ESTIMATING NITRATE–N LOSSES FROM SUBSURFACE DRAINS USING VARIABLE WATER SAMPLING FREQUENCIES

2003 ◽  
Vol 46 (4) ◽  
Author(s):  
X. Wang ◽  
J. R. Frankenberger ◽  
E. J. Kladivko
Keyword(s):  
Water Sampling ◽  
N Losses ◽  
Nitrate N ◽  
Subsurface Drains ◽  
Variable Water

scholarly journals The implications of lag times between nitrate leaching losses and riverine loads for water quality policy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. W. McDowell ◽  
Z. P. Simpson ◽  
A. G. Ausseil ◽  
Z. Etheridge ◽  
R. Law
Keyword(s):  
Water Quality ◽  
Mean Transit Time ◽  
Lag Time ◽  
Practice Change ◽  
N Leaching ◽  
N Losses ◽  
Leaching Losses ◽  
Nitrate N ◽  
The Mean ◽  
Lag Times

AbstractUnderstanding the lag time between land management and impacts on riverine nitrate–nitrogen (N) loads is critical to understand when action to mitigate nitrate–N leaching losses from the soil profile may start improving water quality. These lags occur due to leaching of nitrate–N through the subsurface (soil and groundwater). Actions to mitigate nitrate–N losses have been mandated in New Zealand policy to start showing improvements in water quality within five years. We estimated annual rates of nitrate–N leaching and annual nitrate–N loads for 77 river catchments from 1990 to 2018. Lag times between these losses and riverine loads were determined for 34 catchments but could not be determined in other catchments because they exhibited little change in nitrate–N leaching losses or loads. Lag times varied from 1 to 12 years according to factors like catchment size (Strahler stream order and altitude) and slope. For eight catchments where additional isotope and modelling data were available, the mean transit time for surface water at baseflow to pass through the catchment was on average 2.1 years less than, and never greater than, the mean lag time for nitrate–N, inferring our lag time estimates were robust. The median lag time for nitrate–N across the 34 catchments was 4.5 years, meaning that nearly half of these catchments wouldn’t exhibit decreases in nitrate–N because of practice change within the five years outlined in policy.

scholarly journals Nutrient losses in drainage and surface runoff from a cattle-grazed pasture in Southland

2000 ◽  
pp. 99-104 ◽  
Author(s):  
R.M. Monaghan ◽  
R.J. Paton ◽  
L.C. Smith ◽  
C. Binet
Keyword(s):  
Surface Runoff ◽  
Dairy Herd ◽  
Drainage Water ◽  
Primary Objective ◽  
Stocking Rate ◽  
N Losses ◽  
Pasture Production ◽  
Leaching Losses ◽  
Drinking Water Standard ◽  
Nitrate N

In response to local concerns about the expanding Southland dairy herd, a 4-year study was initiated in 1995 with the primary objective of quantifying nitrate-N losses to waterways from intensively grazed cattle pastures. Treatments were annual N fertiliser inputs of 0, 100, 200 or 400 kg N/ha. Stocking rate was set according to the pasture production on each of these four treatments, and over the 4 years of study ranged between the equivalent of 2.0 cows/ha for the 0N treatment, to 3.0 cows/ha for the treatment receiving 400 kg N/ ha/year. Mean annual losses of nitrate-N in drainage were 30, 34, 46 and 56 kg N/ha for the 0, 100, 200 and 400 kg N/ha/year treatments, respectively. Corresponding mean nitrate-N concentrations in drainage waters were 8.3, 9.2, 12.5 and 15.4 mg/ l, respectively. Very little direct leaching of fertiliser N was observed, even for drainage events in early spring, shortly after urea fertiliser application. The increased nitrate-N losses at higher rates of N fertiliser addition were instead owing to the indirect effect of increasing returns of urine and dung N to pasture. In Years 2 and 3, leaching losses of Ca, Mg, K, Na and sulphate-S averaged 61, 9, 11, 28 and 17 kg/ha/year, respectively, in the 0N fertiliser treatment. Increasing fertiliser N inputs significantly increased calcium and, to a lesser extent, potassium leaching losses but had no effect on losses of other plant nutrients. Surface runoff losses of Total-P, nitrate-N and ammonium- N were less than 0.5 kg/ha/year. For this well-drained Fleming soil, surface runoff was a relatively minor contributor of N to surface water, even for plots receiving high rates of fertiliser N and at a stocking rate of 3.0 cows/ha. Extrapolating these results to a 'typical' dairy pasture in Eastern Southland would suggest that the safe upper limit for annual fertiliser N additions to this site to achieve nitrate in drainage water below the drinking water standard is approximately 170 kg N/ha. Although losses of Ca in drainage were large, returns of this nutrient in maintenance applications of superphosphate-based products and lime should ensure Ca deficiencies are avoided in Southland dairy pastures. Keywords: cation-anion balances, dairy, N fertiliser, nitrate leaching, surface runoff, Southland

