COMPARAISON DE DIFFÉRENTES MÉTHODES D'ANALYSE DE L'AZOTE DU SOL EN RELATION AVEC SA DISPONIBILITÉ POUR LES PLANTES

1987 ◽  
Vol 67 (3) ◽  
pp. 521-531 ◽  
Author(s):  
M. GIROUX ◽  
T. SEN TRAN
Keyword(s):  
Organic Matter ◽  
Soil Nitrogen ◽  
N Uptake ◽  
Relative Yield ◽  
Organic N ◽  
Uv Absorbance ◽  
Soil N ◽  
Plant N Uptake ◽  
Total N ◽  
N Concentration

The objective of this study was to compare several methods of estimating the availability of soil nitrogen to plants. Total soil N, organic matter content, mineralized N during a 2 wk incubation at 35 °C, organic N in 6 N HC1, 0.01 M NaHCO3 and 1 N KCl extracts, and finally mineral N extracted by 2 N KCl were evaluated and contrasted with N uptake by sugar beets cultivated on 19 soils in a greenhouse experiment. The relative yield or plant N uptake gave the highest correlation coefficients when both mineral and organic N fractions in soil extract were considered. The incubation methods gave the best correlation coefficient with relative yield (R2 = 0.85**). N contents in NaHCO3 extract were more correlated with relative yield or N uptake than total N, organic matter contents or N extracted by 6 N HCl or 1 N KCl. The UV absorbance values obtained at 205 nm with 0.01 M NaHCO3 extract were also well correlated with relative yield (R2 = 0.78**) and plant N uptake (R2 = 0.66**). At this wavelength, as well as at 220 nm, the absorbance was affected by mineral and organic N contents in the extract. However, at 260 nm, the UV absorbance was only related to organic N in the extract; consequently these absorbance values were less correlated with relative yield (R2 = 0.49**) or N uptake (R2 = 0.27*). Furthermore, the absorbance measured at 205 nm was too sensitive to NO3-N and organic N concentration and this relationship was not linear in the high-N concentration range. The UV absorbance at 220 nm in the 0.01M NaHCO3 extract seemed to be a promising method to evaluate the availability of soil N. Key words: Soil nitrogen, incubation, ultraviolet absorbance, hydrolyzable nitrogen

Turnover of nitrogen from components of lupin stubble to wheat in sandy soil

Soil Research ◽  
1999 ◽  
Vol 37 (3) ◽  
pp. 575 ◽  
Author(s):  
C. A. Russell ◽  
I. R. P. Fillery
Keyword(s):  
Field Experiments ◽  
Root Zone ◽  
Lignin Content ◽  
N Uptake ◽  
Organic N ◽  
Inorganic N ◽  
Short Term ◽  
Total N ◽  
N Concentration ◽  
Net Mineralisation

The rate of decomposition of 15N-labelled lupin (Lupinus angustifolius) stubble and the use of mineralised 15N by wheat were determined in field experiments on a deep loamy sand previously cropped to lupin. In one experiment, leaf, stem, and pod (pod-valve) components were applied separately to mini-plots that were either left unplanted or subsequently planted to wheat. In the second experiment, leaf and stem components, each of either low or high N concentration, were applied separately to mini-plots which were subsequently planted to wheat. Soil was recovered in layers to a maximum depth of 1 m and subsequently analysed for 15N in NH + 4 , NO-3 , and total N. The net mineralisation of stubble 15N was estimated from the decrease in soil organic 15N (total 15N – inorganic 15N), and the uptake of 15N by wheat was measured periodically. All treatments were characterised by the high retention of lupin stubble 15N in the soil organic matter. Between 9 and 34% of stem and pod 15N, and 19–49% of leaf 15N, was mineralised within a 10-month period. From these data the annual net mineralisation of a typical lupin stubble was estimated at 25–42 kg N/ha, an N benefit similar to that estimated from agronomic trials. Wheat uptake of lupin-stubble 15N ranged from 9 to 27%. Of the stubble components, only the leaf contained sufficient quantities of mineralisable N to be an important source of N for wheat. At wheat maturity in the first experiment, losses of stubble 15N ranged from 13% (leaf) to 7% (stem). In the second experiment, losses of 15N were only observed from the high N treatments (leaf 8%, stem 15·5%). Stubble component chemistry appeared to affect net mineralisation and plant uptake differently. Across both experiments, annual net mineralisation best correlated (R = 0·69) with the N concentration of the stubble components. Wheat N uptake was strongly positively correlated with polysaccharide content (R = 0·89) but negatively correlated with lignin content (R = – 0·79). Although large quantities (58 and 98 kg N/ha) of soil-derived inorganic N were found in the root-zone (–1·0 m) of wheat sown after lupins, and attributed to the decomposition of lupin root systems and surface residues prior to the establishment of each experiment, it is concluded that the short-term decomposition of lupin stubble 15N results in a modest release of inorganic N. Consequently, the primary value of lupin stubble in the N economy of lupin : cereal rotations is to replenish the soil organic N reserve.

