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 Field-scale monitoring of nitrate leaching in agriculture: assessment of three methods

2021 ◽  
Vol 194 (1) ◽  
Author(s):  
Hannah Wey ◽  
Daniel Hunkeler ◽  
Wolf-Anno Bischoff ◽  
Else K. Bünemann
Keyword(s):  
Nitrate Leaching ◽  
Seasonal Pattern ◽  
N Uptake ◽  
In Situ Monitoring ◽  
Soil Conditions ◽  
N Leaching ◽  
Central Plateau ◽  
N Losses ◽  
Monitoring Method ◽  
Water Percolation

AbstractDeterioration of groundwater quality due to nitrate loss from intensive agricultural systems can only be mitigated if methods for in-situ monitoring of nitrate leaching under active farmers’ fields are available. In this study, three methods were used in parallel to evaluate their spatial and temporal differences, namely ion-exchange resin-based Self-Integrating Accumulators (SIA), soil coring for extraction of mineral N (Nmin) from 0 to 90 cm in Mid-October (pre-winter) and Mid-February (post-winter), and Suction Cups (SCs) complemented by a HYDRUS 1D model. The monitoring, conducted from 2017 to 2020 in the Gäu Valley in the Swiss Central Plateau, covered four agricultural fields. The crop rotations included grass-clover leys, canola, silage maize and winter cereals. The monthly resolution of SC samples allowed identifying a seasonal pattern, with a nitrate concentration build-up during autumn and peaks in winter, caused by elevated water percolation to deeper soil layers in this period. Using simulated water percolation values, SC concentrations were converted into fluxes. SCs sampled 30% less N-losses on average compared to SIA, which collect also the wide macropore and preferential flows. The difference between Nmin content in autumn and spring was greater than nitrate leaching measured with either SIA or SCs. This observation indicates that autumn Nmin was depleted not only by leaching but also by plant and microbial N uptake and gaseous losses. The positive correlation between autumn Nmin content and leaching fluxes determined by either SCs or SIA suggests autumn Nmin as a useful relative but not absolute indicator for nitrate leaching. In conclusion, all three monitoring techniques are suited to indicate N leaching but represent different transport and cycling processes and vary in spatio-temporal resolution. The choice of monitoring method mainly depends (1) on the project’s goals and financial budget and (2) on the soil conditions. Long-term data, and especially the combination of methods, increase process understanding and generate knowledge beyond a pure methodological comparison.

Effect of slurry application and mineral nitrogen fertilization on N leaching in different crop combinations

1997 ◽  
Vol 128 (1) ◽  
pp. 79-86 ◽  
Author(s):  
K. SIELING ◽  
O. GÜNTHER-BORSTEL ◽  
H. HANUS
Keyword(s):  
Winter Wheat ◽  
Oilseed Rape ◽  
N Uptake ◽  
N Fertilization ◽  
N Leaching ◽  
Pig Slurry ◽  
N Losses ◽  
Mineral N ◽  
Soil System ◽  
Preceding Crop

Nitrogen (N) fertilizer not used by the crop can increase the risk of nitrate leaching into the groundwater. In two growing seasons, 1990/91 and 1991/92, the relationships between N fertilization and yield, N uptake by the grain and the N leaching in the subsequent percolation period were investigated in a multifactorial field experiment at Hohenschulen Experimental Station near Kiel in NW Germany. The crop rotation was oilseed rape – winter wheat – winter barley, and effects of soil tillage (minimum tillage without ploughing, conventional tillage), application of pig slurry (none, application in autumn, application in autumn and in spring), mineral N fertilization (none, 80 or 200 kg N ha−1 to oilseed rape and 120 or 240 kg N ha−1 to cereals) and application of fungicides (none, intensive) were all tested. In each year, the rotation and the treatments were located on the same plots. Mineral N fertilization and fungicide application increased yield and N uptake by grain or seed in all crops. In contrast, the application of slurry, especially in autumn, had only small effects on yield and N uptake. Nitrogen losses by leaching (measured using porous ceramic cups) were affected mainly by the year and the crop. In 1992/93, averaged over all factors, 80 kg N ha−1 was leached compared with 28 kg N ha−1 the previous year. Oilseed rape reduced N losses, whereas under winter wheat up to 160 kg N ha−1 was leached. Due to a lower N-use efficiency, autumn applications of slurry increased N leaching, and mineral N fertilization of the preceding crop also led to higher N losses.Since the amount of leached N depends both on the nitrogen left by the preceding crop (unused fertilizer N as well as N in residues) and on N uptake by the subsequent crop, it is not possible to apportion the N losses to any particular crop in the rotation. The cropping sequence, together with its previous and subsequent crops, must also be considered.To minimize leaching, N fertilization must meet the needs of the growing crop. In order to improve the efficiency further, investigations must be conducted in order to understand the dynamics of N in the plant–soil system in conjunction with the weather and crop management practices.

