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Ciecko, Z., S. Kalesa, M. Wyszkowski e E. Rolka. "The effect of elevated cadmium content in soil on the uptake of nitrogen by plants". Plant, Soil and Environment 50, No. 7 (10 de dezembro de 2011): 283–94. http://dx.doi.org/10.17221/4034-pse.
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The aim of this study was to determine the effect of cadmium (10, 20, 30 and 40 mg Cd/kg of soil) contamination in soil with the application of different substances (compost, brown coal, lime and bentonite) on the intake of nitrogen by some plants. The correlations between the nitrogen content in the plants and the cadmium concentration in the soil, as well as the plant yield and the content of micro- and macroelements in the plants were determined. Plant species and cadmium dose determined the effects of soil contamination with cadmium on the content of nitrogen. Large doses of cadmium caused an increase in nitrogen content in the Avena sativa straw and roots and in the Zea mays roots. Soil contamination with cadmium resulted in a decrease of nitrogen content in the Avena sativa grain, in above-ground parts and roots of the Lupinus luteus, in the above-ground parts of the Zea mays and in the above-ground parts and roots of Phacelia tanacaetifolia. Among the experimental different substances, the application of bentonite had the strongest and a usually negative effect on the nitrogen content in plants. The greatest effect of bentonite was on Avena sativa grain, above-ground parts Zea mays and Lupinus luteus and Phacelia tanacaetifolia. The content of nitrogen in the plants was generally positively correlated with the content of the macroelements and some of the microelements, regardless of the substances added to the soil.
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Neuberg, M., D. Pavlíková, M. Pavlík e J. Balík. "The effect of different nitrogen nutrition on proline and asparagine content in plant". Plant, Soil and Environment 56, No. 7 (14 de julho de 2010): 305–11. http://dx.doi.org/10.17221/47/2010-pse.
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Mixture of plants (Festulolium: Trifolium pretense L.) was grown in the pot experiment with different forms of nitrogen nutrition. The fertilizers (ammonium sulphate or calcium nitrate or ammonium nitrate) were applied conventionally or according to the CULTAN method (Controlled Uptake Long Term Ammonium Nutrition). The absolute growth rate (AGR) and contents of free asparagine and proline in the aboveground biomass were determined. Additional nitrogen increased the dry weight of biomass and AGR of the plants treated with sidedress application in comparison with plants treated with the CULTAN method. The results suggest increased levels of free proline in CULTAN-treated plants while those of asparagine did not increase. The significance of these observations to the loss of potential yield and the relationship between methods of application is considered.
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Šrámek, F., e M. Dubský. "Effect of slow release fertilizers on container-grown woody plants". Horticultural Science 34, No. 1 (7 de janeiro de 2008): 35–41. http://dx.doi.org/10.17221/1844-hortsci.
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Slow-Release Fertilizers (SRF) Silvamix Forte and Silvagen were tested in two-year experiments with container-grown woody plants (<i>Pyracantha coccinea</i>, <i>Thuja occidentalis</i>). Several fertilizing systems were compared: preplant application of SRF into substrate as the sole nutrient source for a two-year period, preplant application of SRF and soluble fertilizer (PG Mix), and preplant application of SRF and soluble fertilizer together with additional fertilizing by solution of nitrogen fertilizer during both growing periods. A system with controlled-release fertilizer (CRF) Osmocote 5−6 was chosen as a control variant; it was incorporated into substrate before planting in the first year and top-dressed in the second year. CRF Plantacote 6M (mixed into substrate before planting and top-dressed in the second year) and Osmocote 16−18 applied only before planting were tested, too. The experiments showed that SRF Silvamix Forte and Silvagen give results comparable with CFR provided that they were incorporated together with soluble ferti-lizer dose and plants were fertilized by solution of nitrogen fertilizer during both growing periods.
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Galambosi, B., e Y. Holm. "The Effect of Nitrogen Fertilization on the Herb Yield of Dragonhead". Agricultural and Food Science 61, n.º 5 (1 de setembro de 1989): 387–94. http://dx.doi.org/10.23986/afsci.72369.
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The influence of a top-dressing of nitrogen fertilizer (calcium nitrate, CaNO3) on the individual plant height and weight, herb yield and nitrate content of dragonhead (Dracocephalum moldavica L.) was studied in 1987 in Puumala, Finland. The nitrogen doses applied ranged from 0 to 270 kg/ha. Nitrogen fertilization increased both the individual plant height and weight, the fresh and dry herb yield and the nitrate content of the plants. However, no optimum nitrogen dose could be found since the maximum was not reached in most of the cases. An exception was the herb yield (d.w.) of transplanted plants, harvested at the flowering stage, where a nitrogen dose of 70—80 kg/ha gave the highest yield. If the plants were allowed to grow a few weeks more the yield was four fold compared to the earlier harvesting. Sown plants gave a yield two times higher than the transplanted plants, but this was partly due to the greater plant density on the sown plots.
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Krček, M., P. Slamka, K. Olšovská, M. Brestič e M. Benčíková. "Reduction of drought stress effect in spring barley (Hordeum vulgare L.) by nitrogen fertilization". Plant, Soil and Environment 54, No. 1 (14 de janeiro de 2008): 7–13. http://dx.doi.org/10.17221/2781-pse.
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An effect of nitrogen rates (0.0 g, 1.0 g, 2.0 g N per pot) on NRA (nitrate reductase activity) in leaves of spring barley (cultivar Kompakt) was investigated in a pot experiment. Plants were grown under optimum moisture regime and drought stress was induced during the growth stages of tillering, shooting and earing. Before and after respective stress period plants were grown under optimal water regime. In all the fertilized and unfertilized treatments, NRA was significantly higher under optimal water regime than in drought stress conditions. Nitrogen fertilization alleviated adverse effects of drought stress on the yields of grain; the rate of 1 g N per pot increased the grain yield of plants stressed during tillering 3.73 times compared to unfertilized and stressed treatment. When the stress was induced during shooting or earing grain yields declined by over 50% compared to optimal water regime; when compared with stressed and unfertilized treatment, the rate of 1 g N however increased yield by 29% (stress at shooting) and 55% (stress at earing). NRA values were significantly higher when plants were grown under optimum water regime than under stress conditions as well as when fertilized with nitrogen compared to unfertilized control both under optimum water regime and drought stress.
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GIRARDIN, P., A. DELTOUR e M. TOLLENAAR. "EFFECT OF TEMPORARY N STARVATION IN MAIZE ON LEAF SENESCENCE". Canadian Journal of Plant Science 65, n.º 4 (1 de outubro de 1985): 819–29. http://dx.doi.org/10.4141/cjps85-108.
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A prerequisite for an informed strategy regarding nitrogen application in maize (Zea mays L.) is a knowledge of the physiology of plant responses to nitrogen. This study consisted of two experiments on maize plants grown in pails. One experiment was conducted in controlled-environment growth rooms, the other was conducted in the field. N-deficient and control maize plants were evaluated for photosynthetic rate (P), chlorophyll content (CC), nitrogen content, and green leaf area; comparisons between these four parameters were made. During N starvation, rate of senescence (i.e. decrease in green leaf area) of the old leaves was higher in N-deprived plants than in control plants. P and CC of all leaves in the N-deficient treatment decreased during nitrogen withdrawal. After the deprivation period, when the plants were resupplied with N, senescence was delayed relative to control plants. The increase of CC in treatment plants was slower than the recovery of photosynthetic rate; in fact, CC was a poor indicator of photosynthetic activity. The delay in leaf senescence corresponded with regreening in leaves of N-deprived plants following N addition. This delay could be partly explained by an overcompensation in plant N requirement involving both a rapid increase in P, and a slower increase in CC. The effects of resupplying plants with nitrogen following a N-deprivation period lead us to believe that the observed leaf yellowing is actually a premature senescence which is reversible, and that a low N content is not the single causal factor of senescence.Key words: Chlorophyll content, leaf area, photosynthetic rate, Zea mays L.
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Giambalvo, Dario, Gaetano Amato, Davide Borgia, Rosolino Ingraffia, Calogero Librici, Antonella Lo Porto, Guglielmo Puccio, Paolo Ruisi e Alfonso S. Frenda. "Nitrogen Availability Drives Mycorrhizal Effects on Wheat Growth, Nitrogen Uptake and Recovery under Salt Stress". Agronomy 12, n.º 11 (11 de novembro de 2022): 2823. http://dx.doi.org/10.3390/agronomy12112823.
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The arbuscular mycorrhizal (AM) symbiosis is generally considered effective in improving salt tolerance in plants; however, the advantages it offers can vary greatly depending on the context in which it occurs; furthermore, the mechanisms underlying these responses are still unclear. A study was conducted to investigate the role of nitrogen (N) availability on the effectiveness of AM symbiosis in durum wheat (Triticum durum Desf.) plants grown under salt stress. Plants were grown in pots in the absence or in presence of salt stress (soil electrical conductivity of 1.50 and 13.00 dS m−1, respectively), with or without AM fungi inoculation (Rhizophagus irregularis and Funneliformis mosseae), varying the N dose supplied (0 or 80 mg N per pot). Results indicate that AM symbiosis can alleviate the detrimental effects of salt stress on the growth of durum wheat only when plants are grown under sufficient N availability in soil; in such conditions mycorrhizal symbiosis determined an improvement of leaf traits (leaf area, SLA, stability of plasma membranes and SPAD), N uptake, N fertilizer recovery and water use efficiency. On the contrary, when wheat plants were grown in conditions of N deficiency, the mycorrhizal symbiosis had no effect (under salt stress) or even depressive effect (under unstressed condition) on plant growth and N uptake, highlighting how, in some cases, competition for nutrients between plants and AM can arise. This study suggests that N availability in the soil can drive the effects of AM symbiosis in assisting the plant with containing saline stress.
