EFFECT OF DATE OF APPLICATION ON THE FATE OF 15N-LABELLED UREA AND POTASSIUM NITRATE

1990 ◽  
Vol 70 (1) ◽  
pp. 21-31 ◽  
Author(s):  
M. NYBORG ◽  
S.S. MALHI ◽  
E.D. SOLBERG
Keyword(s):  
Field Experiments ◽  
Winter Season ◽  
Potassium Nitrate ◽  
N Fertilizer ◽  
Winter Period ◽  
Late Winter ◽  
N Leaching ◽  
N Loss ◽  
N Losses ◽  
Total Recovery

Previous work in north-central Alberta showed large losses of fall-applied 15N-labelled N fertilizers over the winter, but determination was not made for the summer season. The objective of the present study was to discover the amount of 15N loss during both the non-cropped winter season and during the following cropped season. Field experiments were conducted at two sites with 15N-labelled urea and potassium nitrate (KNO3) applied in early October, late October, late winter and in the spring. The 15N-labelled fertilizers at 50 kg N ha−1 were incorporated into the soil. Plots were sown to barley in spring and harvested when mature. Recovery of 15N in soil samples taken before sowing in spring indicated over-winter N losses from October-applied N at both locations and especially with KNO3. At the Breton site spring recovery of 15N in soil from the October application was 69% with urea and only 30% with KNO3. The mechanism of N loss was primarily denitrification. The amount of 15N immobilized in the soil was greater with urea than KNO3 for both sites. The total recovery of October- or late winter-applied 15N fertilizer at harvest (plants plus soil) was low, with a range of 7–71%. The recovery from spring application was near-complete at the Innisfail site (≥ 84%) but at Breton, which had heavy rain and saturated soil in late June, recovery was low with urea (56%) and especially low with KNO3 (10%). It was estimated that 8 of 45 site-years had sufficient precipitation during June to cause prolonged soil saturation and consequent N loss. In all, major losses of 15N occurred in the non-cropped over-winter period at both sites, and occurred in the cropped season at one site. Key words: Denitrification, fall application of N, leaching, 15N, 15N balance, N fertilizer, N losses, winter application of N

scholarly journals The interaction of seasonal rainfall and nitrogen fertiliser rate on soil N2O emission, total N loss and crop yield of dryland sorghum and sunflower grown on sub-tropical Vertosols

Soil Research ◽  
2016 ◽  
Vol 54 (5) ◽  
pp. 604 ◽  
Author(s):  
G. D. Schwenke ◽  
B. M. Haigh
Keyword(s):  
Crop Yield ◽  
Crop Production ◽  
Field Experiments ◽  
N2o Emission ◽  
N2o Emissions ◽  
N Loss ◽  
N Losses ◽  
Total N ◽  
Tropical Regions ◽  
The Impact

Summer crop production on slow-draining Vertosols in a sub-tropical climate has the potential for large emissions of soil nitrous oxide (N2O) from denitrification of applied nitrogen (N) fertiliser. While it is well established that applying N fertiliser will increase N2O emissions above background levels, previous research in temperate climates has shown that increasing N fertiliser rates can increase N2O emissions linearly, exponentially or not at all. Little such data exists for summer cropping in sub-tropical regions. In four field experiments at two locations across two summers, we assessed the impact of increasing N fertiliser rate on both soil N2O emissions and crop yield of grain sorghum (Sorghum bicolor L.) or sunflower (Helianthus annuus L.) in Vertosols of sub-tropical Australia. Rates of N fertiliser, applied as urea at sowing, included a nil application, an optimum N rate and a double-optimum rate. Daily N2O fluxes ranged from –3.8 to 2734g N2O-Nha–1day–1 and cumulative N2O emissions ranged from 96 to 6659g N2O-Nha–1 during crop growth. Emissions of N2O increased with increased N fertiliser rates at all experimental sites, but the rate of N loss was five times greater in wetter-than-average seasons than in drier conditions. For two of the four experiments, periods of intense rainfall resulted in N2O emission factors (EF, percent of applied N emitted) in the range of 1.2–3.2%. In contrast, the EFs for the two drier experiments were 0.41–0.56% with no effect of N fertiliser rate. Additional 15N mini-plots aimed to determine whether N fertiliser rate affected total N lost from the soil–plant system between sowing and harvest. Total 15N unaccounted was in the range of 28–45% of applied N and was presumed to be emitted as N2O+N2. At the drier site, the ratio of N2 (estimated by difference)to N2O (measured) lost was a constant 43%, whereas the ratio declined from 29% to 12% with increased N fertiliser rate for the wetter experiment. Choosing an N fertiliser rate aimed at optimum crop production mitigates potentially high environmental (N2O) and agronomic (N2+N2O) gaseous N losses from over-application, particularly in seasons with high intensity rainfall occurring soon after fertiliser application.

