of the control experiment (90 % water and 100 % nutrients). We interpreted the rewetting as the transfer of water from the wet to dry zones through roots, a process commonly known as hydraulic redistribution (HR). The occurrence of HR likely prevents the nutrient-rich soil from drying due to permanent wilting and the subsequent decline of root functions. Sustaining rhizosphere wetness is also likely to increase nutrient mobility and uptake. Lack of HR in the absence of nutrients suggests that HR is not entirely a passive, water-potential-gradient driven flow. The density and size of root hairs appeared to be higher (qualitative observation) in the nutrient-rich and dry compartments than in the nutrient-free and dry compartments. We also observed organic coating on sand grains in the rhizosphere of the nutrient-rich and dry compartments. The observations are consistent with prior observations that root hairs and rhizodeposition aid rhizosphere wetting. These findings were synthesized in a conceptual model that explains how plants of dry regions may be adapted to mismatched resources. This study also suggests that separating the bulk of applied nutrients from the frequently irrigated soil region can increase nutrient use efficiency and curtail water pollution from intensive agricultural systems.
7
Nóra Bákonyi. "The effect of apoplastic pH on the nutrient uptake". Acta Agraria Debreceniensis, n. 50 (16 dicembre 2012): 65–71. http://dx.doi.org/10.34101/actaagrar/50/2568.
Testo completoAbstract (sommario):
The pH of soil and rhizosphare –around the roots- determine the mobility and solubility of nutrients. The exudates organic acids of plant able to modify the pH, as well as the microorganisms also take part in mobilization of nutrients. The nutrient solve mostly in mildly acidic and neutral pH. The either assumption of utilization of nutrients is the uptake by roots and of course uptake to the cells to take part in metabolism. The pH of apoplast fluid determines the solubility and uptake of nutrients to the cells.The aim of this study was to examine the effect of nutrient solution and apoplastic pH together with a bacteria based biofertiliser (Phylazonit MC®) on nutrient uptake and pH of apoplast fluid in case of nutrient solution grown plants in laboratory experiment. According to my results, the bicarbonate increased the pH of nutrient solution in due to influence the solubility and uptake of nutrients. The given bicarbonate to the nutrient solution and infiltrated into the apoplazma also modified the pH of the apoplast fluid of the test plants. The effect of bicarbonate and biofertilizer were different on the pH of the apoplast fluid and nutrient solution in nutrient solution experiment.
8
Thomson, V. P., e M. R. Leishman. "Survival of native plants of Hawkesbury Sandstone communities with additional nutrients: effect of plant age and habitat". Australian Journal of Botany 52, n. 2 (2004): 141. http://dx.doi.org/10.1071/bt03047.
Testo completoAbstract (sommario):
Australian soils are naturally low in nutrient concentrations, particularly nitrogen (N) and phosphorus (P). Native plants are well adapted to low-nutrient soils, and can be adversely affected when exposed to higher concentrations of nutrients. The Hawkesbury Sandstone soils in northern Sydney are naturally low in nutrients, but often receive additional nutrient input from urban stormwater run-off. Increases in soil nutrients in urban bushland are associated with the presence of exotic species, and the decline in the diversity of native species. This study tested the hypothesis that high concentrations of nutrients, in particular P, in the disturbed soils of urban bushland, reduce survival of native plants. We examined the survival of native species under five different nutrient concentrations that are typical of nutrient-enriched urban bushland soil, in two glasshouse experiments. The experiments examined both survival of seedlings and survival of 6-month-old plants. We used native species that are adapted to both nutrient-poor and nutrient-rich soils. In general, the survival of native plants decreased with increasing nutrient concentrations. At soil total-P concentrations >200 mg kg–1, most plants died. Seedlings were more sensitive to added nutrients than the 6-month-old plants. Species that were from higher-nutrient soil had consistently higher survival than species from low-nutrient soils, under the nutrient addition treatments. These results suggest that at high soil nutrient concentrations typical of stormwater-affected urban bushland, native plant species of low-nutrient soils will be unable to survive. If ecological restoration works are to be done in such areas, replanting with more mature plants from naturally high-nutrient habitats is likely to be the most successful. However, restoration of these areas may have limited success and they are likely to remain dominated by exotic plant species.
9
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.
10
Havlin, John, e Ron Heiniger. "Soil Fertility Management for Better Crop Production". Agronomy 10, n. 9 (8 settembre 2020): 1349. http://dx.doi.org/10.3390/agronomy10091349.
Testo completoAbstract (sommario):
Increasing crop productivity per unit of land area to meet future food and fiber demand increases both soil nutrient removal and the importance of replenishing soil fertility through efficient nutrient management practices. Significant progress in enhancing nutrient-use efficiency in production agriculture requires improved estimates of plant-available nutrients in the root zone, enhanced crop response to applied nutrients, and reduced offsite nutrient transport. This special issue, Soil Fertility Management for Better Crop Production, presents 15 manuscripts that advance our knowledge of interrelated soil, plant, and management factors important to increasing the nutrient availability and crop recovery of applied nutrients.
11
Ardianti, Arini Ayu, Faris Nur Fauzi Athallah, Restu Wulansari e Kurniawan Sigit Wicaksono. "The relationship Between Soil Chemical Properties and Uptake of Tea Plant Nutrient in PTPN VI Jambi". Jurnal Tanah dan Sumberdaya Lahan 9, n. 1 (1 gennaio 2022): 181–91. http://dx.doi.org/10.21776/ub.jtsl.2022.009.1.20.
Testo completoAbstract (sommario):
Healthy soil could support plant growth by optimizing the availability of nutrients. The availability of nutrients influences the health of tea plants. Nutrient deficiencies would affect the plant physiology that exhibits the plant withering. This study aimed to define the relationship between soil nutrient availability with plant nutrient uptake. This research was conducted by managing secondary data soil chemical properties, and tea plant nutrients analyzed statistically with Pearson correlation. This study only found a significant correlation between soil pH with P and Mg uptake. Correlation results between soil nutrient and plant nutrient uptake obtained a significantly negative correlation on soil pH with P and Mg nutrients with a correlation value of pH-P (r=-0.52), pH-Mg (r=-0.52). There was no correlation between other soil nutrients and plant nutrient uptake. The results of this study can be used to determine the dose of fertilization and the management recommendation of tea plants.
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Slade, A. H., R. J. Ellis, M. van den Heuvel e T. R. Stuthridge. "Nutrient minimisation in the pulp and paper industry: an overview". Water Science and Technology 50, n. 3 (1 agosto 2004): 111–22. http://dx.doi.org/10.2166/wst.2004.0175.
Testo completoAbstract (sommario):
This paper reviews nutrient issues within the pulp and paper industry summarising: nitrogen and phosphorus cycles within treatment systems; sources of nutrients within pulping and papermaking processes; minimising nutrient discharge; new approaches to nutrient minimisation; and the impact of nutrients in the environment. Pulp and paper industry wastewaters generally contain insufficient nitrogen and phosphorus to satisfy bacterial growth requirements. Nutrient limitation has been linked to operational problems such as sludge bulking and poor solids separation. Nutrients have been added in conventional wastewater treatment processes to ensure optimum treatment performance. Minimising the discharge of total nitrogen and phosphorus from a nutrient limited wastewater requires both optimised nutrient supplementation and effective removal of suspended solids from the treated wastewater. In an efficiently operated wastewater treatment system, the majority of the discharged nutrients are contained within the biomass. Effective solids separation then becomes the controlling step, and optimisation of secondary clarification is crucial. Conventional practice is being challenged by the regulatory requirement to reduce nitrogen and phosphorus discharge. Two recent developments in pulp and paper wastewater treatment technologies can produce discharges low in nitrogen and phosphorus whilst operating under conventionally nutrient limited conditions: i) the nutrient limited BAS process (Biofilm-Activated Sludge) which combines biofilm and activated sludge technologies under nutrient limited conditions and ii) an activated sludge process based on the use of nitrogen-fixing bacteria. Aerated stabilisation basins often operate without nutrient addition, relying on settled biomass in the benthal zone feeding back soluble nutrients, or the fixation of atmospheric nitrogen. Thus effective nutrient minimisation strategies require a more detailed understanding of nutrient cycling and utilisation. Where it is not possible to meet discharge constraints with biological treatment alone, a tertiary treatment step may be required. In setting nutrient control guidelines, consideration should be given to the nutrient limitations of the receiving environment, including other cumulative nutrient impacts on that environment. Whether an ecosystem is N or P limited should be integrated with wastewater treatment considerations in the further design and development of treatment technology and regulatory guidelines. End-of-pipe legislation alone cannot predict environmental effects related to nutrients and must be supplemented by an effects-based approach.
