Academic literature on the topic 'Soil nitrogen status'
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Journal articles on the topic "Soil nitrogen status"
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Samokhvalova, V. L., A. O. Khristenko, L. O. Shedey, P. A. Samokhvalova, and O. V. Karatsuba. "Prediction of the different genesis soils nitrogen systems status." Ecology and Noospherology 29, no. 1 (September 23, 2018): 13–25. http://dx.doi.org/10.15421/031803.
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The method for predicting the levels of the easily hydrolysable nitrogen content in soils of various types of Polesie, Forest-steppe and Steppe climatic zones of Ukraine for the assessment of soil quality due to the background conditions, the influence of technological load (for the application of organo-mineral, organic and mineral fertilizer systems), and risk or influence of technogenic pollution by heavy metals (HM) is grounded. In the elaborated methodical approach is obtained a regression equation by the determination of new correlations of soil energy intensity indices (the calorific value of humus, soil energy reserves in a layer up to 20 cm) in conjunction with the humus state and the use of mathematical and statistical analysis for determining the value of easily hydrolysable nitrogen with the ability to predict the quality of soils of various genesis, with the further extension of the method algorithm for different soil types, climatic zones due to technogenic HM pollution and technological load. The technical result of the elaborated method: by improving the determination of the levels of the easily hydrolysable nitrogen content in soils of different genesis for the evaluation of their quality by identifying the most correlated, diagnostically applicable integral basic indicators of soil properties, which allow the informativeness to make managerial decisions and to predict the quality of soils of different genesis in the content of easily hydrolysable nitrogen, as a biogenic element, due to the background conditions and anthropogenic loads with increased accuracy, speed and informativeness. Elaborated method can find application in the ecological standardization of the content of biogenic macroelements, the normalization of loads (technogenic, technological) on the soil system, agroecology for solving the problems of organic agriculture, bioenergy and energy of soil formation; diagnostics, evaluation, forecasting of the soils nitrogen systems state; the quality of humus and macroelement status of soils on indicators of ecological and energy status; effective ecological management of soils due to the background conditions, as well as for various anthropogenic influences and in scientific research for the investigating of biogeochemistry and biogenic macroelements of soil cover. Separate provisions of the elaborated method became an integral part of the proposals on adaptation to the Nitrate Council Directive 91/676 / EEC of 12.12.1991 on the protection of water from pollution caused by nitrates from agricultural sources, as amended by Regulation (EC) № 1882/2003 Cross Nitrogen Balances Handbook. Prospective directions of research in the field of diagnostics, assessment, forecasting of the state of soils nitrogen systems and the normalization of the elemental composition quality, in particular, the content of nutrient nitrogen are determined. In order to overcome the biogenic pollution (excessive accumulation of nitrogen compounds) in the environment (plants, waters), the normalization of nitrogen content in soils of different genesis should include: a) determination of the maximum permissible levels of mobile mineral forms of nitrate nitrogen by the elaboration of environmental requirements for nitrates contamination with plant products; b) normalization of the content of labile easily hydrolysable nitrogen and / or a dose of nitrogen fertilizers in conditions of sufficient and excessive moistening, considering the rapid processes of transformation of nitrogen compounds in soils; c) normalization of the soil nitrogen mineral compounds content in conditions of insufficient moistening and slowing down the processes of circulation of nitrogen compounds of soils. Distinctive features and advantages of the proposed elaboration in comparison with known methods and approaches are: 1) the express obtain of the accurate projected levels of easily hydrolysable nitrogen as a nutrient in the soil with the improving the accuracy of soil diagnosis by the use of the basic integrated indicators; 2) providing opportunity for greater efficiency of forecasting data on the functioning of the nitrogen systems of different genesis soils, quality, environmental and energy state of soils due to the background conditions and anthropogenic loads while minimizing the cost of material resources; 3) empowerment of the user in determination of the easily hydrolysable nitrogen content in the soil without extensive chemical analysis by the choice of regression equations, based on the use of baseline soil properties of a particular type and subtype according to the available information; 4) versatility of the method by the suitability of detected dependencies of the proposed method for all soil types and subtypes, climatic zones and contaminants.
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Samokhvalova, V. L., A. O. Khristenko, L. O. Shedey, P. A. Samokhvalova, and O. V. Karatsuba. "Prediction of soil fertility considering their macronutrient status." Fundamental and Applied Soil Science 18, no. 3-4 (November 25, 2017): 5–20. http://dx.doi.org/10.15421/041711.
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The method for prediction of productive functions of soils, according to their macronutrient status, is grounded on the example of the total concentrations of nitrogen as biogenic macronutrient in different soil types of Polesie, Forest-Steppe and Steppe climatic zones of Ukraine including soils contaminated by heavy metals and fertilized (organic-mineral, organic and mineral system of fertilizer) soils. In the elaborated methodical approach the productive function (fertility) of different genesis soils forecasts by establishing new relationships of total nitrogen content with a humus calorific value, the energy reserves of the soil in layer up to 20 cm, the application of mathematical-statistical analysis. For example, according to the total nitrogen content as a biogenic macronutrient in accordance with the fixed gradations, with a further extension of the method algorithm for different soil types of climatic zones by the influence of technogenic pollution and technological load. The technical result of the elaborated method is to improve the known method of soil fertility prediction, considering their macronutrient status, by the selective choice of the most correlation associated, diagnostics capable of integral indicators of the energy and nitrogen status of the soil, which enhances the informativeness, accuracy and quick speed forecasting of production and ecological functions of different genesis soils with the identification of differences in ecological condition of soils for prediction and regulation of their quality. The elaborated methodological approach may find application in the assessment and ecological standardization of soil quality by chemical elements content, regulation of loads (technogenic, technological) on a soil system, in agroecology by investigating the question of soil fertility monitoring, lands certification of different purpose and use; organic farming, bioenergy and energy of soil formation; diagnosis, evaluation, determination of quality of humus and the state of the chemical elements; in environmental management of soils both for background conditions and different anthropogenic impacts and in research practice – investigating the biogeochemistry and nutrient macronutrients of the soil cover. Distinctive features and advantages of the proposed elaboration in comparison with known methods and approaches are: 1) express obtain of the accurate by predicted levels of total nitrogen content as a nutrient in the soil with the improving of the soil diagnosis accuracy by establishing some interconnected diagnostically suitable indicators of soils humus substances and nitrogen systems functioning, the direction of the mobilization and immobilization of nutrients (C, N) processes, the humification-mineralization and energy intensity of soils, including the negative impacts of anthropogenic pressures and degradation processes; 2) providing the opportunity for increasing effectiveness of predicting data on the functioning of the nitrogen systems of different genesis soils, environmental and energy state of soil and level of their potential fertility due to the background conditions, the application of different fertilization systems, and risk the availability of heavy metals pollution while minimizing the consumption of material resources; 3) expansion of the user’s ability to determine the total nitrogen content in the soil without long-term chemical analytical research due to the choice of regression equations obtained on the basis of the use of baseline soil properties of a certain type and subtype, according to available information; 4) versatility due to suitability of installed dependencies of the proposed method for all soil types and subtypes, climatic zones and contaminants.
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Leeuwen Cornelis, van, de Rességuier Laure, Mary Séverine, Laveau Coralie, Mousset-Libeau Etienne, Marguerit Elisa, Roby Jean-Philippe, and Quiquerez Amélie. "Soil type and soil preparation influence vine development and grape composition through its impact on vine water and nitrogen status." E3S Web of Conferences 50 (2018): 01015. http://dx.doi.org/10.1051/e3sconf/20185001015.