Recovery of 15N-labelled fertilizers applied to barley on two artificially eroded soils in north-central Alberta

1998 ◽  
Vol 78 (2) ◽  
pp. 377-383 ◽  
Author(s):  
R. Pradhan ◽  
R. C. Izaurralde ◽  
S. S. Malhi ◽  
M. Nyborg
Keyword(s):  
Field Experiments ◽  
Water Saturation ◽  
Nutrient Use Efficiency ◽  
N Loss ◽  
Hordeum Vulgare L ◽  
N Losses ◽  
North Central ◽  
Major Mechanism ◽  
Erosion Level ◽  
N Management

Soil erosion induces variability in soil properties which may influence nutrient use efficiency. A 2-yr field study was conducted with the following objectives: (1) to determine the recovery of 15N-labelled fertilizers applied to barley growing on artificially eroded soil, and (2) to compare N losses from nitrate- and ammonia-based N fertilizers. Field experiments were conducted in north-central Alberta in 1991 and 1992 on an Orthic Gray Luvisol (Site 1) and on an Eluviated Black Chernozem (Site 2) soil. At each site, a factorial experiment of three levels of artificial erosion (0, 10 and 20 cm) and three N sources (KNO3, urea, and control) was laid out as a split-plot design with four replications. The 15N-labelled fertilizers (5.63 atom % abundance) were banded in June 1991 at 150 kg N ha−1 within 46-cm by 46-cm steel frame microplots. The proportion of added N recovered by barley (Hordeum vulgare L.) was not affected by erosion level. Periodical water saturation and NO3− availability suggested denitrification as a major mechanism of N loss. The N losses ranged from 12 to 51 g N ha−1 in 1991 and 20 to 80 kg N ha−1 over the 2-yr period, but the N losses did not relate to erosion level. The N losses after 2 yr were greater from KNO3 than from urea at Site 1. Most of the added 15N was found in the surface 0- to 15-cm layer, but amounts of 15N were detected in the 15- to 30-cm or 30- to 45-cm layers. The results call for continued development of N management techniques geared to optimize crop growth and minimize losses from fields. Key words: Artificial erosion, barley, fate of applied N, 15N-labelled fertilizers, N immobilization, N loss

scholarly journals Irrigation and Nitrogen Management for Sprinkler-irrigated Cabbage on Sand

1994 ◽  
Vol 119 (3) ◽  
pp. 427-433 ◽  
Author(s):  
C.A. Sanchez ◽  
R.L. Roth ◽  
B.R. Gardner
Keyword(s):  
Irrigation System ◽  
Maximum Yield ◽  
Sprinkler Irrigation ◽  
Field Studies ◽  
N Fertilizer ◽  
N Leaching ◽  
N Losses ◽  
N Accumulation ◽  
Negative Results ◽  
N Rates