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Ridoutt, Bradley. "An Alternative Nutrient Rich Food Index (NRF-ai) Incorporating Prevalence of Inadequate and Excessive Nutrient Intake". Foods 10, n. 12 (20 dicembre 2021): 3156. http://dx.doi.org/10.3390/foods10123156.
Testo completoAbstract (sommario):
Most nutrient profiling models give equal weight to nutrients irrespective of their ubiquity in the food system. There is also a degree of arbitrariness about which nutrients are included. In this study, an alternative Nutrient Rich Food index was developed (NRF-ai, where ai denotes adequate intake) incorporating prevalence of inadequate and excessive nutrient intake among Australian adults. Weighting factors for individual nutrients were based on a distance-to-target method using data from the Australian Health Survey describing the proportion of the population with usual intake less than the Estimated Average Requirement defined by the Nutrient Reference Values for Australia and New Zealand. All nutrients for which data were available were included, avoiding judgements about which nutrients to include, although some nutrients received little weight. Separate models were developed for females and males and for selected age groups, reflecting differences in nutrient requirements and usual intake. Application of the new nutrient profiling models is demonstrated for selected dairy products and alternatives, protein-rich foods, and discretionary foods. This approach emphasises the need to identify foods that are rich in those specific nutrients for which intake is below recommended levels and can be used to address specific nutrient gaps in subgroups such as older adults. In addition, the new nutrient profiling model is used to explore other sustainability aspects, including affordability (NRF-ai per AUD) and ecoefficiency (NRF-ai/environmental impact score).
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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.
15
Maia, Janini Tatiane Lima Souza, Hermínia Emília Prieto Martinez, Junia Maria Clemente, Marilia Contin Ventrella e Carla do Carmo Milagres. "Growth, nutrient concentration, nutrient accumulation and visual symptoms of nutrient deficiencies in cherry tomato plants". Semina: Ciências Agrárias 40, n. 2 (15 aprile 2019): 585. http://dx.doi.org/10.5433/1679-0359.2019v40n2p585.
Testo completoAbstract (sommario):
Tomato is one of the most popular vegetables, with high nutrient demand. The nutrient concentration can vary depending on the development phase, cultivation system, temperature, soil conditions, luminosity, relative humidity and management practices. The aim of this work was to characterize cherry tomato visual symptoms of deficiency, as well as the effect of nutritional restriction on the development and nutrient concentration of plants cultivated in nutrient solution. Plants of the cherry tomato, cultivar Sindy, were grown in green house. We have used eleven treatments, one control with complete nutrient solution and the other ten omitting respectively the nutrients nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, boron, copper, zinc and iron. The experiment was performed in randomized design with three repetitions. After 60 days, the plants were removed from the solutions and their main symptoms were photographed and described. The traits evaluated were: total dry matter yield, dry matter of leaves, dry matter of stems and dry matter of roots; number of leaves, number of inflorescences; number of fruits and root volume. The concentration and accumulation of nutrients: nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, boron, copper, zinc and iron in leaves, stems and roots were evaluated. Nutrient concentration and accumulation were influenced by the deficiencies imposed. The visual symptoms of deficiency that had appeared firstly were those of phosphorus, boron and iron, respectively. The omissions of the nutrients nitrogen, magnesium and boron were the ones that most compromised the dry matter production of the cherry tomato plants.
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Rose, Laura, Robert Buitenwerf, Michael Cramer, Edmund C. February e Steven I. Higgins. "Effects of nutrient supply on carbon and water economies of C4 grasses". Functional Plant Biology 45, n. 9 (2018): 935. http://dx.doi.org/10.1071/fp17359.
Testo completoAbstract (sommario):
C3 plants can increase nutrient uptake by increasing transpiration, which promotes the flow of water with dissolved nutrients towards the roots. However, it is not clear if this mechanism of nutrient acquisition, termed ‘mass flow’, also operates in C4 plants. This is an important question, as differences in mass flow capacity may affect competitive interactions between C3 and C4 species. To test if mass flow can be induced in C4 species, we conducted an experiment in a semiarid seasonal savanna in South Africa. We grew six C4 grasses in nutrient-poor sand and supplied no nutrients, nutrients to the roots or nutrients spatially separated from the roots. We measured the rates of photosynthesis and transpiration, water-use efficiency (WUE), nitrogen gain and biomass. For all species biomass, N gain, photosynthesis and transpiration were lowest in the treatment without any nutrient additions. Responses to different nutrient positioning varied among species from no effect on N gain to a 50% reduction when nutrients were spatially separated. The ability to access spatially separated nutrients showed a nonsignificant positive relationship with both the response of transpiration and the response of WUE to spatial nutrient separation. This indicates that nutrient acquisition is not regulated by decreasing WUE in C4 grasses. Overall, our study suggests that under elevated CO2, when evaporative demand is lower, C4 species may be at a competitive disadvantage to C3 species when it comes to nutrient acquisition.
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Zandonà, Eugenia, Priscila Oliveira-Cunha e Beatriz Moreira-Ferreira. "PAPEL DOS PEIXES NA RECICLAGEM DE NUTRIENTES EM RIACHOS TROPICAIS". Oecologia Australis 25, n. 02 (16 giugno 2021): 449–63. http://dx.doi.org/10.4257/oeco.2021.2502.14.
Testo completoAbstract (sommario):
Fish can contribute directly and indirectly to nutrient recycling in aquatic environments, affecting community structure and ecosystem processes. Through the excretion of metabolic waste, fish make inorganic nutrients available in the environment that can be used by algae and bacteria. Nitrogen and phosphorus are often limiting nutrients in streams, so fish can be a relevant source of these nutrients. Many factors can influence excretion rates, including diet, body nutrient demand (for reproduction and growth), ontogeny, body size, temperature and other abiotic factors. Currently, two theories propose to explain which factors control excretion rates: 1) The Theory of Ecological Stoichiometry is based on mass balance models and uses the amount of nutrients in the diet and the fish nutrient demand as predictors of excretion rates; and 2) the Metabolic Theory of Ecology that uses body size and temperature as factors that regulate an organism metabolic rates and, thus, its excretion rates. The relative importance of fish as nutrient recyclers in streams varies depending on species intrinsic characteristics and environmental factors. This includes the magnitude of excretion rates from the entire fish community, the nutrient concentration and nutrient input into the stream, the stream nutrient demand and the period of activity and behavior of the fish. For example, species that are abundant in oligotrophic streams have the potential to represent an important source of nutrients. But other peculiarities, such as diet, specific nutrient demands, or migratory behaviors, can make them important sources or sinks of nutrients in a stream. This article reviews studies that address the role of fish as nutrient recyclers and explains the most common techniques used in this type of studies.
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White, Robin R. "346 Nutritional Strategies to Enhance Nutrient Retention in Cattle, Fields, and Farms". Journal of Animal Science 99, Supplement_3 (8 ottobre 2021): 194. http://dx.doi.org/10.1093/jas/skab235.350.
