public read uid=labadz,o=unaffiliated,dc=ecoinformatics,dc=org read uid=datalibrarian,o=unaffiliated,dc=ecoinformatics,dc=org all Dr. Weijin Wang Department of Environment and Resource Management Soil Scientist

GPO Box 2454 Brisbane Queensland 4001 Australia

+61 7 3170 5768 +61 7 3170 5801 weijin.wang@derm.qld.gov.au http://www.derm.qld.gov.au Dr. Barry Salter BSES Ltd Agronomist

26135 Peak Downs Highway Te Kowai Queensland 4741 Australia

+61 (7) 4963 6802 +61 (7) 4954 5167 bsalter@bses.com.au http://www.bses.org.au Field experiment maintenance and data collection Ms. Siobhann McCafferty Institute for Future Environments, Queensland University of Technology Data Librarian

2 George Street Brisbane QLD 4001 Australia

+61 7 3138 0457 siobhann.mccafferty@qut.edu.au Custodian/Steward Australian sugarcane soils generally receive large amounts of N fertiliser each year, ranging from 120 to 200 kg N/ha. In combination with the wet and warm climate and cane trash retention on the soil surface, these soils provide exceptional conditions that favour N2O production. However, the contribution from the Australian sugar industry to the national greenhouse budget remains unclear due to inadequate year-long measurements with continuous or reasonably intensive sampling. There is a need to investigate effective management practices to reduce the greenhouse signature from sugar industry. Recently, grain legume crop rotation and green cane trash blanketing have been considered promising management practices that can reduce the costs associated with fertiliser application and improve soil health and fertility. As legumes fix N from the atmosphere and supply N to the succeeding crop, the rate of fertiliser N application under legume rotation is generally much lower than under continuous sugarcane cropping. The effect of displacement of fertiliser N by biologically fixed N on greenhouse gas emissions associated with sugarcane farming remains to be investigated. In addition, many studies in temperate regions have shown that application of nitrification inhibitor into NH4+-type fertilisers and urea could reduce N2O emissions from N fertiliser by up to 50-60%. However, their effectiveness can be affected by soil temperature and biochemical properties, and field assessment in tropical and subtropical sugarcane farming systems are required. In this study, N2O emissions from a representative sugarcane farm (near Mackay) are measured over 3 years using automatic and manual chambers. The objectives of this study are to: (i) quantify annual N2O emissions from normal sugarcane farming under green cane trash blanketing; (ii) determine whether use of leguminou rotation crops or application of nitrification inhibitor can reduce greenhouse gas emissions; and (iii) improve understanding of the key factors that control N2O emissions from sugarcane soil. N2O Nitrous oxide Methane Greenhouse gas emissions Soybean Legume rotation Green cane trash blanketing Nitrification inhibitors Sugarcane Mackay QLD 0502 0799 0701 anzsrc-for 2009-12-11 2012-12-11 Mackay, Queensland 149.19 149.19 -21.14 -21.14 1310358396942

(1) Bare fallow - sugarcane + no fertiliser N (control). (2) Bare fallow - sugarcane + 150 kg N/ha as urea. (3) Bare fallow - sugarcane + 150 kg N/ha as urea with a nitrification inhibitor DMPP. (4) Soybean fallow - sugarcane + no fertiliser N. (5) Soybean fallow - sugarcane + 75 kg N/ha as urea.

