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Nitrogen (N) is an essential nutrient for plant growth, and ammonium (NH4 +) and nitrate (NO3 -) are two main forms of N that plants absorb from the soil. The total N concentration suitable for blu...

Nitrogen (N) is the mineral nutrient required in greater quantities by plants with deficiencies affecting crop production. Nitrate (NO3-) and ammonium (NH4+) are the inorganic N forms most readily ...

Made available in DSpace on 2020-12-12T01:29:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-10-01 Despite the importance of nitrogen (N) supply to plants, there are still doubts concerning the optimal relations of ammonium and nitrate in the nutrition of yellow passion fruit seedlings. This study aims to evaluate the interaction between nitrogen concentrations and ammonium and nitrate proportions in the nutrition, growth, and dry matter production of passion fruit seedlings grown in a substrate with a nutrient solution. The experiment was conducted in a greenhouse in randomized complete block design with three replications in a 4 × 5 factorial design, consisting of four N concentrations (2.5, 5.0, 10.0 and 20.0 mmol L−1) and five ammonium proportions (0, 25, 50, 75 and 100% in relation to the total N supply). At 60 days after transplanting, green color index; accumulation of N, potassium, calcium, and magnesium in roots and shoots; stem diameter; leaf area; root length; nitrogen use efficiency (NUE); and dry matter of roots and shoots were evaluated. For the formation of seedlings of yellow passion fruit, the nutrient solution should have 13 mmol L−1 of N, with 40% of this nutrient in the form of ammonium. The passion fruit is a plant tolerant to ammonium. However, a critical concentration above 5.7 mmol L−1 of NH4+ in the nutrient solution decreases absorption of cations, NUE, and production of dry matter. Department of Plant Science Research Center of Agricultural Sciences Campus of Ministro Petrônio Portella Federal University of Piauí Department of Soils and Fertilizers Faculty of Agriculture and Veterinary Sciences São Paulo State University São Paulo State University (UNESP) School of Agricultural and Veterinarian Sciences Department of Agronomy Federal Institute of Maranhão Department of Agronomy Federal University of Mato Grosso do Sul Campus Chapadão do Sul Department of Agronomy Universidad de Pamplona Paulo Donato Castellane Department of Soils and Fertilizers Faculty of Agriculture and Veterinary Sciences São Paulo State University São Paulo State University (UNESP) School of Agricultural and Veterinarian Sciences

This study was carried out to investigate the effects of salt (60 mM NaCl) in nigella (Nigella sativa L.) amended with different nitrogen (N) forms. Plants were grown for 2 weeks under hydr...

The objective was to determine the most favorable nitrogen (N) source ratio of ammonium (NH4+) to nitrate (NO3−) for aeroponic culture of Chinese fragrant solomonseal Polygonatum odoratum (Mill.) Druce seedlings. Seedlings were cultured with solutions based on 50% Hoagland formula containing 0:100, 10:90, 20:80, and 30:70 NH4+:NO3− ratios for 21 days. Activities of anti-oxidant enzymes and glutathione contents of leaves with treatments of 10:90 and 20:80 NH4+:NO3− ratios were higher than that of all-nitrate treatment, and malondialdehyde (MDA) concentrations were lower than that of all-nitrate treatment. The maximum quantum yield ϕPo value was normal among all of the treatments, whereas the absorption energy ABS/CSm value with 20:80 NH4+:NO3− treatment was highest and the heat dissipation DIo/CSm value with 20:80 NH4+:NO3− treatment was lowest among all of the treatments. These results supported that moderate proportion of 20% NH4+ in the solution provided optimal growth condition for (P) P. odora...

We conducted an experiment to quantify the effects on substrate pH from nitrogen (N) carrier and concentration. We used four concentrations of N (3.5–14 mM) and five fractions of ammonium (NH4+) (0–80% NH4+ of total N) that are found in commercially available fertilizers. Fertilizers were applied to fallow 14-cm-diameter pots (1.29 L) filled with a 3 peat:1 perlite (v/v) substrate amended with non-residual powdered calcium carbonate to raise the substrate pH to approximately 6.0. Harvests occurred at 20 and 42 days. Significant effects in the model included main effects of N carrier and N concentration, their squared terms, an interaction effect, and a time × N carrier. The fraction of NH4+ accounted for 45.0% of variation in substrate pH, and N concentration accounted for 1.5% of the total R2 of 76.7%. Substrate acidification was likely due to the physiological fertilizer effect and nitrification.

