Influence of Nitrogen Application Time on Nitrogen Absorption, Partitioning, and Yield of Pecan

Nitrogen was applied to mature pecan (Carya illinoinensis Wangenh. C. Koch.) trees annually as a single application at 125 kg·ha-1 N in March or as a split application with 60% (75 kg·ha-1 N) applied in March and the remaining 40% (50 kg·ha-1 N) applied during the first week of October. Nitrogen treatment did not affect yield, and had little effect on the amount of N absorbed. Nitrogen absorption was greater between budbreak and the end of shoot expansion than at other times of the year. Substantial amounts of N were also absorbed between leaf fall and budbreak. Little N was absorbed between the end of shoot expansion and leaf fall, or tree N losses met or exceeded N absorption. Pistillate flowers and fruit accounted for a small portion of the tree's N; ≈0.6% at anthesis and 4% at harvest. The leaves contained ≈25% of the tree's N in May and ≈17% when killed by freezing temperatures in November. Leaves appeared to contribute little to the tree's stored N reserves. Roots ≥1 cm diameter were the largest site of N storage during the winter. Stored N reserves in the perennial parts of the tree averaged 13% of the tree's total N over a three year period. Current year's N absorption was inversely related to the amount of stored N, but was not related to the current or previous year's crop load.

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291 Effect of Nitrogen Fertilization Time on Nitrogen Storage and Return Bloom of Pecan

HortScience ◽

10.21273/hortsci.34.3.492d ◽

1999 ◽

Vol 34 (3) ◽

pp. 492D-492

Author(s):

Laura E. Acuña-Maldonado ◽

Michael W. Smith

Keyword(s):

Nitrogen Fertilization ◽

Nitrogen Storage ◽

Nitrogen Application ◽

Application Time ◽

Split Application ◽

Single Application ◽

N Application ◽

Nitrate N ◽

N Concentration ◽

Return Bloom

A study was conducted to compare a single nitrogen application in March (125 kg N/ha) vs. a split application in March (75 kg N/ha) and October (50 kg N/ha) on 15-year-old `Maramec'. After one season, N application time did not affect return bloom. A split N application increased trunk wood Kjeldahl-N but decreased Kjeldahl-N in the current season's reproductive shoots and 1-year-old branches compared to a single application in March. Kjeldahl-N concentration was not affected by treatment in current season's vegetative shoots, trunk bark or roots. Nitrate-N concentration was not affected by treatment in any tissue sampled. Between the first week of October and the first killing frost in November, Kjeldahl-N increased 29% in current season's shoots, 21% in trunk bark, 32% in roots >1 cm in diameter, and 15% in roots <1 cm in diameter but decreased 42% in trunk wood and 5% in 1-year-old branches. Roots <1 cm in diameter accumulated more nitrate-N than other tissues during November.

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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 ◽

10.1071/sr15286 ◽

2016 ◽

Vol 54 (5) ◽

pp. 604 ◽

Cited By ~ 23

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.

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Processes of ammonia air-surface exchange in a fertilized <i>Zea mays</i> canopy

Biogeosciences Discussions ◽

10.5194/bgd-9-7893-2012 ◽

2012 ◽

Vol 9 (6) ◽

pp. 7893-7941 ◽

Cited By ~ 6

Author(s):

J. T. Walker ◽

M. R. Jones ◽

J. O. Bash ◽

L. Myles ◽

T. Meyers ◽

...

Keyword(s):