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.

scholarly journals Hydrophilic Gel Amendments to Sand Soil Can Increase Growth and Nitrogen Uptake Efficiency of Citrus Seedlings

HortScience ◽  
2004 ◽  
Vol 39 (2) ◽  
pp. 267-271 ◽  
Author(s):  
J.P. Syvertsen ◽  
J.M. Dunlop
Keyword(s):  
Water Use ◽  
Seedling Growth ◽  
N Uptake ◽  
Poncirus Trifoliata ◽  
N Leaching ◽  
Sand Soil ◽  
N Losses ◽  
Total N ◽  
Uptake Efficiency ◽  
N Uptake Efficiency

We tested the hypothesis that amendments of two hydrophilic gels to a sand soil would reduce N leaching losses and increase growth of citrus seedlings. Three-month-old seedlings of `Swingle' citrumelo [Citrus paradisi Macf. × Poncirus trifoliata (L.) Raf.] were transplanted into containers of steam-sterilized Candler sand, amended with a linear acrylamide/acrylate copolymer (PAM), and/or a cross-linked copolymer agronomic gel (AGRO). Two rates of each amendment were applied either alone or together and were either mixed into dry sand prior to seedling transplant, used as a root-dip slurry at transplant or applied to the soil surface in a solution after transplant. Seedlings were grown in the greenhouse for 5 months and irrigated to container capacity with a dilute nutrient solution without leaching. Pots were leached every 2 weeks and total N losses from the soil were measured in the leachate. PAM amendments increased N retention in soil slightly but PAM had no effect on plant growth, water use, N uptake, or N leaching relative to unamended control plants. The AGRO amendments increased seedling growth, plant water use and uptake of N from 11% to 45% above that of the unamended control plants depending on application method. AGRO decreased N concentrations in the leachate to as low as 1 to 6 mg·L-1. Only 6% of the total applied N was leached from the AGRO treatments, which was about half that from the untreated control plants. There was no additional benefit of using both amendments together or of an additional AGRO root dip treatment. The largest plants used the most water, required the most N and had the greatest N uptake efficiency. AGRO amendments clearly enhanced seedling growth, increased their N uptake efficiency, and reduced N losses from this sand soil.

scholarly journals Soil nitrogen dynamics during an oilseed rape (Brassica napus L.) growing cycle in a humid Mediterranean climate

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
N. Villar ◽  
M. Aranguren ◽  
A. Castellón ◽  
G. Besga ◽  
A. Aizpurua
Keyword(s):  
Oilseed Rape ◽  
Mediterranean Climate ◽  
N Uptake ◽  
N Fertilization ◽  
N Leaching ◽  
Brassica Napus L ◽  
N Losses ◽  
Climate Conditions ◽  
Nitrogen Budgets ◽  
Net Mineralization

Abstract Nitrogen budgets help explain the supply pattern of N from the soil to the crop. Through budgeting, an improvement of the N fertilization strategy can be achieved. The objective of the present study, which was carried out under humid Mediterranean climate conditions, was to assess the influence of N fertilization, temperature and soil humidity on soil N dynamics during a whole oilseed rape growing cycle. A field experiment was conducted with two treatments: without N (0 N) and with application of 180 kg N ha−1(180 N). Mineralization was calculated from N balances made throughout the growing cycle, all while taking into account measured N uptake by oilseed rape and N losses by leaching and N2O emissions. Nitrogen net mineralization was negative after fertilization, reaching –6.73 kg N ha−1, day−1, but total net mineralization over the year was similar for the 0 N and 180 N treatments (21 and 8 kg N ha−1, respectively). Temperatures over 5 °C were sufficient for initiating the mineralization processes. In the summer, when the soil water content was below the wilting point, immobilization took place; however, there is a risk of N leaching if rainfall occurs thereafter, mainly in the 180 N treatment.

scholarly journals Assessments of N leaching losses from six case study dairy farms using contrasting approaches to cow wintering

2012 ◽  
pp. 51-55 ◽  
Author(s):  
J.M. Chrystal ◽  
R.M.Monaghan D. Dalley ◽  
T. Styles
Keyword(s):  
Dairy Cow ◽  
N Uptake ◽  
Dairy Herd ◽  
High Potential ◽  
System Level ◽  
N Leaching ◽  
Forage Crops ◽  
N Losses ◽  
Total N ◽  
Leaching Losses