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Abou-Zeid, Hanan Mahmoud. "Nitrogen Biofertilizer Alleviates the Inhibitory Effect of Cadmium on Physiology and Nitrogen Assimilation in Maize Plants". International Journal of Agriculture and Biology 25, n.º 01 (1 de janeiro de 2021): 98–108. http://dx.doi.org/10.17957/ijab/15.1643.
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The present study investigated the role of inoculation with Nitrobien biofertilizer (N-Bio, Azospirillum and azotobacter spp.) on the response of maize plants to cadmium-toxicity (applied as 2 and 10 mM CdSO4). Cd-stress caused a significant reduction in the fresh and dry biomass of leaves and roots as well as a marked disturbance in the anatomical features of roots and stomatal structure and behavior. Cd-stress significantly depressed the total photosynthetic pigments, photochemical efficiency of PS II, total carbohydrates, and proteins content. Furthermore, increasing Cd level prompted oxidative stress measured in terms of malondialdehyde and H2O2 contents in maize plants. Application of N-Bio improved these attributes in Cd-stressed maize plants. Moreover, NO3- uptake and its assimilating enzymes (nitrate reductase, NR; glutamine synthase, GS; and, glutamate dehydrogenase GDH) were significantly increased in N-Bio-pretreated Cd-stressed plants than Cd- stressed ones and that was associated with a decrease of NH4+ content. N-Bio pretreatment also stimulated the accumulation of amino acids and markedly increased endogenous phytohormone content (IAA, GA3) of Cd-stressed maize plants. These results revealed the potentiating effect of N-Bio pretreatment in regulating Cd-induced damages in maize plants. © 2021 Friends Science Publishers
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GIRARDIN, P., M. TOLLENAAR e J. F. MULDOON. "EFFECT OF TEMPORARY N STARVATION ON LEAF PHOTOSYNTHETIC RATE AND CHLOROPHYLL CONTENT OF MAIZE". Canadian Journal of Plant Science 65, n.º 3 (1 de julho de 1985): 491–500. http://dx.doi.org/10.4141/cjps85-071.
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The photosynthetic rate (P) of maize (Zea mays L.) plants grown under growth room conditions was studied during and after a 10-day period of N starvation. The relationships between P and chlorophyll content, and P and nitrogen content were examined. Nitrogen deprivation, from the 18th to the 28th day, induced a decline of maximum photosynthetic rate, respiration and chlorophyll content; this effect was reversible. Recovery of photosynthetic capability occurred within 10 days of the resumption of nitrogen supply. Only partial recovery of chlorophyll content was recorded in the same time period. A low chlorophyll content and a relatively high photosynthetic rate were observed in N-deprived plants 4 days after the return to normal nutrient conditions. Chlorophyll efficiency was significantly greater in N-deficient than in control plants for approximately 1 wk, under light conditions close to saturation. Neither chlorophyll nor nitrogen content was correlated with maximum photosynthetic rate in N-starved plants. Under nitrogen deprivation, chlorphyll activity and leaf senescence (as measured by photosynthetic decline) appeared to be regulated independently.Key words: Nitrogen content, nitrogen deficiency, nitrogen stress, respiration, Zea mays L.
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Archbold, Douglas D., e Charles T. MacKown. "Nitrogen Availability and Fruiting Influence Nitrogen Cycling in Strawberry". Journal of the American Society for Horticultural Science 122, n.º 1 (janeiro de 1997): 134–39. http://dx.doi.org/10.21273/jashs.122.1.134.
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As the primary nutrient applied to and used by strawberry, N allocation and cycling within the plant may play an important role in determining plant vigor and productivity. Our objectives were to determine 1) how N availability and fruit production affect N and fertilizer N (FN) partitioning among and within the vegetative tissues of `Tribute' strawberry (Fragaria ×ananassa Duch.) and 2) if the root N pool is temporary storage N. Plants were fed 15N-depleted NH4NO3 (0.001 atom percent 15N) for the initial 8 weeks, then were grown for 12 weeks with or without NH4NO3 with a natural 15N abundance (0.366 atom percent 15N), and were maintained vegetative or allowed to fruit. The vegetative tissues were sampled at 6 and 12 weeks. Neither N availability or fruiting had consistent effects on dry mass (DM) across all tissues at 6 or 12 weeks. At 6 weeks, the total N content of all tissues except the roots were higher with continuous N than with no N. Nitrogen availability was the dominant treatment effect on all plants at 12 weeks; continuous N increased leaflet, petiole, and total vegetative DM and total N of all tissues. Insoluble reduced N (IRN) was the major N pool within all tissues at 6 and 12 weeks regardless of treatment. Fruiting inhibited root growth and N accumulation at 6 weeks but had little effect at 12 weeks. The roots were a strong dry matter and N sink from 6 to 12 weeks. The FN pools, from the 15N-depleted FN supplied during the initial 8 weeks, exhibited changes similar to those of total N in plants not receiving N, in contrast to plants receiving continuous N where total leaflet and petiole N content increased while FN content declined. Total FN per plant declined nearly 26% over 12 weeks; the decline was greater in plants receiving N continuously than in those not receiving N, but the magnitude of the decline was not affected by fruiting. Increasing atom percent 15N values, primarily in plants receiving continuous N after the initial 8 weeks of receiving 15N-depleted FN, indicated that N cycling occurred through all tissues and N pools, proportionally more in the soluble reduced N pool but quantitatively more in the IRN pool. The root N pool was not a “temporary” N storage site available for re-allocation to other tissues, although N cycling through it was evident. Rather, leaflet N was primarily remobilized to other tissues.
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Šidlauskas, G., e P. Tarakanovas. "Factors affecting nitrogen concentration in spring oilseed rape (Brassica napus L.)". Plant, Soil and Environment 50, No. 5 (10 de dezembro de 2011): 227–34. http://dx.doi.org/10.17221/4026-pse.
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The effect of the duration of the growth season, meaning daily temperature, precipitation rate, growing degree in days, nitrogen rates and application time, stand population density, soil nitrogen content and the interaction among these factors on nitrogen concentration in spring oilseed rape plants of aboveground dry matter. During the vegetative growth season, mature seeds and straw were studied in field experiment with spring oilseed rape (Brassica napus L.) cv. Star over five years. It was found that nitrogen concentration was the highest in the youngest plants. The increase of duration in growth season and precipitation rate had a negative effect on nitrogen concentration in mature seeds. Meanwhile, the increase in growing degree-days and mean daily temperature positively affected seed nitrogen concentration. The relationships between nitrogen concentration in spring oilseed rape plants at different growth stages and climate records was found. Stand population density occurred having a rather negligible effect on nitrogen concentration. Nitrogen fertilizer rates showed strong and positive effect on nitrogen concentration in aboveground dry matter as well as in seed and straw. With the delay of nitrogen application time concentration of nitrogen was increasing.
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YADAVA, PRANJAL, CHETANA AGGARWAL, RACHANA VERMA, KRISHAN KUMAR e ISHWAR SINGH. "Effect of nitrogen-starvation on growth pattern and expression of nitrogen assimilation genes". Indian Journal of Agricultural Sciences 90, n.º 1 (2 de março de 2020): 195–200. http://dx.doi.org/10.56093/ijas.v90i1.98679.
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Studying plant response and adaptation under low nitrogen stress condition is pre-requisite to enhance nitrogen use efficiency in crops. The present study investigated the physiological and molecular responses of maize (Zea mays L.) to nitrogen stress during early vegetative stage. Maize seedlings were grown hydroponically under controlled environmental conditions in phytotron. One set of plants were nutritionally stressed by eliminating nitrogen source in hydroponic culture while the other set was provided with nitrogen (2 mM KNO3). Under nitrogen-starvation condition, plant growth and physiological parameters changed dramatically. Significant reduction in chlorophyll content, total soluble proteins and nitrate reductase activity was observed. Further, nitrogen-starvation resulted into differential expression of genes related to nitrogen-assimilation and metabolism. The present study might be useful to improve our understanding towards plants adaptive response under nitrogen-starvation conditions.
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Chen, Haoran, Sylvie Renault e John Markham. "The Effect of Frankia and Hebeloma crustiliniforme on Alnus alnobetula subsp. Crispa Growing in Saline Soil". Plants 11, n.º 14 (16 de julho de 2022): 1860. http://dx.doi.org/10.3390/plants11141860.
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The mining of the oil sands region of Canada’s boreal forest creates disturbed land with elevated levels of salts. Understanding how native plants respond to salt stress is critical in reclaiming these lands. The native species, Alnus alnobetula subsp. crispa forms nitrogen-fixing nodules with Frankia, and ectomycorrhizae with a number of fungal species. These relationships may make the plant particularly well suited for restoring disturbed land. We inoculated A. alnobetula subsp. crispa with Frankia and Hebeloma crustiliniforme and exposed the plants to 0, 50, or 100 mM NaCl for seven weeks. Frankia-inoculated plants had increased biomass regardless of salt exposure, even though salt exposure reduced nitrogen fixation and reduced the efficiency of nitrogen-fixing nodules. The nitrogen-fixing symbiosis also decreased leaf stress and increased root phosphatase levels. This suggests that N-fixing plants not only have increased nitrogen nutrition but also have increased access to soil phosphorus. Mycorrhizae did not affect plant growth but did reduce nodule numbers and nodule efficiency. These results suggest that the nitrogen-fixing trait is more critical than mycorrhizae. While salt stress inhibits nitrogen-fixing symbiosis, plants still benefit from nitrogen fixation when exposed to salt.
