Solute dynamics and the Ontario nitrogen index: II. Nitrate leaching

2016 ◽  
Vol 96 (2) ◽  
pp. 122-135 ◽  
Author(s):  
C.F. Drury ◽  
W.D. Reynolds ◽  
G.W. Parkin ◽  
J.D. Lauzon ◽  
J.K. Saso ◽  
...  
Keyword(s):  
Root Zone ◽  
Agricultural Soils ◽  
Sandy Loam ◽  
N Leaching ◽  
N Recovery ◽  
N Loss ◽  
Solute Dynamics ◽  
N Management ◽  
N Rates ◽  
Leaching Risk

Nitrogen (N) leaching from soil into surface and ground waters is a concern in humid areas of Canada. As a result, N management protocols, including the Ontario N Index, are widely used to identify N leaching risk, although field assessment remains limited. Nitrogen fertilizer and chloride (Cl) tracer were fall-applied to five agricultural soils in Ontario with different textures and hydrologic soil groups (HSG) to assess the Ontario N Index and characterize inorganic N movement over 1 yr. The treatments included three N rates (0, 100, and 200 kg N ha−1) plus Cl tracer and 200 kg N ha−1 rate without Cl. After spring thaw, N loss from the crop root zone (top 60 cm) ranged from 68% for Brookston clay loam to 99% for Harrow sandy loam. A strong linear relationship between apparent N recovery and apparent Cl recovery indicated that N loss from the root zone occurred primarily by downward leaching. Leaching was controlled by the minimum measured saturated hydraulic conductivity (Ksat), and good estimates of N leaching were obtained using a quasi-theoretical relationship between N loss and Ksat. We concluded that Ontario N Index estimates of N leaching risk might be improved by including site-specific measurements of Ksat.

scholarly journals Assessing the Effects of Nitrification Inhibitor DMPP on Acidification and Inorganic N Leaching Loss from Tea (Camellia sinensis L.) Cultivated Soils with Increasing Urea–N Rates

2021 ◽  
Vol 13 (2) ◽  
pp. 994
Author(s):  
Chunlian Qiao ◽  
Shamim Mia ◽  
Yeqin Wang ◽  
Jiajia Hou ◽  
Burenbayin Xu
Keyword(s):  
Soil Ph ◽  
Nitrification Inhibitor ◽  
N Leaching ◽  
Inorganic N ◽  
N Loss ◽  
N Application ◽  
Leaching Loss ◽  
N Management ◽  
N Rates ◽  
Cultivated Soils

The effects of nitrification inhibitor in tea gardens with different urea–N rates have rarely been assessed. For eight months, a glasshouse experiment was conducted to investigate the effects of a nitrification inhibitor (3, 4–dimethylpyrazole phosphate, DMPP) on the changes of soil pH and inorganic N loss. Urea (0, 300, 500, and 800 kg N ha−1) with or without DMPP (1% of urea–N applied) were added to pots that hosted six plants that were three years old. Next, three leaching events were conducted with 600 mL of water after 7, 35, and 71 days of intervention while soil samples were collected to determine pH and inorganic N. Averaged across sampling dates, urea–N application at an increasing rate reduced soil pH with the lowest values at 800 kg urea–N ha−1. Adding DMPP increased soil pH up to a rate of 500 kg ha−1. Irrespective of the addition of DMPP, gradient urea–N application increased the leaching loss of inorganic N. On overage, DMPP increased soil pH and decreased leaching losses of total inorganic N, suggesting a higher soil N retention. Therefore, we believe that this increase in soil pH is associated with a relatively lower proton release from the reduced nitrification in the DMPP–receiving pots. This nitrification reduction also contributed to the N loss reduction (NO3−–N). Altogether, our results suggest that DMPP can reduce N leaching loss while maintaining the pH of tea–cultivated soils. Therefore, DMPP application has a significant potential for the sustainable N management of tea gardens.