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The influence of soil type and preparation on vine development and grape composition was investigated in a 50 ha estate located in Saint-Emilion (Bordeaux, France) and planted predominantly with Merlot. Part of the vineyard was planted down the slopes and another part of the vineyard was planted on terraces, where soils were profoundly modified through soil preparation. Grape composition (berry weight, sugar, total acidity, malic acid and pH), vigor (pruning weight), vine nitrogen status (Yeast Available Nitrogen (YAN) in grapes) and vine water status (δ13C) was measured at a very high density grid of 10 data points per hectare. Water deficit was globally weak over the estate because of high soil water holding capacity whereas vine nitrogen status was highly variable. Vine vigor and grape composition were predominantly driven by vine nitrogen status. On terraces, where soils were deep, due to invasive soil preparation, water deficits were particularly small or non-existent and vine nitrogen status was highly variable. Grape quality potential was medium to low, except in places with low nitrogen status, but at the expense of low yields. On parcels planted down the slopes water deficits were recorded because vine rooting was limited by compact subsoils. Vine nitrogen status was homogeneous. Grape quality and yield were medium to high and relatively homogeneous. When possible, downhill plantations are to be preferred over terraces because in the latter vine yield and quality parameters are highly variable because of massive soil movements prior to plantation.
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Salehin, Sk Musfiq Us, Gazi Md Mohsin, Tabassum Ferdous, Jobaed Ragib Zaman, Md Jashim Uddin, and Md Khalilur Rahman. "Soil Fertility and Leaf Nutrient Status of Mango Orchard Sites." Dhaka University Journal of Biological Sciences 29, no. 2 (August 26, 2020): 155–63. http://dx.doi.org/10.3329/dujbs.v29i2.48735.
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Twenty soil and leaf samples from 20 orchards of mango (Mangifera indica L.) were collected from different locations of Rajshahi and Satkhira regions to evaluate soil texture, pH, organic matter, available and total nitrogen, phosphorus, potassium and sulfur of soils and the concentration of N and K in mango leaves. The pH of the soil varied from 6.3 - 7.9 and organic matter content varied from 0.72 - 3.60 per cent. The available nitrogen, phosphorus, potassium, and sulfur of the soils ranged from 190 - 510, 39 - 196, 36 - 206 and 25 - 235 mg/kg, respectively. The values of total N, P, K and S were 0.03 - 0.12, 0.022 - 0.210, 0.235 - 0.0.936 and 0.005 - 0.266 per cent, respectively. The dominant soil textural class was silty clay loam. The mean concentration of nitrogen (0.88%) and potassium (0.61%) in the leaf sample was low. The overall fertility status of the soils of Rajshahi and Satkhira regions in relation to mango cultivation is moderate.
Dhaka Univ. J. Biol. Sci. 29(2): 155-163, 2020 (July)
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Van Leeuwen, Cornelis, Philippe Friant, Jean-Pierre Soyer, Ch Molot, Xavier Choné, and Denis Dubourdieu. "Measurement of total nitrogen and assimilable nitrogen in grape juice to assess vine nitrogen status." OENO One 34, no. 2 (June 30, 2000): 75. http://dx.doi.org/10.20870/oeno-one.2000.34.2.1010.
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<p style="text-align: justify;">Five indicators of vine nitrogen status were compared for their accuracy to differentiate two levels of nitrogen fertilization (0 and 45 kg N / ha) : petiole total nitrogen content, leaf blade color intensity measured by a device called “N-tester”, grape juice total nitrogen content, grape juice assimilable nitrogen content and grape juice ammonium content. Differences in must total nitrogen content and must assimilable nitrogen content were highly significant between fertilization levels. They can be considered as two powerful tools to assess vine nitrogen status. Levels of must total nitrogen content and must assimilable nitrogen content were highly correlated.</p><p style="text-align: justify;">Mineralizing must in order to measure its total nitrogen content is difficult, mainly because of the presence of large amounts of sugar. This operation can take more than 12 hours and it can fail because of caramelization and the appearance of foam. We propose mineralizing must by means of microwave. Complete mineralization was obtained in only one hour. No foam or caramelization was observed on any of the samples mineralized.</p><p style="text-align: justify;">Vine nitrogen uptake is likely to vary to a considerable extend with soil parameters, even if no nitrogen fertilization is applied. Figuring among those parameters are: soil organic matter content, organic matter C/N ratio and soil organic matter turnover. The latter depends mainly on soil temperature, soil aeration, soil pH and soil moisture content. Differences in vine nitrogen status depending on the soil type were clearly evidenced by measuring must total nitrogen and must assimilable nitrogen at ripeness. Limited nitrogen uptake, as a result of particular soil conditions, can limit vine vigor and be a quality enhancing factor in red grape production. This emphasizes the role of moderate environmental stress in the production of high quality potential grapes.</p>
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Blank, Robert R., and James A. Young. "Plant-Soil Relationships ofBromus tectorumL.: Interactions among Labile Carbon Additions, Soil Invasion Status, and Fertilizer." Applied and Environmental Soil Science 2009 (2009): 1–7. http://dx.doi.org/10.1155/2009/929120.
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Invasion of western North America by the annual exotic grassBromus tectorumL. (cheatgrass) has been an ecological disaster. High soil bioavailability of nitrogen is a contributing factor in the invasive potential ofB. tectorum. Application of labile carbon sources to the soil can immobilize soil nitrogen and favor native species. We studied the interaction of labile carbon addition (sucrose), with soil invasion status and fertilizer addition on the growth ofB. tectorum. Soils were noninvaded (BNI) andB. tectoruminvaded (BI). Treatments were control, sucrose, combined fertilizer, and sucrose + fertilizer. The greenhouse experiment continued for 3 growth-cycles. After the 1st growth-cycle, sucrose addition reducedB. tectorumaboveground mass almost 70 times for the BI soil but did not significantly reduce growth in the BNI soil.B. tectorumaboveground mass, after the 1st growth-cycle, was over 27 times greater for BI control soils than BNI control soils. Although sucrose addition reduced soil-solution , tissue N was not significantly lowered, suggesting that reduction of soil available N may not be solely responsible for reduction inB. tectorumgrowth. Noninvaded soil inhibits growth ofB. tectorum. Understanding this mechanism may lead to viable control strategies.
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Fenn, M. E., T. G. Huntington, S. B. McLaughlin, C. Eagar, A. Gomez, and R. B. Cook. "Status of soil acidification in North America." Journal of Forest Science 52, Special Issue (January 1, 2006): S3—S13. http://dx.doi.org/10.17221/10152-jfs.
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Forest soil acidification and depletion of nutrient cations have been reported for several forested regions in North America, predominantly in the eastern United States, including the northeast and in the central Appalachians, but also in parts of southeastern Canada and the southern U.S. Continuing regional inputs of nitrogen and sulfur are of concern because of leaching of base cations, increased availability of soil Al, and the accumulation and ultimate transmission of acidity from forest soils to streams. Losses of calcium from forest soils and forested watersheds have now been documented as a sensitive early indicator and a functionally significant response to acid deposition for a wide range of forest soils in North America. For red spruce, a clear link has been established between acidic deposition, alterations in calcium and aluminum supplies and increased sensitivity to winter injury. Cation depletion appears to contribute to sugar maple decline on some soils, specifically the high mortality rates observed in northern Pennsylvania over the last decade. While responses to liming have not been systematically examined in North America, in a study in Pennsylvania, restoring basic cations through liming increased basal area growth of sugar maple and levels of calcium and magnesium in soil and foliage. In the San Bernardino Mountains in southern California near the west coast, the pH of the A horizon has declined by at least 2 pH units (to pH 4.0–4.3) over the past 30 years, with no detrimental effects on bole growth; presumably, because of the Mediterranean climate, base cation pools are still high and not limiting for plant growth.
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Futa, Barbara, Katarzyna Tajchman, Żaneta Steiner-Bogdaszewska, Leszek Drozd, and Tomasz M. Gruszecki. "Preliminary Results of Effect of Rotational Grazing of Farmed Red Deer (Cervus elaphus) on the Biochemical Status of Soil." Agronomy 11, no. 3 (March 15, 2021): 558. http://dx.doi.org/10.3390/agronomy11030558.