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Ma, Changkun, Qian Li, Zhaoxin Song, Lijun Su, Wanghai Tao, Beibei Zhou e Quanjiu Wang. "Irrigation with Magnetized Water Alleviates the Harmful Effect of Saline–Alkaline Stress on Rice Seedlings". International Journal of Molecular Sciences 23, n.º 17 (2 de setembro de 2022): 10048. http://dx.doi.org/10.3390/ijms231710048.
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Saline–alkaline stress suppresses rice growth and threatens crop production. Despite substantial research on rice’s tolerance to saline–alkaline stress, fewer studies have examined the impact of magnetic water treatments on saline–alkaline-stressed rice plants. We explored the physiological and molecular mechanisms involved in saline–alkaline stress tolerance enhancement via irrigation with magnetized water using Nipponbare. The growth of Nipponbare plants was inhibited by saline–alkaline stress, but this inhibition was alleviated by irrigating the plants with magnetized water, as evidenced by greater plant height, biomass, chlorophyll content, photosynthetic rates, and root system in plants irrigated with magnetized water compared to those irrigated with non-magnetized water. Plants that were irrigated with magnetized water were able to acquire more total nitrogen. In addition, we proved that rice seedlings irrigated with magnetized water had a greater root NO3−-nitrogen concentration and root NH4+-nitrogen concentration than plants irrigated with non-magnetized water. These findings suggest that treatment with magnetized water could increase nitrogen uptake. To test this hypothesis, we analyzed the expression levels of genes involved in nitrogen acquisition. The expression levels of OsNRT1;1, OsNRT1;2, OsNRT2;1, OsAMT1;2, OsAMT2;1, OsAMT2;2, OsAMT2;3, OsAMT3;1, OsAMT3;2, and OsAMT3;3 were higher in plants exposed to magnetized water medium compared to those exposed to non-magnetized water media. We further demonstrated that treatment with magnetized water increases available nitrogen, NO3−-nitrogen content, and NH4+-nitrogen content in soil under saline–alkaline stress. Our results revealed that the increased resistance of rice seedlings to saline–alkaline stress may be attributable to a very effective nitrogen acquisition system enhanced by magnetized water.
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Blumenthal, MJ, VP Quach e PGE Searle. "Effect of soybean population density on soybean yield, nitrogen accumulation and residual nitrogen". Australian Journal of Experimental Agriculture 28, n.º 1 (1988): 99. http://dx.doi.org/10.1071/ea9880099.
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The effect of soybean population density on soybean yield, nitrogen accumulation and residual nitrogen was examined at Camden, N.S.W. (34�S.). In the first experiment, treatments were soybeans (cv. Ransom) at 50, 100, 200 and 400 x 103 plants ha-1; maize (cv. XL66); and a weed-free fallow. Total dry matter yields of tops and grain yields were highest at 200x 103 plants ha-1 (6214 and 3720 kg ha-1, respectively). The yield component most affected by population density was number of branches per plant, with values decreasing with increasing population density. The proportion of unfilled pods was highest at the highest population density. Total nitrogen (N) accumulation in the tops and in the grain was also at a maximum at 200x 103 plants ha-1. The rate of dry matter accumulation declined during pod filling at all population densities. N accumulation continued at high rates throughout the growing season except in the 400x 103 plants ha-1 population. There was a trend for residual dry matter and N in residues to increase with increasing population density. After grain and forage harvest of the first experiment, a crop of wheat (cv. Kite) was sown over the whole area to determine residual N available at anthesis and at maturity (experiment 2). The values of N accumulation in the wheat at maturity were 24 kg N ha-l for the maize treatment, 40-60 kg N ha-l for the soybean treatments and 69 kg N ha-1 for the fallow treatment. Grain yield and grain N followed the pattern of dry matter production and N accumulation at final harvest. The data suggest that soybean depletes soil N to a lesser extent than does maize. For the soybean treatments, there was a trend of increasing residual N at the 3 highest population densities (40-60 kg N ha-1). This was probably a result of an increase in N in leaf fall and in decaying tops and roots at the highest population density. The high value (57 kg N ha-l) at the lowest population density may be due to soybean plants at this density not using as much soil N as the other soybean treatments. No benefit in residual N was gained from planting soybeans at a density beyond the optimum for grain yield when residues were removed by forage harvesting.
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Zhou, Yong, Xia Li, Hui Liu, Yubao Gao, Wade J. Mace, Stuart D. Card e Anzhi Ren. "Effects of endophyte infection on the competitive ability of Achnatherum sibiricum depend on endophyte species and nitrogen availability". Journal of Plant Ecology 12, n.º 5 (21 de março de 2019): 815–24. http://dx.doi.org/10.1093/jpe/rtz017.
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Abstract Aims The leaves of almost all terrestrial plant species are colonized by endophytic fungi. Compared to agronomic grasses, which usually harbor few endophytes, native grasses generally possess greater endophyte species diversity. Existing studies examining endophyte effects on natural grasses under competition normally considered the infection status (infected or uninfected), and rarely considered endophyte species. Methods We examined the effects of endophyte infection and of endophyte species on the interspecific competitive ability of a subdominant species, Achnatherum sibiricum, at two nitrogen levels (high nitrogen and low nitrogen). Achnatherum sibiricum plants infected by two different species of endophyte (Epichloë sibirica and E. gansuensis) and uninfected plants were grown in monoculture and binary mixtures with a dominant species, Stipa grandis (six individuals per species for monocultures and three + three individuals of each species in mixtures). Shoot and root biomass, tiller number and total phenolic concentration were measured after 3 months. Moreover, the aggressivity index was calculated to compare the competitive ability of A. sibiricum relative to S. grandis. Important Findings Both E. gansuensis (Eg)- and E. sibirica (Es)-infected A. sibiricum plants showed a greater competitive ability than the uninfected plants under high nitrogen supply, while the opposite result occurred under low nitrogen supply. At high nitrogen levels, Eg plants had a higher tiller number and a greater shoot biomass inhibitory effect on S. grandis than Es plants had when growing in mixture, while Es plants showed better root growth performance than Eg and uninfected plants under mixture conditions at all nitrogen levels. A higher concentration of phenolic compounds in Eg plants than in Es plants might contribute to the higher inhibitory effect of Eg plants on competing plants. Our study indicates that the interaction between endophyte infection and nitrogen availability can alter the competitive ability of the host plant A. sibiricum but that these two endophyte species work in different ways, which may influence the coexistence of A. sibiricum with the dominant species.
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Geneva, M., G. Zehirov, E. Djonova, N. Kaloyanova, G. Georgiev e I. Stancheva. "The effect of inoculation of pea plants with mycorrhizal fungi and Rhizobium on nitrogen and phosphorus assimilation". Plant, Soil and Environment 52, No. 10 (17 de novembro de 2011): 435–40. http://dx.doi.org/10.17221/3463-pse.
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The study evaluated the response of pea (Pisum sativum cv. Avola) to arbuscular mycorrhizal fungi (AM) species Glomus mosseae and Glomus intraradices and Rhizobium leguminosarum bv. viceae, strain D 293, regarding the growth, photosynthesis, nodulation and nitrogen fixation activity. Pea plants were grown in a glasshouse until the flowering stage (35 days), in 4 kg plastic pots using leached cinnamonic forest soil (Chromic Luvisols – FAO) at P levels 13.2 (P1) and 39.8 (P2) mg P/kg soil. The obtained results demonstrated that the dual inoculation of pea plants significantly increased the plant biomass, photosynthetic rate, nodulation, and nitrogen fixation activity in comparison with single inoculation with Rhizobium leguminosarum bv. viceae strain D 293. On the other hand, coinoculation significantly increased the total phosphorus content in plant tissue, acid phosphatase activity and percentage of root colonization. The effectiveness of coinoculation with Rhizobium leguminosarum and Glomus mosseae was higher at the low phosphorus level while the coinoculation with Glomus intraradices appeared to be the most effective at higher phosphorus level.
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Chen, Haoran, e John Markham. "The Interactive Effect of Elevated CO2 and Herbivores on the Nitrogen-Fixing Plant Alnus incana ssp. rugosa". Plants 10, n.º 3 (26 de fevereiro de 2021): 440. http://dx.doi.org/10.3390/plants10030440.
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Many studies have found that future predicted CO2 levels can increase plant mass but dilute N content in leaves, impacting antiherbivore compounds. Nitrogen-fixing plants may balance their leaf C:N ratio under elevated CO2, counteracting this dilution effect. However, we know little of how plants respond to herbivores at the higher CO2 levels that occurred when nitrogen-fixing plants first evolved. We grew Alnus incana ssp. rugosa was grown at 400, 800, or 1600 ppm CO2 in soil collected from the field, inoculated with Frankia and exposed to herbivores (Orgyia leucostigma). Elevated CO2 increased nodulated plant biomass and stimulated the nitrogen fixation rate in the early growth stage. However, nitrogen-fixing plants were not able to balance their C:N ratio under elevated CO2 after growing for 19 weeks. When plants were grown at 400 and 1600 ppm CO2, herbivores preferred to feed on leaves of nodulated plants. At 800 ppm CO2, nodulated plants accumulated more total phenolic compounds in response to herbivore damage than plants in the non-Frankia and non-herbivore treatments. Our results suggest that plant leaf defence, not leaf nutritional content, is the dominant driver of herbivory and nitrogen-fixing plants have limited ability to balance C:N ratios at elevated CO2 in natural soil.