Automated gas sampling chambers (50 cm L * 50 cm W). Manual gas sampling chambers (50 cm L * 50 cm W). The treatments are arranged in a randomised block design with 4 replicates. Each plot measures 20 m L * 14.4 m W. Greenhouse gas fluxes are measured during a fallow period (bare fallow vs. soybean ley) and the first 2 years following sugarcane planting. The automatic gas sampling system measures greenhouse gas fluxes every 2.5 hour. Manual gas samples are taken on 2-3 days per week. The automatic gas sampling system delivers gas samples to an on-site GC and N2O, CO2 and CH4 concentrations are analysed automatically. Gas samples taken with the manual chamber method were stored in sealed glass vials and analysed in laboratory with a GC equiped with TCD, FID and ECD for determination of CO2, CH4 and N2O concentrations, respectively.. MKY_N2O_manual_daily_mean_and_SE_N2O_flux.csv Mean daily Nitrous oxide flux from Sugarcane crop in Mackay, QLD. Using manual chamber method. MKY_N2O_manual_daily_mean_and_SE_N2O_flux.csv 13513 1 #x0A column ,u ecogrid://knb/wang.5.1 Date Date DD/MM/YYYY 0 Fallow_mean_g N2O-N/ha/d Daily N2O flux as g N2O-N/ha/day from "bare fallow - sugarcane + no fertiliser N (control)" treatment. Value is mean of four replicates. N2O-N grams per hectare per day natural Soybean_mean_g N2O-N/ha/d Daily N2O flux as g N2O-N/ha/day from "soybean fallow - sugarcane + no fertiliser N" treatment. Value is mean of four replicates. N2O-N grams per hectare per day natural 150N_mean_g N2O-N/ha/d Daily N2O flux as g N2O-N/ha/day from "Bare fallow - sugarcane + 150 kg N/ha as urea" treatment. Value is mean of four replicates. N2O-N grams per hectare per day natural 150N+inhib_mean_g N2O-N/ha/d Daily N2O flux as g N2O-N/ha/day from "bare fallow - sugarcane + 150 kg N/ha as urea with a nitrification inhibitor DMPP" treatment. Value is mean of four replicates. N2O-N grams per hectare per day natural soybean+75N_mean_g N2O-N/ha/d Daily N2O flux as g N2O-N/ha/day from "soybean fallow - sugarcane + 75 kg N/ha as urea" treatment. Value is mean of four replicates. N2O-N grams per hectare per day natural Fallow_SE Standard error of "bare fallow - sugarcane + no fertiliser N (control)" treatment. Value is calculated from four replicates. N2O-N grams per hectare per day natural Soybean_SE Standard error of "soybean fallow - sugarcane + no fertiliser N" treatment. Value calculated from four replicates. N2O-N grams per hectare per day natural 150N_SE Standard error of "bare fallow - sugarcane + 150 kg N/ha as urea" treatment. Value is calculated from four replicates. N2O-N grams per hectare per day natural 150N+inhib_SE Standard error of "bare fallow - sugarcane + 150 kg N/ha as urea with a nitrification inhibitor DMPP" treatment. Value calculated from four replicates. N2O-N grams per hectare per day natural soybean+75N_SE Standard error of "soybean fallow - sugarcane + 75 kg N/ha as urea" treatment. Value is calculated from four replicates. N2O-N grams per hectare per day natural 144 MKY_N2O_daily_max_min_temp_and_rainfall.csv Daily mean maximum and minimum temperature and daily rainfall MKY_N2O_daily_max_min_temp_and_rainfall.csv 14850 1 #x0A column , ecogrid://knb/wang.7.1 uid=labadz,o=unaffiliated,dc=ecoinformatics,dc=org read uid=datalibrarian,o=unaffiliated,dc=ecoinformatics,dc=org all Date Date measurement recorded DD/MM/YYYY 0 Minimum temperature (°C) Daily minimum temperature celsius natural Maximum temperature (°C) Daily maximum temperature celsius natural Rainfall (mm) Total daily rainfall to 9am millimetres natural 608 MKY_N2O_daily_mean_WFPS.csv Daily mean water filled pore space MKY_N2O_daily_mean_WFPS.csv 19502 1 #x0A column , ecogrid://knb/wang.8.1 uid=labadz,o=unaffiliated,dc=ecoinformatics,dc=org read uid=grace,o=unaffiliated,dc=ecoinformatics,dc=org read uid=datalibrarian,o=unaffiliated,dc=ecoinformatics,dc=org all Date Date measurement recorded DD/MM/YYYY 0 Fallow_mound Daily mean water filled pore space on the bed in the Fallow treatment. percentage natural Fallow_furrow