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.

scholarly journals Water and Nitrogen Productivity of Potato Growth in Desert Areas under Low-Discharge Drip Irrigation

Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 970 ◽  
Author(s):  
Pavel Trifonov ◽  
Naftali Lazarovitch ◽  
Gilboa Arye
Keyword(s):  
Drip Irrigation ◽  
Driving Forces ◽  
Root Zone ◽  
Agricultural Soils ◽  
Potato Crop ◽  
Water Productivity ◽  
Potato Production ◽  
N Leaching ◽  
Limiting Factor ◽  
Potato Growth

Narrow profit margins, resource conservation issues and environmental concerns are the main driving forces to improve fertilizer uptake, especially for potatoes. Potatoes are a high value crop with a shallow, inefficient root system and high fertilizer rate requirements. Of all essential nutrients, nitrogen (N) is often limiting to potato production. A major concern in potato production is to minimize N leaching from the root zone. Therefore, the main objective of this study was to examine the potato crop characteristics under drip irrigation with low-discharge (0.6 L h−1) and to determine the optimal combination of irrigation (40, 60, 80, and 100%) and fertigation (0, 50, and 100%) doses. In this study, the 80% (438.6 mm) irrigation dose and a 50% (50 mg N L−1) fertigation dose (W80%F50%) showed that these doses are sufficient for optimal potato yield (about 40 ton ha−1) in conjunction with water and fertilizer savings. Moreover, this treatment did not exhibit any qualitative changes in the potato tuber compared to the 100% treatments. When considering water productivity and yield, one may select a harsher irrigation regime if the available agricultural soils are not a limiting factor. Thus, higher yields can be obtained with lower irrigation and fertigation doses and a larger area.

scholarly journals Limitations of Improved Nitrogen Management to Reduce Nitrate Leaching and Increase Use Efficiency

2001 ◽  
Vol 1 ◽  
pp. 10-16 ◽  
Author(s):  
James L. Baker
Keyword(s):  
Water Quality ◽  
Nitrate Leaching ◽  
Management Practices ◽  
Nitrate Nitrogen ◽  
Nitrogen Management ◽  
N Leaching ◽  
N Loss ◽  
Use Efficiency ◽  
Rate Method ◽  
N Management

The primary mode of nitrogen (N) loss from tile-drained row-cropped land is generally nitrate-nitrogen (NO3-N) leaching. Although cropping, tillage, and N management practices can be altered to reduce the amount of leaching, there are limits as to how much can be done. Data are given to illustrate the potential reductions for individual practices such as rate, method, and timing of N applications. However, most effects are multiplicative and not additive; thus it is probably not realistic to hope to get overall reductions greater than 25 to 30% with in-field practices alone. If this level of reduction is insufficient to meet water quality goals, additional off-site landscape modifications may be necessary.

Solute dynamics and the Ontario nitrogen index: I. Chloride leaching

2016 ◽  
Vol 96 (2) ◽  
pp. 105-121 ◽  
Author(s):  
W. Daniel Reynolds ◽  
Craig F. Drury ◽  
Gary W. Parkin ◽  
John D. Lauzon ◽  
Joseph K. Saso ◽  
...  
Keyword(s):  
Transport Theory ◽  
Root Zone ◽  
Sandy Loam ◽  
Drainage Water ◽  
Low Risk ◽  
Soil Core ◽  
Southern Ontario ◽  
Risk Levels ◽  
Crop Root ◽  
Solute Dynamics

The nitrogen (N) index for humid temperate southern Ontario, Canada (Ontario N index) incorporates previous and current crop type, fertilizer and (or) manure management, and hydrologic soil group (HSG) to estimate risk for contamination of tile drainage water and groundwater by nitrate leached below the primary crop root zone (top 60 cm of soil). The Ontario N index has received limited ground-truthing, and the leaching component was assessed using chloride tracer (ClTR) on five soils (one sandy loam, two loams, and two clay loams) representing four HSG-based risk levels (HSG-A, high risk; HSG-B, medium risk; HSG-C, low risk; HSG-D, very low risk). A square-wave pulse of ClTR was applied to the soil surfaces in fall 2007 as KCl, and movement and loss of ClTR was tracked over 1–1.2 years using monthly soil core samples collected from the top 60–80 cm. For all five soils, 60–96% of ClTR was leached out of the primary crop root zone (below 60 cm depth) during the noncropping period (October 2007 to March 2008 inclusive), and >80% was leached out of the root zone within 1 year. The percentage of ClTR that leached did not correlate with precipitation or HSG designation, but produced significant (P < 0.05) power function regressions with minimum and harmonic mean saturated soil hydraulic conductivity (Ksat) measured in the top 50–60 cm. ClTR leaching rate appeared to be controlled primarily by Ksat in a manner consistent with infiltration and solute transport theory. It was consequently proposed that solute leaching loss versus Ksat relationships may improve N index risk estimates for both southern Ontario and other humid temperate regions.