Testo completoAbstract (sommario):
Abstract Nutrient retention within livestock systems is a critical goal for enhancing efficiency of food production and promoting sustainable livestock farming. We define nutrient retention as the sequestering of C, N, and P within biotic elements of farming systems in sinks which have minimal loss to environmentally detrimental ends. Our objective is to summarize strategies to improve nutrient retention from ruminant animal production systems using nutritional management. Nutritional strategies for nutrient retention within animals and downstream food products include dilution of maintenance; precision feeding; and nutrient synchrony. Dilution of maintenance is a phenomenon where more efficient animals partition proportionally less of their consumed nutrients to maintenance processes, allowing proportionally greater quantities to be used for productive processes. Precision feeding encompasses numerous strategies, including amino acid feeding; precision carbohydrate feeding; individualized ration formulation; and precise feed delivery; among others. These strategies all precisely match nutrients supplied within a diet to nutrients required by an animal, thereby reducing nutrient overfeeding and waste. Nutrient synchrony is a feeding strategy promoting theoretically optimal microbial growth by ensuring appropriately matched supplies of carbohydrate and N substrates to facilitate fermentation. Improved microbial fermentation also serves to reduce nutrient loss to the environment through enhanced feed digestion efficiency. Evaluating animal feeding strategies and nutrient retention requires considering nutrient sinks beyond the animal and its productive outputs. Such sinks include soil and plant nutrient stores within the ecosystem. For pastured animals in particular, grazing strategies for enhanced forage production and soil C sequestration have been broadly reviewed. Sequestration of N and P within soils and plants have been less broadly reviewed but merit further discussion in the context of attempting to design management to create non-volatile sinks for multiple nutrients simultaneously. Whole-farm strategies for enhanced nutrient sequestration should be evaluated in a multi-nutrient environment to evaluate sustainability outcomes.
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Scagel, Carolyn F., Guihong Bi, Leslie H. Fuchigami e Richard P. Regan. "Nutrient Uptake and Loss by Container-grown Deciduous and Evergreen Rhododendron Nursery Plants". HortScience 46, n. 2 (febbraio 2011): 296–305. http://dx.doi.org/10.21273/hortsci.46.2.296.
Testo completoAbstract (sommario):
The influence of nitrogen (N) fertilizer application on plant allocation, uptake, and demand for other essential nutrients was evaluated from May 2005 to Feb. 2006 in evergreen Rhododendron ‘P.J.M. Compact’ (PJM) and ‘English Roseum’ (ER) and deciduous Rhododendron ‘Gibraltar’ (AZ) grown in containers filled with soilless substrate. Net nutrient uptake and losses were calculated using piecewise regression and uptake efficiency, root absorption capacity, aboveground demand, nutrient use efficiency, and uptake ratios between N and other nutrients (N ratios) were calculated using net uptake between harvest dates. Nitrogen application increased uptake rate of all nutrients, enhanced late-season uptake of many nutrients, and increased the rate of nutrient loss during the winter. Nutrient uptake often occurred as late as November in plants grown with N but was usually undetectable after September in plants grown without additional N fertilizer. Nutrient losses during the winter were not always associated with biomass loss and were related to differences in preferential nutrient allocation to different structures and the plant's ability to export nutrients before biomass loss. Plants with a greater potential for rapid growth were more capable of later-season nutrient uptake than plants with slower growth rates. Nitrogen availability altered N ratios indicating that when adding N to container-grown Rhododendron, fertilizers with higher ratios of N/phosphorus (PJM, AZ), N/calcium (PJM, ER), N/boron (PJM AZ), N/copper (PJM, ER), and N/iron (PJM, ER) and lower ratios of N/potassium (PJM, ER, AZ), N/sodium (PJM, ER, AZ), N/calcium (AZ), N/boron (ER), N/manganese (AZ), and N/zinc (ER) may be needed to optimize growth and minimize nutrient inputs. Increasing N availability altered uptake efficiency, root absorption capacity, aboveground demand, and nutrient use efficiency for several nutrients, indicating that changes in N management practices need to consider how altering N application rates may influence the plant's ability to take up and use other nutrients. This information can be used to develop fertilizer formulations to minimize excess application of nutrients and to evaluate the potential effects of altering N management practices on use of production resources. Our results indicate that nutrient management strategies for perennial crops such as Rhododendron need to take into consideration not only the nutrient demand for current growth, but also how to optimize nutrient availability for uptake that contributes to future growth potential and end-product quality.
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Rozane, Danilo Eduardo, Betania Vahl de Paula, George Wellington Bastos de Melo, Eduardo Maciel Haitzmann dos Santos, Edicarla Trentin, Carina Marchezan, Lincon Oliveira Stefanello da Silva et al. "Compositional Nutrient Diagnosis (CND) Applied to Grapevines Grown in Subtropical Climate Region". Horticulturae 6, n. 3 (4 settembre 2020): 56. http://dx.doi.org/10.3390/horticulturae6030056.
Testo completoAbstract (sommario):
Soil analysis is used to estimate nutrient availability, but nutrient concentrations are not always related to yield in most fruit plants, including grapevines. Thus, additional multivariate mathematical models, such as the compositional nutrient diagnosis (CND), which takes into account leaves nutrient concentration, and yield, can contribute to estimating critical levels or sufficiency bands of elements, as well as to detect deficiency and/or excess of nutrients. The aim of the present study was to establish CND standards, and the critical level and sufficiency band of nutrients, in the grapevine Vitis vinifera L., grown in a subtropical climate region. Leaves were collected in 81 vineyards in the Campanha Gaúcha do Rio Grande do Sul region, Southern Brazil, and analyzed for macro- and micro-nutrient concentration. The yield of each vineyard was assessed. Grapevine nutritional status was calculated through the CND method. CND-r2 indices were effective in establishing the nutritional status of grapevines for macro- and micro-nutrients as sub-optimal, excessive, or balanced. The CND methodology established the critical level and sufficiency bands of nutrients more accurately than the current recommendations for grapevines. Multi-nutrient associations were more effective than the single nutrient determination in defining the threshold of a given nutrient that can reduce grapevine yield.
21
Scalon, Marina Corrêa, Imma Oliveras Menor, Renata Freitag, Karine S. Peixoto, Sami W. Rifai, Beatriz Schwantes Marimon, Ben Hur Marimon Junior e Yadvinder Malhi. "Contrasting strategies of nutrient demand and use between savanna and forest ecosystems in a neotropical transition zone". Biogeosciences 19, n. 15 (5 agosto 2022): 3649–61. http://dx.doi.org/10.5194/bg-19-3649-2022.
Testo completoAbstract (sommario):
Abstract. The total demand for and uptake of nutrients by vegetation is rarely quantified or compared across vegetation types. Here, we describe different nutrient use and allocation strategies in neotropical savanna (cerrado) and transitional forest (cerradão) tree communities composed of different species, report leaf nutrient resorption and calculate ecosystem-level nutrient use efficiency. We couple net primary productivity (NPP) estimates with nutrient stoichiometry to quantify nutrient demand and nutrient flows at the whole-stand scale for different components of vegetation biomass. Species from the two vegetation communities showed similar mean nutrient concentrations and nutrient resorption efficiency, except for wood P concentration that was fourfold higher in cerrado than cerradão species. The cerradão showed higher canopy NPP, while fine roots and wood NPP were similar for the two vegetation types. Nutrient requirement in the two vegetation types was dominated by the demands of the canopy, with canopy resorption generally contributing more than 50 % of the total canopy demand for nutrients, while less than 35 % of N, P, K, Ca and Mg were allocated to wood or fine roots. Proportionally, cerrado showed higher nutrient demand from fine roots (over 35 % of the total nutrient demand) and for the wood component (over 13 % of the total nutrient demand), while ∼ 60 %–70 % of the cerradão nutrient demand was allocated to the canopy. The proportional difference in nutrient allocation to the different biomass components suggests cerrado species allocate less nutrients to a given fine root biomass, but more nutrients to a given wood biomass. Our findings suggest that cerradão species are more limited in P and K than cerrado species, inducing higher resorption to compensate for low uptake. Moreover, we found that N uptake for cerradão was higher with lower N use efficiency, i.e. the amount of production per nutrient unit, leading higher N demand compared to the cerrado. This difference in nutrient dynamics explains how similar soils and the same climate dominated by savanna vegetation can also support forest-like formations. Tree species composition is likely the major factor regulating nutrient use, limiting vegetation transitions and influencing nutrient demand at landscape scales.
22
Song, Jinnan, Jingli Yang e Byoung Ryong Jeong. "Characterization of Physiology, Photosynthesis, and Nutrition Based on Induced Deficiencies of Macro- and Micronutrients in Basil (Ocimum basilicum L.)". Agronomy 14, n. 1 (17 gennaio 2024): 208. http://dx.doi.org/10.3390/agronomy14010208.