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Sadras, V. O., e L. J. Wilson. "Nitrogen accumulation and partitioning in shoots of cotton plants infested with two-spotted spider mites". Australian Journal of Agricultural Research 48, n.º 4 (1997): 525. http://dx.doi.org/10.1071/a96146.
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In cotton (Gossypium hirsutum L.), leaves are the main site of nitrogen reduction and constitute a large reservoir of organic nitrogen. Foliar herbivores, therefore, are likely to have detrimental effects on the nitrogen economy of the plant. A field experiment was conducted to investigate the effects of two-spotted spider mites (Tetranychus urticae Koch) on the accumulation and partitioning of nitrogen in cotton shoots. Control plants and plants infested with mites 3 times in the growing season were compared. Once established, mite colonies grew exponentially. After peaking at 35–64 mites/leaf, mite numbers declined sharply. Mites markedly affected both shoot nitrogen accumulation and partitioning. The amount of nitrogen in shoots of mite-infested plants peaked earlier than in controls, and reached maximum values that were 50–69% of the controls. Early infestation (at the onset of reproductive growth) had a greater effect than infestations initiated during active reproductive growth. The concentration of nitrogen in leaves declined faster in mite-infested plants than in controls, mostly due to accelerated leaf senescence. This rapid decline in leaf nitrogen concentration could be one of the factors involved in the collapse of mite colonies in heavily infested plants. Nitrogen concentration of stems and reproductive organs was generally greater in mite-infested plants than in controls. Allometric analysis showed that this was related to both the small size of mite-infested plants, and true increases in nitrogen content probably associated with translocation from senescing leaves.
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Liang, Yueming, Xunyang He, Xiangbi Chen, Yirong Su, Fujing Pan e Lening Hu. "Low Frequency of Plants Associated with Symbiotic Nitrogen-Fixers Exhibits High Frequency of Free-Living Nitrogen Fixing Bacteria: A Study in Karst Shrub Ecosystems of Southwest China". Forests 13, n.º 2 (21 de janeiro de 2022): 163. http://dx.doi.org/10.3390/f13020163.
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Plants associated with symbiotic nitrogen-fixers and soil free-living nitrogen-fixing bacteria are good indicators for detecting the source of nitrogen in natural ecosystems. However, the community composition and diversity of plants associated with symbiotic nitrogen-fixers and soil free-living nitrogen-fixing bacteria in karst shrub ecosystems remain poorly known. The community composition and diversity of soil free-living nitrogen-fixing bacteria and plants, as well as the soil physical–chemical properties were investigated in 21 shrub plots (including different topographies and plant types). The frequency of plants associated with symbiotic nitrogen-fixers was found to be low in the 21 shrub plots. The soil free-living nitrogen-fixing bacterial community structure varied among the 21 shrub soils. Based on a variance partitioning analysis, topography, plant type, and soil pH explained 48.5% of the observed variation in bacterial community structure. Plant type had a predominant effect on community structure, and topography (aspect and ascent) and soil pH had minor effects. A negative correlation between the abundance of the soil free-living nitrogen-fixing bacterial community and the richness index for plants associated with symbiotic nitrogen-fixers was observed. The result of the low frequency of plants associated with symbiotic nitrogen-fixers highlights the importance of sources of fixed nitrogen by soil free-living nitrogen-fixing bacteria in the nitrogen limitation shrub ecosystem of the karst regions.
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Pavlíková, D., M. Neuberg, E. Žižková, V. Motyka e M. Pavlík. " Interactions between nitrogen nutrition and phytohormone levels in Festulolium plants". Plant, Soil and Environment 58, No. 8 (21 de agosto de 2012): 367–72. http://dx.doi.org/10.17221/367/2012-pse.
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This study aims to reveal and to compare effect of two various systems of nitrogen nutrition, namely injection and sidedress application, on the levels of NO3– and phytohormones (cytokinins, abscisic acid (ABA), indole-3-acetic acid (IAA)) in Festulolium plants. Calcium nitrate (CN) or ammonium sulphate (AS) were used as N source in the pot experiment. The yield of Festulolium above and below ground biomass was more substantially enhanced after sidedress application of both AS or CN in comparison with injection application. The levels of endogenous cytokinins peaked 5 days after application regardless the form of N source and the method of application. The increased concentration of endogenous cytokinins as well as the enhanced content of selected free amino acid suggest that N applied sidedress can maintain better distribution patterns of nutrients and provide improved conditions for growth and nitrogen uptake. The nitrogen application affected ABA concentrations on all tested treatments. The correlation between NO3– and ABA concentrations ranged from 0.77 to 0.89. A significant IAA increase was recorded in plants after ammonium nitrogen sidedress application and it was confirmed that applications of nitrate reduced IAA concentration (correlation between NO3– and IAA for AS treatment R2 = 0.77–0.94).
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Bijelic, Z., Z. Tomic e D. Ruzic-Muslic. "The effect of nitrogen fertilization on production and qualitative properties of sown grasslands in the system of sustainable production". Biotehnologija u stocarstvu 27, n.º 3 (2011): 615–30. http://dx.doi.org/10.2298/bah1103615b.
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Nitrogen fixation in grass-leguminous mixtures is not sufficient to satisfy the nitrogen requirements of plants, therefore it is necessary to compensate this deficiency by nitrogen from mineral fertilizers. Objective of this study is to present the effect of N application in grass-leguminous mixtures on their production and qualitative properties, i.e. to give an answer to the question if application of nitrogen fertilizers results in the increase or decrease of yield, quality and changes in the structural composition of the grassland. N from mineral fertilizers, especially considerable amounts of nitrogen, changes the structural composition of grasslands - the share of leguminous plants decreases and share of grasses increases. Yield of dry matter increases with added nitrogen fertilizers. The amounts of nitrogen fertilizer which exceed the requirements of plants reduce the economical justification of fertilization and sometimes can have even opposite effect. Nitrogen fertilization increases the content of crude proteins and protein yield, whereas other quality parameters decrease or remain unchanged. Too much nitrogen in crops leads to nitrate accumulation in plants which is undesirable quality parameter.
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Markham, John H., e Corinthe Zekveld. "Nitrogen fixation makes biomass allocation to roots independent of soil nitrogen supply". Canadian Journal of Botany 85, n.º 9 (setembro de 2007): 787–93. http://dx.doi.org/10.1139/b07-075.
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Biomass allocation patterns in plants are known to be affected by soil nitrogen availability. Since nitrogen availability can depress symbiotic nitrogen fixation, and nitrogen fixation can make plant growth independent of soil nitrogen availability but is energetically costly, it is unclear how allocation patterns in nitrogen-fixing species should respond to variation in soil nitrogen availability. We examined the effect of nitrogen source and concentration on the growth and allocation patterns in the nitrogen-fixing shrub Alnus viridis subsp. crispa (Aiton) Turrill. Plants were grown with either NH4+-N or NO3–-N at a range of low N concentrations, from 0 to 2 mmol·L–1, and either inoculated with Frankia or not. Plants without nodules had 25.l% lower biomass and had double the allocation to roots at all but the 2 mmol·L–1 nitrogen concentration. Even though nodulated plants increased growth with nitrogen concentration, allocation to roots as a fraction of total biomass did not vary in these plants, suggesting increased growth resulted from more efficient nitrogen acquisition. Allocation to roots was a significant predictor of plant growth in non-nodulated plants (r2 = 0.318, for linear least squares fit with log mass) but not for nodulated plants (r2 = 0.108). As nitrogen concentrations increased, allocation to nodules, specific nodule numbers, and the proportion of nitrogen fixed by the plants decreased, demonstrating a shift to soil nitrogen use.
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Farhangi-Abriz, S., R. Faegi-Analou e N. Nikpour-Rashidabad. "Foliar Application of Sodium Molybdate Enhanced Nitrogen Uptake and Translocation in Soybean Plants by Improving Nodulation Process Under Salt Stress". Cercetari Agronomice in Moldova 50, n.º 3 (1 de setembro de 2017): 71–82. http://dx.doi.org/10.1515/cerce-2017-0027.
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Abstract Soil salinity with different harmful effects on plant growth and productivity is one of the main reasons in diminishing biological nitrogen fixation and nitrogen assimilation in legume plants. Molybdate has a key role on nitrogen metabolism of plants and can be has a beneficial effect on it. Thus, this experiment was conducted to evaluate the effects of sodium molybdate spraying (0.2 and 0.4% solutions in water) on nodulation, nitrogen uptake and translocation in soybean plants under different levels of salt stress (0, 5 and 10 dS m−1 NaCl, respectively). Salinity reduced the nodulation, root and shoot growth and special flavonoids content in roots, which are have a key role in nodulation includes, daidzein, genistein, coumestrol and glycitein, also diminished nitrogenase, glutamine synthetase (GS), glutamate dehydrogenase (GDH), glutamine oxoglutarate aminotransferase (GOGAT) and nitrate reductase (NR) activities in nodes, nitrogen content of nodes, roots and leaves, nitrogen uptake and translocation by soybean plants. Under salt stress and nonsaline condition, sodium molybdate treatments improved the nodulation by increasing flavonoids content of roots, also these treatments enhanced the plant growth and nitrogenase, GS, GDH, GOGAT and NR activities of nodes. Furthermore, nitrogen content of nodes, roots and leaves, nitrogen uptake and translocation by soybean plants improved by sodium molybdate applications. Both of the sodium molybdate doses, exposed the similar effects on improving nodulation and nitrogen metabolism of soybean.