scholarly journals Humic acid and nitrogen dose application in corn crop under alkaline soil conditions

2021 ◽  
Vol 25 (10) ◽  
pp. 657-663
Author(s):  
Kamran Azeem ◽  
Farah Naz ◽  
Arshad Jalal ◽  
Fernando S. Galindo ◽  
Marcelo C. M. Teixeira Filho ◽  
...  
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Grain Yield ◽  
Block Design ◽  
N Uptake ◽  
Soil Conditions ◽  
Alkaline Soil ◽  
Total N ◽  
Positive Effects ◽  
N Concentration

ABSTRACT Humic acid (HA), as a bio-stimulant and a major component of organic matter (OM), can improve plant physiology, soil fertility, and nutrient availability, mainly in low OM soils. Nitrogen (N) is one of the most important nutrients that affect several metabolic and biochemical activities, leading to improved plant development. This study was conducted to investigate the combined effect of HA and N doses on soil organic matter (SOM) and total N concentration, N uptake, corn growth, and grain yield under conventional tillage at Peshawar, Pakistan. Treatments were tested in a randomized block design with four replicates arranged in a factorial scheme 3 × 4 + 1. The respective doses of HA (1.5, 3,0 and 4.5 kg ha-1) were applied at the corn sowing, whereas N doses (80, 120, 160, and 200 kg ha-1) were applied in three splits (1/3 at sowing, 1/3 at the V5 stage, and remaining 1/3 at the tasselling stage) with one control (no HA and N). The application of HA, regardless of the applied doses, had positive effects on SOM, N concentration, N uptake, corn development, and grain yield. However, the application of 4.5 kg ha-1 of HA was the most effective in promoting SOM (0.83%) and total N (0.31%), shoot biomass (10610 kg ha-1), N uptake (1.13%), and grain yield (3780 kg ha-1), even when combined with the N doses of 80, 120 and 160 kg N ha-1. Increasing N doses positively influenced SOM, N concentration, N uptake, and corn growth. The greatest grain yield was obtained at 150 kg ha-1 of N regardless of HA applied doses.

scholarly journals Effects of two wood-based biochars on the fate of added fertilizer nitrogen—a 15N tracing study

2021 ◽  
Author(s):  
Subin Kalu ◽  
Gboyega Nathaniel Oyekoya ◽  
Per Ambus ◽  
Priit Tammeorg ◽  
Asko Simojoki ◽  
...  
Keyword(s):  
Plant Uptake ◽  
Plant Biomass ◽  
Application Rate ◽  
Control Treatment ◽  
Organic N ◽  
N Leaching ◽  
Soil N ◽  
Mineral N ◽  
Total N ◽  
Application Rates

