scholarly journals Spring temperatures affect senescence and N uptake in autumn and N storage for winter in Rhynchospora alba (Cyperaceae)

2019 ◽  
Vol 71 (4) ◽  
pp. 1551-1561
Author(s):  
Kyelle Byne ◽  
Peter Ryser
Keyword(s):  
N Uptake ◽  
Tracer Uptake ◽  
15N Tracer ◽  
Physiological Factors ◽  
Total N ◽  
Cold Temperatures ◽  
Root Senescence ◽  
The Status ◽  
Functional Consequences ◽  
Autumn Senescence

Abstract Environmental and physiological factors underlying variation in timing of autumn senescence are not well known. We investigated how the time of the onset of the growth in spring affects senescence and its functional consequences for nitrogen (N) uptake in autumn and storage of N for the winter, in a species that each year develops its bulbils for storage and overwintering anew. Rhynchospora alba was grown outdoors with two treatments, identical except for a 3 week difference in the start of growth in May. Leaf and root growth and senescence, and N uptake were recorded from August to November. By August, late-starting plants had caught up in size and total N content, but had smaller bulbils. They had a higher δ 13C, indicating a higher stomatal conductance during growth. Leaf and root senescence were delayed, extending 15N tracer uptake by 4 weeks. Nevertheless, after senescence, plants with an early start had 55% more N in their overwintering bulbils, due to earlier and more efficient remobilization. We conclude that timing of senescence in R. alba is a result of an interplay between the status of winter storage and cold temperatures, constrained by a trade-off between prolonged nutrient uptake and efficient remobilization of nutrients.

Nitrogen budget of wheat growing on a Riverine clay soil

2000 ◽  
Vol 51 (7) ◽  
pp. 867 ◽  
Author(s):  
C. J. Smith ◽  
F. X. Dunin ◽  
R. Poss ◽  
J. F. Angus
Keyword(s):  
Stem Elongation ◽  
N Uptake ◽  
15N Tracer ◽  
Wagga Wagga ◽  
Water Retention Capacity ◽  
Mineral N ◽  
Total N ◽  
Leaching Losses ◽  
N Supply ◽  
Net Mineralisation

The fate of nitrogen in wheat grown on a Mesotrophic, Red Kandosol near Wagga Wagga was studied in the 1993 growing season, which had above-average rainfall: 417 mm (31 May–30 November 1993) compared with an average (June–November) of 289 mm. Nitrogen supply (fertiliser and mineralisation) was partitioned between crop uptake, gaseous and leaching losses, and residual mineral N in the soil profile. The study plots were 2 adjacent 5-ha areas. At stem elongation (Zadock’s decimal code 31), one area was topdressed with urea at 14 g N/m2 (fertilised crop). The total N supply to the fertilised crop was 29 g N/m2—8 g N/m2 of mineral N in the soil at sowing, net mineralisation of 5.3 g N/m2, and fertiliser inputs of 1.7 and 14 g N/m2. The corresponding value for the non-fertilised crop was 15 g N/m2. The urea application produced a 50% increase in above-ground biomass (1521 and 1008 g/m2 dry matter at harvest) and a 1.8-fold increase in grain yield (692 and 384 g/m2). The proportion of the total N supply recovered in the crops was similar (55% and 60% for the non-fertilised and fertilised treatments, respectively). Leaching losses were low (0.4 and 0.5 g N/m2), even though ≈100 mm drained beyond the root-zone (equivalent to 24% of the seasonal rainfall). The periods of saturated soil required to generate drainage also caused denitrification losses of 1.7 and 3.4 g N/m2 for the non-fertilised and fertilised treatments, respectively. Increased net mineralisation and reduced crop N uptake that began a month prior to anthesis were responsible for the substantial amounts of mineral N remaining in the soil after harvest (4.7 and 4.3 g N/m2, respectively). The low NO3 leaching loss associated with high drainage was explained by displacement flow mechanics operating in soil that has a high water retention capacity, which is confirmed by Br and 15N tracer analysis. The N balance was closed for the non-fertilised crop, but a discrepancy of 2.8 g N/m2 remains for the fertilised crop. The uncertainty of ≈10% of the fertilised treatment may possibly be due to ammonia volatilisation following topdressing with urea.

scholarly journals Biochar and urease inhibitor mitigate NH3 and N2O emissions and improve wheat yield in a urea fertilized alkaline soil