scholarly journals Nitrogen losses from grazed dairy pasture, as affected by nitrogen fertiliser application

1995 ◽  
pp. 21-25
Author(s):  
S.F. Ledgard ◽  
D.A. Clark ◽  
M.S. Sprosen ◽  
G.J. Brier ◽  
E.K.K. Nemaia
Keyword(s):  
Soil Depth ◽  
Major Effect ◽  
N Fixation ◽  
Ammonia Loss ◽  
N Losses ◽  
Nitrogen Fertiliser ◽  
Nitrate N ◽  
N Treatment ◽  
Fertiliser Application ◽  
Over Time

Abstract Inputs and losses of nitrogen (N) were determined in dairy farmlets receiving nominally 0, 200 or 400 kg N/ha/yr as urea at Dairying Research Corporation No. 2 dairy, Hamilton. In year 1, N, fixation by white clover was estimated by r5N dilution at 212, 165 and 74 kg N/ha/yr in the 0, 200 and 400 N treatments respectively. Removal of N in milk was 76, 89 and 92 kg N/ha in the 0, 200 and 400 N farmlets respectively. Loss of N into the air by denitrification was low (6-15 kg N/ha/yr), and increased with N application. Ammonia loss into the air was estimated by micrometeorological mass balance at 15, 45 and 63 kg Nlhalyr in the 0, 200 and 400 N treatments respectively. Most of the increase in ammonia loss was attributed to direct loss after fertiliser application. Leaching of nitrate was estimated using ceramic cup samplers at 1 m soil depth, in conjunction with lysimeters, to be 74, 101 and 204 kg NlhaJyr during the second winter when rainfall and drainage (55@-620 mm) were relatively high. Nitrate-N concentrations in leachates increased gradually over time in the 400 N treatment to an average of 37 mg/l during the second winter, whereas the corresponding values for the 0 and 200 N treatments were 12 and 18 mg/l. Preliminary measurements of groundwater suggest that :ihe nitrate-N concentration is increasing under the 400 N farmlet relative to the other two farmlets. Thus, the 400 N treatment had a major effect by greatly reducing N, fixation and increasing N losses, whereas the 200 N treatment had relatively little effect on N, fixation or on nitrate leaching. However, these results refer to the first 18 months of the trial and further measurements are required over time to determine the longer-term effects of these treatments, particularly on nitrate levels in groundwater. Keywords: ammonia loss, dairying, denitrification, groundwater, leaching, nitrogen fertiliser, N, fixation

scholarly journals Comparing Nitrate-N Losses through Leaching by Field Measurements and Nitrogen Balance Estimations

