Impact of biogas digestate typology on nutrient recovery for plant - PowerPoint PPT Presentation

Impact of biogas digestate typology on nutrient recovery for plant growth: accessibility indicators for fertilization J. JIMENEZ *, M. GRIGATTI ** , D. PATUREAU*, prediction N. BERNET * * LBE, Univ Montpellier, INRA, 102 avenue des Etangs, 11100, Narbonne, France ** Department of Agricultural and Food Sciences, Alma Mater Studiorum, University of Bologna, Bologna, Italy

« Reverse engeneering» concept Environmental Environment water – constraints air – soil Environment Organic residues Targeted al Biorefjnery services CH 4 Compromi se manageme nt Several proces Input ses managem soil & plant ent Process and conditions Typology Needs of .02 Treatment train quality / the conception safety agrosyste

Anaerobic digestion: energy and agronomical value Biogas CH 4 +CO 2 +H 2 +H 2 O+ NH 3 +H 2 S Biodegradable OM NH4 (sugars, lipids, proteins) Microorganisms OM Biodegradable OM NH4 Water Water No biodegradable MO No biodegradable MO (lignin, complex (lignin, complex proteins, …) proteins, …) Mineral Mineral (P, K, µlements) (P, K, µlements Substrate, raw matter Anaerobic Raw digestate digestion .03

Anaerobic digestion: agronomical value NH4 Microorganisms OM Biodegradable OM Water No biodegradable MO (lignin, complex proteins, …) Mineral (P, K, µlements Raw digestate All the ingredients are present! State? Availability, accessibility? Stability? Toxicity? Environment efgects? .04

Digestates quality variability .05 Guilayn et al. (2019). Valorization of non-agricultural digestates: a review for achieving added-value products.

Questions and strategy proposed Focus on biogas digestates agronomic value…. • Digestates are able to substitute all or in part N and P chemical fertilizers:  Is it possible to fjnd some characterization indicators to predict N and P availability on soil?  Has the typology of digestates an impact on N and P availability for soil and plants? How? • Strategy proposed:  Perform soil incubations and plant pot trials to better understand the digestates N and P fate after land spreading  Apply existing chemical accessibility characterization to digestates: N and P speciation  Use digestates sample from difgerent typologies .06

Material and Methods Digestates samples choice Name Origin Digestates typology by Guilayn et Agri_1 Dry batch AD of cow manure al. (2019) Agri_2 Liquid AD of pig manure Agri_3 Dry Batch AD of wheat straw Sludge_1 Liquid AD of wastewater sludge Sludge_2 Compost of digestate FFMSW_1 Dry AD of municipal wastes FFMSW_2 Compost of dry continuous AD of municipal wastes BW_1 Liquid AD of biowastes Centr_1 Liquid phase of a AD of centralised (mainly agro-industrial substrate) Centr_2 Solid phase of a AD of centralised (mainly agro-industrial substrate) as D1, D2, BD: Data from Grigatti et al. 2019 -> P .07 Guilayn et al. (2019). Valorization of non-agricultural digestates: a review for achieving added-value products Grigatti et al. (2019) Organic wastes as alternative sources of phosphorus for plant nutrition in a calcareous soil

Material and Methods Global analysis : TS, VS, C, P (ICP), N ( N et C: elementary analysis) Accessibility characterization : N P SPOM: Available proteins and NH 4 Water-P: Available P + accessibility Deionized water, ambient T, x1 (24h) Deionized water +CaCl2 (10mM), T=30°C x2 (1h) Extraction power NaHCO3-P: labile P REOM: low bounded proteins NaHCO3 (0.5M), pH= 8.5, ambient T, x1 (24h) NaCl+NaOH (10mM), T=30°C x 4 (15min) NaOH-P: Metal bounded P SEOM: complex proteins and humic NaOH (0.1M), ambient T, x1 (24h) acids-like NaOH (1M), T=30°C x 4 (1h) HCl-P: Ca bounded P PEOM: non accessible N HCl (1M), ambient T, x1 (24h) H2SO4 (72%), T=30°C x 2 (3h) Successfully NEOM-P: non extractible P use for C and NEOM: non extractible N N Successfully bioaccessibili use for P ty in AD availability from .08 composts

Material and Methods Plant pot trials Soil Incubations • 250 g of soil in 3 replicates, 25°C; • 1 kg of each difgerent treated soil in 3 • Digestate/soil rate of 170 kg N ha -1 replicates. • Chemical reference Ctrl + : N (as • 0.8 g of seeds of Italian ryegrass NH 4 NO 3 ) and P and K (as KH 2 PO 4 ) (Lolium multifmorum subsp. Italicum), cv. Sprint • A non-treated soil Ctrl- • Harvest: ryegrass plants cut collected • Olsen-P : Soil samples collected at day: at 28, 56 and 84 days -> Shoots 0, 14, 28, 56, 84 and extracted with • 84 days: Roots 0.5 M NaHCO3 (pH 8.5), 30 min • Mineral N : Soil samples collected at • Analysis on plant tissues: days 0, 14, 28, 56 and 84 with 1M KCl DW (dry weight), P(ICP), N (elementar analysis) for 30 min .09 All the samples were freeze-dried and grounded at 1mm -> reduce the particle size efgect in the incubation and in plant growth experiments