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The aim of the study was to identify the trends and dynamics of changes in the chemical and biochemical properties of soil induced by rotational grazing of farmed deer. Soils pH and the content of mineral nitrogen forms, total nitrogen, and organic carbon were determined in the study and the activity of three soil enzymes. The monitored soils were slightly acidic and neutral, with pH in 1 mol KCldm−3 ranging from 6.37 to 7.03. The contents of content of organic carbon, total nitrogen in the monitored soils were in the range of 9.42–19.37 gkg−1 and 1.13–2.24 gkg−1, respectively, while the contents of N-NH4+ and N-NO3− of 1.34–7.08 mgkg−1 and 102.8–619.5 mgkg−1, respectively. The mean levels of nitrate nitrogen in the pasture soils were lower than that in the mown soil. The soils from the pastures were characterized by a higher level of available phosphorus, potassium, and magnesium forms than the mown soil. In the deer grazing areas, the activity of all enzymes was clearly higher than in the soil from the control plot. The results of the present pilot study have demonstrated a positive effect of cervid grazing on the biochemical parameters of the soil environment.
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Varnagirytė-Kabašinskienė, I. "Complex study of foliage nutrient status in ash fertilized Scots pine stands in Lithuania." Journal of Forest Science 54, No. 5 (May 22, 2008): 195–206. http://dx.doi.org/10.17221/16/2008-jfs.
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In Lithuania, a typical Scots pine stand under the influence of wood ash and nitrogen fertilization, containing different treatments and the control, was analyzed. The study aim was to interpret the foliage and soil analyses, and to find possible indications in the soil-plant relation in the stand. The analyses of the foliage nutrient status in the Scots pine stand when wood ash with/without N was recycled to the forest showed that the significance analyses of changes in the nutrient composition in the soil and needles were the best initial tool for the response evaluation. The comparison of the nutrient concentrations with optimal amounts, critical levels of deficiency or target levels for ratios to N, and applied graphical analyses, could also provide possible indications in the soil-plant relation.
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Maharjan, M., K. D. Awasthi, K. R. Pande, and N. Thapa. "Nutrient status of rangeland in upper Mustang." Banko Janakari 24, no. 1 (September 24, 2015): 41–46. http://dx.doi.org/10.3126/banko.v24i1.13489.
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The study aimed at assessing the nutrient status of rangeland in upper Mustang. The assessment is necessary to know about the soil quality or productivity of soil of rangeland. Livestock rearing is one of the main occupations in upper Mustang but nowadays due to lack of palatable species for livestock, people are leaving the occupation which is directly affecting their livelihood status. Therefore this research was carried out to find out if the soil nutrient is the reason behind the lack of availability of palatable species in the rangeland. For soil sampling, north and south aspects were taken. In case of altitude, 3850 m, 3650 m and 3450 m were taken. Soil samples were taken from soil profile up to 60cm depth at interval of 20 cm. Available phosphorus and available potassium were found to be high at north aspect but total nitrogen was found to be high at south aspect. Both total nitrogen and available phosphorus were found to be high at 3650 m. Available potassium was gradually decreased with increasing altitude. Total nitrogen, available potassium and available phosphorus were gradually decreased with increasing soil depth. Nutrient status was high at top soil (0-20 cm).The soil nutrient (Nitrogen, Phosphorus, Potassium) status was found to be good in the study area. Further research on biophysical and ecological aspect of Rangeland in Upper Mustang is necessary to manage it properly.Banko Janakari, Vol. 24, No. 1, PP. 41-46
Dissertations / Theses on the topic "Soil nitrogen status"
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Au, William R. "Relationships between microbial physiological status and nitrogen availability in forest soils." Thesis, McGill University, 1998. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=21506.
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Although the physiological nitrogen demand of the soil microbial biomass is a major determinant of N mineralization in forest soils, the exact nature of the relationship is unclear. This study investigated the relationships between a respiration-based indicator of microbial physiological N demand (NIR) and N availability in forest soils. NIR was found to correlate significantly with net mineralized N in the field and annual foliar litterfall N fluxes. In a laboratory incubation, NIR was shown to be sensitive to changes in soil available C and N pools. These results demonstrated that microbial physiological N demand is determined by relative availabilities of labile C and N, and that it is significantly related to N cycling in forest soils. Results from a seasonal study of a forested watershed suggest that nutrient availability determined tree production and soil C availability, which in turn determined microbial physiological N demand and nitrogen dynamics in the forest.
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Colocho, Hurtarte Luis Carlos. "Plant Nitrogen status driving soil organic matter mineralization in the rhizosphere." Universidade Federal de Viçosa, 2016. http://www.locus.ufv.br/handle/123456789/10440.
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Os fatores que regulam a dinâmica do Carbono (C) e Nitrogênio (N) do solo na rizosfera são ainda pouco compreendidos. A mineralização de C na rizosfera pode ser fortemente influenciada pelo estado nutricional da planta, a concentração de CO2 na atmosfera e a temperatura do ambiente, entre outros. Em este estudo, avaliamos o status nutricional de N em plantas de Eucalyptus spp. e sua influência na dinâmica do C e do N n a rizosfera. Realizamos um experimento usando um rhizobox dividido em dois compartimentos. No compartimento de cima plantas foram cultivadas e areia lavada e supridas com uma solução nutritiva contendo todos o nutrientes e a mesma solução porém sem N . No compartimento inferior o contato das raízes com o solo foi limitado usando uma membrana de nylon com abertura de 5 μm. Observamos uma maior razão raiz:parte aérea e maiores concentrações de CO2 no solo das plantas com deficiência de N. As raízes das plantas deficientes em N, apresentaram maiores concentrações em relação as plantas não deficientes em N, de citrato e tallose, e menores concentrações de sucrose e aminoácidos. A análise de C e N da fração de matéria orgânica ligada aos minerais , junto com os dados obtidos pela termoquimolise indicam um aumento na mineralização de C e uma modificação na dinâmica do N. Devido a impossibilidade de contato físico direto com o solo, pela presença da membrana de nylon, a única forma de modificar o solo seria então pela exsudação de compostos pelas raízes. O contrastante conteúdo de aminoácidos e açúcares na raiz, junto com os dados do extrato da solução do solo e de mineralização de C, indica que a composição destes exsudatos diferiu em razão da deficiência de N. Enquanto as plantas deficientes em N exsudaram mais ácidos orgânicos, as plantas com ótimo status nutricional foram capazes de exsudar compostos energeticamente ricos. Os dados de δ13C da matéria orgânica ligada aos minerais indica que as plantas deficientes em N afetaram um maior volume de solo que as plantas supridas de N. Tudo isto mostra que, diferentes mecanismos de efeito priming foram dominantes, dependendo do status nutricional da planta. Em plantas deficiente de N, a mineralização de C no solo foi dominada pelo mecanismo chamado de “mineração de N”, enquanto no solo das plantas supridas de N o mecanismo dominante foi a “estequiometria microbiana”. Este trabalho demostra pela primeira vez, ao nosso saber, a atuação de diferentes mecanismos de efeito priming n a mesma planta, sobre diferente status de N . Assim ressaltando, a importância do manejo de nutrientes na dinâmica do C da rizosfera.