Zea Mays ◽

Temporal Dynamics ◽

Daily Maximum ◽

N Losses ◽

Surface Exchange ◽

Total N ◽

Soil Emissions ◽

Source Sink ◽

Resistance Modeling ◽

Process Level

Abstract. Recent incorporation of coupled soil biogeochemical and bi-directional NH3 air-surface exchange algorithms into regional air quality models holds promise for further reducing uncertainty in estimates of NH3 emissions from fertilized soils. While this represents a significant advancement over previous approaches, the evaluation and improvement of such modeling systems for fertilized crops requires process level field measurements over extended periods of time that capture the range of soil, vegetation, and atmospheric conditions that drive short term (i.e., post fertilization) and total growing seasonNH3 fluxes. This study examines the processes of NH3 air-surface exchange in a fertilized corn (Zea mays) canopy over the majority of a growing season to characterize soil emissions after fertilization and investigate soil-canopy interactions. Micrometeorological flux measurements above the canopy, measurements of soil, leaf apoplast and dew/guttation chemistry, and a combination of in-canopy measurements, inverse source/sink, and resistance modeling were employed. Over a period of approximately 10 weeks following fertilization, daily mean and median net canopy-scale fluxes yielded cumulative total N losses of 8.4% and 6.1%, respectively, of the 134 kg N ha−1 surface applied to the soil as urea ammonium nitrate (UAN). During the first month after fertilization, daily mean emission fluxes were positively correlated with soil temperature and soil volumetric water. Diurnally, maximum hourly average fluxes of ≈700 ng N m−2 s−1 occurred near mid-day, coincident with the daily maximum in friction velocity. Net emission was still observed 5 to 10 weeks after fertilization, although mid-day peak fluxes had declined to ≈125 ng N m−2 s−1 A key finding of the surface chemistry measurements was the observation of high pH (7.0 – 8.5) in leaf dew/guttation, which reduced the ability of the canopy to recapture soil emissions during wet periods. In-canopy measurements near peak LAI indicated that the concentration of NH3 just above the soil surface was highly positively correlated with soil volumetric water, which likely reflects the influence of soil moisture on resistance to gaseous diffusion through the soil profile and hydrolysis of remaining urea. Inverse source/sink and resistance modeling indicated that the canopy recaptured ≈73% of soil emissions near peak LAI. Stomatal uptake may account for 12–34% of total uptake by foliage during the day compared to 66–88% deposited to the cuticle. Future process-level \\NH3 studies in fertilized cropping systems should focus on the temporal dynamics of net emission to the atmosphere from fertilization to peak LAI and improvement of soil and cuticular resistance parameterizations.

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Soil Type Modifies the Impacts of Warming and Snow Exclusion on Carbon and Nutrient Losses

10.21203/rs.3.rs-1139295/v1 ◽

2021 ◽

Author(s):

Stephanie M. Juice ◽

Paul G. Schaberg ◽

Alexandra M. Kosiba ◽

Carl E. Waite ◽

Gary J. Hawley ◽

...

Keyword(s):

Climate Change ◽

Nutrient Cycling ◽

Soil Type ◽

Soil Characteristics ◽

Nutrient Loss ◽

Climate Projections ◽

Nutrient Losses ◽

N Losses ◽

Total N ◽

The Impact

Abstract The varied and wide-reaching impacts of climate change are occurring across heterogeneous landscapes. Despite the known importance of soils in mediating biogeochemical nutrient cycling, there is little experimental evidence of how soil characteristics may shape ecosystem response to climate change. Our objective was to clarify how soil characteristics modify the impact of climate changes on carbon and nutrient leaching losses in temperate forests. We therefore conducted a field-based mesocosm experiment with replicated warming and snow exclusion treatments on two soils in large (2.4 m diameter), in-field forest sapling mesocosms. We found that nutrient loss responses to warming and snow exclusion treatments frequently varied substantially by soil type. Indeed, in some cases, soil type nullified the impact of a climate treatment. For example, warming and snow exclusion increased nitrogen (N) losses on fine soils by up to four times versus controls, but these treatments had no impact on coarse soils. Generally, the coarse textured soil, with its lower soil-water holding capacity, had higher nutrient losses (e.g., 12-17 times more total N loss from coarse than fine soils), except in the case of phosphate, which had consistently higher losses (23-58%) from the finer textured soil. Furthermore, the mitigation of nutrient loss by increasing tree biomass varied by soil type and nutrient. Our results suggest that potentially large biogeochemical responses to climate change are strongly mediated by soil characteristics, providing further evidence of the need to consider soil properties in Earth system models for improving nutrient cycling and climate projections.

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Quantifying nitrogen losses in oil palm plantations: models and challenges

10.5194/bg-2016-177 ◽

2016 ◽

Cited By ~ 1

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.

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Nitrogen balances in temperate perennial grass and clover dairy pastures in south-eastern Australia

Australian Journal of Agricultural Research ◽

10.1071/ar07022 ◽

2007 ◽

Vol 58 (12) ◽

pp. 1167 ◽

Cited By ~ 20

Author(s):

R. J. Eckard ◽

D. F. Chapman ◽

R. E. White

Keyword(s):

