DOI: 10.5061/dryad.qv9s4mwn7
title: N2O and CO2 fluxes and related environmental conditions in response to manure and synthetic fertilization treatments, with and without a urease inhibitor

description: Agricultural best management practices (BMPs) intended to solve one
 environmental challenge may have unintended climate impacts. For example,
 manure injection is often promoted for its potential to reduce runoff and
 N loss as NH3, but the practice has been shown to increase N2O, a powerful
 GHG, compared to surface application. Urease inhibitor application with N
 fertilizer is another BMP that can enhance N retention by reducing NH3
 emissions, but its impact on N2O emissions is mixed. Thus, we measured
 N2O, CO2, soil mineral N availability, soil moisture, soil temperature,
 and yield in a two-year perennial hayfield trial with four fertilization
 treatments (manure injection, manure broadcast, synthetic urea, and
 control) applied with or without a urease inhibitor in Alburgh, VT (n=4
 treatment replicates; 32 total subplots). This dataset includes the daily
 N2O and CO2 fluxes in every subplot on each sampling day in our trial,
 along with cumulative emissions for 2020 and 2021. We also include the
 other variables that we measured (listed above) and relevant weather data
 (precipitation and air temperature). Note that during the second treatment
 application in 2021, the incorrect treatment was applied to one synthetic
 urea subplot. We therefore excluded this subplot from our analysis of
 daily fluxes after 30 July 2021 (n=3 synthetic urea replicates). Details
 about our sampling methods are available in the corresponding manuscript.
description: # N2O and CO2 fluxes and related environmental conditions in response to
 manure and synthetic fertilization treatments, with and without a urease
 inhibitor Agricultural
 best management practices (BMPs) intended to solve one environmental
 challenge may have unintended climate impacts. For example, manure
 injection is often promoted for its potential to reduce runoff and N loss
 as NH3, but the practice has been shown to increase N2O, a powerful GHG,
 compared to surface application. Urease inhibitor application with N
 fertilizer is another BMP that can enhance N retention by reducing NH3
 emissions, but its impact on N2O emissions is mixed. Thus, we measured
 N2O, CO2, soil mineral N availability, soil moisture, soil temperature,
 and yield in a two-year perennial hayfield trial with four fertilization
 treatments (manure injection, manure broadcast, synthetic urea, and
 control) applied with or without a urease inhibitor in Alburgh, VT (n=4
 treatment replicates; 32 total subplots). This dataset includes the daily
 N2O and CO2 fluxes in every subplot on each sampling day in our trial,
 along with cumulative emissions for 2020 and 2021. We also include the
 other variables that we measured (listed above) and relevant weather data
 (precipitation and air temperature). Note that during the second treatment
 application in 2021, the incorrect treatment was applied to one synthetic
 urea subplot. We therefore excluded this subplot from our analysis of
 daily fluxes after 30 July 2021 (n=3 synthetic urea replicates). Details
 about our sampling methods are available in the corresponding manuscript.
 ## Description of the data and file structure *NA stands for not
 available* * date: sampling date * plot: subplot number *  treatment:
 Treatment applied to the specified subplot. This references both the
 nitrogen source/application method (manure broadcast, manure injection,
 synthetic urea, and control) and whether urease inhibitor was applied with
 the main fertilization treatment (w/inhib if inhibitor was also applied) *
 inhib: none if urease inhibitor was not applied, inhib if urease inhibitor
 was applied * fert: nitrogen source/application method (Broadcast = manure
 broadcast; Fertilizer = synthetic urea; Inject = manure injection; and
 Control = no nitrogen applied) * dst: days since treatment application *
 kgCO2C_per_haday: daily CO2 fluxes (kg CO2-C ha-1 day-1) *
 gN2ON_per_haday: daily N2O fluxes (g N2O-N ha-1 day-1) * avgsoiltemp_C:
 soil temperature (°C) adjacent to the static gas sampling chamber at the
 time of sampling, averaged between two temperature measurements per
 subplot * mean_air_temp_C: for sampling dates in 2020, average air
 temperature (°C) is the average daily temperature at Borderview Research
 Farm, while for sampling dates in 2021, average air temperature (°C) is
 the average air temperature during the 45-minute gas flux sampling period
 for each subplot. (We measured N2O and CO2 fluxes using a photoactoustic
 gas monitor in 2020 and a gas chromatograph in 2021. During each sampling
 day in 2021, chamber lids were deployed on the static chambers for 45
 minutes, during which time gas samples were collected every 15 minutes,
 from 0 minutes to 45 minutes. Average air temperature during this
 45-minute period was used in the equation converting N2O and CO2 from a
 volume to mass basis [see “Materials and Methods” in main manuscript].) We
 only used average air temperature to calculate N2O and CO2 fluxes in 2021,
 because when using the photoacoustic gas monitor in 2020, the instrument
 automatically took air temperature into account when reporting on gas
 concentrations. * year: sampling year * precip_monthly_CM: monthly
 precipitation (cm) * precip_daily_DB: total daily precipitation (cm) the
 day before sampling * VWC: volumetric water content (%), averaged between
 two time domain reflectometry readings per subplot * mg_NO3_kg_soil: soil
 NO3- concentration (mg NO3-N kg dry soil-1) adjacent to the static gas
 sampling chamber at the time of sampling (soil sampling depth = 0-20 cm) *
 mg_NH4_kg_soil: soil NH4+ concentration (mg NH4-N kg dry soil-1) adjacent
 to the static gas sampling chamber at the time of sampling (soil sampling
 depth = 0-20 cm) * A note on the following columns: AUC stands for “area
 under the curve.” We calculated each annual measurement period’s
 cumulative values for N2O and CO2 emissions, soil temperature, soil
 moisture, soil NO3- concentration, and soil NH4+ concentration by
 integrating the area under the curve of the time series of daily values
 using the pracma package in RStudio (Borchers, 2022; RStudio Team, 2022).
 * no3.AUC: Cumulative soil NO3- concentration during each annual
 measurement period (14 Aug-16 Nov. 2020; 19 May-17 Nov. 2021). * nh4.AUC:
 Cumulative soil NH4+ concentration during each annual measurement period
 (14 Aug-16 Nov. 2020; 19 May-17 Nov. 2021). * co2.AUC: Cumulative CO2
 emissions during each annual measurement period (18 June-16 Nov. 2020; 19
 May-17 Nov. 2021) * n2o.AUC: Cumulative N2O emissions during each annual
 measurement period (18 June-16 Nov. 2020; 19 May-17 Nov. 2021) *
 soiltemp.AUC: Cumulative soil temperature during each annual measurement
 period (18 June-16 Nov. 2020; 19 May-17 Nov. 2021) * VWC.AUC: Cumulative
 volumetric water content during each annual measurement period (18 June-16
 Nov. 2020; 19 May-17 Nov. 2021) * precip.AUC: Cumulative precipitation
 (cm) during each annual measurement period (18 June-16 Nov. 2020; 19
 May-17 Nov. 2021) ## Code/Software All data analyses were conducted in R
 studio (RStudio Team, 2022) **References** Borchers, H.W. (2022). pracma:
 Practical Numerical Math Functions. R package version 2.3.8.
 RStudio Team. (2022).
 RStudio: Integrated Development Environment for R. RStudio, PBC, Boston,
 MA.