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Knavel, Dean E. "Effects of Previous Tillage System and Nitrogen Rates on Yield and Nitrogen Concentration and Recovery by Turnip". HortScience 21, n.º 6 (dezembro de 1986): 1337–38. http://dx.doi.org/10.21273/hortsci.21.6.1337.
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Abstract Foliage dry weight for a fall turnip (Brassica rapa L. Rapifera group) crop grown in plowed no-till (NT) plots that previously contained a cover crop of hairy vetch (Vicia villosa Roth.) (NT + V) was greater for plants grown in plots that were previously treated with N at 0 and 56 kg·ha−1 than with 112 kg·ha−1. There were significant linear effects of N rates on fresh root and dry foliage weights of turnip plants in plots that had not contained vetch (NT − V), but not for plants in NT + V plots. About 64 and 48 kg·ha−1 of N were recovered by turnip plants grown in NT + V plots that were previously treated with N at 0 and 56 kg·ha−1, respectively. The previous tillage treatments had no effect on turnip root yield.
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Atanasova, E. "Effect of nitrogen sources on the nitrogenous forms and accumulation of amino acid in head cabbage". Plant, Soil and Environment 54, No. 2 (7 de fevereiro de 2008): 66–71. http://dx.doi.org/10.17221/438-pse.
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The effect of two different nitrogen sources: ammonium nitrate and calcium nitrate, applied at increased rates, on the content of the total nitrogen, protein and non-protein nitrogen, and the content and composition of amino acids in head cabbage leaves was studied. The higher nitrogen accumulation was established at the ammonium nitrate fertilization compared to the calcium nitrate, but the application of Ca(NO<sub>3</sub>)<sub>2</sub> resulted in a higher content of nitrate nitrogen. More protein nitrogen was also observed in plants with Ca(NO<sub>3</sub>)<sub>2</sub> fertilization. The highest applied fertilizer rate of ammonium nitrate resulted in a significant reduction of the protein nitrogen compared to increased free amino acids. The total content of amino acids increased gradually with the increase of nitrogen rates in plants fertilized with NH<sub>4</sub>NO<sub>3</sub>. When Ca(NO<sub>3</sub>)<sub>2</sub> was applied, nitrogen rates higher than 500 mg/kg soil suppressed the synthesis of amino acids. A greater increase was observed as regards the levels of arginine, proline and some essential amino acids as lysine, phenylalanine and histidine. The increase of proline and alanine could serve as an indicator for unbalanced nitrogen nutrition.
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Kirova, E., D. Nedeva, A. Nikolova e G. Ignatov. "Changes in the biomass production and total soluble protein spectra of nitrate-fed and nitrogen-fixing soybeans subjected to gradual water stress". Plant, Soil and Environment 51, No. 5 (19 de novembro de 2011): 237–42. http://dx.doi.org/10.17221/3580-pse.
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The effect of the sources of nitrogen nutrition (nitrogen fixation or nitrate assimilation) and a gradual water stress on the relative water content, total fresh and dry biomass production, leaf growth, and changes in the total soluble protein spectra were studied. The plants were cultivated as soil cultures in a naturally illuminated greenhouse. Comparative studies were carried out with respect to well-watered, control plants. Nitrogen-fixing control and drought plants had relatively smaller root development but better relative water content and large leaf area on the last sampling day than nitrate-fed soybean plants. Water deficit effects on plant biomass at the end of the period studied (21 days) were independent on the nitrogen source. There was no qualitative difference in the total soluble protein spectra of nitratefed and nitrogen-fixing soybean leaves neither with the progress of development nor under drought conditions. But there was a difference in response to drought in termostable proteins of nitrate-fed and nitrogen-fixing plants. The quantity of termostable proteins in inoculated control plants was lower in some degree compared to uninoculated ones. In inoculated plants the water stress caused an increase in the amount of soluble termostable proteins
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Xu, Yi Xin, Hua Yong Zhang, Zong Han Li, Fei Li e Xiang Xu. "Assessing the Eutrophication Status of Qixing Wetland and the Effect of Plants". Advanced Materials Research 807-809 (setembro de 2013): 1870–74. http://dx.doi.org/10.4028/www.scientific.net/amr.807-809.1870.
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The comprehensive trophic level index has been applied to assess eutrophication status of QiXing Wetland. The five subzones of QiXing Wetland with different vegetation pattern have different eutrophication status. The comprehensive trophic level index is mainly affected by TN and TP at high concentration of nitrogen and phosphorus. Therefore, the plant communities can significantly influence on eutrophication status of the wetland through removing nitrogen and phosphorus in water. Three mainly dominant plants in wetland are Phragmites australis, Nelumbo nucifera and Typha orientalis Presl. The ability to remove nitrogen and phosphorus of these three plant communities were investigated. Typha orientalis Presl community has the maximum efficiency in removing nitrogen and phosphorus in water. Therefore, Typha orientalis Presl is more suitable for the purification of the water.
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Shu-Li, NIU, e JIANG Gao-Ming. "Effect of Elevated CO2 on Legume Plants With Nitrogen Fixation". Chinese Journal of Plant Ecology 27, n.º 6 (2003): 844–51. http://dx.doi.org/10.17521/cjpe.2003.0121.
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Maevskaya, S. N., e N. G. Bukhov. "Effect of Light Quality on Nitrogen Metabolism of Radish Plants". Russian Journal of Plant Physiology 52, n.º 3 (maio de 2005): 304–10. http://dx.doi.org/10.1007/s11183-005-0046-1.
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Becker, Silvia Jiménez, Maria Teresa Lao e Mari Luz Segura. "Effect and Empirical Models of Nitrogen Uptake Under Different Nitrogen Sources in Dieffenbachia amoena". HortScience 43, n.º 2 (abril de 2008): 575–79. http://dx.doi.org/10.21273/hortsci.43.2.575.
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Adjusting fertility programs according to peak demand periods will help prevent periodic nutrient disorders during crop growth, allowing enhanced use efficiency of water and fertilization. The objectives of this article were to investigate 1) the evolution of the changes in the concentration of nitrate and ammonium in the recycled solution with different N-NO3 –/N-NH4 + ratios; 2) the influence of the N form supply (N-NO3 – or N-NH4 +) on the nitrogen uptake, the nitrogen:water uptake ratio, and nitrogen use and uptake efficiency; and 3) the development of empirical models that would allow the prediction of nitrogen nutritional needs of Dieffenbachia amoena to increase the N use efficiency in a recycled system. To achieve these aims, N uptake has been correlated to climate parameters such as temperature, vapor pressure deficit and global radiation, and growth parameters such as leaf area index. The trial was carried out with Dieffenbachia amoena plants growing in a recycled system with expanded clay as substrate. The crop was placed in an INSOLE (Buried Solar Greenhouse), the plants being supplied with equal amounts of N, differing in the percentage of the N form applied (NO3 –:NH4 +): TA (100:0), TB (50:50), and TC (0:100). The nitrogen form generated important changes in the pH and nitrate and ammonium concentration in nutritive solution during the recirculating solution. In N-NO3 – treatment, pH increased and nitrate concentration showed a tendency to drop slightly. N-NH4 + treatment showed an abrupt N-NH4 + concentration decrease, and N-NO3 – concentration increased along with a pH drop. Also, the nitrogen form applied to the Dieffenbachia amoena crop affects nitrogen uptake. Nitrogen uptake rates and nitrogen uptake concentration were higher in the plants supplied with N-NH4 + or NO3 –+NH4 + than in the plants provided with N-NO3 – alone. The supply of a combination of 50:50 NO3 –+NH4 + improved the N use efficiency. The study also indicated the possibility of predicting the N uptake rate and N uptake concentration using the proposed models.
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Aflakpui, G. K. S., P. J. Gregory e R. J. Froud-Williams. "GROWTH AND BIOMASS PARTITIONING OF MAIZE DURING VEGETATIVE GROWTH IN RESPONSE TO STRIGA HERMONTHICA INFECTION AND NITROGEN SUPPLY". Experimental Agriculture 38, n.º 3 (19 de junho de 2002): 265–76. http://dx.doi.org/10.1017/s0014479702003022.
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The effect of the root hemiparasitic angiosperm Striga hermonthica on the gowth, photosynthesis and partitioning of biomass in maize was studied in glasshouse experiments in two seasons. In both seasons, nitrogen was applied to the plants at rates equivalent to 20, 60 and 120 kg ha−1. There was no significant Striga×nitrogen interaction on the responses measured. Averaged across all nitrogen treatments, maize plants infected with S. hermonthica had smaller leaf areas and accumulated less biomass, than did uninfected plants. The leaf area of infected and uninfected plants increased asymptotically from emergence to the final harvest (about the 18-leaf stage) at which time the leaf area of infected plants was 63% that of uninfected plants. The rates of photosynthesis of the youngest, fully expanded leaves of infected plants, averaged across N treatments, were significantly lower than for uninfected plants. However, stomatal conductance and the sub-stomatal CO2 concentration were unaffected by Striga infection. Although infection with Striga significantly reduced shoot biomass (dry weight at final harvest was 37% that of uninfected plants in 1995 and 63% in 1996), there were no significant effects of Striga infection on root biomass so that the infected plants partitioned a significantly greater proportion of their total biomass to roots compared with the uninfected plants. The allometric coefficients, though, were similar for both infected and uninfected plants. Averaged across infected and uninfected plants, application of nitrogen increased total leaf area per plant and root and shoot biomass but did not change the proportion of total biomass partitioned to roots. These results did not show a major effect of nitrogen on the relative growth response of maize to infection with Striga.