Daily mean water filled pore space on the furrow in the Fallow treatment. percentage natural Soybean_mound Daily mean water filled pore space on the bed in the Soybean treatment. percentage natural Soybean_furrow Daily mean water filled pore space on the furrow in the Soybean treatment. percentage natural 348 MKY_N2O_auto_daily_mean_and_SE_N2O_flux.csv Daily nitrous oxide flux mean and standard error from automatic chambers MKY_N2O_auto_daily_mean_and_SE_N2O_flux.csv 24579 1 #x0A column , ecogrid://knb/wang.10.1 uid=labadz,o=unaffiliated,dc=ecoinformatics,dc=org read uid=grace,o=unaffiliated,dc=ecoinformatics,dc=org read uid=datalibrarian,o=unaffiliated,dc=ecoinformatics,dc=org all data_obtained Whether data was obtained from automatic chambers or from manual chambers, when the automatic sampler was broken. Auto data obtained from automatic chambers manual datqa obtained from manual chambers Date Date data was recorded DD/MM/YYYY 0 Fallow_sugarcane_mean_N2O-N g/ha/d Daily mean nitrous oxide flux for the fallow sugarcane treatment. Calculated from four replicates, two chambers on the bed and two in the furrow. N2O-N grams per hectare per day natural Fallow_sugarcane_SE Standard error of daily nitrous oxide flux for the fallow sugarcane treatment. Calculated from four replicates, two chambers on the bed and two in the furrow. N2O-N grams per hectare per day natural Soybean_sugarcane_mean_N2O-N g/ha/d Daily mean nitrous oxide flux for the soybean sugarcane treatment. Calculated from five replicates, three chambers on the bed and two in the furrow N2O-N grams per hectare per day natural Soybean+sugarcane_SE Standard error of daily nitrous oxide flux for the soybean sugarcane treatment. Calculated from five replicates, three chambers on the bed and two in the furrow. N2O-N grams per hectare per day natural Fallow_sugarcane+150N_mean_N2O-N g/ha/d Daily mean nitrous oxide flux for the fallow sugarcane + 150 N kg/ha treatment. Calculated from four replicates, two chambers on the bed and two in the furrow. N2O-N grams per hectare per day natural Fallow_sugarcane+150N_SE Standard error of daily nitrous oxide flux for the fallow sugarcane + 150 N kg/ha treatment. Calculated from four replicates, two chambers on the bed and two in the furrow. N2O-N grams per hectare per day natural Soybean_sugarcane+75N_mean_N2O-N g/ha/d Daily mean nitrous oxide flux for the soybean sugarcane + 75 N kg/N/ha treatment. Calculated from five replicates, three chambers on the bed and two in the furrow N2O-N grams per hectare per day natural Soybean_sugarcane+75N_SE Standard error of daily nitrous oxide flux for the soybean sugarcane + 75 N kg/ha treatment. Calculated from five replicates, three chambers on the bed and two in the furrow. N2O-N grams per hectare per day natural 403 MKY_N2O_soil_Nmin_0-30cm.csv Mineral nitrogen (kg N/ha) in the top 0-30cm depth of soil MKY_N2O_soil_Nmin_0-30cm.csv 659 1 #x0A column , ecogrid://knb/wang.11.1 uid=labadz,o=unaffiliated,dc=ecoinformatics,dc=org read uid=grace,o=unaffiliated,dc=ecoinformatics,dc=org read uid=datalibrarian,o=unaffiliated,dc=ecoinformatics,dc=org all Date Date soil was sampled DD/MM/YYYY 0 Fallow Mean kilograms of nitrogen per hectare in the 0-30cm depth of soil for the fallow treatment. Calculated from 8 replicates. kilogramsNitrogenperhectare natural Fallow_SE Standard error of the mean kilograms of nitrogen per hectare in the 0-30cm depth of soil for the fallow treatment. Calculated from 8 replicates. kilogramsNitrogenperhectare natural Soybean Mean kilograms of nitrogen per hectare in the 0-30cm depth of soil for the soybean treatment. Calculated from 8 replicates. kilogramsNitrogenperhectare natural Soybean_SE Standard error of the mean kilograms of nitrogen per hectare in the 0-30cm depth of soil for the soybean treatment. Calculated from 8 replicates. kilogramsNitrogenperhectare natural 150 kg N Mean kilograms of nitrogen per hectare in the 0-30cm depth of soil for the 150 kg N/ha treatment. Calculated from 8 replicates. kilogramsNitrogenperhectare