AbstractA 15N tracing pot experiment was conducted using two types of wood-based biochars: a regular biochar and a Kon-Tiki-produced nutrient-enriched biochar, at two application rates (1% and 5% (w/w)), in addition to a fertilizer only and a control treatment. Ryegrass was sown in pots, all of which except controls received 15N-labelled fertilizer as either 15NH4NO3 or NH415NO3. We quantified the effect of biochar application on soil N2O emissions, as well as the fate of fertilizer-derived ammonium (NH4+) and nitrate (NO3−) in terms of their leaching from the soil, uptake into plant biomass, and recovery in the soil. We found that application of biochars reduced soil mineral N leaching and N2O emissions. Similarly, the higher biochar application rate of 5% significantly increased aboveground ryegrass biomass yield. However, no differences in N2O emissions and ryegrass biomass yields were observed between regular and nutrient-enriched biochar treatments, although mineral N leaching tended to be lower in the nutrient-enriched biochar treatment than in the regular biochar treatment. The 15N analysis revealed that biochar application increased the plant uptake of added nitrate, but reduced the plant uptake of added ammonium compared to the fertilizer only treatment. Thus, the uptake of total N derived from added NH4NO3 fertilizer was not affected by the biochar addition, and cannot explain the increase in plant biomass in biochar treatments. Instead, the increased plant biomass at the higher biochar application rate was attributed to the enhanced uptake of N derived from soil. This suggests that the interactions between biochar and native soil organic N may be important determinants of the availability of soil N to plant growth.

scholarly journals Ethephon Reduces Maize Nitrogen Uptake but Improves Nitrogen Utilization in Zea mays L.

2022 ◽  
Vol 12 ◽  
Author(s):  
Yushi Zhang ◽  
Yubin Wang ◽  
Churong Liu ◽  
Delian Ye ◽  
Danyang Ren ◽  
...  
Keyword(s):  
Grain Yield ◽  
Plant Density ◽  
N Uptake ◽  
Utilization Efficiency ◽  
N Application ◽  
Total N ◽  
N Concentration ◽  
High Plant Density ◽  
Ethephon Treatment ◽  
N Use

Increasing use of plant density or/and nitrogen (N) application has been introduced to maize production in the past few decades. However, excessive planting density or/and use of fertilizer may cause reduced N use efficiency (NUE) and increased lodging risks. Ethephon application improves maize lodging resistance and has been an essential measure in maize intensive production systems associated with high plant density and N input in China. Limited information is available about the effect of ethephon on maize N use and the response to plant density under different N rates in the field. A three-year field study was conducted with two ethephon applications (0 and 90 g ha−1), four N application rates (0, 75, 150, and 225 kg N ha−1), and two plant densities (6.75 plants m−2 and 7.5 plants m−2) to evaluate the effects of ethephon on maize NUE indices (N agronomic efficiency, NAE; N recovery efficiency, NRE; N uptake efficiency, NUpE; N utilization efficiency, NUtE; partial factor productivity of N, PFPN), biomass, N concentration, grain yield and N uptake, and translocation properties. The results suggest that the application of ethephon decreased the grain yield by 1.83–5.74% due to the decrease of grain numbers and grain weight during the three experimental seasons. Meanwhile, lower biomass, NO3- and NH4+ fluxes in xylem bleeding sap, and total N uptake were observed under ethephon treatments. These resulted in lower NAE and NUpE under the ethephon treatment at a corresponding N application rate and plant density. The ethephon treatment had no significant effects on the N concentration in grains, and it decreased the N concentration in stover at the harvesting stage, while increasing the plant N concentration at the silking stage. Consequently, post-silking N remobilization was significantly increased by 14.10–32.64% under the ethephon treatment during the experimental periods. Meanwhile, NUtE significantly increased by ethephon.