The objective of this study was to test if the effects of different nitrogen forms on potato growth depend on the plant growth stage. Plants from different potato cultivars were treated with different forms of nitrogen before tuber initiation and after tuber formation. A nitrification inhibitor was used to prevent the transformation of ammonium (NH4+) to nitrate (NO3−). Plant growth, tuber formation, leaf area, leaf chlorophyll content, and tuber yield were assessed. The results obtained over 2 years indicate that plants treated with NO3-nitrogen (N) before or at tuber initiation produced more tubers per plant than those treated with NH4-N. However, plants treated with NH4-N develop tubers earlier. Additionally, after tuber formation, plants treated with NH4-N had better shoot growth than plants treated with NO3-N. A larger leaf area with higher leaf chlorophyll content resulted in greater dry matter accumulation and higher tuber yield at harvest for plants treated with NH4-N.

Ammonium and nitrate are the major forms of nitrogen (N) present in tropical soils. An experiment was conducted to assess the influence of nitrate and ammonium forms (NO3−, NH4+, and mix of NO3− + NH4+), and levels (1.5–12.0 mM) of N on the growth and nutrition of cacao (Theobroma cacao L). Growth parameters were significantly influenced by N forms, and nitrogen supplied as NH4+ proved better for the growth of cacao compared with NO3− form and mixtures of these two forms. Irrespective of the forms of N, levels of N had no significant effect on plant growth parameters. Nutrient efficiency ratios (NERs) (shoot dry matter produced per unit of nutrient uptake) for macronutrients were sulfur>phosphorus>calcium>magnesium>nitrogen>potassium (S>P>Ca>Mg>N>K) and for micronutrients NERs were in the order of copper>boron>zinc>iron>manganese (Cu>B>Zn>Fe>Mn).

To-date, assessments of nitrogen use efficiency (NUE) of sugarcane have not included the contribution of its components, nitrogen uptake efficiency (NUpE) and nitrogen utilization efficiency (NUtE). This study determined these values, based on biomass and plant nitrogen (N) content, in two four-month-old pot-grown genotypes. The treatments included six N regimes, with nitrate (NO3—N) or ammonium (NH4+-N) supplied alone, or as NO3−-N for the first 6 weeks and then NH4+-N until harvest, each as 4 or 20 mM. Regardless of the N form, NUE was higher at four than at 20 mM due to significantly higher NUpE at low N supply. The results indicated that there was luxury N uptake and preference for NH4+-N nutrition, which resulted in the highest determined NUE. There were significant differences between genotypes in biomass, morphological growth parameters, N uptake, total plant N and NUE, the latter matching previously established sucrose yield-based NUE field rankings.

Effects of nutrient solution composition ratio on (Tulipa gesneriana L.) cv, ʹApricot Parrotʹ and ʹDaytonaʹ growth and flowering were studied hydroponics. Plants were grown with five treatments respectively: S1(0), S2(0.01), S3(0.02) S4(0.03) and S5(0.04) meq L.-1 ammonium or 0,0.38, 0.74, 0.11 and 0.14 ammonium (NH4+)/NH4+nitrate (NO3)−ratios. Flowering was accelerated by increase of ammonium level for both cultivars. Nutrition solution was not significant on the stem length of Daytona cultivar, but maximum flowering stem length occurred S2 solution for Apricot Parrot cultivar. Increasing ammonium level, decreased potassium concentration in the aerial parts. Total nitrogen of new bulbs decreased with increasing ammonium level for both cultivars. Maximum bulblet production rate occurred in plants that were fed with S5 solution. Maximum flower longevity was in S2 solution for both cultivars. growth and quality of tulip were affected by ammonium level in nutrient solution, so for obtain the best flo...