natural 150 kg N_SE Standard error of the mean kilograms of nitrogen per hectare in the 0-30cm depth of soil for the 150 kg N/ha treatment. Calculated from 8 replicates. kilogramsNitrogenperhectare natural 150 kg N + DMPP Mean kilograms of nitrogen per hectare in the 0-30cm depth of soil for the 150 kg N/ha with nitrification inhibitor treatment. Calculated from 8 replicates. kilogramsNitrogenperhectare natural 150 kg N + DMPP_SE Standard error of the mean kilograms of nitrogen per hectare in the 0-30cm depth of soil for the 150 kg N/ha with nitrification inhibitor treatment. Calculated from 8 replicates. kilogramsNitrogenperhectare natural Soybean + 75 kg N Mean kilograms of nitrogen per hectare in the 0-30cm depth of soil for the soybean with 75 kg N/ha treatment. Calculated from 8 replicates. kilogramsNitrogenperhectare natural Soybean + 75 kg N_SE Standard error of the mean kilograms of nitrogen per hectare in the 0-30cm depth of soil for the soybean with 75 kg N/ha treatment. Calculated from 8 replicates. kilogramsNitrogenperhectare natural 12 MKY_N2O_Soybean_biomass.csv Biomass of soybean crop sampled on 12/4/2010. Three 1 metre sections were hand harvested from each plot. MKY_N2O_Soybean_biomass.csv 213 1 #x0A column , ecogrid://knb/wang.13.1 uid=labadz,o=unaffiliated,dc=ecoinformatics,dc=org read uid=grace,o=unaffiliated,dc=ecoinformatics,dc=org read uid=datalibrarian,o=unaffiliated,dc=ecoinformatics,dc=org all Treatment Treatment Sampled Soybean fallow - sugarcane + no fertiliser N Soybean fallow - sugarcane + no fertiliser N Soybean fallow - sugarcane + 75 kg N/ha as urea Soybean fallow - sugarcane + 75 kg N/ha as urea Mean dry weight (t/ha) Mean dry weight (t/ha). Oven dried at 60 degrees celcius. Calculated from 11 values. tonnePerHectare natural Standard error of dry weight (t/ha) Standard error of the mean dry weight (t/ha). Calculated from 11 values. tonnePerHectare natural 2 MKY_N2O_Soybean_yield.csv Soybean yield (t/ha). Harvested 25/5/2010. Four 1 metre sections harvested per plot. MKY_N2O_Soybean_yield.csv 240 1 #x0A column , ecogrid://knb/wang.14.1 uid=labadz,o=unaffiliated,dc=ecoinformatics,dc=org read uid=grace,o=unaffiliated,dc=ecoinformatics,dc=org read uid=datalibrarian,o=unaffiliated,dc=ecoinformatics,dc=org all Treatment Treatment sampled Soybean fallow - sugarcane + no fertiliser N Soybean fallow - sugarcane + no fertiliser N Soybean fallow - sugarcane + 75 kg N/ha as urea Soybean fallow - sugarcane + 75 kg N/ha as urea Mean soybean yield dry weight (t/ha) Mean Soybean yield (t/ha). Calculated from 16 values. tonnePerHectare natural Standard Error of Soybean yield Dry weight (t/ha) Standard error of soybean yield (t/ha). Calculated from 16 values. tonnePerHectare natural 2 MKY_N2O_Sugarcane_yield.csv Sugarcane yield harvested on 18/7/2011. 2 full undisturbed rows per plot harvested to calculate yield. MKY_N2O_Sugarcane_yield.csv 375 1 #x0A column , ecogrid://knb/wang.15.1 uid=grace,o=unaffiliated,dc=ecoinformatics,dc=org read uid=labadz,o=unaffiliated,dc=ecoinformatics,dc=org read uid=datalibrarian,o=unaffiliated,dc=ecoinformatics,dc=org all treatment Treatment sampled Bare fallow - sugarcane + no fertiliser N (control) Bare fallow - sugarcane + no fertiliser N (control) Bare fallow - sugarcane + 150 kg N/ha as urea Bare fallow - sugarcane + 150 kg N/ha as urea Bare fallow - sugarcane + 150 kg N/ha as urea with a nitrification inhibitor DMPP Bare fallow - sugarcane + 150 kg N/ha as urea with a nitrification inhibitor DMPP Soybean fallow - sugarcane + no fertiliser N Soybean fallow - sugarcane + no fertiliser N Soybean fallow - sugarcane + 75 kg N/ha as urea Soybean fallow - sugarcane + 75 kg N/ha as urea cane yield t/ha Mean sugarcane yield (t/ha). Calculated from 8 values. tonnePerHectare natural cane yield SE Standard error of mean sugarcane yield (t/ha). Calculated from 8 values. tonnePerHectare natural 5 Daily N2O flux as g N2O-N/ha/day from fallow plots. Value is a mean of four replicates. millimetres percentage kilograms of nitrogen per hectare