Seasonal Dynamics of Fertilizer-Derived Hydrolysable NH3 in an Arable Soil of Northeast China

2012 ◽  
Vol 496 ◽  
pp. 502-506
Author(s):  
Hui Jie Lü ◽  
Hong Bo He ◽  
Xu Dong Zhang
Keyword(s):  
Early Stage ◽  
Grain Filling ◽  
Anthropogenic Sources ◽  
Organic N ◽  
Soil N ◽  
Fertilizer N ◽  
Maize Crop ◽  
Total N ◽  
Growing Period ◽  
Residual Fertilizer N

Fertilizer applications to soil are widely known to be the most important anthropogenic sources to influence soil N turnover in agricultural ecosystems. More information is required on the relationships between soil organic N (SON) forms in order to predict the maintenance, transformation and stability of soil N. Accordingly, 15N-labeled (NH4)2SO4 (totally 200 kg N/ha) was applied to a maize crop throughout the entire growing period to investigate the distribution and the dynamics of fertilizer-derived N in hydrolyzable-NH3 fraction by measuring the labeled N in them. The accumulation of 15N in hydrolyzable-NH3 fraction was time-dependent although the total N concentration changed only slightly. The transformation of the residual fertilizer N to hydrolyzable-NH3-15N was maximal during the silking and grain filling stages, suggesting the fertilizer N was immobilized at an early stage during the growing period. The rapid decrease of 15N in hydrolyzable-NH3 pool indicated that hydrolyzable-NH3-15N was a temporary pool for fertilizer N retention and was able to release fertilizer N for uptake by the current crop

scholarly journals LEAF TOTAL NITROGEN CONCENTRATION AS AN INDICATOR OF NITROGEN STATUS FOR PLANTLETS AND YOUNG PLANTS OF EUCALYPTUS CLONES

2015 ◽  
Vol 39 (4) ◽  
pp. 1127-1140 ◽  
Author(s):  
Eric Victor de Oliveira Ferreira ◽  
Roberto Ferreira Novais ◽  
Bruna Maximiano Médice ◽  
Nairam Félix de Barros ◽  
Ivo Ribeiro Silva
Keyword(s):  
Total Nitrogen ◽  
Block Design ◽  
Nitrogen Concentration ◽  
Soil N ◽  
Total N ◽  
Chlorophyll Meter ◽  
N Concentration ◽  
Total Nitrogen Concentration ◽  
N Status ◽  
Leaf N

The use of leaf total nitrogen concentration as an indicator for nutritional diagnosis has some limitations. The objective of this study was to determine the reliability of total N concentration as an indicator of N status for eucalyptus clones, and to compare it with alternative indicators. A greenhouse experiment was carried out in a randomized complete block design in a 2 × 6 factorial arrangement with plantlets of two eucalyptus clones (140 days old) and six levels of N in the nutrient solution. In addition, a field experiment was carried out in a completely randomized design in a 2 × 2 × 2 × 3 factorial arrangement, consisting of two seasons, two regions, two young clones (approximately two years old), and three positions of crown leaf sampling. The field areas (regions) had contrasting soil physical and chemical properties, and their soil contents for total N, NH+4-N, and NO−3-N were determined in five soil layers, up to a depth of 1.0 m. We evaluated the following indicators of plant N status in roots and leaves: contents of total N, NH+4-N, NO−3-N, and chlorophyll; N/P ratio; and chlorophyll meter readings on the leaves. Ammonium (root) and NO−3-N (root and leaf) efficiently predicted N requirements for eucalyptus plantlets in the greenhouse. Similarly, leaf N/P, chlorophyll values, and chlorophyll meter readings provided good results in the greenhouse. However, leaf N/P did not reflect the soil N status, and the use of the chlorophyll meter could not be generalized for different genotypes. Leaf total N concentration is not an ideal indicator, but it and the chlorophyll levels best represent the soil N status for young eucalyptus clones under field conditions.

scholarly journals Nitrogen Nutrition of Greenhouse Pepper. II. Effects of Nitrogen Concentration and NO3: NH4 Ratio on Growth, Transpiration, and Nutrient Uptake