Testo completoAbstract (sommario):
Basil (Ocimum basilicum L.) contains abundant nutrients and is considered an economically important edible vegetable. The optimal nutrient levels will increase the productivity and basil quality. However, prominent research on basil regarding the diagnostic nutrient deficiency standard and the corresponding nutrient uptake is still scarce. To this end, the basil plants were hydroponically cultured and subjected to one of 14 nutrient solution treatments, corresponding to the omission of a single nutrient element (designated as -N, -P, -K, -Ca, -Mg, -NH4+, -NO3−, -S, -Fe, -Mn, -B, -Zn, -Mo, and -Cu) and a complete nutrient solution (CS) as the control. The most common nutrient deficiency symptoms were chlorosis, stunted roots and growth, and even leaf necrosis and abscission, in particular of -N, -P, -NO3−, and -Fe. We also found that basil is a NH4+-sensitive species. The photosynthetic capacity (photosynthesis pigments, Fv/Fm ratio, and greenness index) was disturbed to varying degrees when a single nutrient was omitted from the nutrient solution. Additionally, the omission of a specific single nutrient confers significant differences in the tissue nutrients, regardless of the macronutrients and micronutrients considered. Concomitantly, multivariate analysis suggested the correlations among certain important nutrients were distinctly different under different treatments (correlation analysis); the influences of different nutrient deficiencies on the tissue nutrient concentrations showed similarity (principal component analysis). Collectively, the growth, physiological, and biochemical changes studied in this trial not only improved our knowledge for diagnosing nutrient deficiency symptoms for practical cultivation but also provided a comprehensive understanding of the internal nutrient associations in basil.
23
Benmoussa, Mohamed, e Laurent Gauthier. "Modeling Nutrient Uptake and Prolonged Use of Nutrient Solutions in Soilless Tomato Culture". HortScience 30, n. 4 (luglio 1995): 761F—761. http://dx.doi.org/10.21273/hortsci.30.4.761f.
Testo completoAbstract (sommario):
In soilless culture, the buffering capacity of the root environment for nutrients is low. This, combined with fluctuations of climatic factors and changes in nutrient uptake rates, can lead to nutrient imbalances. In order to achieve high yield and better quality, it is necessary to keep the nutrient concentrations in the root environment at the target levels. This requires frequent analysis and adjustments to the nutrient solution. Currently, leaching of the growing media or renewal of the nutrient solution is commonly used to avoid accumulation or depletion of nutrient in the root environment. However, this practice lowers the efficiency of fertilizers and can lead to the contamination of the ground water. One way to remedy to this problem is through the use of nutrients uptake models to track the composition of the nutrient solutions. The objective of this study was to develop such models. Such models can be used to maintain balanced nutrient solutions for longer periods. This can lead to reduced leaching and improved fertilizer use efficiency. Macronutrient (N, P, K, Ca, and Mg) uptake models were developed for tomato plants grown in an NFT system using data collected from experiments conducted in the Laval Univ. greenhouses. Analysis of the experimental results showed that the main factors affecting nutrients uptakes are light and transpiration.
24
Benmoussa, Mohamed, e Laurent Gauthier. "Modeling Nutrient Uptake and Prolonged Use of Nutrient Solutions in Soilless Tomato Culture". HortScience 30, n. 4 (luglio 1995): 761F—761. http://dx.doi.org/10.21273/hortsci.30.4.761.
Testo completoAbstract (sommario):
In soilless culture, the buffering capacity of the root environment for nutrients is low. This, combined with fluctuations of climatic factors and changes in nutrient uptake rates, can lead to nutrient imbalances. In order to achieve high yield and better quality, it is necessary to keep the nutrient concentrations in the root environment at the target levels. This requires frequent analysis and adjustments to the nutrient solution. Currently, leaching of the growing media or renewal of the nutrient solution is commonly used to avoid accumulation or depletion of nutrient in the root environment. However, this practice lowers the efficiency of fertilizers and can lead to the contamination of the ground water. One way to remedy to this problem is through the use of nutrients uptake models to track the composition of the nutrient solutions. The objective of this study was to develop such models. Such models can be used to maintain balanced nutrient solutions for longer periods. This can lead to reduced leaching and improved fertilizer use efficiency. Macronutrient (N, P, K, Ca, and Mg) uptake models were developed for tomato plants grown in an NFT system using data collected from experiments conducted in the Laval Univ. greenhouses. Analysis of the experimental results showed that the main factors affecting nutrients uptakes are light and transpiration.
25
Gao, Jie, Jiangfeng Wang e Yanhong Li. "Effects of Soil Nutrients on Plant Nutrient Traits in Natural Pinus tabuliformis Forests". Plants 12, n. 4 (7 febbraio 2023): 735. http://dx.doi.org/10.3390/plants12040735.
Testo completoAbstract (sommario):
In light of global warming, the interaction between plant nutrient traits and soil nutrients is still unclear. Plant nutrient traits (e.g., N and P) and their stoichiometric relationships (N/P ratio) are essential for plant growth and reproduction. However, the specific role of soil nutrients in driving variation in plant nutrient traits remains poorly understood. Fifty natural Pinus tabuliformis forests were used as the research object to clarify the interaction between plant nutrient traits and soil nutrients. We show that: (1) The Nmass, Pmass and N/P ratios of leaves were significantly higher than those of roots. The N/P ratio of both leaves and roots was less than 14. (2) Leaf nutrient traits showed diverse relationship patterns with root nutrient traits throughout the growing period. Significant changes were found in root nutrient PC2 (the second principal component of root nutrient traits) and leaf nutrient PC1 (the first principal component of leaf traits), and non-significant changes were found in other relationships between leaf and root traits (p > 0.05). Root nutrient traits explained 36.4% of the variance in leaf nutrient traits. (3) With the increase in soil nutrient PC2 (related to N), leaf PC2 (related to N) showed a significant trend of first decreasing and then increasing (p < 0.05). Only the soil Nmass was significantly correlated with the leaf Nmass (p < 0.05), which demonstrated that the growth and survival of Pinus tabuliformis forests were mainly affected by N-limitation.
26
Anderson, Wendy B., e William G. Eickmeier. "Physiological and morphological responses to shade and nutrient additions of Claytonia virginica (Portulacaceae): implications for the "vernal dam" hypothesis". Canadian Journal of Botany 76, n. 8 (1 agosto 1998): 1340–49. http://dx.doi.org/10.1139/b98-134.
Testo completoAbstract (sommario):
Because of their unique phenology and physiology, spring ephemeral herbs are believed to play an important role in intrasystem nutrient cycling in deciduous forest ecosystems. It was hypothesized that they function as a "vernal dam" by temporarily sequestering nutrients and preventing leaching from the system during a period of high nutrient availability. However, spring ephemerals require high-irradiance growing conditions. How do their physiological and morphological responses to ambient light and shade limit their ability to sequester excess nutrients? We performed field experiments using Claytonia virginica L. as a model to test several responses to shade and increasing levels of nutrient additions. We also examined the biomass responses and nutrient storage capacities of other spring ephemeral herbs. In C. virginica, shading reduced ribulose 1,5-bisphosphate carboxylase-oxygenase (Rubisco) activity, photosynthesis rate, specific leaf weight, leaf width/length (W/L), and biomass; nutrient additions increased W/L and biomass only under unshaded conditions. Other herbs responded similarly but reached maximum biomass at lower nutrient addition levels than C. virginica. Shading reduced and nutrient additions increased nitrogen and phosphorus concentrations in both C. virginica and other herbs. Shaded herbs generally reached nutrient saturation at lower nutrient addition levels than unshaded herbs. Overall, unshaded plants sequestered larger amounts of nutrients than shaded plants. This pattern is best explained by a reduction in biomass under shaded conditions. We concluded that C. virginica and other spring herbs, although important components in forest nutrient cycling in the early spring, are limited in their capacity to store excess nutrients, particularly when shaded.Key words: Claytonia virginica, nutrient cycling, spring ephemerals, vernal dam.
27
Grant, Cynthia, Noura Ziadi, Bernard Gagnon, Don Flaten e Jeff Schoenau. "Integrating knowledge of nutrient forms and dynamics into improved nutrient management practices: Atribute to Régis Simard". Canadian Journal of Soil Science 89, n. 2 (1 maggio 2009): 133–44. http://dx.doi.org/10.4141/cjss07095.