Six field studies were conducted from 1980-88 to evaluate the response of cabbage (Brassica oleracea L., Capitata group) to sprinkler irrigation and sprinkler-applied N fertilizer on a coarse-textured soil. The plots were irrigated using a modified self-moving lateral sprinkler irrigation system that applied five levels of water and five levels of N (liquid NH4NO3) in specified combinations of central composite rotatable design. Cabbage yields were significantly increased by water and N applications in all experiments. The N rates predicted for maximum yield exceeded typical cabbage N fertilizer recommendations. However, the above-average plant populations used in these studies resulted in above-average yields and plant N accumulation. Deficit and excess irrigation produced negative results. Generally, cabbage production was optimized and N losses to the environment were minimized when crops were irrigated for evapotranspiration (ET) replacement. However, even when irrigated for ET replacement, these data demonstrate the potential for N leaching at high N rates, presumably as a result of rainfall.

scholarly journals Nitrogen Export From a Watershed Subjected to Partial Salvage Logging

2001 ◽  
Vol 1 ◽  
pp. 440-448 ◽  
Author(s):  
Maria Herrmann ◽  
William E. Sharpe ◽  
David R. DeWalle ◽  
Bryan R. Swistock
Keyword(s):  
N Uptake ◽  
Additional Stress ◽  
N Leaching ◽  
Northern Red Oak ◽  
N Loss ◽  
N Losses ◽  
Salvage Logging ◽  
Mountain Watersheds ◽  
Creek Watershed ◽  
Southwestern Pennsylvania

Logging has been shown to induce nitrogen (N) leaching. We hypothesized that logging a watershed that previously exhibited forest decline symptoms would place additional stress on the ecosystem and result in greater N loss, compared to harvesting vigorous forests. We conducted a 10-year (1988 to 1998) assessment of N export from the Baldwin Creek watershed in southwestern Pennsylvania that was partially clearcut to salvage dead and dying northern red oak. N export from the watershed increased significantly following salvage logging operations and did not completely return to prelogging levels by the end of the study period. The largest annual NO3-N export of 13 kg/ha was observed during the first year after harvesting, an increase of approximately 10 kg/ha. Compared to data from other Appalachian Mountain watersheds in North Carolina, West Virginia, and Pennsylvania, calculated N loss for Baldwin Creek was considerably greater. Longer periods of reduced N uptake due to slow revegetation of salvage logged areas, coupled with increased amounts of N available to leaching, could have accounted for the large N losses observed for Baldwin Creek. Salvage logging of dead and dying trees from forested watersheds in this region appears to have the potential to result in much larger N losses than previously reported for harvest of healthy stands.

scholarly journals Integration of measures to mitigate reactive nitrogen losses to the environment from grazed pastoral dairy systems

2014 ◽  
Vol 152 (S1) ◽  
pp. 45-56 ◽  
Author(s):  
R. M. MONAGHAN ◽  
C. A. M. DE KLEIN
Keyword(s):  
Nitrification Inhibitor ◽  
N Leaching ◽  
N Loss ◽  
N Losses ◽  
Mitigation Options ◽  
N Efficiency ◽  
Farm Systems ◽  
Dairy Systems ◽  
Autumn And Winter ◽  
The Impact

SUMMARYThe need for nitrogen (N) efficiency measures for dairy systems is as great as ever if we are to meet the challenge of increasing global production of animal-based protein while reducing N losses to the environment. The present paper provides an overview of current N efficiency and mitigation options for pastoral dairy farm systems and assesses the impact of integrating a range of these options on reactive N loss to the environment from dairy farms located in five regions of New Zealand with contrasting soil, climate and farm management attributes. Specific options evaluated were: (i) eliminating winter applications of fertilizer N, (ii) optimal reuse of farm dairy effluent, (iii) improving animal performance through better feeding and using cows with higher genetic merit, (iv) lowering dietary N concentration, (v) applying the nitrification inhibitor dicyandiamide (DCD) and (vi) restricting the duration of pasture grazing during autumn and winter. The Overseer®Nutrient Budgeting model was used to estimate N losses from representative farms that were characterized based on information obtained from detailed farmer surveys conducted in 2001 and 2009. The analysis suggests that (i) milk production increases of 7–30% were associated with increased N leaching and nitrous oxide (N2O) emission losses of 3–30 and 0–25%, respectively; and (ii) integrating a range of strategic and tactical management and mitigation options could offset these increased N losses. The modelling analysis also suggested that the restricted autumn and winter grazing strategy resulted in some degree of pollution swapping, with reductions in N leaching loss being associated with increases in N loss via ammonia volatilization and N2O emissions from effluents captured and stored in the confinement systems. Future research efforts need to include farm systems level experimentation to validate and assess the impacts of region-specific dairy systems redesign on productivity, profit, environmental losses, practical feasibility and un-intended consequences.