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Harbur, Matthew M., e Micheal D. K. Owen. "Influence of relative time of emergence on nitrogen responses of corn and velvetleaf". Weed Science 54, n.º 5 (outubro de 2006): 917–22. http://dx.doi.org/10.1614/ws-05-167r1.1.
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Nitrogen (N) management markedly affects weed competition with crops. The effect of N availability on plant competition varies with a plant's abilities to capture and use N. Accordingly, we expected the N effect on plant competition to change with the relative emergence time of competing individuals. This hypothesis was tested by growing corn and velvetleaf plants in target and neighbor roles and comparing their N responses. Sowing times were varied, so that target plant emergent dates were constant, whereas neighbor plants were sown to emerge 7 d before, with, or 7 d after targets. Seedlings were fertilized daily with 2.5 mmol (“low N”) or 10.0 mmol (“high N”) ammonium nitrate (NH4NO3). Corn had greater total weight, leaf area, and root-to-shoot ratio (RSR) than velvetleaf. Different dry weights may have reflected seed weights; corn seed weight was greater than velvetleaf. Regardless of role, corn and velvetleaf dry weight and leaf area were greater with high N than low N; in contrast, RSR was lower with high N than low N. The RSR response to N availability suggested plant resources were shifted from N foraging, toward competition for photosynthetically active radiation (PAR). In target plants of each species, dry weight and leaf area increased linearly with time between target and neighbor emergence. Conversely, dry weight and leaf area of neighbor plants decreased with time between target and neighbor emergence. The N response of neighbor plants increased with time of emergence between target and neighbor emergence. Larger plants likely required more N to sustain growth than smaller plants; plants that emerged earlier likely had greater daily N requirements than those that emerged later. These results support factoring in emergence when predicting N effects on plant competition. Optimal N provisioning for integrated weed management may differ with emergence times of competing plants.
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Akter, Asma, e Jan Klečka. "Water stress and nitrogen supply affect floral traits and pollination of the white mustard, Sinapis alba (Brassicaceae)". PeerJ 10 (18 de abril de 2022): e13009. http://dx.doi.org/10.7717/peerj.13009.
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Changes in environmental conditions are likely to have a complex effect on the growth of plants, their phenology, plant-pollinator interactions, and reproductive success. The current world is facing an ongoing climate change along with other human-induced environmental changes. Most research has focused on the impact of increasing temperature as a major driving force for climate change, but other factors may have important impacts on plant traits and pollination too and these effects may vary from season to season. In addition, it is likely that the effects of multiple environmental factors, such as increasing temperature, water availability, and nitrogen enrichment are not independent. Therefore, we tested the impact of two key factors—water, and nitrogen supply—on plant traits, pollination, and seed production in Sinapis alba (Brassicaceae) in three seasons defined as three temperature conditions with two levels of water and nitrogen supply in a factorial design. We collected data on multiple vegetative and floral traits and assessed the response of pollinators in the field. Additionally, we evaluated the effect of growing conditions on seed set in plants exposed to pollinators and in hand-pollinated plants. Our results show that water stress impaired vegetative growth, decreased flower production, and reduced visitation by pollinators and seed set, while high amount of nitrogen increased nectar production under low water availability in plants grown in the spring. Temperature modulated the effect of water and nitrogen availability on vegetative and floral traits and strongly affected flowering phenology and flower production. We demonstrated that changes in water and nitrogen availability alter plant vegetative and floral traits, which impacts flower visitation and consequently plant reproduction. We conclude that ongoing environmental changes such as increasing temperature, altered precipitation regimes and nitrogen enrichment may thus affect plant-pollinator interactions with negative consequences for the reproduction of wild plants and insect-pollinated crops.
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Zhou, Jialong, Zhelun Xu, Shanshan Zhong, Youli Yu, Zhongyi Xu, Daolin Du e Congyan Wang. "Nitrogen Influence to the Independent Invasion and the Co-Invasion of Solidago canadensis and Conyza canadensis via Intensified Allelopathy". Sustainability 14, n.º 19 (22 de setembro de 2022): 11970. http://dx.doi.org/10.3390/su141911970.
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The allelopathy of alien plants is critical to their successful invasion. In nature, two alien plants can co-invade the same habitat. Changes in the forms of nitrogen may have the potential to alter the invasion process of alien plants by causing alterations in their allelopathy. This study aimed to evaluate the individual and combined allelopathy of two alien plants from the Asteraceae family, Solidago canadensis L. and Conyza canadensis (L.) Cronq. This study examined the effects of aqueous leaf extracts of the two alien plants with different nitrogen forms (NO3−N, NH4−N, and CO(NH2)2−N, and the mixed nitrogen forms at a 1:1:1 ratio) on the seed germination and seedling growth of the horticultural Asteraceae species Lactuca sativa L. using a germination bioassay. The allelopathy of the two alien plants significantly reduced the seed germination and seedling growth of L. sativa. Extracts from S. canadensis produced stronger allelopathy on the seed germination and seedling growth of L. sativa compared with those from C. canadensis. The mixture of extracts from the two alien plants produced an antagonistic effect when compared with the effects of extracts from each plant species. The addition of nitrogen intensified the allelopathy of the two alien plants on the seed germination and seedling growth of L. sativa. The degree of influence of nitrogen on the individual and combined allelopathy of the two alien plants was similar. Thus, nitrogen deposition may facilitate the independent invasion and co-invasion of the two alien plants via intensified allelopathy.
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Makus, D. J. "115 EFFECT OF NITROGEN SOURCE AND LEVEL ON VEGETABLE AMARANTH". HortScience 29, n.º 5 (maio de 1994): 444f—444. http://dx.doi.org/10.21273/hortsci.29.5.444f.
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On 3 Aug. 1993, 20-day-old `Hinn Choy' plants (Amaranthus tricolor L.) were-planted on 15 × 15 cm spacings in 4-row beds at 1.3 m row spacings in a Leadvale silt loam soil. Nitrogen sources of NH4, NO3 and NH4 NO3 were used at rates of 0, 100 and 200 kg/ha, and were split-applied at and 1 week after transplanting. All treatments received both supplemental K and P at the rate of 90 kg/ha at planting. Plants were harvested 31 days after transplanting. Plants given the NH, source were taller, and were higher in yield, leaf chlorophyll, total carotenoids and Mn (dry wt basis) than were plants given other N-sources. NO3-N fertilizer increased leaf Fe and Cu, and residual soil K and NO3, but reduced Mn levels. Leaf blade Ca was highest when NH4NO3 fertilizer was used. Increasing N-rates decreased both soil pH linearly and leaf blade Ca but linearly increased soil EC, NO3, and S and leaf blade N, K, S, P, NO3, Fe, chlorophyll and carotenoids.
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Tufail, Muhammad Aammar, María Touceda-González, Ilaria Pertot e Ralf-Udo Ehlers. "Gluconacetobacter diazotrophicus Pal5 Enhances Plant Robustness Status under the Combination of Moderate Drought and Low Nitrogen Stress in Zea mays L." Microorganisms 9, n.º 4 (17 de abril de 2021): 870. http://dx.doi.org/10.3390/microorganisms9040870.
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Plant growth promoting endophytic bacteria, which can fix nitrogen, plays a vital role in plant growth promotion. Previous authors have evaluated the effect of Gluconacetobacter diazotrophicus Pal5 inoculation on plants subjected to different sources of abiotic stress on an individual basis. The present study aimed to appraise the effect of G. diazotrophicus inoculation on the amelioration of the individual and combined effects of drought and nitrogen stress in maize plants (Zea mays L.). A pot experiment was conducted whereby treatments consisted of maize plants cultivated under drought stress, in soil with a low nitrogen concentration and these two stress sources combined, with and without G. diazotrophicus seed inoculation. The inoculated plants showed increased plant biomass, chlorophyll content, plant nitrogen uptake, and water use efficiency. A general increase in copy numbers of G. diazotrophicus, based on 16S rRNA gene quantification, was detected under combined moderate stress, in addition to an increase in the abundance of genes involved in N fixation (nifH). Endophytic colonization of bacteria was negatively affected by severe stress treatments. Overall, G. diazotrophicus Pal5 can be considered as an effective tool to increase maize crop production under drought conditions with low application of nitrogen fertilizer.
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Pytlarz-Kozicka, M. "The effect of nitrogen fertilization and anti-fungal plant protection on sugar beet yielding". Plant, Soil and Environment 51, No. 5 (19 de novembro de 2011): 232–36. http://dx.doi.org/10.17221/3579-pse.