Ammonium Nitrate ◽

Management Practices ◽

Perennial Grass ◽

Dairy Farms ◽

Nutrient Inputs ◽

N Losses ◽

Total N ◽

South Eastern ◽

Eastern Australia ◽

South Eastern Australia

Nitrogen (N) fertiliser use on dairy pastures in south-eastern Australia has increased exponentially over the past 15 years. Concurrently, imports of supplementary feed onto dairy farms have increased, adding further nutrients to the system. These trends raise questions about the environmental effects of higher nutrient inputs to dairy farms. To gauge possible effects, annual N balances were calculated from an experiment where N inputs and losses were measured for 3 years from non-irrigated grass/clover pastures receiving either no N fertiliser (Control) or 200 kg N/ha applied annually as ammonium nitrate or urea. Estimated total N inputs, averaged over the 3 years, were 154, 314, and 321 kg N/ha.year for the control, ammonium nitrate, and urea treatments, respectively, while N outputs in meat and milk were 75, 99, and 103 kg N/ha.year, respectively. The corresponding calculated N surplus was 79, 215, and 218 kg N/ha.year for the 3 treatments, respectively, and the ratio of product N/total-N inputs for the 3 treatments ranged from 50% in the control to 32% for both N treatments. Total N losses averaged 56, 102, and 119 kg N/ha.year, leaving a positive N balance of 23, 112, and 99 kg N/ha.year for the control, ammonium nitrate, and urea treatments, respectively. The ratio of product N/total-N inputs or the N surplus may be useful in monitoring the efficiency of conversion of N into animal products and the potential environmental effect at a whole-farm scale. However, additional decision support or modelling tools are required to provide information on specific N losses for a given set of conditions and management inputs. Given the large range in N losses there is opportunity for improving N-use efficiency in dairy pastures through a range of management practices and more tactical use of grain and N fertiliser.

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Ammonia Emissions from Dairy Lagoons in the Western U.S.

Transactions of the ASABE ◽

10.13031/trans.12646 ◽

2018 ◽

Vol 61 (3) ◽

pp. 1001-1015 ◽

Cited By ~ 2

Author(s):

April B. Leytem ◽

David L. Bjorneberg ◽

C. Al Rotz ◽

Luis E. Moraes ◽

Ermias Kebreab ◽

...

Keyword(s):

Physicochemical Characteristics ◽

Ammonia Emission ◽

Dispersion Modeling ◽

N Losses ◽

Total N ◽

Inverse Dispersion ◽

South Central ◽

Liquid Storage ◽

Wind Events ◽

On Farm

Abstract. Ammonia (NH3) emissions from dairy liquid storage systems can be a source of reactive nitrogen (N) released to the environment, with a potential to adversely affect sensitive ecosystems and human health. However, little on-farm research has been conducted to estimate these emissions and determine the factors that may affect these emissions. Six lagoons in south-central Idaho were monitored for one year using open-path Fourier transform spectrometry, with NH3 emissions estimated using inverse dispersion modeling (WindTrax software). Lagoon physicochemical characteristics thought to contribute to NH3 emissions were also monitored over this period. Average total emissions from the lagoons ranged from 12 to 43 kg NH3 ha-1 d-1, or 5.4 to 85 kg NH3 d-1. Emissions from the settling basin on one dairy were 30% of the total emissions from the liquid storage system, indicating that basins are important sources of on-farm NH3 emissions. Emissions generally trended greater during the summer, when temperatures were greater. High wind events and agitation of the lagoons created temporary increases in NH3 emissions irrespective of temperature. Lagoon physicochemical characteristics, such as total Kjeldahl nitrogen (TKN) and total ammoniacal nitrogen (TAN), were highly correlated with emissions (r = 0.52 and 0.55, respectively). Regression models were developed to predict on-farm NH3 emissions and indicated that TKN, TAN, wind speed, air temperature, and pH were the main drivers of these emissions. An on-farm N balance suggested that lagoon NH3-N losses represented 9% of total N lost from the facility, 65% of total lagoon N, and 5% of dairy herd N intake. A process-based model (Integrated Farm System Model) estimated values for N excretion and NH3-N loss from the lagoon within 5% of that measured on-farm. More on-farm research is needed to better refine both process-based models and emission factor estimates to more accurately predict NH3 emissions from lagoons on dairies in the western U.S. Keywords: Ammonia, Emission, Inverse dispersion, Manure.

