Towards efficient N cycling in intensive maize: role of cover crops and application methods of digestate liquid fraction
Data files
Sep 12, 2023 version files 40.48 KB
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DATASET.xlsx
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README.md
Abstract
Digestate, a by-product of biogas production, is widely recognized as a promising renewable nitrogen (N) source with high potential to replace synthetic fertilizers. Yet, inefficient digestate use can lead to pollutant N losses as ammonia (NH3) volatilization, nitrous oxide (N2O) emissions and nitrate (NO3-) leaching. Cover crops may reduce some of these N losses and recycle the N back into the soil after incorporation, but the net effect on the N balance depends on the cover crop species. In a one-year field study, we tested the effects of two application methods (i.e., surface broadcasting, BDC; and shallow injection, INJ) of the liquid fraction of separated co-digested cattle slurry (DLF), combined with different winter cover crop options (CCs, i.e., rye, white mustard or bare fallow), as starter fertilizer for maize. Later in the season, side-dressing with urea was required to fulfill maize N-requirements. We tested treatment effects on yield, N-uptake, N-use efficiency parameters, and N-losses in the form of N2O emissions and NO3- leaching. Cover crop development and biomass production were strongly affected by their contrasting frost tolerance, with spring-regrowth for rye, while mustard was winter killed. After the cover crops, injection of DLF increased N2O emissions significantly compared with BDC (emission factor of 2.69 vs. 1.66%). Nitrous oxide emissions accounted for a small part (11-13%) of the overall yield-scaled N losses (0.46 - 0.97 kg N Mg grain-1). The adoption of CCs reduced fall NO3- leaching, being 51% and 64% lower for mustard and rye than under bare soil. In addition, rye reduced NO3- leaching during spring and summer after termination by promoting N immobilization, thus leading to -57% lower annual leaching losses compared to mustard. Our study confirms the potential of CCs to reduce NO3- leaching, but it also highlights that their residue can increase N losses once terminated and that they may cause yield reductions. DLF application method modified N-loss pathways, but not the cumulative yield-scaled N losses. Overall, these insights contribute to inform an evidence-based design of cropping systems in which nutrients are recycled more efficiently.
README: Towards efficient N cycling in intensive maize: role of application method of digestate liquid fraction and cover crops
Author/Principal Investigator Information
Name: Federico Capra
ORCID:0000-0001-5034-0781
Institution: Catholic University of the Sacred Heart
Email:federico.capra@unicatt.it
Author/Associate or Co-investigator Information
Name: Andrea Fiorini
Institution: Catholic University of the Sacred Heart
Email: andrea.fiorini@unicatt.it
SHARING/ACCESS INFORMATION
Licenses/restrictions placed on the data:
None
Links to publications that cite or use the data:
Please see the publication associated with these data in GCB Bioenergy (doi: https://doi.org/10.1111/gcbb.13036)
DATA & FILE OVERVIEW
File List: DATASET
The worksheets
1 WINTER: data from "winter cover crops monitoring period" (from 6 October 2018 to 9 April 2019)
- PLOT the elementar plot (from 1 to 27)
- BLOCK the block (from 1 to 3)
- TH thesis (Bare soil, BS; Mustard, M and Rye, R)
- WFPS Water Filled Pore Space (weighted average for the monitoring period), %
- CCS_BIOM Cover crops DM production, Mg ha-1
- CCS_N Cover crops N content, g kg-1
- CCS_C Cover crops C content, g kg-1
- CCS_CN Cover crops C/N ratio
- CCS_NYIELD Cover crops N release, Mg ha-1
- CCS_CYIELD Cover crops C release, Mg ha-1
- NO3_up NO3-N content in the soil in the 0-10 cm layer (weighted average for the monitoring period), g kg-1
- NO3_down NO3-N content in the soil in the 10-30 cm layer (weighted average for the monitoring period), g kg-1
- NH4_up NH4-N content in the soil in the 0-10 cm layer (weighted average for the monitoring period), g kg-1
- NH4_down NH4-N content in the soil in the 10-30 cm layer (weighted average for the monitoring period), g kg-1
- N2O N2O-N cumulative emissions of winter monitoring period, kg ha-1
- NO3_leached NO3-N cumulative leaching losses of winter monitoring period, kg ha-1