Testo completoAbstract (sommario):
Régis Simard and his colleagues developed a research program focussing on the agronomic and environmental impacts of nutrients in agricultural systems. The success of this program resulted from an integrated approach, linking assessment of nutrient availability to an understanding of nutrient dynamics in the soil, and applying this understanding to development of improved management practices for a variety of nutrient sources. Research into nutrient availability conducted by Régis and his co-workers led to improvements in quantification of nutrient supply, using traditional soil analysis with batch chemical extraction as well as ionic exchange membranes (IEMs) and electro-ultrafiltration (EUF). Ion exchange membranes are now used as a tool in routine soil fertility assessments and in agronomic and environmental research to study nutrient ion release rates. Additionally, intensive analytical techniques, such as sequential extraction and X-ray absorption near-edge structure (XANES) were developed and used to characterize the forms and relative availability of soil nutrients for plant uptake or environmental effects. Characterization of nutrient pools improved understanding of nutrient dynamics in the soil, allowing a more accurate assessment of the agronomic value and environmental risk of nutrients applied to agricultural systems. Building on this knowledge, Régis and his colleagues developed improved methods of utilizing manures, composts, paper mill sludge (PMS) and liming by-products, effectively diverting nutrients from the waste stream into a resource for crop production. This paper describes the contributions of Régis and his colleagues to the improvement of agronomically and environmentally sustainable nutrient management practices, based on an integrated research approach that provided a clear understanding nutrient availability and soil nutrient dynamics. Key words: Chemical extraction, integrated nutrient management, ion exchange membranes, paper mill sludge, soil phosphorus, soil potassium
28
May, Geoffrey M., e Marvin P. Pritts. "Phosphorus, Zinc, and Boron Influence Yield Components in `Earliglow' Strawberry". Journal of the American Society for Horticultural Science 118, n. 1 (gennaio 1993): 43–49. http://dx.doi.org/10.21273/jashs.118.1.43.
Testo completoAbstract (sommario):
The main effects and interactions of soil-applied P, B, and Zn on yield and its components were examined in the field at two pH levels with `Earliglow' strawberries (Fragaria × ananassa Duch.). Applied nutrients had significant effects on several yield components, but responses depended on the levels of other nutrients or the soil pH At a soil pH of 5.5, yield responded linearly to B and quadratically to P. At pH 6.5, P interacted with B and Zn. Fruit count per inflorescence was the yield component most strongly associated with yield followed by individual fruit weight. However, these two yield components responded differently to soil-applied nutrients. Foliar nutrient levels generally did not increase with the amount of applied nutrient, but often an applied nutrient had a strong effect on the level of another nutrient. Leaf nutrient levels were often correlated with fruit levels, but foliar and fruit levels at harvest were not related to reproductive performance. Our study identifies some of the problems inherent in using foliar nutrient levels to predict a yield response and demonstrates how plant responses to single nutrients depend on soil chemistry and the presence of other nutrients.
29
Masriah, Masriah. "Pengaruh Berbagai Perlakuan Nutrisi Larutan Hidroponik Pada Pertumbuhan Tanaman Kangkung (Ipomoea aquatica)". BIOSCIENTIAE 17, n. 2 (2 giugno 2021): 47. http://dx.doi.org/10.20527/b.v17i2.3452.
Testo completoAbstract (sommario):
Hydroponic cultivation systems are often applied to overcome the shortage of agricultural land in this case food crops, especially vegetables. Nutrient Film Technique (NFT) is the one of various ways to grow crops hydroponically. Hydroponic systems are carried out without the use of soil media and it can be an alternative solution for the efficient use of land. Uniformity of nutrients and nutrient solution concentration levels required to be adjusted. Nutrient solution as a water supply source and minerals. Nutrition is an important factor for the growth and quality of hydroponic plants should be appropriate in terms of the number of ion composition of nutrients. This study aimed to determined the effect of various treatments of hydroponic nutrient solution on plant growth kale. This study used a completely randomized design (CRD) with 4 treatments and 5 replications. Kale seed sowing in the growing media rockwool and nourished by nutrient A, nutrient B, combination of nutrients A and B (3: 1), or a combination of nutrients A and B (1: 3). Plant growth parameters such as plant height, number of leaves, wet weight, dry weight, and dry weight without root measured. Data were analyzed using analysis of variance ANOVA and DMRT test with α = 95%. The results showed that affect the nutrient solution hydroponic plant growth kale. Kale plants with a combination of nutrient A and nutrient B ratio of 3: 1 (treatment C) give the best response compared with other treatments.
30
Moore, C. Mark. "Diagnosing oceanic nutrient deficiency". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 374, n. 2081 (28 novembre 2016): 20150290. http://dx.doi.org/10.1098/rsta.2015.0290.
Testo completoAbstract (sommario):
The supply of a range of nutrient elements to surface waters is an important driver of oceanic production and the subsequent linked cycling of the nutrients and carbon. Relative deficiencies of different nutrients with respect to biological requirements, within both surface and internal water masses, can be both a key indicator and driver of the potential for these nutrients to become limiting for the production of new organic material in the upper ocean. The availability of high-quality, full-depth and global-scale datasets on the concentrations of a wide range of both macro- and micro-nutrients produced through the international GEOTRACES programme provides the potential for estimation of multi-element deficiencies at unprecedented scales. Resultant coherent large-scale patterns in diagnosed deficiency can be linked to the interacting physical–chemical–biological processes which drive upper ocean nutrient biogeochemistry. Calculations of ranked deficiencies across multiple elements further highlight important remaining uncertainties in the stoichiometric plasticity of nutrient ratios within oceanic microbial systems and caveats with regards to linkages to upper ocean nutrient limitation. This article is part of the themed issue ‘Biological and climatic impacts of ocean trace element chemistry’.
31
Schoenau, J. J., e J. G. Davis. "Optimizing soil and plant responses to land-applied manure nutrients in the Great Plains of North America". Canadian Journal of Soil Science 86, n. 4 (1 agosto 2006): 587–95. http://dx.doi.org/10.4141/s05-115.
Testo completoAbstract (sommario):
Animal manures are recognized as valuable sources of plant nutrients in cropping systems and also play a role in soil improvement through the input of organic matter. Using recent research examples from Saskatchewan and Colorado, this paper covers beneficial management practices for effective recycling of manure nutrients applicable to the Great Plains region of North America. Challenges in using animal manures as fertilizers include low nutrient content per unit weight, variability and availability of nutrient content, and a balance of available nutrients that often does not meet the relative nutrient requirements of the crop. Examples of imbalances that may arise requiring special management considerations include low available N content relative to available P for many solid manures, and low available S relative to N for some liquid manures. Application decisions are best supported by manure and soil analyses, with nutrient balance issues addressed by rate adjustments and the addition of supplemental commercial fertilizer to avoid deficiency or loading of specific nutrients. Placement of manure into the soil by injection or incorporation is desirable in that nutrient losses by volatilization and runoff are reduced and crop recovery is increased. Balancing the rate of nutrient application with crop requirement and removal over time is key to avoiding nutrient loading on soils receiving repeated applications of manure. Key words: Manure management, nutrient cycling, beneficial management practices, Great Plains
32
Gautam, Tilak Prasad, e Tej Narayan Mandal. "Storage and Flux of Nutrients in Disturbed and Undisturbed Tropical Moist Forest of Eastern Nepal". International Journal of Forestry Research 2018 (18 ottobre 2018): 1–12. http://dx.doi.org/10.1155/2018/8516321.
Testo completoAbstract (sommario):
The disturbance activities in tropical forests shrink the nutrient cycling between the vegetation and soil. To understand the nutrient cycling in undisturbed and disturbed stands of mixed deciduous tropical forest of eastern Nepal, plant biomass was estimated within seventy randomly established sampling plots. The biomass values were multiplied with nutrient concentration of respective parts to estimate the nutrient stocks. The nutrient concentrations varied widely amongst components. In trees, concentrations of all nutrients were highest in leaves followed in decreasing order by fine roots (<5 mm) and twigs and then by branches, bole, and coarse roots. The contribution of different components to total nutrient stocks was in the following order: tree > stand fine root > shrub > herb, in both stands. The relative contribution of different components of trees to total nutrient stocks was in the following order: bole > coarse root > branch > leaf > twig > fine roots. In trees, leaves and fine roots had greater gross uptake of nutrients than other components. The concentrations of different nutrients in the plants are in the following order: nitrogen > potassium > phosphorus. Total nutrient return to the soil through the litterfall is almost 1.5 times greater than that from fine roots in both forests. In conclusion, various types of forest disturbances had adverse effect on the nutrient stocks and nutrient dynamics.