The factors that regulate the dynamics of soil Carbon (C) and Nitrogen (N) in the rhizosphere are still poorl y understood. The soil C mineralization in the rhizosphere ca n be heavil y influenced by plant’s nutritional status, atmospheric CO2 concentration and temperature, among others. In this study, we assess the influence of Eucalyptus spp. N status on the C and N dynamics in the rhizosphere. We performed an experiment us ing two compartment rhizobox. In the upper compartment, plants were cultivated in washed sand and supplied with a solution containing all nutrients or all nutrients but N. The lower compartment limited the contact of the roots with the soil using a 5 μm mesh nylon membrane. We observed a higher root-shoot ratio for the N deficient plants and an increase in its soil CO2 concentration. The roots of the –N planted treatment had higher concentrations of citrate and tallose and lower concentration of sucrose and aminoacids, when compared to the +N planted treatment. The C and N anal ysis of the mineral associated organic matter fraction, together with the thermochemol ysis data showed an increase in C mineralization in both planted treatments and changes in N dynamics. As the roots had no physical contact with the soil due to the nylon membrane, the changes in the soil must have been consequence of root exudation. The contrasting sugar and aminoacid root content, together with the citrate concentration in soil solut ion extract and the C mineralization data, indicate that exudate composition changed due to the plants N status. The data indicates that the plants in the –N treatment exudated more organic acids than the plants of the +N treatment. Still the exudate comp osition of the plants with the +N treatment may had a higher energetic content and thus affected differentl y the soil microbial communities. The δ13C data indicate that the N deficient plants affected a higher volume of soil than the plants of the +N treatment. All this together shows different priming mechanisms were dominant due to the plants N status. As the plants were N deficient, the mineralization of soil C was driven by the “N-mining” mechanism while in the soil of the +N planted treatment the dominant mechanism was “microbial stoichiometry”. This work demonstrates, to our knowledge, by the first time using the same plants, different priming mechanisms due to the plants N status. Thus highlighting, the importance of plants nutrient management in the rhizosphere C dynamics.
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Guo, Jingqi. "THE INFLUENCE OF TALL FESCUE CULTIVAR AND ENDOPHYTE STATUS ON ROOT EXUDATE CHEMISTRY AND RHIZOSPHERE PROCESSES." UKnowledge, 2014. http://uknowledge.uky.edu/pss_etds/50.
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Tall fescue (Lolium arundinaceum (Schreb.) Darbysh.) is a cool-season perennial grass used in pastures throughout the Southeastern United States. The grass can harbor a fungal endophyte (Epichloë coenophiala) thought to provide the plant with enhanced resistance to biotic and abiotic stress. However, the alkaloids produced by the common variety of the endophyte cause severe animal health issues resulting in a considerable amount of research focused on eliminating the toxic class of alkaloids while retaining the positive abiotic and biotic stress tolerance attributes of the other alkaloids. In doing so, very little attention has been paid to the direct influence the fungal-plant symbiosis has on rhizosphere processes. Therefore, my objectives were to study the influence of this relationship on plant biomass production, root exudate composition, and soil biogeochemical processes using tall fescue cultivars PDF and 97TF1 without an endophyte (E-), or infected with the common toxic endophyte (CTE+), or with two novel endophytes (AR542E+, AR584E+). I found that root exudate composition and plant biomass production were influenced by endophyte status, tall fescue cultivar, and the interaction of cultivar and endophyte. Cluster analysis showed that the interaction between endophyte and cultivar results in a unique exudate profile. These interactions had a small but perceptible impact on soil microbial community structure and function with an equally small and perceptible impact on carbon and nitrogen cycling in soils from rhizobox and field sites. These studies represent the first comprehensive analysis of root exudate chemistry from common toxic and novel endophyte infected tall fescue cultivars and can be used to help explain in part the observed changes in C and N cycling and storage in pastures throughout the Southeast U.S..
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Neary, Erika L., Daniel G. Neary, Steven T. Overby, and Sally M. Haase. "Prescribed Fire Impacts on Soil Carbon and Nitrogen." Arizona-Nevada Academy of Science, 2002. http://hdl.handle.net/10150/296593.
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Au, William R. "Relationships between microbial physiological status and nitrogen availability in forest soils." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ50713.pdf.
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Masilionytė, Laura. "Skirtingo našumo dirvožemių pokyčiai ekologinėje ir tausojamojoje žemdirbystės sistemose." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20111207_081456-68509.
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1. Ištirti skirtingo humusingumo glėjiškame rudžemyje alternatyviose intensyviajai žemdirbystės sistemose su daugiamečių žolių atolu ir tarpinių pasėlių biomase į dirvožemį įterptų biogeninių elementų kiekį ir jų poveikį sėjomainos augalų produktyvumui. 2. Įvertinti su trąšomis įterptų ir su derliumi prarastų biogeninių elementų NPK balansą ekologinės bei tausojamosios žemdirbystės sistemose ir nustatyti judriųjų fosforo ir kalio pokyčius dirvožemyje. 3. Nustatyti tausojamosios ir ekologinės žemdirbystės sistemose tarpiniuose pasėliuose augintų augalų biomasėje sukaupto azoto poveikį Nmin. dinamikai dirvožemyje. 4. Ištirti naudotų trąšų ir tarpinių pasėlių poveikį humuso ir jo sudėties pokyčiams ekologinės bei tausojamosios žemdirbystės sistemose. 5. Įvertinti ekologinės ir tausojamosios žemdirbystės sistemose naudotų agropriemonių poveikį pagrindinių dirvožemio fizikinių rodiklių stabilumui, agrofitocenozių dominantėms ir augaluose sukauptai bendrajai energijai.1. In the cropping systems alternative to the intensive cropping system, set up on a gleyic Cambisol with a different humus status, perennial grasses and biomass of catch crops are a significant reserve of biogenic elements for the productivity of crop rotation plants. 2. In the organic and sustainable cropping systems, farmyard manure and biogenic elements incorporated with it have a greater positive effect on the NPK balance and changes in available phosphorus and potassium in the soil compared with green manure. 3. Catch crops are important from the environmental viewpoint, since by accumulating nitrogen in their biomass they reduce Nmin. concentration in the soil and become a reserve of nutrients for succeeding plants. 4. In the soil with a different humus status, alternative cropping systems have a diverse effect on humus stability and changes in its quality. 5. In the sustainable and organic cropping systems, catch crops and their biomass play an important role for soil physical parameters, agrophytocenoses dominants and total energy.
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Botha, Elizabeth Johanna. "Estimating nitrogen status of crops using non-destructive remote sensing techniques." Thesis, University of Limpopo, 2001. http://hdl.handle.net/10386/2562.
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Brown, Susann Melissa. "Nitrogen mineralization in boreal forest stands of northwestern Quebec." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0022/MQ29664.pdf.
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Tacilla, Villanueva Antonio. "Impacts of Fertilization on Soil Properties in Loblolly Pine Plantations in the Southeastern United States." Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/54020.
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We examined the effects of periodic nitrogen (N) and phosphorus (P) fertilizer applications on the O horizon and mineral soil in loblolly pine (Pinus taeda L.) plantations over a 12-year period. To accomplish this, we used 9 experimental sites located across the south, which were grouped using the CRIFF Classification System. Group 1—CRIFF A, B (poorly-drained Ultisols); group 2—CRIFF C, D, G (sandy Spodosols and Entisols); and group 3—CRIFF E, F (well-drained Ultisols). Fertilization rates were 135, 202, and 269 kg N ha-1 at 4 years application frequency. This resulted in a cumulative N application rate of 540, 808, and 1076 kg ha-1. P was added at 10% of the N rate. Fertilization increased the mass, N content, and P content of the O horizon in all soil groups. Fertilization did not impact mineral soil N. No significant increases in total N trends were observed to a depth of 1 m. Likewise, total inorganic N (NH4+ + NO3-) was not affected by fertilization. These results suggest that N fertilization will have little effect on long-term soil N availability regardless of soil types. In contrast, fertilization increased extractable P in soil CRIFF groups 1, 2, and 3 by 26, 60, and 4 kg P ha-1 respectively suggesting potential for long-term soil P availability and site quality improvement. However, the low extractable P in soil group 3 implies additional fertilization with P for the next rotation for sites included into this soil group.Master of Science
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Selhorst, Adam Louis. "Carbon Sequestration By Home Lawn Turfgrass Development and Maintenance in Diverse Climatic Regions of the United States." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1306499049.