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Khadim Dawar ◽  
Shah Fahad ◽  
M. M. R. Jahangir ◽  
Iqbal Munir ◽  
Syed Sartaj Alam ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Grain Yield ◽  
Block Design ◽  
N Uptake ◽  
Nitrous Oxide Emissions ◽  
N2o Emissions ◽  
Urease Inhibitor ◽  
Alkaline Soil ◽  
Total N ◽  
N Assimilation

AbstractIn this study, we explored the role of biochar (BC) and/or urease inhibitor (UI) in mitigating ammonia (NH3) and nitrous oxide (N2O) discharge from urea fertilized wheat cultivated fields in Pakistan (34.01°N, 71.71°E). The experiment included five treatments [control, urea (150 kg N ha−1), BC (10 Mg ha−1), urea + BC and urea + BC + UI (1 L ton−1)], which were all repeated four times and were carried out in a randomized complete block design. Urea supplementation along with BC and BC + UI reduced soil NH3 emissions by 27% and 69%, respectively, compared to sole urea application. Nitrous oxide emissions from urea fertilized plots were also reduced by 24% and 53% applying BC and BC + UI, respectively, compared to urea alone. Application of BC with urea improved the grain yield, shoot biomass, and total N uptake of wheat by 13%, 24%, and 12%, respectively, compared to urea alone. Moreover, UI further promoted biomass and grain yield, and N assimilation in wheat by 38%, 22% and 27%, respectively, over sole urea application. In conclusion, application of BC and/or UI can mitigate NH3 and N2O emissions from urea fertilized soil, improve N use efficiency (NUE) and overall crop productivity.

scholarly journals Combined application of biochar with fertilizer promotes nitrogen uptake in maize by increasing nitrogen retention in soil

Biochar ◽  
2021 ◽  
Author(s):  
Jing Peng ◽  
Xiaori Han ◽  
Na Li ◽  
Kun Chen ◽  
Jinfeng Yang ◽  
...  
Keyword(s):  
Crop Yield ◽  
N Uptake ◽  
Nitrogen Retention ◽  
N Recovery ◽  
Chemical Fertilizers ◽  
Total N ◽  
Residual Rate ◽  
The Third ◽  
Combined Application ◽  
Entire Experiment

AbstractCombined application of biochar with fertilizers has been used to increase soil fertility and crop yield. However, the coupling mechanisms through which biochar improves crop yield at field scale and the time span over which biochar affects carbon and nitrogen transformation and crop yield are still little known. In this study, a long-term field trial (2013–2019) was performed in brown soil planting maize. Six treatments were designed: CK—control; NPK—application of chemical fertilizers; C1PK—low biochar without nitrogen fertilizer; C1NPK, C2NPK and C3NPK—biochar at 1.5, 3 and 6 t ha−1, respectively, combined with chemical fertilizers. Results showed that the δ15N value in the topsoil of 0–20 cm layer in the C3NPK treatment reached a peak of 291 ‰ at the third year (2018), and demonstrated a peak of 402 ‰ in the NPK treatment in the initial isotope trial in 2016. Synchronously, SOC was not affected until the third to fourth year after biochar addition, and resulted in a significant increase in total N of 2.4 kg N ha−1 in 2019 in C3NPK treatment. During the entire experiment, the 15N recovery rates of 74–80% were observed highest in the C2NPK and C3NPK treatments, resulting in an annual increase in yields significantly. The lowest subsoil δ15N values ranged from 66‰ to 107‰, and the 15N residual rate would take 70 years for a complete decay to 0.001% in the C3NPK. Our findings suggest that biochar compound fertilizers can increase C stability and N retention in soil and improve N uptake by maize, while the loss of N was minimized. Biochars, therefore, may have an important potential for improving the agroecosystem and ecological balance. Graphic abstract

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.

scholarly journals Residual effect of clover-rich leys on soil nitrogen and successive grain crops

2008 ◽  
Vol 17 (1) ◽  
pp. 73 ◽  
Author(s):  
A. NYKÄNEN ◽  
A. GRANSTEDT ◽  
L. JAUHIAINEN
Keyword(s):  
Field Experiments ◽  
Clayey Soil ◽  
N Uptake ◽  
Residual Effect ◽  
Red Clover ◽  
N Leaching ◽  
N Fixation ◽  
Mineral N ◽  
Total N ◽  
Biological N Fixation