Results Digestates characterization and variability .010

Results Digestates P and N speciation Water_i Water_org NaHCO3_i NaHCO3_org NaOH_i SPOM_NH4 SPOM_Norg REOM HCl_0.1 SEOM PEOM NEOM NaOH_org HCl_i HCl_org NEOM 100% 100% 90% 80% 80% 70% 60% 60% otal P (%TP) 50% %N 40% 40% 30% 20% 20% T 10% 0% 0% Agri_1 Agri_2 Agri_3 FFMSW_1 FFMSW_2 BW_1 Centr_1 Centr_2 Sludge_1 Sludge_2 Agri_1 Agri_2 Agri_3 Sludge_1 Sludge_2 FFMSW_1 FFMSW_2 BW_1 Centr_1 Centr_2 D1 D2 BD Grigatti et al. 2019 Difgerent patterns of speciation -> difgerent N and P recovery by plants? .011 Grigatti et al. (2019) Organic wastes as alternative sources of phosphorus for plant nutrition in a calcareous soil

Results Soil incubation: P evolution RPE (% of P_Ctrl+ ) Agri_1 Agri_2 Agri_3 Sludge_1 Sludge_2 FFMSW_1 FFMSW_2 BW_1 N_min (%N) Centr_1 Centr_2 Agri_1 Agri_2 Agri_3 100,00 35,00% Sludge_1 Sludge_2 FFMSW_1 FFMSW_2 BW_1 Centr_1 25,00% Centr_2 90,00 15,00% 80,00 5,00% -5,00% 70,00 -15,00% 60,00 -25,00% Immobilization: soil Relative Percent Extractable/Ctrl+ micro-organisms growth 50,00 -35,00% 0 10 20 30 40 50 60 70 80 90 40,00 days 0 10 20 30 40 50 days High Immobilization of N for soil Digestates treatment 50-90% of the microorganisms growth: freeze-dried Chemical P performance, poor fjxation -> samples use (a lot of available NH4 availability for plant! removed!) P fjxation occurs for Agri_1, 2 and 3 and FFMSW_1 Mineralized N correlated negatively with C/N and PEOM (N from holocellulose-like RPE and Organic Water-P correlated (r=- extraction) 0.68, p<0.05) .012 (r =-0.72, -0.58 respectively, p<0.05)

Results Plant pot tests: total biomass harvested (gDW) Shoots (gDW) Roots (g DW) 4,50 4,00 3,50 3,00 2,50 2,00 1,50 Low tissue: Agri_2, 1,00 FFMSW_2 0,50 close to ctrl- 0,00 High tissue: Centr_1, Ctrl+ Agri_1 Agri_2 Agri_3 Sludge_1 Sludge_2 FFMSW_1 FFMSW_2 BW_1 Centr_1 Centr_2 Ctrl- BW_1 .013 No signicifjcant difgerence on shoots and roots : Kruskal-Wallis test p=0.89 and 0.23 respectively

Results Apparent Recovery Fraction (ARF) ARF (%) = Plant pot tests: P on plant tissues 8% Roots_P (ARF %) Shoots_P (ARF%) Low values vs literature: average 41% 7% Careful: these tests are made on Total ARF (% of applied P) 6% freeze-dried samples-> ammonium impact! 5% 4% 3% 2% 1% 0% -1% NH4_raw digestate NH4_freeze-dried 100 Equivalent chemical nutrient: K_eq_P > 100%; except Agri-2- k_eq_N 90 (%) 5% 8% -4% 25% 25% 11% 11% 16% 15% 22% >35% 80 Centr_1>FFMSW_1> BW_1 > Sludge_1=Sludge_2> 70 Agri_1>Centr_2>Sludge_1>Sludge_2> Centr_2>BW_2> N-NH4 (g/kg TS) 60 Agri_3> FFMSW_2>Agri_2 Centr_1> FFMSW_1> 50 40 FFMSW_2>Agri_2 30 >Agri_1>Agri_3 20 10 0 Agri_1 Agri_2 Agri_3 Sludge_1 Sludge_2 FFSMW_1 FFMSW_2 BW_1 Centr_1 Centr_2 Plant growth was afgected by all the treatments for ARF_N only for shoots .014 (Kruskall-Willis, p < 0.021) Plant growth was afgected by all the treatments for ARF_P only for shoots (Kruskall- Willis, p=0.021)

Results Plant pot tests: correlations with P digestates characteristics Fibrous-like digestates Sludge digestate Intermediate and low ARF Sludge digestate compost Water-P digestates NaHCO3_org (r=0.62, p=0.025) Water-P (r=0.49, p=0.09) .015

Results Plant pot tests: correlations with N digestates characteristics Nitrates (r=0.72, p=0.017) SPOM_NH4 (r=0.61, p=0.062) SPOM_Norg (r = -0.59, p = 0.067) C/N (r=-0.82, p=0.004) This study Linear (This study) 0,2 Grigatti et al. data_digestate&composts 0,15 Shoots-N 0,1 f(x) = - 0,01x + 0,18 R² = 0,67 0,05 0 5 10 15 20 25 30 -0,05 -0,1 C/N .016

Take-home messages • N and P accessibility speciation of digestates vary  according substrates nature (typology)  have an impact on soil incubation and nutrient recovery  Are correlated to nutrient recovery by soil and plants! • Apparent nutrient recovery by plants  Shoots-P: correlated with Water-P (soluble and most available P)  Roots-P: correlated with organic NaHCO3-P (Olsen-P, labile P)  Shoots-N: correlated with C/N and PEOM-N (fjbrous characteristic)  Roots-N: correlated with SPOM-NH4 and Nitrates (soluble and most inorganic N) • Need to  validate this tendency  soil incubation with not prepared samples -> no evident conclusion for N plant recovery  Use the speciation to control fertilizers addition  Similar strategy for micropollutants (organic, biological, metals) and others negative parameters which have an impact on .017 environment