Full textBooks on the topic "Soil nitrogen status"
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Plunkett, Mark. An Evaluation of Nitrogen Status Tests for Yield and Quality Improvement in Winter Wheat Production. Dublin: University College Dublin, 1999.
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Marion, Carol I. Effects of nitrogen source, rate and a nitrification inhibitor on soil nitrogen status and mineral composition of strawberry. 1992.
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Mignon, B., and M. Monod. Zoonotic infections with dermatophyte fungi. Oxford University Press, 2011. http://dx.doi.org/10.1093/med/9780198570028.003.0077.
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Dermatophytes are highly specialized pathogenic fungi which are the most common agents of superficial mycoses. These fungi grow exclusively in the stratum corneum, nails or hair utilising them as sole nitrogen and carbon sources. Dermatophyte species are recognized and classified as antropophilic, zoophilic, or geophilic, depending on their major reservoir in nature (humans, animals, and soil, respectively). Zoophilic dermatophytes may result in zoonoses when humans are exposed to these organisms and dermatophytosis is considered to be one of the most common zoonotic diseases. The majority of zoonotic dermatophytoses are caused by four species: Microsporum canis (usually derived from pet animals, particularly cats and dogs), Trichophyton verrucosum (usually derived from cattle), Arthroderma vanbreuseghemii (usually derived from cats and dogs) and Arthroderma benhamiae (usually derived from guinea-pigs). Infection results most often from direct contact with an infected animal, but may be also acquired indirectly through contact with a contaminated environment. While clinical disease is rarely serious, the lesions can result in disfigurement and pain. Diagnosis is based on history, clinical appearance and diagnostic procedures, e.g. direct microscopic examination of scales, hair or nail and fungal culture. Specific treatment is generally required to resolve lesions, and this may be prolonged depending on the fungal species and the host status. Identifying animals as the source of infection for people can help in the prevention of recurrence or new infections, especially in children, by adequately treating affected pets and their environments. Immunoprophylaxis is an attractive means of controlling infection in animals, and the development and widespread use of efficacious T. verrucosum vaccines in certain countries has already proved valuable in the management of cattle ringworm.
Book chapters on the topic "Soil nitrogen status"
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Kõlli, Raimo, Karin Kauer, and Tõnu Tõnutare. "Nitrogen Status of Estonian Agricultural Landscapes’ Soil Cover." In Nitrogen in Agricultural Landscape, 164–96. First edition. | Boca Raton : CRC Press, 2021.: CRC Press, 2021. http://dx.doi.org/10.1201/9780429351358-8.
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Meng, J. H., X. Z. You, and Z. Q. Cheng. "Evaluating soil available nitrogen status with remote sensing." In Precision agriculture '15, 175–82. The Netherlands: Wageningen Academic Publishers, 2015. http://dx.doi.org/10.3920/978-90-8686-814-8_21.
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Mahajan, Gopal Ramdas, Bappa Das, Bhaskar Gaikwad, Dayesh Murgaokar, Kiran Patel, and Rahul M. Kulkarni. "Spectral and Smartphone-Based Tools to Monitor Plant and Soil Nitrogen Status for Site-Specific Nitrogen Management in Crop Plants." In Soil Management For Sustainable Agriculture, 259–82. Boca Raton: Apple Academic Press, 2022. http://dx.doi.org/10.1201/9781003184881-15.
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Hergert, Gary W. "Status of Residual Nitrate-Nitrogen Soil Tests in the United States of America." In SSSA Special Publications, 73–88. Madison, WI, USA: Soil Science Society of America, 2015. http://dx.doi.org/10.2136/sssaspecpub21.c8.
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Rusinamhodzi, Leonard, James Njeru, John E. Sariah, Rama Ngatoluwa, and Phlorentin P. Lagwen. "Tillage effect on agronomic efficiency of nitrogen under rainfed conditions of Tanzania." In Conservation agriculture in Africa: climate smart agricultural development, 246–55. Wallingford: CABI, 2022. http://dx.doi.org/10.1079/9781789245745.0014.
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Abstract Nitrogen (N) deficiency is a common feature in soils managed by smallholder farmers in Africa. Crop residue retention, in combination with no-till (NT), may be a pathway to improve agronomic use efficiency of applied N for small-scale farmers under the predominant rainfed conditions. This chapter reports on the results of a study carried out over two cropping seasons in the long rains of 2014 and 2015 on two sites: (i) on-farm (Mandela); and (ii) a research station (SARI) in eastern Tanzania. The experiment consisted of two tillage systems, conventional tillage (CT) and Conservation Agriculture (CA), with a minimum of 2.5 t ha-1 crop residue cover maintained in the plots during the experiment. CT consisted of soil inversion through tillage and removal of crop residues. In the on-farm experiment, maize was grown in plots with four rates of N application: 0, 27, 54 and 108 kg N ha-1. In the on-station trial, five rates were used: 0, 20, 40, 60 and 100 kg N ha-1. Maize yield and agronomic efficiency (AE) of N were used to assess and compare the productivity of the tested treatments. The results showed that tillage, soil type and rate of N application influenced crop productivity. In the clay soils, the differences between tillage practices were small. Under CT, AE ranged between 21.6 and 53.9 kg/kg N, and it was 20.4-60.6 kg/kg N under CA. The lowest fertilizer application rate of 27 kg ha-1 often had the largest AE across the soil types and tillage practices. In the on-station trials at SARI, the largest AE of 24.6 kg/kg N was recorded under CA with 40 kg N ha-1. As in the on-farm trials, the highest N application rate on-station did not lead to the largest AE. In the CT, AE ranged between 11.5 and 16.8 kg/kg N compared with a range of 15.1 to 24.6 kg/kg N for the CA treatment. Overall, crop residue retention, in combination with NT, is important to improve soil moisture and use efficiency of applied nutrients. Additionally, the initial soil fertility status is also important in determining the magnitude of short-term crop response to applied nutrients. Innovative pathways are needed to achieve the multiple objectives played by maize crop residues for results reported here to be sustainable. However, efficiency of nutrient use needs to be assessed, together with returns on investments, as small yields may mean high nutrient use efficiency but not necessarily significant increased returns at the farm level.
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Goulding, Keith, T. Scott Murrell, Robert L. Mikkelsen, Ciro Rosolem, Johnny Johnston, Huoyan Wang, and Marta A. Alfaro. "Outputs: Potassium Losses from Agricultural Systems." In Improving Potassium Recommendations for Agricultural Crops, 75–97. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-59197-7_3.
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AbstractPotassium (K) outputs comprise removals in harvested crops and losses via a number of pathways. No specific environmental issues arise from K losses to the wider environment, and so they have received little attention. Nevertheless, K is very soluble and so can be leached to depth or to surface waters. Also, because K is bound to clays and organic materials, and adsorbed K is mostly associated with fine soil particles, it can be eroded with particulate material in runoff water and by strong winds. It can also be lost when crop residues are burned in the open. Losses represent a potential economic cost to farmers and reduce soil nutritional status for plant growth. The pathways of loss and their relative importance can be related to: (a) the general characteristics of the agricultural ecosystem (tropical or temperate regions, cropping or grazing, tillage management, interactions with other nutrients such as nitrogen); (b) the specific characteristics of the agricultural ecosystem such as soil mineralogy, texture, initial soil K status, sources of K applied (organic, inorganic), and rates and timing of fertilizer applications. This chapter provides an overview of the main factors affecting K removals in crops and losses through runoff, leaching, erosion, and open burning.