2015 ◽  
Vol 46 (10) ◽  
pp. 1229-1243 ◽  
Author(s):  
Virginia Aparicio ◽  
José Luis Costa ◽  
Hernán Sainz Rozas ◽  
Daniel Gimenez ◽  
Fernando García
Keyword(s):  
Nitrogen Balance ◽  
Field Measurements ◽  
N Losses ◽  
Nitrate N

scholarly journals Effectiveness of Nutrient Management on Water Quality Improvement: A Synthesis on Nitrate-Nitrogen Loss from Subsurface Drainage

2021 ◽  
Vol 64 (2) ◽  
pp. 675-689
Author(s):  
Wenlong Liu ◽  
Yongping Yuan ◽  
Lydia Koropeckyj-Cox
Keyword(s):  
Water Quality ◽  
Nutrient Management ◽  
Fertilizer Application ◽  
Organic Fertilizers ◽  
Corn Yield ◽  
Fertilizer Rate ◽  
N Losses ◽  
Nitrate N ◽  
Management Plans ◽  
Fertilizer Rates

HighlightsFertilizer rate was found to be the most important factor controlling flow-weighted nitrate-N concentrations.Organic fertilizer may significantly increase nitrate-N losses, but N content of manures can be variable.We did not find significant differences in nitrate-N export among fertilizer application methods or timing.Split fertilization reduced nitrate-N export at lower fertilizer rates (<167 kg N ha-1) but not at higher rates.Fertilizer N recommendations need re-evaluation to consider both environmental and economic effects.Abstract. Nutrient management, as described in NRCS Code 590, has been intensively investigated, with research largely focused on crop yields and water quality. Yet, due to complex processes and mechanisms in nutrient cycling (especially the nitrogen (N) cycle), there are many challenges in evaluating the effectiveness of nutrient management practices across site conditions. We therefore synthesized data from peer-reviewed publications on subsurface-drained agricultural fields in the Midwest U.S. with corn yield and drainage nitrate-N (NO3-N) export data published from 1980 to 2019. Through literature screening and data extraction from 43 publications, we obtained 577 site-years of data with detailed information on fertilization, corn yields, precipitation, drainage volume, and drainage NO3-N load/concentration or both. In addition, we estimated flow-weighted NO3-N concentrations ([NO3-N]) in drainage for those site-years where only load and volume were reported. Furthermore, we conducted a cost analysis using synthesized and surveyed corn yield data to evaluate the cost-effectiveness of different nutrient management plans. Results from the synthesis showed that N fertilizer rate was strongly positively correlated with corn yields, NO3-N loads, and flow-weighted [NO3-N]. Reducing N fertilizer rates can effectively mitigate NO3-N losses from agricultural fields; however, our cost analysis showed negative economic returns for continuous corn production at lower N rates. In addition, organic fertilizers significantly boosted corn yields and NO3-N losses compared to inorganic fertilizers at comparable rates; however, accurate quantification of plant-available N in organic fertilizers is necessary to guide appropriate nutrient management plans because the nutrient content may be highly variable. In terms of fertilizer application methods, we did not find significant differences in NO3-N export in drainage discharge. Lastly, impact of fertilization timing on NO3-N export varied depending on other factors such as fertilizer rate, source, and weather. According to these results, we suggest that further efforts are still required to produce effective local nutrient management plans. Furthermore, government agencies such as USDA-NRCS need to work with other agencies such as USEPA to address the potential economic losses due to implementation of lower fertilizer rates for water quality improvement. Keywords: Conservation practice, Corn yields, Cost-effectiveness, NO3-N loss, Nutrient management, Subsurface drainage, Midwest U.S.

Effects of fertilizer timing and variable rate N on nitrate–N losses from a tile drained corn-soybean rotation simulated using DRAINMOD-NII

2019 ◽  
Vol 21 (2) ◽  
pp. 311-323 ◽  
Author(s):  
Grace L. Wilson ◽  
David J. Mulla ◽  
Jake Galzki ◽  
Aicam Laacouri ◽  
Jeff Vetsch ◽  
...  
Keyword(s):  
Variable Rate ◽  
N Losses ◽  
Nitrate N
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