DOI: 10.5285/836dfb2e-bc6f-47d2-b924-8261be671391
title: Greenhouse gas emissions, nitrogen use efficiency and biomass from digestate experiments on winter wheat at North Wyke and Henfaes, UK (2017)

description: The data contains nitrogen (N) offtake, N emissions (ammonia and nitrous oxide), soil parameters (pH, EC, NH4+, NO3−), biomass and grain production from a winter wheat field experiment located at Bangor University (Henfaes Research Station in North Wales) and Rothamsted Research (North Wyke (NW) in Devon). Data were collected between  April 2017 and August 2017. Measurements and soil and plant samples were taken from 45 plots in a randomized complete block design. Sixteen extra mini-plots at the prevailing wind (south westerly) edge of the experiment site were used at NW for NH3 volatilization measurements. The treatments were control (C, without N application), food based digestate (D), food based digestate + the nitrification inhibitor 3,4-dimethylpyrazole (DMPP; D+NI), acidified food based digestate (AD), acidified food based digestate + the nitrification inhibitor 3,4-dimethylpyrazole (DMPP; AD+NI). Four rates of ammonium nitrate (NH4NO3; 75, 150, 225 and 300 kg N ha−1)  were applied to compare yields and fertilizer replacement rate of the digestate treatments (targeted at 190 kg N  ha−1). Soil pH, soil electrical conductivity (EC), soil NH4+ and soil NO3−, NH3 volatilization, N2O emissions were measured periodically for C, D, D+NI, AD and AD+NI and nitrogen concentration in grain and straw, grain yield and plant biomass for all treatments.

Nitrogen offtake, losses and fluxes were used to determine the N use efficiency (NUE) and fertilizer replacement rate of the digestate treatments.

Measurements were undertaken by members of staff from Bangor University, School of Environment, Natural Resources & Geography and Rothamsted Research, Sustainable Agricultural Sciences – North Wyke.

Data was collected for the Newton Fund project “UK-China Virtual Joint Centre for Improved Nitrogen Agronomy”. Funded by Biotechnology and Biological Sciences Research Council (BBSRC) and NERC -  Ref BB/N013468/1
description: Cumulative ammonia (NH3) emissions were measured using a wind tunnel technique (with 0.02 M H3PO4 acid traps) at a daily resolution for seven days following digestate application, except the first day where NH3 volatilization was measured twice at Henfaes Farm and three times at North Wyke.

Nitrous oxide emissions were measured using a combination of static manual and static automatic (combined with an Isotopic  Nitrous Oxide (N2O) Analyser, Los Gatos Research Inc. San Jose, CA, USA) chambers at Henfaes Farm, and only static manual chambers at North Wyke. Using the manual static chambers, the resolution of Nitrous Oxide (N2O) measurements following Nitrogen (N) fertiliser application was 3 x weekly for weeks 1 and 2, 2 x weekly for weeks 3 and 4, and 1 x weekly thereafter. Using the automatic static chambers, the resolution of N2O measurements following N fertiliser application was approximately every six hours.

Samples for soil ammonium (NH4+) and nitrate (NO3−) analyses were collected at the same temporal resolution as the N2O sampling using manual static chambers.

Winter wheat yield and biomass measurements were done the day of harvest (fresh weight) and subsamples were used to determine grass and grain moisture after 24 hours at 80 degrees Celsius.

All results were entered into Excel spreadsheets providing individual datasets for each set of N parameters. Data were exported from Excel as .csv files for ingestion into the EIDC.