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Sugar beet yielding and, thus, the profitability of its cultivation depends on various conditions. These are mainly a dose of nitrogen fertilizing and anti-fungal plant protection. Based on the research carried out in a private-owned farm in Biała commune, Opole province, Poland, it was observed that the most important factors influencing plant development and root yield of sugar beets (var. Kassandra and Cortina) were genetic features of the investigated varieties and fungal control. They increased considerably root yield and sugar content. The doubled nitrogen dose from 90 to 180 kg N/ha enhanced a slight, statistically insignificant, root yield increase and a lower sugar content in beet roots. The three-year research showed that weather conditions during the vegetation period had a decisive effect on sugar beet plants development and fungal infestation. The variety Cortina was characterized with a significantly higher yield and a higher content of treacle forming compounds in the roots. The increase of N rate from 90 to 180 kg N/ha caused a significant increase of average root mass, leaves and dry matter yield and potassium and N-NH<sub>2</sub> in roots, but it also lowered sugar content. In the years with favorable conditions for fungal infestation, the use of fungicides helped to obtain a higher leaf/root ratio, higher root mass, higher root and leaf yield and higher dry matter and sugar yields. However, it did not have an effect on the content of chemical compounds producing treacle in sugar beet roots.
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Matsera, Olha. "EFFECT OF SOWING METHOD AND N APPLICATION ON SEED YIELD AND N USE EFFICIENCY OFWINTER OILSEED RAPE". Agriculture and Forestry, n.º 4 (18 de dezembro de 2020): 76–85. http://dx.doi.org/10.37128/2707-5826-2020-4-7.
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In the conditions of the Right-Bank Forest-Steppe, the cultivation of winter rapeseed crops after winter wheat usually leads to a delay in sowing the latter and deterioration of autumn plant development. Based on data from a field experiment conducted in 2016/2017, 2017/2018 and 2018/2019, the aim of this study was to investigate how sowing delay affects seed yield, nitrogen uptake by seeds and significant efficiency of nitrogen use by winter rape plants; to check the ability of autumn and spring application of nitrogen fertilizers to compensate for the negative impact of delays in sowing crops; and estimate the minimum autumn development for optimal seed yield. To solve the set tasks, a combination of four sowing dates (from the first week of August to the third week of September) and four autumn nitrogen applications (0, 30, 60 and 90 kg / ha per year) was fixed. In each of these 16 variants, nitrogen application was performed 5 times in the spring (0/0, 40/40, 80/80, 120/120, 140/140 kg / ha, etc.) in order to estimate the individual nitrogen reaction curves. Nitrogen accumulation by aboveground mass of plants in autumn, seed yield and nitrogen uptake by seeds were determined. It was found that sowing the crop after mid-September significantly reduced yields. Application of nitrogen fertilizers in autumn in the amount of at least 30 kg / ha per year increased the yield and absorption of nitrogen seeds without any significant interaction with the sowing period and spring application of nitrogen fertilizers. Increasing the dose of spring fertilizer application to 130 kg / ha increased seed yield. Nitrogen utilization efficiency decreased with increasing application rate when winter oilseed rape plants used nitrogen applied in the fall to a lesser extent than in the spring. In order to achieve high yields, it was necessary for the above-ground mass of plants to absorb nitrogen at the level of at least 10-15 kg / ha at the end of the autumn vegetation. From an ecological point of view, the optimal autumn development of plants should be achieved by choosing an adequate sowing date, rather than using additional nitrogen in autumn.
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Singh, Abhai Pratap, Rashmi Singh, Usha Mina, M. P. Singh e C. K. Varshney. "Effects of different doses of nitrogen treatments on isoprene emission from Ficus glomerata". Journal of Applied and Natural Science 2, n.º 1 (1 de junho de 2010): 13–16. http://dx.doi.org/10.31018/jans.v2i1.86.
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In the present investigation on the effect of nitrogen treatments on emission of isoprene from Ficus glomerata has been evaluated. Four sets of plants were treated with following four doses of nitrogen in the form of ammonium nitrate solution (i) 10 mM (ii) 50 mM (iii) 100 mM (iv) 200 (mM) and control set was designed without any treatment. Nitrogen treated as well as control plants were sampled for isoprene emission using a dynamic flow through enclosure chamber technique and samples were analysed with the help of GC-FID. Isoprene emissions from control, 10 mM, 50 mM, 100 mM, and 200 mM nitrogen treated plants were found to be 27.5 ± 4 μgg-1h-1, 56 ± 6 μgg-1h-1, 91 ± 11 μgg-1h-1, 101 ± 10 μgg-1h-1, and 15 ± 4 μgg-1h-1 respectively. Lowest isoprene emission (15 ± 4 μgg-1h-1) was noticed in plants treated with 200 mM nitrogen. Isoprene emissions were found to increase exponentially in plants treated with nitrogen up to 100 mM. Nevertheless, plants treated with 200 mM nitrogen exhibited decrease in emission by 46 per cent, probably on account of nitrite toxicity and reduction in soil pH at high nitrogen dose.
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Terrer, César, Sara Vicca, Bruce A. Hungate, Richard P. Phillips e I. Colin Prentice. "Mycorrhizal association as a primary control of the CO2 fertilization effect". Science 353, n.º 6294 (30 de junho de 2016): 72–74. http://dx.doi.org/10.1126/science.aaf4610.
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Plants buffer increasing atmospheric carbon dioxide (CO2) concentrations through enhanced growth, but the question whether nitrogen availability constrains the magnitude of this ecosystem service remains unresolved. Synthesizing experiments from around the world, we show that CO2 fertilization is best explained by a simple interaction between nitrogen availability and mycorrhizal association. Plant species that associate with ectomycorrhizal fungi show a strong biomass increase (30 ± 3%, P < 0.001) in response to elevated CO2 regardless of nitrogen availability, whereas low nitrogen availability limits CO2 fertilization (0 ± 5%, P = 0.946) in plants that associate with arbuscular mycorrhizal fungi. The incorporation of mycorrhizae in global carbon cycle models is feasible, and crucial if we are to accurately project ecosystem responses and feedbacks to climate change.
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Kim, Tehryung, Harry A. Mills e Hazel Y. Wetzstein. "364 Studies on the Effects of Nitrogen Source on Pecan Nutrient Uptake and Plant Growth and Development". HortScience 35, n.º 3 (junho de 2000): 455B—455. http://dx.doi.org/10.21273/hortsci.35.3.455b.
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As a plant nutrient, nitrogen is the element in highest demand in terms of quantity and makes up about 2% to 3% of plant dry matter. In this study, we evaluated the effect of nitrogen source on plant growth and nutrient uptake in pecan (Carya illinoensis). Seedlings were hydroponically grown under three nitrogen nutrient regimes where the ratio of nitrate: ammonium was varied, i.e., 3:1, 1:1, and 1:3. High ammonium nutrition had an inhibiting effect on seedling growth. Plants grown under 1:3 (nitrate: ammonium) exhibited significantly lower biomass, decreased root/shoot ratio, and lower specific leaf weight than other treatments. Total nitrogen uptake on a dry weight basis was highest in the high ammonium treatment. In the equal molar treatment (1:1 nitrate: ammonium), plants exhibited preferential uptake of ammonium-form nitrogen. Ammonium-form nitrogen is generally used in pecan orchard practice. Our data suggest that further studies evaluating the effects of nitrogen source are warranted to determine if similar detrimental effects on pecan growth occur in the field. Such studies would be useful for optimizing current fertilization practices.
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Le, Won Je, e Hojoung Lee. "Response to Salinity Stress in Plants and nitrogen effect: About hormone signaling pathway and root development". Institute of Life Science and Natural Resources 30 (31 de dezembro de 2022): 15–22. http://dx.doi.org/10.33147/lsnrr.2022.30.1.15.
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Around the world, 110 billion hectares of cultivated land in more than 100 countries are affected by soil salinity due to rapid climate change. Salinity and drought stress among various abiotic stresses are the main causes of significant decrease in crop production worldwide. In the 21st century, there are also predictions that 50% of the arable land will be affected by soil salinity. To alleviate the salt stress of crops and further increase production, mechanisms related to various physiological phenomena related to plant salt stress should be identified at the molecular level. In addition, plants can not move, so in order to successfully grow and develop in a given environment, various nutrients including micronutrients such as iron, manganese, and zinc are needed as well as large nutrients such as nitrogen, phosphorus and potassium. Most of these soil nutrients are absorbed into the plant body through the underground root system of a wide range of plants. In particular, nitrogen is one of the essential macronutrients for plant growth and crop productivity. Plants evolved various mechanisms to adapt to unbalanced nitrogen conditions. However, plants absorb nitrates with the help of nitrogen-fixing-related bacteria around their roots, as they cannot absorb nitrogen directly from the atmosphere. To meet the growing demand for food resources, the large amount of synthetic nitrogen fertilizer supplied to crops increased dramatically as synthetic nitrogen fertilizers began to be developed, resulting in a significant increase in crop yields. However, most of the nitrates deposited in the soil are not absorbed by plants but spread to the surrounding environment, leading to serious environmental and ecological pollution. Thus, identification of regulatory genes associated with in-depth understanding of nitrate absorption, assimilation and their use mechanisms is a key prerequisite for improving nitrogen use efficiency (NUE) in crops, and consequently is critical for maintaining agricultural stability.
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Kirova, E., D. Nedeva, A. Nikolova e G. Ignatov. "Changes in the electrophoretic spectra of antioxidant enzymes in nitrate-fed and nitrogen-fixing soybean subjected to gradual water stress". Acta Agronomica Hungarica 52, n.º 4 (1 de março de 2005): 323–32. http://dx.doi.org/10.1556/aagr.52.2004.4.1.