HortScience ◽  
2001 ◽  
Vol 36 (7) ◽  
pp. 1252-1259 ◽  
Author(s):  
A. Bar-Tal ◽  
B. Aloni ◽  
L. Karni ◽  
R. Rosenberg
Keyword(s):  
Nutrient Uptake ◽  
Nitrogen Nutrition ◽  
Nitrogen Concentration ◽  
N Uptake ◽  
Total N ◽  
Hydroponic System ◽  
Leaf Chlorophyll ◽  
N Source ◽  
N Concentration ◽  
Canopy Nitrogen

The objective of this research was to study the effects of N concentration and N-NO3: N-NH4 ratio in the nutrient solution on growth, transpiration, and nutrient uptake of greenhouse-grown pepper in a Mediterranean climate. The experiment included five total N levels (0.25 to 14 mmol·L-1, with a constant N-NO3: N-NH4 ratio of 4) and five treatments of different N-NO3: N-NH4 ratios (0.25 to 4, with a constant N concentration of 7 mmol·L-1). Plants were grown in an aero-hydroponic system in a climate-controlled greenhouse. The optimum N concentrations for maximum stem and leaf dry matter (DM) production were in the range of 8.0 to 9.2 mmol·L-1. The optimum N-NO3: N-NH4 ratio for maximal stem DM production was 3.5. The optimum value of N concentration for total fruit DM production was 9.4 mmol·L-1. Fruit DM production increased linearly with increasing N-NO3: N-NH4 ratio in the range studied. The N concentration, but not N source, affected leaf chlorophyll content. Shorter plants with more compacted canopies were obtained as the N-NO3: N-NH4 ratio decreased. The effect of N concentration on transpiration was related to its effect on leaf weight and area, whereas the effect of a decreasing N-NO3: N-NH4 ratio in reducing transpiration probably resulted from the compacted canopy. Nitrogen uptake increased as the N concentration in the solution increased. Decreasing the N-NO3: N-NH4 ratio increased the N uptake, but sharply decreased the uptake of cations, especially Ca.

scholarly journals Fertilizer Placement Effects on Soil Nitrogen and Use by Drip-irrigated and Plastic-mulched Tomatoes

HortScience ◽  
1990 ◽  
Vol 25 (7) ◽  
pp. 767-769 ◽  
Author(s):  
Wilton P. Cook ◽  
Douglas C. Sanders
Keyword(s):  
Soil Moisture ◽  
N Uptake ◽  
Fruit Size ◽  
Infiltration Rate ◽  
Moisture Level ◽  
Plastic Mulch ◽  
Fertilizer Placement ◽  
Total N ◽  
Soil Moisture Level ◽  
N Concentration

The effects of fertilizer placement and soil moisture level on soil N movement, uptake, and use by tomato plants (Lycopersicon esculentum Mill) grown with drip irrigation and plastic mulch were evaluated at two locations on two types of sandy soils. Broadcast or band fertilizer placement had no effect on fruit size, fruit number, or total yield. Fruit size was increased at one location, and the incidence of blossom-end rot was decreased by increased frequency of irrigation. Nitrate-N distribution within the bed was not affected by initial N placement. In the soil with a rapid infiltration rate, NO3-N levels in the center of the bed were always low, with highest concentration observed in the areas of the bed most distant from the drip tube. In the soil with the slower infiltration rate, NO3-N concentrations were more uniform throughout the bed, with highest concentrations in the bed center: Increasing soil moisture levels (–20 kPa vs. –30 kPa) resulted in increased leaching and reduced NO3-N concentration throughout the bed. Foliage N concentration was not affected by N placement, but decreased seasonally. Total N uptake by the above-ground portion of the plants was not affected by fertilizer placement or soil moisture level.

scholarly journals Interactions between uptake of amino acids and inorganic nitrogen in wheat plants

2011 ◽  
Vol 8 (6) ◽  
pp. 11311-11335 ◽  
Author(s):  
E. Gioseffi ◽  
A. de Neergaard ◽  
J. K. Schjoerring
Keyword(s):  
Amino Acids ◽  
Nutrient Solution ◽  
Inorganic Nitrogen ◽  
N Uptake ◽  
Organic N ◽  
Arable Soils ◽  
Inorganic N ◽  
N Losses ◽  
Total N ◽  
N Source