The expansion of the southern dairy herd in New Zealand has raised a number of concerns about the sustainability of grazing brassica forage crops. Here we provide an assessment of the contribution of these crops to the potential for N losses to water at a wholefarm system level, and compare these with metrics derived for systems that use alternative approaches for wintering cows. The risks of nutrient losses to water from six Monitor Farms that use contrasting approaches to dairy cow wintering were assessed using the Overseer® Nutrient budgets model (Overseer). This modelling assessment was supplemented with detailed information about the management of effluent generated from off-paddock cow wintering facilities such as wintering pads and covered housing. Predictions of N losses from individual farm blocks indicated that both winter- and summer-grazed brassica forage crops have a relatively high potential for N leaching losses. Expressed at a whole-system level (i.e. accounting for the milking platform, winter forage crop and other support land), the winter forage crops accounted for between 11 and 24% of total N leaching losses, despite representing only 4 to 9% of the area. The high N leaching losses predicted for summer-grazed forage crops were attributed to the limited opportunity for N uptake of excreted urinary N by the following new pasture. Another risk identified for some farms was the current practice of applying effluents collected from off-paddock facilities to land during winter. These assessments suggest that off-paddock cow wintering systems can help to minimise N losses from farms to water, although the storage and safe return to land of effluents and manures generated from the housing facilities is essential if this potential benefit is to be realised. Our assessments also suggest that summer crop paddocks have a relatively high potential for N leaching losses, although further research is needed to confirm this. Keywords: dairy cow wintering, Southland, nitrate leaching, grazed brassica forage crops.

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

NLEAP Computer Model and Multiple Linear Regression Prediction of Nitrate Leaching in Vegetable Systems

2002 ◽  
Vol 12 (2) ◽  
pp. 250-256 ◽  
Author(s):  
Hudson Minshew ◽  
John Selker ◽  
Delbert Hemphill ◽  
Richard P. Dick
Keyword(s):  
Linear Regression ◽  
Multiple Linear Regression ◽  
Nitrate Leaching ◽  
Cover Crops ◽  
N Uptake ◽  
N Leaching ◽  
Residual Soil ◽  
Vegetable Crops ◽  
Crop N Uptake ◽  
Mlr Model

Predicting leaching of residual soil nitrate-nitrogen (NO3-N) in wet climates is important for reducing risks of groundwater contamination and conserving soil N. The goal of this research was to determine the potential to use easily measurable or readily available soilclimatic-plant data that could be put into simple computer models and used to predict NO3 leaching under various management systems. Two computer programs were compared for their potential to predict monthly NO3-N leaching losses in western Oregon vegetable systems with or without cover crops. The models were a statistical multiple linear regression (MLR) model and the commercially available Nitrate Leaching and Economical Analysis Package model (NLEAP 1.13). The best MLR model found using stepwise regression to predict annual leachate NO3-N had four independent variables (log transformed fall soil NO3-N, leachate volume, summer crop N uptake, and N fertilizer rate) (P < 0.001, R2 = 0.57). Comparisons were made between NLEAP and field data for mass of NO3-N leached between the months of September and May from 1992 to 1997. Predictions with NLEAP showed greater correlation to observed data during high-rainfall years compared to dry or averagerainfall years. The model was found to be sensitive to yield estimates, but vegetation management choices were limiting for vegetable crops and for systems that included a cover crop.

Agricultural practices and diffuse nitrogen pollution in Denmark: empirical leaching and catchment models

1999 ◽  
Vol 39 (12) ◽  
pp. 257-264 ◽  
Author(s):  
Hans E. Andersen ◽  
Brian Kronvang ◽  
Søren E. Larsen
Keyword(s):  
Agricultural Land ◽  
Root Zone ◽  
Agricultural Practices ◽  
Animal Manure ◽  
Annual Runoff ◽  
N Leaching ◽  
N Loss ◽  
Total N ◽  
Model Calculations ◽  
N Removal

An empirical leaching model was applied to data on agricultural practices at the field level within 6 small Danish agricultural catchments in order to document any changes in nitrogen (N) leaching from the root zone during the period 1989-96. The model calculations performed at normal climate revealed an average reduction in N-leaching that amounted to 30% in the loamy catchments and 9% in the sandy catchments. The reductions in N leaching could be ascribed to several improvements in agricultural practices during the study period: (i) regulations on livestock density; (ii) regulations on the utilisation of animal manure; (iii) regulations concerning application practices for manure. The average annual total N-loss from agricultural areas to surface water constituted only 54% of the annual average N leached from the root zone in the three loamy catchments and 17% in the three sandy catchments. Thus, subsurface N-removal processes are capable of removing large amounts of N leached from agricultural land. An empirical model for the annual diffuse N-loss to streams from small catchments is presented. The model predicts annual N-loss as a function of the average annual use of mineral fertiliser and manure in the catchment and the total annual runoff from the unsaturated zone.

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