TY - JOUR

T1 - Ammonia volatilization after application of urea to winter wheat over 3 years affected by novel urease and nitrification inhibitors

AU - Ni, Kang

AU - Pacholski, Andreas Siegfried

AU - Kage, Henning

PY - 2014/12/1

Y1 - 2014/12/1

N2 - Ammonia emission from urea application negatively affects both environmental quality and human health, and so it is desirable to minimize nitrogen loss by ammonia volatilization and to improve nitrogen use efficiency. This field study aimed to assess the effects of recently introduced urease (N-(2-nitrophenyl) phosphoric triamide, 2-NPT) and nitrification inhibitors (mixture of dicyandiamide and 1H-1,2,4-triazol) on NH3 emissions following urea application as compared to calcium ammonium nitrate (CAN) in Northern Germany. The measurements were carried out in winter wheat (Triticum aestivum) in the years 2011–2013 covering in total 12 urea application dates. Urea was applied as unamended granulated urea, or combined with urease or nitrification inhibitor or with both inhibitors. Fertilizers were applied in multi-plot field trials with four replications and ammonia losses were measured simultaneously by a combination of a calibrated dynamic chamber and passive samplers. Application date strongly affected relative NH3 loss (% of applied N) due to seasonal variation of soil moisture, temperature, and rainfall. Initial soil moisture showed a strong effect on NH3 emission. Averaged over the three vegetation periods, relative NH3 losses from unamended urea amounted to 8%, with mean emissions of 5%, 4%, and 17% for split N applications in March, April, and early June, respectively. Compared with treatment without urease inhibitor, the urease inhibitor addition reduced emissions by 26–83%, resulting in emissions similar to that from CAN. Analyzing the total data set, no significant effect of the nitrification inhibitor on NH3 emission was observed while at specific applications significantly higher as well as lower emissions compared to unamended urea were detected. The results highlight that NH3 emissions after field application of urea are highly variable under north German climate conditions and simple emission factors should be reevaluated. Urease inhibitor and appropriate application timing are effective measures to reduce NH3 emission from field applied urea.

AB - Ammonia emission from urea application negatively affects both environmental quality and human health, and so it is desirable to minimize nitrogen loss by ammonia volatilization and to improve nitrogen use efficiency. This field study aimed to assess the effects of recently introduced urease (N-(2-nitrophenyl) phosphoric triamide, 2-NPT) and nitrification inhibitors (mixture of dicyandiamide and 1H-1,2,4-triazol) on NH3 emissions following urea application as compared to calcium ammonium nitrate (CAN) in Northern Germany. The measurements were carried out in winter wheat (Triticum aestivum) in the years 2011–2013 covering in total 12 urea application dates. Urea was applied as unamended granulated urea, or combined with urease or nitrification inhibitor or with both inhibitors. Fertilizers were applied in multi-plot field trials with four replications and ammonia losses were measured simultaneously by a combination of a calibrated dynamic chamber and passive samplers. Application date strongly affected relative NH3 loss (% of applied N) due to seasonal variation of soil moisture, temperature, and rainfall. Initial soil moisture showed a strong effect on NH3 emission. Averaged over the three vegetation periods, relative NH3 losses from unamended urea amounted to 8%, with mean emissions of 5%, 4%, and 17% for split N applications in March, April, and early June, respectively. Compared with treatment without urease inhibitor, the urease inhibitor addition reduced emissions by 26–83%, resulting in emissions similar to that from CAN. Analyzing the total data set, no significant effect of the nitrification inhibitor on NH3 emission was observed while at specific applications significantly higher as well as lower emissions compared to unamended urea were detected. The results highlight that NH3 emissions after field application of urea are highly variable under north German climate conditions and simple emission factors should be reevaluated. Urease inhibitor and appropriate application timing are effective measures to reduce NH3 emission from field applied urea.

KW - Ecosystems Research

KW - ammonia

KW - calibration

KW - inhibitor

KW - nitrate

KW - nitrification

KW - nutrient use efficiency

KW - seasonal variation

KW - soil moisture

KW - volatilization

UR - http://www.scopus.com/inward/record.url?scp=84907375116&partnerID=8YFLogxK

U2 - 10.1016/j.agee.2014.08.007

DO - 10.1016/j.agee.2014.08.007

M3 - Journal articles

VL - 197

SP - 184

EP - 194

JO - Agriculture, Ecosystems and Environment

JF - Agriculture, Ecosystems and Environment

SN - 0167-8809

ER -