Digestate Application on Grassland: Effects of Application Method and Rate on GHG Emissions and Forage Performance

The application of digestate as a fertilizer offers a promising alternative to synthetic inputs on permanent grasslands, with benefits for productivity and environmental performance. This four-year study evaluated the impact of two digestate application methods—disc injection (I) and band spreading...

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Main Authors: Petr Šařec, Václav Novák, Oldřich Látal, Martin Dědina, Jaroslav Korba
Format: Article
Language:English
Published: MDPI AG 2025-05-01
Series:Agronomy
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Online Access:https://www.mdpi.com/2073-4395/15/5/1243
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author Petr Šařec
Václav Novák
Oldřich Látal
Martin Dědina
Jaroslav Korba
author_facet Petr Šařec
Václav Novák
Oldřich Látal
Martin Dědina
Jaroslav Korba
author_sort Petr Šařec
collection DOAJ
description The application of digestate as a fertilizer offers a promising alternative to synthetic inputs on permanent grasslands, with benefits for productivity and environmental performance. This four-year study evaluated the impact of two digestate application methods—disc injection (I) and band spreading (S)—combined with four dose variants (0, 20, 40, and 80 m<sup>3</sup>·ha<sup>−1</sup>), including split-dose strategies. Emissions of ammonia (NH<sub>3</sub>), carbon dioxide (CO<sub>2</sub>), and methane (CH<sub>4</sub>) were measured using wind tunnel systems immediately after application. Vegetation status was assessed via Sentinel-2-derived Normalized Difference Vegetation Index, Normalized Difference Water Index, and Modified Soil Adjusted Vegetation Index, and agronomic performance through dry matter yield (DMY), net energy for lactation (NEL), and relative feed value (RFV). NH<sub>3</sub> and CO<sub>2</sub> emissions increased proportionally with digestate dose, while CH<sub>4</sub> responses suggested a threshold effect, but considering solely the disc injection, CH<sub>4</sub> flux did not increase markedly with higher application rates. Disc injection resulted in significantly lower emissions of the monitored fluxes than band spreading. The split-dose I_40+40 variant achieved the highest DMY (3.57 t·ha<sup>−1</sup>) and improved forage quality, as indicated by higher NEL values. The control variant (C, no fertilization) had the lowest yield and NEL. These results confirm that subsurface digestate incorporation in split doses can reduce emissions while supporting yield and forage quality. Based on the findings, disc injection at 40+40 m<sup>3</sup>·ha<sup>−1</sup> is recommended as an effective option for reducing emissions and maintaining productivity in managed grasslands.
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spelling doaj-art-8a7f06063d8a48b6b3d4393820c9ab7d2025-08-20T03:47:49ZengMDPI AGAgronomy2073-43952025-05-01155124310.3390/agronomy15051243Digestate Application on Grassland: Effects of Application Method and Rate on GHG Emissions and Forage PerformancePetr Šařec0Václav Novák1Oldřich Látal2Martin Dědina3Jaroslav Korba4Department of Machinery Utilization, Faculty of Engineering, Czech University of Life Sciences Prague, Kamycka 129, 165 00 Prague, Czech RepublicDepartment of Machinery Utilization, Faculty of Engineering, Czech University of Life Sciences Prague, Kamycka 129, 165 00 Prague, Czech RepublicAgrovyzkum Rapotin Ltd., Zemedelska 2520/16, 787 01 Sumperk, Czech RepublicCzech Agrifood Research Center, Drnovska 507/73, 161 06 Prague, Czech RepublicDepartment of Machinery Utilization, Faculty of Engineering, Czech University of Life Sciences Prague, Kamycka 129, 165 00 Prague, Czech RepublicThe application of digestate as a fertilizer offers a promising alternative to synthetic inputs on permanent grasslands, with benefits for productivity and environmental performance. This four-year study evaluated the impact of two digestate application methods—disc injection (I) and band spreading (S)—combined with four dose variants (0, 20, 40, and 80 m<sup>3</sup>·ha<sup>−1</sup>), including split-dose strategies. Emissions of ammonia (NH<sub>3</sub>), carbon dioxide (CO<sub>2</sub>), and methane (CH<sub>4</sub>) were measured using wind tunnel systems immediately after application. Vegetation status was assessed via Sentinel-2-derived Normalized Difference Vegetation Index, Normalized Difference Water Index, and Modified Soil Adjusted Vegetation Index, and agronomic performance through dry matter yield (DMY), net energy for lactation (NEL), and relative feed value (RFV). NH<sub>3</sub> and CO<sub>2</sub> emissions increased proportionally with digestate dose, while CH<sub>4</sub> responses suggested a threshold effect, but considering solely the disc injection, CH<sub>4</sub> flux did not increase markedly with higher application rates. Disc injection resulted in significantly lower emissions of the monitored fluxes than band spreading. The split-dose I_40+40 variant achieved the highest DMY (3.57 t·ha<sup>−1</sup>) and improved forage quality, as indicated by higher NEL values. The control variant (C, no fertilization) had the lowest yield and NEL. These results confirm that subsurface digestate incorporation in split doses can reduce emissions while supporting yield and forage quality. Based on the findings, disc injection at 40+40 m<sup>3</sup>·ha<sup>−1</sup> is recommended as an effective option for reducing emissions and maintaining productivity in managed grasslands.https://www.mdpi.com/2073-4395/15/5/1243ammoniadisc injectionband spreadingfluxremote sensing
spellingShingle Petr Šařec
Václav Novák
Oldřich Látal
Martin Dědina
Jaroslav Korba
Digestate Application on Grassland: Effects of Application Method and Rate on GHG Emissions and Forage Performance
Agronomy
ammonia
disc injection
band spreading
flux
remote sensing
title Digestate Application on Grassland: Effects of Application Method and Rate on GHG Emissions and Forage Performance
title_full Digestate Application on Grassland: Effects of Application Method and Rate on GHG Emissions and Forage Performance
title_fullStr Digestate Application on Grassland: Effects of Application Method and Rate on GHG Emissions and Forage Performance
title_full_unstemmed Digestate Application on Grassland: Effects of Application Method and Rate on GHG Emissions and Forage Performance
title_short Digestate Application on Grassland: Effects of Application Method and Rate on GHG Emissions and Forage Performance
title_sort digestate application on grassland effects of application method and rate on ghg emissions and forage performance
topic ammonia
disc injection
band spreading
flux
remote sensing
url https://www.mdpi.com/2073-4395/15/5/1243
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AT vaclavnovak digestateapplicationongrasslandeffectsofapplicationmethodandrateonghgemissionsandforageperformance
AT oldrichlatal digestateapplicationongrasslandeffectsofapplicationmethodandrateonghgemissionsandforageperformance
AT martindedina digestateapplicationongrasslandeffectsofapplicationmethodandrateonghgemissionsandforageperformance
AT jaroslavkorba digestateapplicationongrasslandeffectsofapplicationmethodandrateonghgemissionsandforageperformance