Legume-based leys form the basis for crop rotations in organic farming as they fix nitrogen (N) from the atmosphere for the succeeding crops. The age, yield, C:N, biological N fixation (BNF) and total N of red clover-grass leys were studied for their influence on yields, N uptake and N use efficiency (NUE) of the two sequential cereal crops planted after the leys. Mineral N in deeper soil (30-90 cm) was measured to determine N leaching risk. Altogether, four field experiments were carried out in 1994-1998 at two sites. The age of the ley had no significant effect on the yields and N uptake of the two subsequent cereals. Surprisingly, the residual effect of the leys was negligible, at 0–20 kg N ha-1yr-1. On the other hand, the yield and C:N of previous red clover-grass leys, as well as BNF-N and total-N incorporated into the soil influenced subsequent cereals. NUEs of cereals after ley incorporation were rather high, varying from 30% to 80%. This might indicate that other factors, such as competition from weeds, prevented maximal growth of cereals. The mineral N content deeper in the soil was mostly below 10 kg ha-1 in the sandy soil of Juva, but was 5-25 kg ha-1 in clayey soil of Mietoinen.;

scholarly journals Nitrogen Uptake by Table Beet—Validation of a Model

2002 ◽  
Vol 127 (6) ◽  
pp. 1013-1017 ◽  
Author(s):  
Carmen Feller ◽  
Matthias Fink
Keyword(s):  
Brassica Oleracea ◽  
N Uptake ◽  
Model Parameters ◽  
Potential Range ◽  
Vegetable Crops ◽  
Fresh Matter ◽  
Total N ◽  
Brussels Sprouts ◽  
Sowing Dates ◽  
Plant Densities

To reduce nitrogen (N) losses from vegetable fields, fertilizer recommendations should be adjusted according to the large range in yield and thus in N uptake of vegetable crops. Therefore, a model was used to predict total N uptake based on expected yield. The model has been validated successfully in a series of studies for Brussels sprouts (Brassica oleracea L. var. gemmifera), white cabbage (Brassica oleracea L. var. capitata) and kohlrabi (Brassica oleracea L. var. gongylodes). The objective of this study was to validate the model for table beet (Beta vulgaris L. var. conditiva), a crop with a considerable variability in N uptake, which is caused by a large potential range of selecting sowing dates, plant densities and cultivars. Field experiments were carried out over two years. Fifty-five combinations of N fertilizer levels, plant densities, cultivars and sowing dates were tested. Plants were sampled at 2- or 3-week intervals, and fresh matter, dry matter and N content of leaves and roots were measured. Crop specific model parameters for table beets were determined from independent data. The model wverestimated N uptake for N-limiting conditions, but for optimally fertilized table beets measured and estimated N uptake showed a close correlation (R2 = 0.93) when total yield was used as an input parameter for the model. Although the error of estimation (35 kg·ha-1) was considerable, studies with other vegetable crops using the model found the error even higher if other tools, such as look-up tables, were used for predicting N uptake.

scholarly journals Quantifying nitrogen losses in oil palm plantations: models and challenges

2016 ◽  
Author(s):  
Lénaïc Pardon ◽  
Cécile Bessou ◽  
Nathalie Saint-Geours ◽  
Benoît Gabrielle ◽  
Ni’matul Khasanah ◽  
...  
Keyword(s):  
Oil Palm ◽  
Cropping Systems ◽  
N Uptake ◽  
Clay Content ◽  
Field Measurements ◽  
Growth Cycle ◽  
Rooting Depth ◽  
Perennial Crop ◽  
N Losses ◽  
Total N

Abstract. Oil palm is the most rapidly expanding tropical perennial crop. Its cultivation raises environmental concerns, notably related to the use of nitrogen (N) fertilisers and associated pollution and greenhouse gas emissions. While numerous and diverse models exist to estimate N losses from agriculture, very few are available for tropical perennial crops. Moreover, there has been no critical analysis of the performances of existing models in the specific context of tropical perennial cropping systems. We assessed the capacity of 11 models and 29 sub-models to estimate N losses in a typical oil palm plantation over a 25-year-growth cycle, through leaching and runoff, and emissions of NH3, N2, N2O, and NOx. Estimates of total N losses were very variable, ranging from 21 to 139 kg N ha−1 yr−1. On average, 31 % of the losses occurred during the first three years of the cycle. Leaching comprised about 80 % of the losses. Based on a comprehensive Morris sensitivity analysis, the most influential variables were soil clay content, rooting depth and oil palm N uptake. We also compared model estimates with published field measurements. Many challenges remain to model more accurately processes related to the peculiarities of perennial tropical crop systems such as oil palm.

scholarly journals Nitrogen dressing and nutrient absorption of lilies (Asiatic hybrids) on sandy soils.