scholarly journals Evaluating Different Catch Crop Strategies for Closing the Nitrogen Cycle in Cropping Systems—Field Experiments and Modelling

2021 ◽  
Vol 13 (1) ◽  
pp. 394
Author(s):  
Matthias Böldt ◽  
Friedhelm Taube ◽  
Iris Vogeler ◽  
Thorsten Reinsch ◽  
Christof Kluß ◽  
...  
Keyword(s):  
Field Experiments ◽  
Cropping Systems ◽  
N Uptake ◽  
Red Clover ◽  
Farming Systems ◽  
Grain Legume ◽  
Winter Period ◽  
N Leaching ◽  
Catch Crops ◽  
Cereal Grain

For arable stockless farming systems, the integration of catch crops (CC) during the fallow period might be a key for closing the nitrogen (N) cycle, reducing N leaching and increasing the transfer of N to the subsequent crop. However, despite considerable research efforts, the fate of N in such integrated systems remains unclear. To address this, a two-year field experiment was carried out in northern Germany with different CC, including frost-tolerant and frost-killed CC. The experiment started following a two-year ryegrass/red clover ley, which was subsequently sown with a cereal (CE) or a grain legume (field pea, PE). This provided two contrasting systems with high residual N in autumn. The results showed high N uptake of the CC, ranging from 84 to 136 kg N ha−1 with PE as the pre-crop, and from 33 to 110 kg N ha−1 with CE. All CC reduced N leaching compared with the control, a bare fallow over autumn/winter. Of the various CC, the frost-killed CC showed higher leaching compared with the other CCs, indicating mineralisation of the CC residue in the later autumn/winter period. The process based APSIM (Agricultural Production SIMulator) model was used to simulate N cycling for a cereal grain legume rotation, including a frost-killed and a frost resistant CC. While the model simulated the biomass and the N uptake by the crops, as well as the reduction of N leaching with the use of CC well, it under-estimated N leaching from the frost-killed CC. The study showed that all CC were affective at reducing N leaching, but winter hard catch crops should be preferred, as there is a risk of increased leaching following the mineralisation of residues from frost-killed CC.

scholarly journals Effects of Changing Fertilization since the 1980s on Nitrogen Runoff and Leaching in Rice–Wheat Rotation Systems, Taihu Lake Basin

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 886
Author(s):  
Yaqin Diao ◽  
Hengpeng Li ◽  
Sanyuan Jiang ◽  
Xinyan Li
Keyword(s):  
Algal Blooms ◽  
Field Experiments ◽  
Taihu Lake ◽  
Crop Yields ◽  
Fertilization Rate ◽  
Freshwater Ecosystems ◽  
Lake Basin ◽  
N Loss ◽  
N Losses ◽  
Total N