The method of fertilizer nitrogen (N) application can affect N uptake in tall fescue and therefore its yield and quality. Subsurface-banding (knife) of fertilizer maximizes fescue N uptake in the poorly-drained clay-pan soils of southeastern Kansas. This study was conducted to determine if knifed N results in greater N uptake than the conventional top-dress application method in a deep, well-drained soil of east-central Kansas. The experiment, conducted in a Smolan silty clay loam soil, was a split-plot with fertilizer nitrogen rates 0, 140 and 280 kg N ha−1 applied as urea-ammonium nitrate (UAN, 28% N), knifed or top-dressed. Soil inorganic N [ammonium (NH4)- and nitrate (NO3–N)] and N in roots and plant tops were measured at various times during the growing season. At final harvest, most of the knifed N (99.7%) was accounted for in plant tissue (roots and tops) and soil, with more than half of the knifed N remaining as soil inorganic N. With the top-dressed method, 27% was unaccounted for and pr...

A greenhouse experiment was conducted to study and quantify the daily uptake rate of nitrate, ammonium, phosphoric acid, potassium, calcium, magnesium, and sulfate (NO3−, NH4+, H2PO4−, K+, Ca2+, Mg2+ and SO42−) and to characterize the uptake daily pattern at different plant ages in a lettuce crop. The uptake rates per gram of plant fresh weight were calculated at 2-hour intervals through sampling the nutrient solution and analyzing it by NO3−/NH4+ conductivity and inductively coupled plasma atomic emission spectrometry (ICP-AES). The uptake rate of nitrogen, phosphorus and potassium (N, P and K) per unit mass of plant decreased with plant age following a reduction in plant relative growth rate. No significant differences were found in the absorption of Ca, Mg and sulfur (S) between the different weeks of growth. The daily absorption patterns showed no preference for the absorption of any of the ions during the daytime. A significant reduction in the absorption peaks of all the ions with increasing...

The effects of soil residual nitrate (NO3-N) and ammonium (NH4-4) on wheat (Triticum aestivum L.) grain yield and N uptake were evaluated in a three-year experiment from 1991 to 1993, in the province of Quebec, Canada. Soil samples were collected at harvest from the depth of 0-30 and 30–60 cm from 20 wheat sites and analyzed in the laboratory for NO3-N and NH4-N. Wheat yield and N-uptake was also determined. Using statistical analysis system (SAS) and Matlab, data were analyzed and the best-fitted regression equations were plotted. Significant amounts of soil NO3-N was found in the soil ranging from 31.6 to 61.6 kg/ha. The amount of soil NH4-N varied from 9.2 to 23.3 kg/ha. The statistical effects of model parameters indicated that soil NO3-N and soil NH4-N significantly influenced wheat yield and N uptake. It may be possible to investigate wheat behavior at harvest using soil residual NO3-N and NH4-N.

In nodulated young Inga edulis plants, nodule and plant growth, nitrogen (N) in xylem sap and tissues total contents of amino acid, ureide, and nitrate were determined in response to nutrition with nitrate, ammonium, or no mineral N. Additionally, the amount of soluble sugars in the different plant tissues was quantified. It was found that mineral N improved plant growth in height and diameter especially with ammonium. However, nitrate dramatically reduced nodule dry weight on a root dry weight basis and impaired N organic transport by xylem sap. Additionally, a higher amount of amino acids was observed in the roots and nodules of plants fed with mineral N but sugar levels remained constant. Although nitrate inhibited symbiosis, data support the idea that I. edulis is able to use both molecular and mineral nitrogen during the life cycle.

The effects of nitrogen (N) forms (ammonium- or nitrate-N) on plant growth under salinity stress [150 mmol sodium chloride (NaCl)] were studied in hydroponically cultured cotton. Net fluxes of sodium (Na+), ammonium (NH4+), and nitrate (NO3−) were also determined using the Non-Invasive Micro-Test Technology. Plant growth was impaired under salinity stress, but nitrate-fed plants were less sensitive to salinity than ammonium-fed plants due mainly to superior root growth by the nitrate-fed plants. The root length, root surface area, root volume, and root viability of seedlings treated with NO3-N were greater than those treated with NH4-N with or without salinity stress. Under salinity stress, the Na+ content of seedlings treated with NO3-N was lower than that in seedlings treated with NH4-N owing to higher root Na+ efflux. A lower net NO3− efflux was observed in roots of nitrate-fed plants relative to the net NH4+ efflux from roots of ammonium-fed plants. This resulted in much more nitrogen accumulation in ...