33
TS, Pradeep, Vanathi D, Udhya Kumar K, Mohana Priya R e Balaganesh B. "Nutrient Balance and Nutrient Use Efficiency of Irrigated Pigeon Pea [Cajanus cajan (L.) Millsp.] under Various Integrated Nutrient Management Practices". Journal of Experimental Agriculture International 46, n. 6 (30 aprile 2024): 170–77. http://dx.doi.org/10.9734/jeai/2024/v46i62468.
Testo completoAbstract (sommario):
Aims: To evaluate the nutrient balance and nutrient use efficiency of irrigated pigeon peas under various integrated fertilizers Place and Duration of Study: The field trial was conducted at Instructional Farm (North), Karunya Institute of Technology and Sciences, Coimbatore. Methodology: During the growth phase of the pigeon pea crop, the soil's nitrogen, phosphorus, and potassium levels were monitored to assess their essential nutrient balance. This evaluation was conducted for each treatment, considering the specific nutrient application given to the crop. Additionally, the total quantity of nutrient uptake and the efficiency of nitrogen, phosphorus, and potassium utilization were calculated. Results: Higher availability of nutrients and nutrient uptake at harvest and the maximum values of computed balance and gain values in the nutrient balance studies and agronomic efficiency were observed in the integrated application of 75% RDF + 25% N eq as vermicompost (T2) Conclusion: The integrated application of 75% RDF + 25% N eq as vermicompost (T2) resulted in maximum available nutrients, plant uptake, agronomic efficiency and computed balance nutrient gain.
34
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.
35
Marinov, I., S. C. Doney e I. D. Lima. "Response of ocean phytoplankton community structure to climate change over the 21st century: partitioning the effects of nutrients, temperature and light". Biogeosciences 7, n. 12 (2 dicembre 2010): 3941–59. http://dx.doi.org/10.5194/bg-7-3941-2010.
Testo completoAbstract (sommario):
Abstract. The response of ocean phytoplankton community structure to climate change depends, among other factors, upon species competition for nutrients and light, as well as the increase in surface ocean temperature. We propose an analytical framework linking changes in nutrients, temperature and light with changes in phytoplankton growth rates, and we assess our theoretical considerations against model projections (1980–2100) from a global Earth System model. Our proposed "critical nutrient hypothesis" stipulates the existence of a critical nutrient threshold below (above) which a nutrient change will affect small phytoplankton biomass more (less) than diatom biomass, i.e. the phytoplankton with lower half-saturation coefficient K are influenced more strongly in low nutrient environments. This nutrient threshold broadly corresponds to 45° S and 45° N, poleward of which high vertical mixing and inefficient biology maintain higher surface nutrient concentrations and equatorward of which reduced vertical mixing and more efficient biology maintain lower surface nutrients. In the 45° S–45° N low nutrient region, decreases in limiting nutrients – associated with increased stratification under climate change – are predicted analytically to decrease more strongly the specific growth of small phytoplankton than the growth of diatoms. In high latitudes, the impact of nutrient decrease on phytoplankton biomass is more significant for diatoms than small phytoplankton, and contributes to diatom declines in the northern marginal sea ice and subpolar biomes. In the context of our model, climate driven increases in surface temperature and changes in light are predicted to have a stronger impact on small phytoplankton than on diatom biomass in all ocean domains. Our analytical predictions explain reasonably well the shifts in community structure under a modeled climate-warming scenario. Climate driven changes in nutrients, temperature and light have regionally varying and sometimes counterbalancing impacts on phytoplankton biomass and structure, with nutrients and temperature dominant in the 45° S–45° N band and light-temperature effects dominant in the marginal sea-ice and subpolar regions. As predicted, decreases in nutrients inside the 45° S–45° N "critical nutrient" band result in diatom biomass decreasing more than small phytoplankton biomass. Further stratification from global warming could result in geographical shifts in the "critical nutrient" threshold and additional changes in ecology.
36
Illukpitiy, Prabodh, e Jason P. DeKoff. "An Economic Assessment of Nutrient Removal from Switchgrass Production". Research in Applied Economics 11, n. 2 (30 giugno 2019): 26. http://dx.doi.org/10.5296/rae.v11i2.14998.
Testo completoAbstract (sommario):
The on-site loss of nutrients due to biomass removal creates additional costs for ethanol production however this aspect has not been properly incorporated in economic analyses of biomass production and processing. This study investigates costs of on-site nutrient losses in switchgrass fields in Tennessee. The replacement cost methodology was applied to measure on-site cost of nutrient losses due to biomass removal and was based on the costs of replacing nutrients removed from the production site. The estimated costs for total on-site nutrient loss due to biomass removal show a substantial loss of nutrients in switchgrass fields. The loss of major nutrients from biomass removal represents the major part of on-site economic costs. A declining trend of nutrient costs per Mg of harvested biomass was observed with increasing in harvesting time. The internalization of on-site costs of nutrient losses is possible by adopting an appropriate harvest schedule for switchgrass.
37
Tiani, Kendra A., Patrick J. Stover e Martha S. Field. "The Role of Brain Barriers in Maintaining Brain Vitamin Levels". Annual Review of Nutrition 39, n. 1 (21 agosto 2019): 147–73. http://dx.doi.org/10.1146/annurev-nutr-082018-124235.
Testo completoAbstract (sommario):
It is increasingly recognized that tissue-specific nutrient deficiencies can exist in the absence of whole-body deficiency and that these deficiencies may result from disease or disease-related physiological processes. Brain and central nervous system tissues require adequate nutrient levels to function. Many nutrients are concentrated in the cerebrospinal fluid relative to the serum in healthy individuals, and other nutrients resist depletion in the presence of whole-body nutrient depletion. The endothelial, epithelial, and arachnoid brain barriers work in concert to selectively transport, concentrate, and maintain levels of the specific nutrients required by the brain while also blocking the passage of blood-borne toxins and pathogens to brain and central nervous system tissues. These barriers preserve nutrient levels within the brain and actively concentrate nutrients within the cerebrospinal fluid and brain. The roles of physical and energetic barriers, including the blood–brain and blood–nerve barriers, in maintaining brain nutrient levels in health and disease are discussed.
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Elsdon, Travis S., e Karin E. Limburg. "Nutrients and their duration of enrichment influence periphyton cover and biomass in rural and urban streams". Marine and Freshwater Research 59, n. 6 (2008): 467. http://dx.doi.org/10.1071/mf07085.
Testo completoAbstract (sommario):
Although it is well known that land use affects nutrient dynamics and algal growth in streams, the responses to different durations of nutrient supply are poorly understood. The associations of benthic (periphyton-dominated) biomass with concentrations of dissolved nitrogen and phosphorus in rural and urban streams in New York were quantified. Biomass was significantly greater (2-fold) in the urban compared with the rural stream, which was associated with differences in dissolved nutrients. Experimental field enrichment of nutrient concentrations and duration of exposure altered benthic periphyton. Increasing nutrients by 60–99% of ambient concentrations increased periphyton percentage cover and biomass. Periphyton abundance also increased with increasing duration of exposure to nutrients (2, 4 and 8 weeks); however, short-term pulses of nutrients (2 weeks) had no significant effect in the rural stream. These results indicate that effective management of nutrient delivery, by reducing time periods of high nutrient load, will minimise impacts to benthic environments.
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Pandey, Meena, Jiban Shrestha, Subash Subedi e Kabita Kumari Shah. "ROLE OF NUTRIENTS IN WHEAT: A REVIEW". Tropical Agrobiodiversity 1, n. 1 (18 giugno 2020): 18–23. http://dx.doi.org/10.26480/trab.01.2020.18.23.