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Kenjebaeva, S., P. Berliner, M. Silberbush, and S. H. Lips. "Nitrogen status and growth responses of wheat, and separation of osmotic from ion-specific effects of salinity by control of soil matric potential." In Root Demographics and Their Efficiencies in Sustainable Agriculture, Grasslands and Forest Ecosystems, 457–69. Dordrecht: Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-011-5270-9_37.
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Fleck, Stefan, Nadine Eickenscheidt, Bernd Ahrends, Jan Evers, Erik Grüneberg, Daniel Ziche, Juliane Höhle, et al. "Nitrogen Status and Dynamics in German Forest Soils." In Ecological Studies, 123–66. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-15734-0_5.
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Singh, V. K., B. S. Dwivedi, S. S. Rathore, R. P. Mishra, T. Satyanarayana, and K. Majumdar. "Timing Potassium Applications to Synchronize with Plant Demand." In Improving Potassium Recommendations for Agricultural Crops, 363–84. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-59197-7_13.
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AbstractPotassium (K) demand by crops is almost as high as that of nitrogen (N) and plays a crucial role in many plant metabolic processes. Insufficient K application results in soil K mining, deficiency symptoms in crops, and decreased crop yields and quality. Crop K demands vary with crop types, growth patterns, nutrient needs at different physiological stages, and productivity. Science-based K application in crops needs to follow 4R Nutrient Stewardship to ensure high yield, improved farm income, and optimum nutrient use efficiency. Studies around the world report widespread K deficiency, ranging from tropical to temperate environments. Long-term experiments indicate significant yield responses to K application and negative K balances where K application is either omitted or applied suboptimally. Limited understanding of K supplementation dynamics from soil non-exchangeable K pools to the exchangeable and solution phases and over-reliance on native K supply to meet crop demand are major reasons for deficit of K supply to crops. Research on optimum timing of K fertilizer application in diverse climate–soil–crop systems is scarce. The common one-time basal K management practice is often not suitable to supply adequate K to the crops during peak demand phases. Besides, changes in crop establishment practices, residue retention, or fertigation require new research in terms of rate, time, or source of K application. The current review assesses the synchrony of K supply from indigenous soil system and from external sources vis-à-vis plant demand under different crops and cropping systems for achieving high yield and nutrient use efficiency.
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Monib, M., M. E. Hassan, H. H. Abo-Taleb, A. Metwally, and N. A. Hegazi. "Contribution of integrated symbiotic and associative systems of biological nitrogen fixation to N-status of intercropped legumes and non-legumes in sandy soils of Egypt." In Nitrogen Fixation with Non-Legumes, 255–60. Dordrecht: Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-011-5232-7_29.
Full textConference papers on the topic "Soil nitrogen status"
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Crema, A., G. Vandini, M. Boschetti, F. Nutini, D. Cillis, and R. Casa. "Interaction between soil variability and maize nitrogen status assessment from Sentinel-2." In 12th European Conference on Precision Agriculture. The Netherlands: Wageningen Academic Publishers, 2019. http://dx.doi.org/10.3920/978-90-8686-888-9_56.
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Karklina, Ilze, Zaiga Anna Zvaigzne, and Jelena Stola. "Chemical properties of needles as an indicator of nutrient status of fertilized coniferous stands." In Research for Rural Development 2020. Latvia University of Life Sciences and Technologies, 2020. http://dx.doi.org/10.22616/rrd.26.2020.012.
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Enhanced forest growth may respond to demand of woody resources and contribute to the climate change mitigation. Forest soil treatment with fertilizers, as well as drainage and thinning enhance forest growth. The analysis of needles is an established method in forest science to identify the nutrient status in the forest stand and need for forest soil enrichment with fertilizers. The aim of this research is to estimate the efficiency of forest soil enrichment with wood ash and ammonium nitrate in order to eliminate nutrient deficiency in forest stands. Forest soil was enriched with wood ash fertilizer or ammonium nitrate in 2016–2017. The current year needles were collected from fertilized and control plots, from three trees in each plot. The samples were collected in the period 2018–2019. Total nitrogen (g kg-1), calcium (g kg-1), magnesium (g kg-1), and potassium (g kg-1) were analyzed in the collected samples. The chemical properties of collected needles were compared at the individual object level to estimate the impact of fertilizer on forest stand. A statistically significant increase in the concentrations of potassium and phosphorus was detected in some plots treated with wood ash and ammonium nitrate. In addition, a correlation analysis conducted between the variables of chemical properties of needles and soil showed few significant correlations between nutrient content in needles and in soil samples.
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Grigorova-Pesheva, Bilyana, Biser Hristov, and Kameliya Petrova. "ANALYSIS OF THE MICROBIOLOGICAL CHARACTERISTICS OF THE DIFFERENT SOIL HORIZONS OF FOREST SOILS FROM THE TERRITORY OF VITOSHA NATURE PARK." In 22nd SGEM International Multidisciplinary Scientific GeoConference 2022. STEF92 Technology, 2022. http://dx.doi.org/10.5593/sgem2022/3.1/s14.41.
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The status, abundance and diversity of soil microbial communities are one of the main basic indicators for the assessment and monitoring of forest ecosystems. In the context of the important role that microorganisms play in forest ecosystems, it is crucial to study and monitor their abundance in soil habitats. In order to supplement the knowledge about the soil microbial communities in the different soil horizons, we studied 16 soil profiles from the territory of Vitosha Nature Park. The soils from tested areas 1-8 are determined as Dystric Cambisols and the soils form tested areas 9-16 as Umbrisols. The main soil characteristics: pH, total nitrogen content, humus and organic carbon content have been studied using standard laboratory analyses. The total microbial number of the individual soil horizons have been established respectively for the Dystric Cambisols A and B horizons, for the Umbrisols A1 and A horizons. The Koch method was used. The percentage distribution of the main microbial groups: spore-forming and non-sporeforming microorganisms, actinomycetes and micromycetes have been determined. For all studied soils, a decrease in the total microflora with an increase in the depth of the soil profile was found. In Umbrisols this decrease is less compared to Dystric Cambisols. In both soil types, the results show a significant reduction in the group of micromycetes in the underlying soil horizon, regardless of soil type. In soils with higher acidity, a higher percentage of the micromycetes is observed, regardless of soil type and soil horizon. Higher values of the correlation coefficient were found when comparing the microbial abundance in the lower soil horizons with the humus content, compared to the upper soil horizons.
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Karlsons, Andis, Anita Osvalde, and Laura Abolina. "NITROGEN AND PHOSPHORUS EFFECT ON AMERICAN CRANBERRY GROWTH, YIELD AND MINERAL ELEMENT COMPOSITION." In 22nd SGEM International Multidisciplinary Scientific GeoConference 2022. STEF92 Technology, 2022. http://dx.doi.org/10.5593/sgem2022/3.1/s13.33.
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The industrial cultivation of American cranberry (Vaccinium macrocarpon Aiton) in Latvia was started during last 20 years with total plantings of more than 125 ha today. As a native wetland plant, commonly cranberries grows on poor, acid soils and are characterized as nutrients low requiring crop, however, balanced plant nutrition is vitally important to realize the full potential of cranberries as crop, to ensure adequate growth and yield production. Previous results obtained by authors from different cranberry producing plantings in Latvia frequently showed inadequate cranberry tissue supply with N and P. A field trial were established to examine the impact of N and P fertilizer rates on cranberry yield, fruit quality, morphological factors, and mineral element supply. Field experiments on cranberry cultivar �Bergman� were conducted during 2019 cropping season in a commercial plantation established on an excavated peat bog in Latvia. The cranberries received five levels of N (0 to 40 kg N ha-1) and P (0 to 30 kg P ha-1) as well as N and P treatment combinations applied in spring. Cranberry leaf analyses and soil (peat) testing were used as a diagnostics tool to reveal nutrient (N, P, K, Ca, Mg, S, Fe, Mn, Zn, Cu, Mo, B), soil pH and EC status. In general, crop characters were significantly influenced by different levels of N and P. As expected, the results showed that combined N and P treatments with the highest rates: N30/P20 and N40/P30 resulted in the highest yields and yield parameters, as well as ensured optimal N and P concentrations in cranberry tissues. It should be noted that the rates of applied fertilizers were environmentally safe as the nutrient concentrations recommended for peat growing medium were not exceeded.