scholarly journals Fate of 15N-urea applied to wheat-soybean succession crop

Bragantia ◽  
2004 ◽  
Vol 63 (2) ◽  
pp. 265-274 ◽  
Author(s):  
Antonio Enedi Boaretto ◽  
Eduardo Scarpari Spolidorio ◽  
José Guilherme de Freitas ◽  
Paulo Cesar Ocheuze Trivelin ◽  
Takashi Muraoka ◽  
...  
Keyword(s):  
Root Zone ◽  
Soil Surface ◽  
Wheat Root ◽  
Wheat Crop ◽  
N Recovery ◽  
N Loss ◽  
N Application ◽  
Grain Productivity ◽  
15N Urea ◽  
Irrigated Wheat

The wheat crop in São Paulo State, Brazil, is fertilized with N, P and K. The rate of applied N (0 to 120 kg.ha-1) depends on the previous grown crop and the irrigation possibility. The response of wheat to rates and time of N application and the fate of N applied to irrigated wheat were studied during two years. Residual N recovery by soybean grown after the wheat was also studied. The maximum grain productivity was obtained with 92 kg.ha-1 of N. The efficiency of 15N-urea utilization ranged from 52% to 85%. The main loss of applied 15N, 5% to 12% occurred as ammonia volatilized from urea applied on soil surface. The N loss by leaching even at the N rate of 135 kg.ha-1, was less than 1% of applied 15N, due to the low amount of rainfall during the wheat grown season and a controlled amount of irrigated water, that were sufficient to moisten only the wheat root zone. The residual 15N after wheat harvest represents around 40% of N applied as urea: 20% in soil, 3% in wheat root system and 16% in the wheat straw. Soybean recovered less than 2% of the 15N applied to wheat at sowing or at tillering stage.

scholarly journals EFFECTS OF WINTER COVER CROPS AND N APPLICATIONS ON VEGETABLE CROP PRODUCTION SYSTEMS

HortScience ◽  
1995 ◽  
Vol 30 (3) ◽  
pp. 429e-429
Author(s):  
K.M. Batal ◽  
M.R. Hall ◽  
D.M. Granberry ◽  
J.T. Garrett ◽  
D.R. Decoteau ◽  
...  
Keyword(s):  
South Carolina ◽  
Cover Crops ◽  
Soil Profile ◽  
Nitrogen Availability ◽  
Root Zone ◽  
N Leaching ◽  
Crimson Clover ◽  
Winter Cover ◽  
Winter Cover Crops ◽  
N Rates

A vegetable production system using winter cover crops and N rates was evaluated for several years in Georgia, South Carolina, and North Carolina. Snap bean, cucumber, tomato, potato, and sweetpotato crops were tested at different locations. Cover crop plots produced higher yields and better quality in all locations as seasons progressed over 4 years. Soil N levels in fallow, wheat, and clover plots were similar at initiation, but N gradually increased in clover plots in successive years. Yield and quality of root crops improved with Crimson clover without N applications compared to fallow plots with 60 kg N/ha. Effects on yield and tuber size are discussed. Nitrate and NH4-N in the soil profile from 15- to 150-cm depth were monitored at all locations. Nitrogen availability, depletion, and leaching below the root zone were determined. At low N rate, clover plots had slightly higher NO3 in the soil profile; however, at high N rate, N supply by clover was not as critical, and N leaching was detected at much lower depths than at low N rates.

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.