2 DIGESTATE: data from "digestate monitoring period" (from 9 April 2019 to 12 June 2019)
- PLOT the elementar plot (from 1 to 27)
- BLOCK the block (from 1 to 3)
- TH thesis (Bare soill, Mustard and Rye). Those are the main-plots
- STH subthesis: DLF application method (Surface broadcast, BDC or shallow injection, INJ) plus unfertilized control (C). Those are the subplots
- SUBJECT a unique code to identify the main plots which represent the randomization factor in the mixed model analysis
- WFPS Water Filled Pore Space (weighted average for the monitoring period), %
- NO3_up NO3-N content in the soil in the 0-10 cm layer (weighted average for the monitoring period), g kg-1
- NO3_down NO3-N content in the soil in the 10-30 cm layer (weighted average for the monitoring period), g kg-1
- NH4_up NH4-N content in the soil in the 0-10 cm layer (weighted average for the monitoring period), g kg-1
- NH4_down NH4-N content in the soil in the 10-30 cm layer (weighted average for the monitoring period), g kg-1
- N2O N2O-N cumulative emissions of DLF monitoring period, kg ha-1
- NO3_leached NO3-N cumulative leaching losses of DLF monitoring period, kg ha-1
- NH3 cumulative NH3-N losses after digestate application, kg ha-1
3 UREA: data from "urea monitoring period" (from 12 June 2019 to 4 October 2019)
- PLOT the elementar plot (from 1 to 27)
- BLOCK the block (from 1 to 3)
- TH thesis (Bare soill, Mustard and Rye). Those are the main-plots
- STH subthesis: DLF application method (Surface broadcast, BDC or shallow injection, INJ) plus unfertilized control (C). Those are the subplots
- SUBJECT a unique code to identify the main plots which represent the randomization factor in the mixed model analysis
- WFPS Water Filled Pore Space (wheighted average for the monitoring period), %
- NO3_up NO3-N content in the soil in the 0-10 cm layer (weighted average for the monitoring period), g kg-1
- NO3_down NO3-N content in the soil in the 10-30 cm layer (weighted average for the monitoring period), g kg-1
- NH4_up NH4-N content in the soil in the 0-10 cm layer (weighted average for the monitoring period), g kg-1
- NH4_down NH4-N content in the soil in the 10-30 cm layer (weighted average for the monitoring period), g kg-1
- N2O N2O-N cumulative emissions of Urea monitoring period, kg ha-1
- NO3_leached NO3-N cumulative leaching losses of Urea monitoring periog, kg ha-1
- NH3 cumulative NH3-N losses after urea application, kg ha-1
4 YEAR: data from year-round monitoring (from 6 October 2018 to 4 October 2019)
- PLOT the elementar plot (from 1 to 27)
- BLOCK the block (from 1 to 3)
- TH thesis (Bare soill, Mustard and Rye). Those are the main-plots
- STH subthesis: DLF application method (Surface broadcast, BDC or shallow injection, INJ) plus unfertilized control (C). Those are the subplots
- SUBJECT a unique code to identify the main plots which represent the randomization factor in the mixed model analysis
- GRAINYIELD maize grain DM yield, Mg ha-1
- PLANTYIELD maiz biomass DM production, Mg ha-1
- NPLANT N uptake by maize plant, kg ha-1
- NGRAIN N uptake by maize grain, kg ha-1
- NTOT N uptake by maize plant plus grain, kg ha-1
- NUE Nitrgen Use Efficiency of maize crop, kg grain kg-1 N supply
- NUPE Nitrogen Uptake Efficiency, kg of total N uptake kg-1 N supply
- NUTE Nitrogen Utilization Efficiency, kg grain kg-1 total N uptake
- WFPS Water Filled Pore Space (wheighted average for the monitoring period), %
- NO3_up NO3-N content in the soil in the 0-10 cm layer (weighted average for year-round monitoring period), g kg-1
- NO3_down NO3-N content in the soil in the 10-30 cm layer (weighted average for year-round monitoring period), g kg-1
- NH4_up NH4-N content in the soil in the 0-10 cm layer (weighted average for year-round monitoring period), g kg-1
- NH4_down NH4-N content in the soil in the 10-30 cm layer (weighted average for year-round monitoring period), g kg-1
- N2O annual cumulative N2O-N emissions, kg ha-1
- EF_ANNUAL emission factor for N2O-N: annual N2O-N losses as % of applied N
- NO3_leached year-round cumulative NO3-N leaching losses, kg ha-1
- NH3 cumulative annual NH3-N losses, kg ha-1
- N_LOSSES annual cumulative N losses as sum of N2O-N + NH3-N + NO3-N
- YSC_NH3 yield-scaled NH3-N losses, kg N kg-1 grain
- YSC_N2O yield-scaled N2O-N losses, kg N kg-1 grain
- YSC_NO3 yield-scaled NO3-N losses, kg N kg-1 grain
- YSC_NTOT cumulative yield-scaled N-losses, kg N kg-1 grain