Abstract. Soil-borne amino acids may constitute a nitrogen (N) source for plants in various terrestrial ecosystems but their importance for total N nutrition is unclear, particularly in nutrient-rich arable soils. One reason for this uncertainty is lack of information on how the absorption of amino acids by plant roots is affected by the simultaneous presence of inorganic N forms. The objective of the present study was to study absorption of glycine (Gly) and glutamine (Gln) by wheat roots and their interactions with nitrate (NO3–) and (NH4+) during uptake. The underlying hypothesis was that amino acids, when present in nutrient solution together with inorganic N, may lead to down-regulation of the inorganic N uptake. Amino acids were enriched with double-labelled 15N and 13C, while NO3– and NH4+ acquisition was determined by their rate of removal from the nutrient solution surrounding the roots. The uptake rates of NO3– and NH4+ did not differ from each other and were about twice as high as the uptake rate of organic N when the different N forms were supplied separately in concentrations of 2 mM. Nevertheless, replacement of 50 % of the inorganic N with organic N was able to restore the N uptake to the same level as that in the presence of only inorganic N. Co-provision of NO3– did not affect glycine uptake, while the presence of glycine down-regulated NO3– uptake. The ratio between 13C and 15N were lower in shoots than in roots and also lower than the theoretical values, reflecting higher C losses via respiratory processes compared to N losses. It is concluded that organic N can constitute a significant N-source for wheat plants and that there is an interaction between the uptake of inorganic and organic nitrogen.

scholarly journals Evaluation of nitrogen availability indices and their relationship with plant response on acidic soils of India

2013 ◽  
Vol 59 (No. 6) ◽  
pp. 235-240 ◽  
Author(s):  
Bordoloi LJ ◽  
Singh AK ◽  
Manoj-Kumar ◽  
Patiram ◽  
S. Hazarika
Keyword(s):  
Nitrogen Availability ◽  
N Uptake ◽  
Reliable Estimate ◽  
Plant Responses ◽  
N Availability ◽  
Soil N ◽  
Acidic Soils ◽  
Total N ◽  
Large Variability ◽  
Available N

Plant&rsquo;s nitrogen (N) requirement that is not fulfilled by available N in soil has to be supplied externally through chemical fertilizers. A reliable estimate of soil N-supplying capacity (NSC) is therefore essential for efficient fertilizer use. In this study involving a pot experiment with twenty acidic soils varying widely in properties, we evaluated six chemical indices of soil N-availability viz. organic carbon (C<sub>org</sub>), total N (N<sub>tot</sub>), acid and alkaline-KMnO<sub>4</sub> extractable-N, hot KCl extractable-N (KCl-N) and phosphate-borate buffer extractable-N (PBB-N), based on their strength of correlation with available-N values obtained through aerobic incubation (AI-N) and anaerobic incubation (ANI-N), and also with the dry matter yield (DMY), N percentage and plant (maize) N uptake (PNU). In general, the soils showed large variability in NSC as indicated by variability in PNU which ranged from 598 to 1026 mg/pot. Correlations of the N-availability indices with AI-N and ANI-N decreased in the order: PBB-N (r = 0.784** and 0.901**) &gt; KCl-N (r = 0.773** and 0.743**) &gt; acid KMnO<sub>4</sub>-N (r = 0.575** and 0.651**) &ge; C<sub>org</sub> (r = 0.591** and 0.531**) &ge; alkaline KMnO<sub>4</sub>-N (r = 0.394** and 0.548**) &gt; N<sub>tot</sub> (r = 0.297** and 0.273*). Of all the indices evaluated, PBB-N showed the best correlations with plant parameters as well (r = 0.790** and 0.793** for DMY and PNU, respectively). Based on the highest correlations of PBB-N with biological indices as well as plant responses, we propose PBB-N as an appropriate index of N-availability in the acidic soils of India and other regions with similar soils.

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