Nitrate leaching as influenced by fertilization in the Brown soil zone

1993 ◽  
Vol 73 (4) ◽  
pp. 387-397 ◽  
Author(s):  
C. A. Campbell ◽  
R. P. Zentner ◽  
F. Selles ◽  
O. O. Akinremi
Keyword(s):  
Soil Moisture ◽  
Nitrate Leaching ◽  
Root Zone ◽  
N Uptake ◽  
Triticum Aestivum L ◽  
N Leaching ◽  
Fertilizer N ◽  
Brown Soil ◽  
Soil Zone ◽  
N Rates

The possibility of nitrates being leached into groundwater supplies from improper use of fertilizers is a concern to society. Two experiments were conducted on a loam soil in the Brown soil zone at Swift Current, Saskatchewan. In the first experiment, continuous wheat (Triticum aestivum L.), grown under various fertilizer-N management systems and with and without cereal trap strips (tall stubble, 0.4–0.6 m) to capture snow and enhance soil-moisture storage, was compared with short stubble cut at the standard height (0.15–0.2 m). Prior to seeding in spring 1991, tall stubble had stored 14.7 ha-cm of soil moisture at 0–1.2-m depth compared with 10.9 ha-cm under short-stubble treatment. Because growing-season precipitation in 1991 was much higher than normal (302 mm from 1 May to 31 My), considerable NO3-N was leached below the rooting zone of wheat (1.2 m), particularly in the tall-stubble treatment. Leaching patterns were as expected in short stubble, with major leaching occurring only at the highest N rate (125 kg ha−1), where yield and N-uptake response had levelled off. However, in tall stubble, the amount of NO3-N leached beyond the root zone under the 0 and 25 kg N ha−1 rates was similar to that under the 125 kg N ha−1 rate. This result was attributed to poor tillering obtained at low N rates, which contributed to lower evapotranspiration, thereby permitting more moisture to be leached and enhancing N mineralization. When we used a leaching model (NLEAP) to simulate our results, it gave lower estimates of NO3 leached and did not reveal the interaction of NO3-N leaching with N rates that was observed under tall stubble. The second experiment measured soil NO3-N distribution to 2.4 m under two fallow–wheat–wheat systems after a 24-yr period. One system received only N, the other, N + P fertilizer. The results corroborated those obtained under tall stubble in the first experiment: the poorly fertilized system had the most NO3-N below the root zone. The results of this study suggest that the key to reducing nitrate leaching is the adoption of proper fertilization practices, since too little fertilization may potentially be as detrimental to groundwater pollution as too much. Key words: Fertilizer N, N uptake, snow management, crop rotations, NO3 leaching

scholarly journals Modelling the risk of nitrate leaching from two soils amended with five different biosolids

2005 ◽  
Vol 29 (4) ◽  
pp. 619-626 ◽  
Author(s):  
Rodrigo Studart Corrêa ◽  
Robert Edwin White ◽  
Anthony James Weatherley
Keyword(s):  
Sewage Sludge ◽  
Plant Nutrition ◽  
Root Zone ◽  
Field Capacity ◽  
Land Application ◽  
N Leaching ◽  
N Loss ◽  
Application Rates ◽  
Agricultural Use ◽  
Composted Sludge

High N concentrations in biosolids are one of the strongest reasons for their agricultural use. However, it is essential to understand the fate of N in soils treated with biosolids for both plant nutrition and managing the environmental risk of NO3--N leaching. This work aimed at evaluating the risk of NO3--N leaching from a Spodosol and an Oxisol, each one treated with 0.5-8.0 dry Mg ha-1 of fresh tertiary sewage sludge, composted biosolids, limed biosolids, heat-dried biosolids and solar-irradiated biosolids. Results indicated that under similar application rates NO3--N accumulated up to three times more in the 20 cm topsoil of the Oxisol than the Spodosol. However, a higher water content held at field capacity in the Oxisol compensated for the greater nitrate concentrations. A 20 % NO3--N loss from the root zone in the amended Oxisol could be expected. Depending on the biosolids type, 42 to 76 % of the NO3--N accumulated in the Spodosol could be expected to leach down from the amended 20 cm topsoil. NO3--N expected to leach from the Spodosol ranged from 0.8 (composted sludge) to 3.5 times (limed sludge) the amounts leaching from the Oxisol treated alike. Nevertheless, the risk of NO3--N groundwater contamination as a result of a single biosolids land application at 0.5-8.0 dry Mg ha-1 could be considered low.

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