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Muntyan, Victoria S., Alla S. Saksaganskaia, Alexey N. Muntyan, Mariia E. Vladimirova, and Marina L. Roumiantseva. "STRESS AND IMMUNITY OF NODULE BACTERIA SINORHIZOBIUM MELILOTI: LOCALIZATION, POLYMORPHISM AND PHYLOGENY OF GENETIC DETERMINANTS." In 22nd SGEM International Multidisciplinary Scientific GeoConference 2022. STEF92 Technology, 2022. http://dx.doi.org/10.5593/sgem2022/6.1/s25.15.
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Sinorhizobium meliloti are agriculturally valuable species of soil bacteria that form nitrogen-fixing symbiosis with alfalfa plants. Global climate changes lead to an increase of agricultural areas subjected to salinity. Current knowledge about about high-salt stress impact on soil saprophitic root nodulated microsymbionts of legumes is weakly studied and rhizobia gene pool responsible for salt tolerance are fragment and far from clear. An increase of bacteria nonspecific resistance (immune status) to unfavorable stress factors can occur through the induction of defense mechanisms like restrictionmodification systems and CRISPR/cas systems which are aimed to protect bacteria cells from bacteriophages widespread in soil microbiome. The aim of this research was to evaluate the role of the megaplasmid pSymA in the formation of ecological genome of S. meliloti, which is related to stress tolerance and to determine the location of elements of adaptive immune systems protecting root nodule bacteria against external foreign DNA. The analysis was done on 11 genes, products of which involved in response to ion stress and synthesis of osmoprotectors. It was found that 6 out of 11 genes were found in the genomes of all analyzed S. meliloti strains, while it was not a case for other 5 genes. It was found that, unlike chromosome, megaplasmid I of S. meliloti accumulated copies of 4 from 5 genes, except kdpA gene, which is represented by a single copy and localized on megaplasmid I in all so far studied strains. It was predicted that closest phylogenetic relatives of genes whose products are involved in response to ion stress as well in synthesis of osmoprotectors are homologous genes of closely related S. medicae species. The exception was for betI2, for which the closest phylogenetic relative was homologous gene of Klebsiella pneumonia, and another exception is kdpA gene introduced onto megaplasmid-I from actinobacteria. Regarding elements of immune systems it was revealed that nonsymbiotic plasmids of S. meliloti harbored incomplete elements of RMS-I, -II, and - III systems, while the 4 complete RMS-IV systems were detected on a single plasmid. It was found out that corresponding methylases had similarities with similar enzymes detected in nitrogen-fixing strains of Agrobacterium tumefaciens, Mezorhizobium sp., Bradyrhizobium sp. CRISPR sequences were not detected on megaplasmid-I, while they were on chromosome, megaplasmid-II and on cryptic plasmids. So, it was concluded that megaplasmid-I of S. meliloti are enriched in copies of genes related to osmotic stress tolerance, but it role in immune status of rhizobia is requested further elucidation.
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Karklina, Ilze, Andis Lazdins, Jelena Stola, Aldis Butlers, Zaiga Anna Zvaigzne, and Dana Purvina. "Soil carbon stock in fertilized forest stands with mineral soils." In Research for Rural Development 2021 : annual 27th International scientific conference proceedings. Latvia University of Life Sciences and Technologies, 2021. http://dx.doi.org/10.22616/rrd.27.2021.007.
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Forest mineral soil is one of the terrestrial carbon pools, and changes in forest management practices can affect the carbon stock in forest soil. The purpose of the study is to estimate temporal fertilization impact on mineral soil organic carbon stock, depending on fertilizers applied, forest stand type, different dominant tree species of the stands. Coniferous and birch forest stands with mineral soil in the central and eastern part of Latvia were selected for the experiment. The fertilizers used were wood ash and nitrogen containing mineral fertilizer. No significant differences in organic carbon stock in O horizon were detected 2–5 years after fertilization. A tendency of smaller organic carbon stock in upper mineral soil layers (0–10 cm, 10–20 cm) was found in most part of objects. Significantly smaller organic carbon stock was found in upper mineral soil layers (0–10 cm and 10–20 cm) in birch stands with wet mineral soil treated with ammonium nitrate if compared to the control plots, possibly due to a different soil moisture regime of forest stands. The positive and significant correlations between soil organic carbon and nitrogen stocks were found in most part of the objects.
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Prikhodko, A. V., and N. V. Karaeva. "Overview of various crops used for green manure." In CURRENT STATE, PROBLEMS AND PROSPECTS OF THE DEVELOPMENT OF AGRARIAN SCIENCE. Federal State Budget Scientific Institution “Research Institute of Agriculture of Crimea”, 2020. http://dx.doi.org/10.33952/2542-0720-2020-5-9-10-41.
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The aim of our research was to determine the influence of different green manure crops on the process of organic matter entry into the soil, changes in physical and chemical properties of soil, etc. The yields of green mass of sweet clover and sainfoin were the highest – 29.1 and 27.1 t/ha, respectively. Triticale and rye surpassed these crops in the dry matter yield by 0.10-0.30 t/ha and in the organic matter entry into the soil by 0.16-0.36 t/ha. Incorporation of green manures into a farming system contributed to the increase in the amount of nitrogen that is available to the succeeding crop from 0.17 to 1.73 mg/100 g, or 10.4 times. The most considerable increase in the amount of nitrogen was after sainfoin (13.5 times more) and vetch (12.3 times higher). The higher Р2О5 and К2О content in the soil was observed after phacelia used for green manure (3.27 and 32.7, respectively).
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Heaney, Natalie, Mufidat Mamman, Hajara Tahir, Ahmed Al-Gharib, and Chuxia Lin. "Effects of Softwood Biochar on the Status of Nitrogen Species and Trace Elements in Soils." In The 3rd World Congress on New Technologies. Avestia Publishing, 2017. http://dx.doi.org/10.11159/icepr17.148.
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Merkel, K. A., and E. P. Vibe. "THE PREVALENCE OF INFECTIOUS LODGING OF SEEDLINGS OF COMMON PINE IN AUTUMN SOWING AT THE NURSERY OF SFNR" ERTIS ORMANY»." In STATE AND DEVELOPMENT PROSPECTS OF AGRIBUSINESS Volume 2. DSTU-Print, 2020. http://dx.doi.org/10.23947/interagro.2020.2.38-40.
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Phytopathological studies of the state of shoots of common pine (Pinus sylvestris L.) of autumn sowing when grown in protected soil with the use of Agrotex covering material were carried out. The results of survey showed that when using fertilizers and soil activators-nitrogen, phosphorus, boric acid, EM EKO KZ Soil, EM EKO KZ soil (NPK) and humus, there is a drop in seedlings from 7.5 to 32.6%. The main reason for the death of shoots was the development and spread of infectious pathogens of seedlings. The species composition of pathogenic microflora in diseased plants is represented by a group of soil fungi belonging to the anamorphic division-Fusarium, Alternaria. Evaluation of the experience of introducing substances into the soil during autumn sowing showed that their use, as a rule, does not affect the resistance of plants to infectious pathogens, with the exception of boric acid, which has fungicidal activity.
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Kozlovskaya, V. F. "Prospects for the rhizosphere microorganisms integration into agricultural practice as biofertilizers." In CURRENT STATE, PROBLEMS AND PROSPECTS OF THE DEVELOPMENT OF AGRARIAN SCIENCE. Federal State Budget Scientific Institution “Research Institute of Agriculture of Crimea”, 2020. http://dx.doi.org/10.33952/2542-0720-2020-5-9-10-141.