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The nitrogen footprint of food products in the European Union

The Journal of Agricultural Science ◽

10.1017/s0021859613000786 ◽

2013 ◽

Vol 152 (S1) ◽

pp. 20-33 ◽

Cited By ~ 80

Author(s):

A. LEIP ◽

F. WEISS ◽

J. P. LESSCHEN ◽

H. WESTHOEK

Keyword(s):

European Union ◽

Crop Yields ◽

Essential Element ◽

Mineral Fertilizer ◽

N Leaching ◽

The European Union ◽

N Losses ◽

Total N ◽

Reactive N ◽

Livestock Products

SUMMARYNitrogen (N) is an essential element for plants and animals. Due to large inputs of mineral fertilizer, crop yields and livestock production in Europe have increased markedly over the last century, but as a consequence losses of reactive N to air, soil and water have intensified as well. Two different models (CAPRI and MITERRA) were used to quantify the N flows in agriculture in the European Union (EU27), at country-level and for EU27 agriculture as a whole, differentiated into 12 main food categories. The results showed that the N footprint, defined as the total N losses to the environment per unit of product, varies widely between different food categories, with substantially higher values for livestock products and the highest values for beef (c. 500 g N/kg beef), as compared to vegetable products. The lowest N footprint of c. 2 g N/kg product was calculated for sugar beet, fruits and vegetables, and potatoes. The losses of reactive N were dominated by N leaching and run-off, and ammonia volatilization, with 0·83 and 0·88 due to consumption of livestock products. The N investment factors, defined as the quantity of new reactive N required to produce one unit of N in the product varied between 1·2 kg N/kg N in product for pulses to 15–20 kg N for beef.

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EFFECT OF ADDED MONOCALCIUM PHOSPHATE MONOHYDRATE AND AERATION ON NITROGEN RETENTION BY LIQUID HOG MANURE

Canadian Journal of Soil Science ◽

10.4141/cjss87-065 ◽

1987 ◽

Vol 67 (3) ◽

pp. 687-692 ◽

Cited By ~ 7

Author(s):

A. F. MACKENZIE ◽

J. S. TOMAR

Keyword(s):

Sus Scrofa ◽

Crop Production ◽

Nitrogen Retention ◽

N Losses ◽

N Content ◽

Total N ◽

N Retention ◽

Monocalcium Phosphate ◽

Hog Manure ◽

Sus Scrofa Domesticus

Retention of nitrogen in manure to be used for crop production and to reduce environmental pollution is an essential management component. The effects of monocalcium phosphate monohydrate (MCPM) and aeration on N retention in liquid hog (Sus scrofa domesticus) manure (LHM) were investigated under laboratory conditions. The manure received 0, 20 or 40 g of MCPM kg−1 of LHM (0, 250 or 500 g MCPM kg−1 manure solids) and was incubated over a 15-d period with and without aeration. Manure pH decreased with added MCPM and then remained constant, but pH increased with time when MCPM was not added. Losses of NH3 from hog manure were significantly reduced by added MCPM, but increased significantly with aeration where MCPM was not added to the manure. The NH4-N content of LHM was higher where MCPM was added to the manure. Conversely, the NH4-N content tended to decrease with aeration in the absence of MCPM. Total N content of LHM was significantly decreased where MCPM was not added to the manure. Aeration had no significant effect on total N. It was concluded that addition of MCPM can increase the NH4-N content of LHM by decreasing NH3-N losses through acidification of the manure. Key words: Aeration, Ca(H2PO4)2∙H2O, hog manure, pH reduction, NH3 loss

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The effect of work level and dietary intake on sweat nitrogen losses in a hot climate

British Journal Of Nutrition ◽

10.1079/bjn19720124 ◽

1972 ◽

Vol 27 (3) ◽

pp. 543-552 ◽

Cited By ~ 5

Author(s):

J. S. Weiner ◽

J. O. C. Willson ◽

Hamad El-Neil ◽

Erica F. Wheeler

Keyword(s):

Normal Diet ◽

Physical Work ◽

N Loss ◽

N Losses ◽

Total N ◽

Adequate Diet ◽

N Concentration ◽

Hot Climate ◽

Rate Of Increase ◽

Work Level

1. Nitrogen intakes, and N output in urine, faeces and sweat have been measured in six young Tanzanian men who were accustomed to a hot climate. The measurements were done while the subjects were receiving first a normal and then a low-N diet; and when they were performing moderate physical work, and had undergone a period of acclimatization.2. When the subject were acclimatized and working on a normal diet, their sweat output increased, with a fall in its N concentration. Total sweat N loss increased from an average of 0.10 to 0.71 g/d.3. The effect of the low-N diet was to decrease both the sweat N concentration, and the rate of increase of total N loss in sweat, as sweat volume increased.4. It is estimated that maximum sweat N losses would not exceed 1 g/d on an adequate diet, or 0.5 g/d on a low-protein diet. Our results provide no basis for recommending extra protein allowances to cover sweat N losses for workers in tropical climates.

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