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The effect of two sources of nitrogen (nitrogen fixation or nitrate assimilation) and gradual water stress on theelectrophoretic spectra of peroxidase, catalase and superoxide dismutase was studied in soybean leaves. An increase in H2O2 production was observed, especially after the prolonged drought treatment. At 50% drought the activity of anionic peroxidase activity for isoenzymes Nos. 2 and 7+8 significantly increased (by 54 and 18%, respectively) in the leaves of nitrate-fed plants compared to the control plants; for nitrogen-fixing plants these values were 31 and 14%, respectively. In the case of cationic peroxidases, the application of 50% drought led to the inhibition of the moderately fast isoenzymes (Nos. 2 and 3, with Rm 0.5 and 0.65, respectively) and the activation of the fastest moving isoenzyme (No. 4, with Rm 0.8) in nitrate-fed soybean. The same tendency was observed in the leaves of nitrogen-fixing plants. The effect of restricted soil humidity on SOD activity was expressed as a change in the activity of some of the isoenzymes. There was a clear tendency for the SOD isoenzyme activity to increase after the exposure of nitrate-fed and nitrogen-fixing soybean plants to 50% drought treatment. high catalase activity was registered in control nitrate-fed plants. Generally the catalase isoenzyme activity in control nitrogen-fixing plants had low values. Both intensities of water stress (30 and 50% drought) caused an increase in the catalase activity, and this increase was much higher for nitrogen-fixing plants. Therefore, soybean plants responded to drought treatment by changes in the antioxidant enzyme activity, as these changes were partially dependent on the source of nitrogen. The results suggested that nitrogen-fixing soybean plants were more resistant to gradual water stress.
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Casey, Christine A., e Michael J. Raupp. "Effect of Supplemental Nitrogen Fertilization on the Movement and Injury of Azalea Lace Bug (Stephanitis pyrioides(Scott)) to Container-grown Azaleas". Journal of Environmental Horticulture 17, n.º 2 (1 de junho de 1999): 95–98. http://dx.doi.org/10.24266/0738-2898-17.2.95.
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Abstract Certain arthropods feed selectively and perform better on plants and plant tissues with elevated levels of nitrogen. Yet it is a common practice to use supplemental nitrogen in the production and maintenance of woody landscape plants. The link between elevated nitrogen levels and improved performance of herbivorous arthropods is particularly strong for sap suckers in the order Heteroptera, the majority of which are phloem feeders. There have been no studies to date on the effects of fertilization of woody plants on important mesophyll-feeding Heteroptera, such as azalea lace bug. We examined the relationship between the movement and injury of azalea lace bug and levels of fertilization of azaleas. The objective of this study was to determine if this insect responded to supplemental nitrogen fertilization in a way similar to many phloem-feeding Heteroptera and mesophyll-feeding Acarina. In these taxa, numerous studies documented improved performance and increased host plant injury as a result of supplemental nitrogen fertilization. We measured injury and colonization by azalea lace bug of azaleas receiving four levels of nitrogen fertilization. Plants with elevated nitrogen levels were preferentially chosen by azalea lace bug but did not exhibit greater levels of leaf injury.
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Adebusola, Adewole, Odjegba Victor, Iwuala Emmanuel e Afroz Alam. "Effect of nitrogen application on the phytochemical production in Jatropha curcas L. (Angiosperms: Euphorbiaceae) during drought conditions". Plant Science Today 6, n.º 2 (28 de abril de 2019): 183–89. http://dx.doi.org/10.14719/pst.2019.6.2.523.
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Nitrogen is an important nutrient for the successful metabolism of plants, but its occurrence in soil is always very limited. This nutrient has a significant role to preserve plants during various stress conditions by altering the production rate of phytochemicals as defense weapons. Hence, this study was carried out to analyze the effect of nitrogen supply on the phytochemical composition and relative water content in Jatropha curcas L. under a simulated drought condition. The selected seedlings were grown from stem cuttings and categorized into different treated three groups along with the control. After the completion of the experiment, the growth pattern and phytochemical production were investigated. An increased malondialdehyde activity (MDA) was reported with a reduction in relative water content (RWC) of the leaf and in the biomass of seedlings under drought stress. A significant decrease in the levels of alkaloids, phenol, flavonoids and tannins with an increase in saponins and terpenoids was also observed in only simulated drought stressed plants. While a significant increase in the levels of total alkaloid, tannins, flavonoids and phenols was observed in those plants where exogenous nitrogen was supplied before the start of drought periods, unlike in treated and control plants. Therefore, it was revealed that application of Nitrogen enabled the plants to possess protective mechanism through the production of phytochemicals that facilitate the cell membrane to reduce the detrimental effects caused by drought stress.
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Aliyev, Z. H. "Azerbaijan effects on Agrochemical Indications and Effect of Erosion Process on Plant Productivity". Pesticide Science and Pest Control 1, n.º 3 (8 de agosto de 2022): 01–04. http://dx.doi.org/10.58489/2833-0943/012.
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Taking all these into account, it is important to increase the fertility of the soil from the erosion process in Ismayilli and to prevent the washing of fodder crops from perennial herbs. The cultivation of these plants in the mountainous regions protects the slopes from the terrible erosion process and provides the animals with a strong fodder. It is proved by the results of the research that restoration of fertility and ecological balance of erosion lands and the implementation of soil-agro-technical measures to increase productivity are of great importance. Due to the application of these measures, I, as a result of improving the water and physical properties of the affected land, prevent surface water flows. In addition, the results of the study have been proven by the fact that, for certain reason, erosion and erosion hazards are most likely to be taken over by the sowing of perennial herbs. Thus, perennial herbs, in particular, accumulate the nitrogen atmosphere of the legumes, enriches the soil with organic matter, accelerates the formation of water-resistant granular - topical structure and improves its water-physical properties, which in turn facilitates the rapid digestion of foodstuffs.
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Jingang, Liang, Luan Ying, Jiao Yue, Sun Shi, Wu Cunxiang, Wu Haiying, Zhang Mingrong, Zhang Haifeng, Zheng Xiaobo e Zhang Zhengguang. "High-methionine soybean has no significant effect on nitrogen-transforming bacteria in rhizosphere soil". Plant, Soil and Environment 64, No. 3 (21 de março de 2018): 108–13. http://dx.doi.org/10.17221/750/2017-pse.
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Transgenic plants may induce shifts in the microbial community composition that in turn alter microbially-mediated nutrient cycling in soil. Studies of how specific microbial groups respond to genetically modified (GM) planting help predict potential impacts upon processes performed by these groups. This study investigated the effect of transgenic high-methionine soybean cv. ZD91 on nitrogen-fixing and ammonia-oxidizing bacterial populations. A difference in nitrogen-fixing or ammonia-oxidizing bacteria community composition was not found, suggesting that cv. ZD91 does not alter the bacterial populations in rhizosphere soil. This study increases our understanding of the potential effect of transgenic soybean on microbial functional groups within soil by suggesting that nitrogen-transforming bacteria may be useful for future investigations on the GM crops impact in the soil ecosystem.
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SAIA, S., E. BENÍTEZ, J. M. GARCÍA-GARRIDO, L. SETTANNI, G. AMATO e D. GIAMBALVO. "The effect of arbuscular mycorrhizal fungi on total plant nitrogen uptake and nitrogen recovery from soil organic material". Journal of Agricultural Science 152, n.º 3 (7 de fevereiro de 2013): 370–78. http://dx.doi.org/10.1017/s002185961300004x.
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SUMMARYArbuscular mycorrhizal (AM) fungi increase nitrogen (N) uptake by their host plants, but their role in plant N capture from soil organic material is still unclear. In particular, it is not clear if AM fungi compete with the host plant for the N coming from the decomposing organic matter (OM), especially when the AM extraradical mycelium (ERM) and plant roots share the same soil volume. The goal of the present research was to study the effects of AM fungi on wheat N capture after the addition of 15N-labelled OM to soil. Durum wheat (Triticum durum) was grown under controlled conditions in a sand:soil mix and the following treatments were applied: (1) AM inoculation with Glomus mosseae and uninoculated control; and (2) soil amended with 15N-enriched maize leaves and unamended soil. The addition of OM reduced plant growth and N uptake. The AM fungi increased both plant growth and N uptake compared with uninoculated control plants and the effect was enhanced when wheat was grown in soil amended with OM compared with the unamended control. Although AM fungi increased soil N mineralization rates and total plant N uptake, they strongly reduced wheat N recovery from OM, suggesting that AM fungi have marked effects on competition between plants and bacteria for the different N sources in soil.
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Fehér, Bernadett, Ibolya Demeter, Tibor Aranyos, Attila Tomócsik e Mariann Makádi. "The effect of wet compost extract on the root tubers of green pea". Acta Agraria Debreceniensis, n.º 72 (16 de maio de 2017): 51–54. http://dx.doi.org/10.34101/actaagrar/72/1586.
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Nitrogen plays significant role in the life of plants, it could be the main limiting factor of plant growth. Sustainable plant nutrition pays attention to satisfy the plants’ nutrient demand without chemical fertilizers, e.g. by bounding the atmospheric nitrogen. The nitrogen fixing organizations play important role in supplying plants with nitrogenbecause the N2-fixingbacteria can fix high amounts of nitrogen.Many effects of the sewage sludge compost extracts is known in the literature. We studied the effect of sewage sludge compost water extract in laboratory conditions on the growth of Rhizobium spp. isolated from green pea, while in a small plot experiment thepea-Rhizobium symbiosis were studied on sandy soil in the Nyírség region. The extract was produced under aerobic conditions. The compost extract was applied before and/or after sowing. In the laboratory experiments we used the sterile version of extract, in different doses.In our work we present the effect of compost water extract on the number of green pea roots nodules, dry weight of the plant and reproduction of the Rhizobium bacteria.