Testo completoAbstract (sommario):
Wheat (Triticum aestivum L.) is an important cereal crop that provides ample nutritious calories for humans and animals. The nutrient plays a vital role in the production of wheat. In this review, previous works were evaluated to investigate the role of nutrients, nutrient deficiency and toxicity in wheat. Both macro and micronutrients are necessary for wheat plants. Every nutrient has its own character and is involved in different metabolic processes of plant life. Nutrient deficiency and toxicity conditions inhibit normal plant growth and exhibit characteristic symptoms. For optimal growth, development, and production, plants need all the necessary nutrients in balance. A balanced application of the primary nutrients (N, P, K), secondary nutrient (S) and some other micronutrients (Zn, B) are needed to enhance wheat production. The soil tests and the demand for crop nutrients should be assessed to identify the quantity of fertilizer recommended for the crop. This study would be a valuable means to wheat growers and researchers for sustainable and higher wheat production.
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Liu, Ao, Aixi Han e Li Chai. "Assessing the Nutrient Adequacy in China’s Food Supply from 1965 to 2018". Nutrients 13, n. 8 (9 agosto 2021): 2734. http://dx.doi.org/10.3390/nu13082734.
Testo completoAbstract (sommario):
Nutritional intake has important impacts on human health. A sufficient supply of nutrients is required to ensure high-level nutrition in a population. Assessment of nutrient supply adequacy can help to develop evidence-based policies and thereby promote public health. This study estimates the supply adequacy of nutrients in China’s food system from 1965 to 2018 at the national level, aiming to reveal whether the supply of nutrients meets the demand. The results show that the nutrient supply in China’s food system has experienced a sharp increase in the past five decades, and the deficiency in nutrient supply has been greatly mitigated. Although most nutrients such as potassium are already sufficiently supplied in China’s current food system, some nutrients, especially calcium and zinc, still need a further enlarged supply to improve the nutrition condition of the Chinese population. Besides encouraging a healthy diet, supply-side regulation, e.g., fortification and enrichment, is also needed to improve nutrient availability. This study helps people better understand the development and current situation of nutrient adequacy in China’s food supply, thereby providing information and implications for policymakers.
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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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Zhang, Peng, Zhiyi Cui, Xiaojin Liu e Daping Xu. "Above-Ground Biomass and Nutrient Accumulation in Ten Eucalyptus Clones in Leizhou Peninsula, Southern China". Forests 13, n. 4 (29 marzo 2022): 530. http://dx.doi.org/10.3390/f13040530.
Testo completoAbstract (sommario):
Selecting suitable clones and regulating nutrients for Eucalyptus plantation are a key management practice for improving productivity and nutrient use. Therefore, this study evaluated growth performance, above-ground biomass, nutrient content (nitrogen, phosphorus, potassium, calcium, and magnesium) and nutrient use efficiency (NUE) of ten Eucalyptus Clones for three sites in Leizhou Peninsula. The present study showed a significant genetic variation among clones in growth parameters. Organs have different characteristics in biomass and nutrient content. Stemwood had the highest biomass but lowest total nutrient concentration. While, the stembark exhibited high contents of nutrients and biomass. On average, the NUE of clones was in the following order: phosphorus > magnesium > nitrogen > potassium > calcium. Taken together, among ten clones tested, clones LH1-9211, TH9224, DH32-13, M1 and DH32-22 showed consistently growth and production performance, as well, their NUE were superior in ten clones. Maximum amount of biomass was allocated to economically harvestable component (stemwood) and nutrients in non-harvestable components (stembark and foliage). While nutrients are removed from the planting area as part of the harvest, we can calculate nutrients loss by NUE and biomass. These findings provided useful insights for selection of Eucalyptus Clones and regulating nutrient export during the harvest of Eucalyptus Clones from a planted forest system.
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Mitra, Aditee, e Kevin J. Flynn. "Promotion of harmful algal blooms by zooplankton predatory activity". Biology Letters 2, n. 2 (marzo 2006): 194–97. http://dx.doi.org/10.1098/rsbl.2006.0447.
Testo completoAbstract (sommario):
The relationship between algae and their zooplanktonic predators typically involves consumption of nutrients by algae, grazing of the algae by zooplankton which in turn enhances predator biomass, controls algal growth and regenerates nutrients. Eutrophication raises nutrient levels, but does not simply increase normal predator–prey activity; rather, harmful algal bloom (HAB) events develop often with serious ecological and aesthetic implications. Generally, HAB species are outwardly poor competitors for nutrients, while their development of grazing deterrents during nutrient stress ostensibly occurs too late, after the nutrients have largely been consumed already by fast-growing non-HAB species. A new mechanism is presented to explain HAB dynamics under these circumstances. Using a multi-nutrient predator–prey model, it is demonstrated that these blooms can develop through the self-propagating failure of normal predator–prey activity, resulting in the transfer of nutrients into HAB growth at the expense of competing algal species. Rate limitation of this transfer provides a continual level of nutrient stress that results in HAB species exhibiting grazing deterrents protecting them from top-down control. This process is self-stabilizing as long as nutrient demand exceeds supply, maintaining the unpalatable status of HABs; such events are most likely under eutrophic conditions with skewed nutrient ratios.
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Aarons, Sharon R., Cameron J. P. Gourley e J. Mark Powell. "Estimating Excreted Nutrients to Improve Nutrient Management for Grazing System Dairy Farms". Animals 13, n. 8 (19 aprile 2023): 1404. http://dx.doi.org/10.3390/ani13081404.
Testo completoAbstract (sommario):
Improving nutrient management in grazing system dairy farms requires determining nutrient flows through animals, the placement of cows within farms and potential for collection, and the re-use and loss of nutrients. We applied a model incorporating data collected at a range of temporal and spatial scales to quantify nutrient excretion in all locations that lactating herds visited on five days over a year on 43 conventional and organic grazing system dairy farms. The calculated nutrient loads excreted by cows in different places were highly skewed; while N, P and K deposited loads were consistent across the year, S, Ca and Mg loads varied between sampling times and seasons. The greatest mean and range in nutrient loads were deposited in paddocks, with the smallest amounts deposited in dairy sheds. All excreted nutrient loads increased with farm and herd sizes and milk production. Mean daily loads of 112, 15, 85, 11, 22 and 13 kg of N, P, K, S, Ca and Mg were deposited by the herds which, when standardised to a 305-day lactation, amounted to 24, 4, 20, 3, 5 and 3 t excreted annually, respectively. In addition to routine manure collection in dairy sheds, ensuring collection and recycling of nutrients excreted on feed pads and holding areas would decrease potential nutrient losses by 29% on average. Non-collected, recycled nutrients were disproportionately returned to paddocks in which cows spent time overnight, and except for S and Ca, nutrient loading rates were greater than rates applied as fertilisers. These data demonstrate the extent of excreted nutrients in grazing dairy systems and indicate the need to account for these nutrients in nutrient management plans for Australian dairy farms. We propose incorporating excretion data in current budgeting tools using data currently collected on most Australian grazing system dairy farms.
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Roberts, Roland K. "Plant Nutrient Demand Functions for Tennessee with Prices of Jointly Applied Nutrients". Journal of Agricultural and Applied Economics 18, n. 2 (dicembre 1986): 107–12. http://dx.doi.org/10.1017/s0081305200006154.
Testo completoAbstract (sommario):
AbstractSeveral studies have estimated plant nutrient demand functions for nitrogen, phosphate, and potash. All included own-price effects but excluded prices of jointly applied nutrients. In this study, nutrient demand functions, which include prices of all three nutrients, are estimated for Tennessee by seemingly unrelated regression. Results suggest that cross-price eflfects are important in determining plant nutrient demand, at least in the case of Tennessee, and that multicollinearity need not be a hindrance in all cases to including cross-price eflfects in plant nutrient demand models.
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Mukhina, Irina, Elena Rizhiya e Tatiana Bankina. "Biochar Effect on Nutrients Availability to Barley". Environmental Research, Engineering and Management 76, n. 2 (3 luglio 2020): 43–53. http://dx.doi.org/10.5755/j01.erem.76.2.21854.