1989 ◽  
Vol 37 (3) ◽  
pp. 269-272
Author(s):  
J.H.G. Slangen ◽  
G.J. Krook ◽  
C.H.M. Hendriks ◽  
N.A.A. Hof
Keyword(s):  
Nutrient Uptake ◽  
Field Experiments ◽  
N Uptake ◽  
Sandy Soils ◽  
Plant Analysis ◽  
Split Application ◽  
Total N ◽  
N Efficiency ◽  
Asiatic Hybrids ◽  
Bulb Yield

The effect of different amounts (0, 75, 150 and 225 kg/ha) and timings of split application of N on yield and nutrient uptake of 3 hybrid cultivars grown for bulbs was investigated. Efficiency of N-uptake was determined by soil and plant analysis with field experiments in 1983, 1984 and 1985. Leaching of fertilizers applied before planting induced low nutrient efficiencies in sandy soils. Dividing the total N-dressings into 4 monthly applications from Mar. to June or Apr. to July led to a higher N-efficiency, though fertilizers were easily leached with high rainfall. A total of 150 kg N/ha appeared to be adequate. Concentrations of plant nutrients (P, K, Ca, Mg and Na) in mature plants of cultivars Aristo, Connecticut King and Enchantment are presented in relation to bulb yield and N-uptake. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Residual effects of nitrogen fertiliser on the yield and N composition of succeeding cereal crops and on soil chemical properties of an Ethiopian highland Vertisol

2000 ◽  
Vol 80 (1) ◽  
pp. 63-69 ◽  
Author(s):  
Selamyihun Kidanu ◽  
D. G. Tanner ◽  
Tekalign Mamo
Keyword(s):  
N Uptake ◽  
Chemical Properties ◽  
Residual Effect ◽  
Residual Effects ◽  
Cereal Crops ◽  
N Recovery ◽  
N Application ◽  
Total N ◽  
Current Season ◽  
The Mean

A trial was conducted on an Ethiopian Vertisol from 1990 to 1995 to determine the residual effects of fertiliser N applied to tef [Eragrostistef (Zucc.) Trotter] on the grain and straw yield, N content, and total N uptake of succeeding crops of durum wheat (Triticum turgidum var. durum) and tef. The mean agronomic efficiency of 60 kg fertiliser N ha−1 was 13.1 kg grain kg−1 fertiliser N applied in the current year and 5.4 kg grain kg−1 fertiliser N applied in the previous year. Thus, the residual fertiliser N benefit was equivalent to 41.2% of the response to current season N application for the two cereal crops. The mean rates of apparent recovery of fertiliser N were 65.8% for current season N application and 31.0% for previous season N application. Soil organic matter and nitrate levels increased linearly in response to both previous and current season N application rates. The current study demonstrates that the residual effect of fertiliser N enhanced the yields and N contents of the grain and straw of both wheat and tef, resulting in a significant increase in total N uptake. Any analysis of the profitability of fertiliser N response should reflect the multi-year benefit period. Key words: N recovery, N residue, N uptake, tef, wheat

Time of Application of Nitrogen Fertilizer to Maize at Samaru, Nigeria

1973 ◽  
Vol 9 (2) ◽  
pp. 113-120 ◽  
Author(s):  
M. J. Jones
Keyword(s):  
Nitrogen Nutrition ◽  
N Uptake ◽  
Rainfall Distribution ◽  
Total N ◽  
Plant Nitrogen ◽  
Yield Increase ◽  
Time Of Application ◽  
Nitrate N ◽  
One Year

SUMMARYMaize was grown for three years at three levels of nitrogen, 56, 112 and 224 kg. N ha.−1, involving altogether nine different timing and splitting treatments. Measurements were made of grain yield, plant nitrogen status and total-N-uptake, and, in one year, movement of nitrate-N in control plot soils. Where only 56 kg. N ha.−1was applied, its time of application made very little difference to yield; at higher rates of nitrogen an unsplit application as late as seven weeks was very inefficient, but only at the highest rate did a split application give any appreciable yield increase over an unsplit application to the seed bed. Consideration of the soil nitrate-N data and the long-term pattern of rainfall distribution leads to the conclusion that leaching is unlikely to be a serious problem in the nitrogen nutrition of early-planted maize.

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