The nitrogen (N) loss associated with intensive agricultural activities is a significant cause of eutrophication and algal blooms in freshwater ecosystems. Taihu Lake has experienced serious surface water quality deterioration and eutrophication problems since the 1980s. The objective of this study is to examine the effect of fertilization changes since the 1980s on the N loss with runoff and leaching in the rice–wheat cropping rotation system. According to the results published in the literature since the 1980s, we set up four fertilization scenarios—N1980s: a fertilization rate of 350 kg N·ha−1·year−1 with 30% in manure fertilization to simulate fertilization in the 1980s; NA1990s: a fertilization rate of 500 kg N·ha−1·year−1 with 10% in manure fertilization to simulate fertilization in the early 1990s; NL1990s: fertilization rate of 600 kg N·ha−1·year−1 with 10% in manure fertilization to simulate fertilization in the late 1990s; and N2000s: fertilization rate of 550 kg N·ha−1·year−1 with all chemicals to simulate fertilization in the 2000s. Then, we calibrated and validated the DNDC (denitrification–decomposition) model through field experiments in two rice–wheat rotation seasons from November 2011 to October 2013 and simulated the N loss with runoff and leaching since the 1980s. The results show that N losses with leaching in the four periods (N 1980s, NA1990s, NL1990s, and N2000s) were 5.2 ± 2.1, 9.4 ± 3.2, 14.4 ± 4.6 and 13.5 ± 4.6 kg N·ha−1·year−1, respectively. N losses with surface runoff were 7.9 ± 3.9, 18.3 ± 7.2, 25.4 ± 10.2, and 26.5 ± 10.6 kg N·ha−1·year−1, respectively. The total N loss through runoff and leaching showed an increasing trend from 1980 to the late 1990s, when it reached its peak. The increase in N export to water due to fertilizer application occurs mainly during the rainy season from March to August, and especially from June to August, when rainfall events and intensive rice fertilization activities are frequent. After the 1990s, when the fertilizer rate was above 500 kg N·ha−1·year−1, the crop yields no longer increased significantly, which indicates that the optimized fertilization rate to balance crop yields and N loss to water is lower than 500 kg N·ha−1·year−1. The increase in fertilizer use has been unnecessary since the early 1990s, and at least about 30% of the N loss could have been prevented without reducing crop yields.

scholarly journals Characteristics of Early-Winter Caribou, Rangifer tarandus caribou, Feeding Sites in the Southern Purcell Mountains, British Columbia

2003 ◽  
Vol 117 (3) ◽  
pp. 352 ◽  
Author(s):  
Trevor A. Kinley ◽  
John Bergenske ◽  
Julie-Anne Davies ◽  
David Quinn
Keyword(s):  
British Columbia ◽  
Rangifer Tarandus ◽  
Winter Season ◽  
Subalpine Forest ◽  
Winter Period ◽  
Late Winter ◽  
Abies Lasiocarpa ◽  
Rangifer Tarandus Caribou ◽  
Early Winter ◽  
Winter Habitat

Mountain Caribou are a rare ecotype of Woodland Caribou (Rangifer tarandus caribou) inhabiting the high-snowfall region of southeastern British Columbia, and are defined by their late-winter reliance on arboreal hair lichen of the genus Bryoria. During early winter, there is considerable variation in habitat use among populations. We snow-trailed Caribou in the southern Purcell Mountains during early winter to determine foraging patterns for the Purcell population. When snow was ≤51 cm deep, Caribou fed on Grouseberry (Vaccinium scoparium), the terrestrial lichen Cladonia, and arboreal lichens of the genus Bryoria. When snow was ≥62 cm deep, they ate exclusively arboreal lichens. In both periods, Caribou ate arboreal lichen from essentially every downed tree or branch encountered and fed with a higher intensity at downed trees than standing trees. During the low-snow period, Caribou fed at fewer trees but used those with greater lichen abundance, and fed more intensively at each, compared to the deep-snow period. In comparison to trees occurring on the foraging path but at which Caribou did not feed, those from which arboreal lichen was foraged intensively were of larger diameter, had greater lichen abundance, and were more likely to be Subalpine Fir (Abies lasiocarpa) or Engelmann Spruce (Picea engelmannii) and less likely to be Whitebark Pine (Pinus albicaulis), Lodgepole Pine (P. contorta) or Alpine Larch (Larix lyalli). The shift in diet between the low-snow and deep-snow periods reflected two modes of foraging within the early winter period, distinct from one another and apparently also distinct from the late-winter season. Management for early-winter habitat will require retention of some commercially significant forest across extensive areas, both near the subalpine forest – subalpine parkland ecotone and lower in the subalpine forest.