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Chemical fertilizers are a quick way to increase nutrients in the soil, but their use is economically costly and dangerous for the environment. Plant Growth Promoting Bacteria (PGPB) are able to increase the bioavailability of fertilizers through biological nitrogen (N) fixation, as well as potassium (K), phosphorus (P), and zinc (Zn) solubilization. The enhanced amount of soluble macro- and microelements in the close proximity of soil-root interface increases the fertilizer use efficiency ~ by 20-40 %.
Reports on the topic "Soil nitrogen status"
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Bonfil, David J., Daniel S. Long, and Yafit Cohen. Remote Sensing of Crop Physiological Parameters for Improved Nitrogen Management in Semi-Arid Wheat Production Systems. United States Department of Agriculture, January 2008. http://dx.doi.org/10.32747/2008.7696531.bard.
Full textAbstract:
To reduce financial risk and N losses to the environment, fertilization methods are needed that improve NUE and increase the quality of wheat. In the literature, ample attention is given to grid-based and zone-based soil testing to determine the soil N available early in the growing season. Plus, information is available on in-season N topdressing applications as a means of improving GPC. However, the vast majority of research has focused on wheat that is grown under N limiting conditions in sub-humid regions and irrigated fields. Less attention has been given to wheat in dryland that is water limited. The objectives of this study were to: (1) determine accuracy in determining GPC of HRSW in Israel and SWWW in Oregon using on-combine optical sensors under field conditions; (2) develop a quantitative relationship between image spectral reflectance and effective crop physiological parameters; (3) develop an operational precision N management procedure that combines variable-rate N recommendations at planting as derived from maps of grain yield, GPC, and test weight; and at mid-season as derived from quantitative relationships, remote sensing, and the DSS; and (4) address the economic and technology-transfer aspects of producers’ needs. Results from the research suggest that optical sensing and the DSS can be used for estimating the N status of dryland wheat and deciding whether additional N is needed to improve GPC. Significant findings include: 1. In-line NIR reflectance spectroscopy can be used to rapidly and accurately (SEP <5.0 mg g⁻¹) measure GPC of a grain stream conveyed by an auger. 2. On-combine NIR spectroscopy can be used to accurately estimate (R² < 0.88) grain test weight across fields. 3. Precision N management based on N removal increases GPC, grain yield, and profitability in rainfed wheat. 4. Hyperspectral SI and partial least squares (PLS) models have excellent potential for estimation of biomass, and water and N contents of wheat. 5. A novel heading index can be used to monitor spike emergence of wheat with classification accuracy between 53 and 83%. 6. Index MCARI/MTVI2 promises to improve remote sensing of wheat N status where water- not soil N fertility, is the main driver of plant growth. Important features include: (a) computable from commercial aerospace imagery that include the red edge waveband, (b) sensitive to Chl and resistant to variation in crop biomass, and (c) accommodates variation in soil reflectance. Findings #1 and #2 above enable growers to further implement an efficient, low cost PNM approach using commercially available on-combine optical sensors. Finding #3 suggests that profit opportunities may exist from PNM based on information from on-combine sensing and aerospace remote sensing. Finding #4, with its emphasis on data retrieval and accuracy, enhances the potential usefulness of a DSS as a tool for field crop management. Finding #5 enables land managers to use a DSS to ascertain at mid-season whether a wheat crop should be harvested for grain or forage. Finding #6a expands potential commercial opportunities of MS imagery and thus has special importance to a majority of aerospace imaging firms specializing in the acquisition and utilization of these data. Finding #6b on index MCARI/MVTI2 has great potential to expand use of ground-based sensing and in-season N management to millions of hectares of land in semiarid environments where water- not N, is the main determinant of grain yield. Finding #6c demonstrates that MCARI/MTVI2 may alleviate the requirement of multiple N-rich reference strips to account for soil differences within farm fields. This simplicity will be less demanding of grower resources, promising substantially greater acceptance of sensing technologies for in-season N management.
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Banin, Amos, Joseph Stucki, and Joel Kostka. Redox Processes in Soils Irrigated with Reclaimed Sewage Effluents: Field Cycles and Basic Mechanism. United States Department of Agriculture, July 2004. http://dx.doi.org/10.32747/2004.7695870.bard.
Full textAbstract:
The overall objectives of the project were: (a) To measure and study in situ the effect of irrigation with reclaimed sewage effluents on redox processes and related chemical dynamics in soil profiles of agricultural fields. (b) To study under controlled conditions the kinetics and equilibrium states of selected processes that affect redox conditions in field soils or that are effected by them. Specifically, these include the effects on heavy metals sorption and desorption, and the effect on pesticide degradation. On the basis of the initial results from the field study, increased effort was devoted to clarifying and quantifying the effects of plants and water regime on the soil's redox potential while the study of heavy metals sorption was limited. The use of reclaimed sewage effluents as agricultural irrigation water is increasing at a significant rate. The relatively high levels of suspended and, especially, dissolved organic matter and nitrogen in effluents may affect the redox regime in field soils irrigated with them. In turn, the changes in redox regime may affect, among other parameters, the organic matter and nitrogen dynamics of the root zone and trace organic decomposition processes. Detailed data of the redox potential regime in field plots is lacking, and the detailed mechanisms of its control are obscure and not quantified. The study established the feasibility of long-term, non-disturbing monitoring of redox potential regime in field soils. This may enable to manage soil redox under conditions of continued inputs of wastewater. The importance of controlling the degree of wastewater treatment, particularly of adding ultrafiltration steps and/or tertiary treatment, may be assessed based on these and similar results. Low redox potential was measured in a field site (Site A, KibutzGivat Brenner), that has been irrigated with effluents for 30 years and was used for 15 years for continuous commercial sod production. A permanently reduced horizon (Time weighted averaged pe= 0.33±3.0) was found in this site at the 15 cm depth throughout the measurement period of 10 months. A drastic cultivation intervention, involving prolonged drying and deep plowing operations may be required to reclaim such soils. Site B, characterized by a loamy texture, irrigated with tap water for about 20 years was oxidized (Time weighted average pe=8.1±1.0) throughout the measurement period. Iron in the solid phases of the Givat Brenner soils is chemically-reduced by irrigation. Reduced Fe in these soils causes a change in reactivity toward the pesticide oxamyl, which has been determined to be both cytotoxic and genotoxic to mammalian cells. Reaction of oxamyl with reduced-Fe clay minerals dramatically decreases its cytotoxicity and genotoxicity to mammalian cells. Some other pesticides are affected in the same manner, whereas others are affected in the opposite direction (become more cyto- and genotoxic). Iron-reducing bacteria (FeRB) are abundant in the Givat Brenner soils. FeRB are capable of coupling the oxidation of small molecular weight carbon compounds (fermentation products) to the respiration of iron under anoxic conditions, such as those that occur under flooded soil conditions. FeRB from these soils utilize a variety of Fe forms, including Fe-containing clay minerals, as the sole electron acceptor. Daily cycles of the soil redox potential were discovered and documented in controlled-conditions lysimeter experiments. In the oxic range (pe=12-8) soil redox potential cycling is attributed to the effect of the daily temperature cycle on the equilibrium constant of the oxygenation reaction of H⁺ to form H₂O, and is observed under both effluent and freshwater irrigation. The presence of plants affects considerably the redox potential regime of soils. Redox potential cycling coupled to the irrigation cycles is observed when the soil becomes anoxic and the redox potential is controlled by the Fe(III)/Fe(II) redox couple. This is particularly seen when plants are grown. Re-oxidation of the soil after soil drying at the end of an irrigation cycle is affected to some degree by the water quality. Surprisingly, the results suggest that under certain conditions recovery is less pronounced in the freshwater irrigated soils.