Testo completoAbstract (sommario):
Biochar can serve as a soil ameliorant preventing nutrient leaching. Due to its porous structure and chemical composition, it can also adsorb elements on its surface. However, various biochars have different sorption ability, and the mechanistic understanding of nutrient storage in biochar is missing. It is not clear if nutrients adsorbed by biochar will be available for plants. Therefore, it is necessary to investigate biochar efficacy in pure substrates to characterise its specific influence on plants. In this study, the sorption capacity and ability of the wood-based biochar to provide barley plants with nutrients was investigated. The sorption capacity of biochar was investigated by saturating it with Gelrigel nutrient solution. Then nutrient-enriched biochar was tested for its effect on barley growth in comparison with non-enriched biochar. The results of the sorption experiment showed that the wood-based biochar could adsorb high amounts of nutrients such as ammonium (NH4+), potassium, calcium and phosphate (PO43-), but not nitrate (NO3-). Nutrient-enriched biochar showed an ability to support 46% higher dry biomass of barley than non-enriched biochar. These results suggest a potential of nutrient-enriched biochar for recovering essential nutrients for plants.
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Cai, Zhi-quan, e Frans Bongers. "Contrasting nitrogen and phosphorus resorption efficiencies in trees and lianas from a tropical montane rain forest in Xishuangbanna, south-west China". Journal of Tropical Ecology 23, n. 1 (gennaio 2007): 115–18. http://dx.doi.org/10.1017/s0266467406003750.
Testo completoAbstract (sommario):
Tropical montane rain forest is widely considered to be a highly threatened hotspot of global diversity (Brummitt & Nic Lughadha 2003), and one of the least understood humid tropical forest ecosystems in terms of nutrient cycling (Bruijnzeel & Proctor 1995). There is, therefore, an urgent need to improve our understanding of nutrient cycling processes in this ecosystem, including the absorption of nutrients (mainly N and P) from senescing leaves, which may be a key component of adaptive mechanisms that conserve limiting nutrients (Killingbeck 1996). Nutrients which are not resorbed, however, will be circulated through litterfall in the longer term (Aerts 1996). The degree of nutrient resorption affects litter quality, which consequently affects decomposition rates and soil nutrient availability (Aerts & Chapin 2000). The importance of resorption in nutrient conservation has led to general hypotheses that species adapted to nutrient-poor environments have high resorption efficiencies (Richardson et al. 2005), and that low leaf nutrient concentrations are associated with high resorption efficiencies within species (Aerts 1996, Kobe et al. 2005). Nutrient resorption has also been shown not to differ greatly between growth forms (e.g. shrubs, grasses, forbs and trees) (Aerts 1996). However, its relative importance among plant functional groups is still highly controversial (Richardson et al. 2005).
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Parent, Léon-Étienne. "Diagnosis of the nutrient compositional space of fruit crops". Revista Brasileira de Fruticultura 33, n. 1 (marzo 2011): 321–34. http://dx.doi.org/10.1590/s0100-29452011000100041.
Testo completoAbstract (sommario):
Tissue analysis is a useful tool for the nutrient management of fruit orchards. The mineral composition of diagnostic tissues expressed as nutrient concentration on a dry weight basis has long been used to assess the status of 'pure' nutrients. When nutrients are mixed and interact in plant tissues, their proportions or concentrations change relatively to each other as a result of synergism, antagonism, or neutrality, hence producing resonance within the closed space of tissue composition. Ternary diagrams and nutrient ratios are early representations of interacting nutrients in the compositional space. Dual and multiple interactions were integrated by the Diagnosis and Recommendation Integrated System (DRIS) into nutrient indexes and by Compositional Nutrient Diagnosis into centered log ratios (CND-clr). DRIS has some computational flaws such as using a dry matter index that is not a part as well as nutrient products (e.g. NxCa) instead of ratios. DRIS and CND-clr integrate all possible nutrient interactions without defining an ad hoc interactive model. They diagnose D components while D-1 could be diagnosed in the D-compositional Hilbert space. The isometric log ratio (ilr) coordinates overcome these problems using orthonormal binary nutrient partitions instead of dual ratios. In this study, it is presented a nutrient interactive model as well as computation methods for DRIS and CND-clr and CND-ilr coordinates (CND-ilr) using leaf analytical data from an experimental apple orchard in Southwestern Quebec, Canada. It was computed the Aitchison and Mahalanobis distances across ilr coordinates as measures of nutrient imbalance. The effect of changing nutrient concentrations on ilr coordinates are simulated to identify the ones contributing the most to nutrient imbalance.
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Lancaster, Phillip A., DeAnn Presley, Walt Fick, Dustin Pendell, Adam Ahlers, Andrew Ricketts e Minfeng Tang. "224 Net Nutrient Conversion of Human-Edible Nutrients in the Beef Supply Chain". Journal of Animal Science 100, Supplement_2 (12 aprile 2022): 108. http://dx.doi.org/10.1093/jas/skac064.182.
Testo completoAbstract (sommario):
Abstract Beef is a good source of several vitamins and minerals but data on the net contribution to the human diet is lacking. The objective was to quantify the net nutrient contribution of the beef supply chain to Fe, Zn, Se, P, B12, B6, riboflavin, niacin, and choline in the human diet. Beef cattle production parameters for the beef supply chain were as described by Baber et al. (2018; 10.1093/tas/txy086) with the red meat and liver yield from each production segment estimated using literature values of serially harvested beef cattle. Nutrient concentration of feeds was acquired from feed composition tables in beef, swine, poultry, and equine nutrient requirement texts, and the nutrient concentration of beef and liver was based on 2018 USDA Food and Nutrient Database for Dietary Studies. Nutrient absorption values of feeds, red meat, and liver were acquired from the literature for humans or swine if human studies were unavailable. The human-edible conversion ratio was < 1.0 for all nutrients except for P and B12 when only red meat yield was considered indicating that the beef supply chain consumed more human-edible nutrients than it produced. Results were similar when liver yield was added although the ratios were closer to 1 for other nutrients. After adjusting for the absorptability of nutrients, the beef supply chain was a net contributor of niacin, P, and B12 in the human diet with or without liver. The net nutrient contribution is driven primarily by the ratio of nutrient concentration and absorbability of nutrients in beef relative to corn. In the current production scenario, the combined ratio of nutrient concentration multiplied by the ratio of absorbability must equal 15.17 or 12.45 to achieve equilibrium between nutrient consumed and produced for red meat or red meat plus liver yield, respectively. In conclusion, current beef production system is a net contributor of human-absorbable P, B12, and niacin to the human diet.
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Xaxiri, Eirini, Evangelos Darivakis, Ioannis Karavidas, Georgia Ntatsi e Dimitrios Savvas. "Comparing the Nutritional Needs of Two Solanaceae and One Cucurbitaceae Species Grown Hydroponically under the Same Cropping Conditions". Plants 12, n. 20 (22 ottobre 2023): 3642. http://dx.doi.org/10.3390/plants12203642.
Testo completoAbstract (sommario):
Switching over to closed-loop soilless culture systems, thus preventing pollution of water resources by nitrates and saving water and fertilizers, requires accurate estimations of the mean nutrient-to-water uptake ratios. To contribute to this objective, three fruit vegetable species (tomato, eggplant, cucumber) were grown hydroponically in a floating system under identical cropping conditions to quantify species differences in nutrient uptake. The composition of the nutrient solution used to feed the crops was identical for all species. The total water consumption and the concentrations of most nutrients (K, Ca, Mg, N, P, Fe, Mn, Zn, Cu, B) in the nutrient solution and the plant tissues were measured at crop establishment and at two different crop developmental stages. The obtained data were used to determine the uptake concentrations (UCs) using two mass balance models, one based on nutrient removal from the nutrient solution and a second based on nutrient recovery in the plant tissues. The experiment was conducted in the spring–summer season. The results revealed that the nutrient uptake concentrations were substantially different between species for all nutrients except for N, while there were also significant interactions between the two methods used for their estimation of some nutrients. Thus, the UCs of N, P, Ca, and some micronutrients were significantly higher when its estimation was based on the removal of nutrients from the nutrient solution compared to recovery from plant tissues, presumably because with the first method, losses due to denitrification or precipitation could not be separated from those of plant uptake. The comparison of the three greenhouse vegetables revealed a similar UC for nitrogen, while cucumber generally showed significantly lower UCs for P and for the micronutrients Fe, Zn, and Cu at both cropping stages compared to the two Solanaceae species. The obtained results can be used to precisely adjust the nutrient supply in closed-loop soilless cultivations to the plant uptake thus avoiding both depletion and accumulation of nutrients in the root environment.