Nitrogen efficiency of urea and calcium ammonium nitrate for maize (Zea mays) in humid and subhumid regions of Nigeria

1987 ◽  
Vol 109 (1) ◽  
pp. 47-51 ◽  
Author(s):  
Y. Arora ◽  
L. A. Nnadi ◽  
A. S. R. Juo
Keyword(s):  
Zea Mays ◽  
Ammonium Nitrate ◽  
Field Experiments ◽  
Nitrogen Efficiency ◽  
N Leaching ◽  
Fertilizer N ◽  
Maize Crop ◽  
Total Recovery ◽  
Calcium Ammonium Nitrate ◽  
N Source

SummaryField experiments on efficiency of fertilizer N applied as calcium ammonium nitrate (CAN) and urea to no-tillage maize (Zea mays) were conducted under humid (Onne) and subhumid (Mokwa) conditions. At both the locations the rate of N was 150 kg/ha.A comparison of apparent crop recovery of applied N indicated that CAN was a more effective N source than urea under subhumid conditions (Mokwa) but that urea was more effective under humid conditions (Onne). In 1981, percentages of applied N recovered by the maize crop at Onne were 28 and 50% from CAN and urea, respectively, whereas the recovery at Mokwa was 46 and 34%, respectively. Total recovery by crop and soil (0–120cm) of CAN at Onne with divided application was equivalent to that at Mokwa with single application at planting (54%). However, the total recovery of urea was much lower at Mokwa (40%) than at Onne (60%). The results in 1982 followed similar trends. Excessive N leaching loss from CAN under humid conditions and volatilization loss from urea under subhumid conditions are considered to be the reasons for poor efficiency of fertilizer N.

scholarly journals Effects of Zeolitic Urea on Nitrogen Leaching (NH4-N and NO3-N) and Volatilization (NH3) in Spodosols and Alfisols

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1921
Author(s):  
Ayaz Ahmad ◽  
Shahzada Sohail Ijaz ◽  
Zhenli He
Keyword(s):  
Soil Amendment ◽  
Ammonia Volatilization ◽  
Agricultural Soils ◽  
N Leaching ◽  
Nh3 Volatilization ◽  
N Loss ◽  
N Losses ◽  
Urea Nitrogen ◽  
Urea Fertilizer ◽  
Very High

Global use of urea nitrogen (N) fertilizer is increasing, but N losses are still very high (40–70%). Zeolites have the capability of holding NH4+, thus reducing N losses when applied as a soil amendment. However, application of a large quantity of zeolite is costly and inconvenient. In this study, zeolitic fertilizers were evaluated to select the best formulation with reduced leaching of NH4-N and NO3-N and NH3 volatilization in agricultural soils (Alfisol and Spodosol). The treatments included the following: T0 = control, T1 = urea fertilizer, T2 = zeo-urea (1:1), T3 = zeo-urea (2:1), T4 = zeo-urea (3:1), T5 = zeo-urea (1:2), and T6 = zeo-urea (1:3). Leaching was performed at 4, 8, 12, 19, 25, 32, 39 and 45 days after the soils were treated with the designated fertilizers, including control, and packed into columns. Leachate samples were collected after each leaching event and analyzed for the concentrations of NH4-N and NO3-N and the quantity of leachate. Ammonia volatilization was recorded at days 1, 5, 9, 13 and 20 of soil treatments. Results indicate that zeolitic fertilizer formulations effectively reduced N losses. NH4-N loss was reduced by 13% and 28% by zeo-urea (1:1) in Alfisol and Spodosol soils, respectively, whereas zeo-urea (2:1) and zeo-urea (3:1) effectively decreased NO3-N leaching in Alfisol. Volatilization loss of NH3 was reduced by 47% in Spodosol and 32% in Alfisol soil with zeo-urea (1:1) as compared with that of urea fertilizer. The results suggest that zeo-urea (1:1) is an effective fertilizer formulation for reducing N losses, especially in Alfisol, as compared with conventional urea fertilizer.

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