CRUCIAL: a long-term field trial to assess waste recycling impacts on environment and production system integrity

Transcription

1 CRUCIAL: a long-term field trial to assess waste recycling impacts on environment and production system integrity Jakob Magid 1, Pernille Poulsen 1, Jonas Stevens Lekfeldt 1, Kristian Kofoed Brandt 1, Ole Nybroe 1, Peter Engelund Holm 2, Charlotte Kjærgaard 3, Lars Stoumann Jensen 1 1 Dept of Agriculture and Ecology, 2 Dept of Basic Science and the Environment, Faculty of Life Sciences, Copenhagen University, 3 Dept of Agroecology, Aarhus University

2

3 Sandy loam soil (17% clay representative of the better half of DK soil

4

5 CRUCIAL - long-term field trial Treatments are: - Composted household waste (normal and accelerated level) - Sewage sludge (normal and accelerated level) - Human urine - Cattle manure (accelerated level) - Deep litter - Cattle slurry - NPK fertilizer - Green manure - Unfertilized - One/two spare treatment available - One extra block on side of exp. available

6 Rationale The CRUCIAL facility was developed with the view to establish a historical site that can contribute to our knowledge on cycling of matter, and plant and soil quality, and the impact on the environment and the integrity of agricultural production systems The cycling of matter is broadly defined and includes e.g. nutrients, heavy metals, and xenobiotics (i.e. medicinal residues), pathogens and other microorganisms as well as genes

7 The Frankenstein effect How bad can it get? Accelerated treatments Presently > 100 yr dose

8 Null hypothesis When ecotoxicological limits for heavy metals have been approached realistically there will be no (unexpected) adverse effects on soil quality, environment and production system integrity

9 Total Carbon in soil ( ) % C (by dry weight) U GM CS HU NPK S SA DL CMA CH CHA Year

10 bulk density (g*l -1 ) %C (CRUCIAL block 2)

11 Retention curves for selected amendments in the CRUCIAL soil U vs Col 33 CS vs Col 33 SA vs Col 33 CMA vs Col 33 CHA vs Col 33 pf water content (cm 3 cm -3 ) Retention curves for 100 cm 3 samples. Each point is a mean of six replicate samples (+/- sd). Amendments: U) unfertilized (since 2002); CS) Cattle Slurry; SA) Accelerated Sludge; CMA) Cattle Manure Accelerated; CHA) Composted Householdwaste Accelerated

12 Total soil P (2009) Total-P ( g * g -1 ) U GM CS HU NPK S SA DL CMA CH CHA

13 Olsen P 2007 (NaHCO3) mg per kg soil Olsen P ( g * g -1 ) U GM CS HU NPK S SA DL CMA CH CHA.

14 DK ecotox limit 30 ppm 25 Total Cu in soil (2009) 20 Cu ( g * g -1 ) U GM CS HU NPK S SA DL CMA CH CHA

15 DK ecotox limit Total soil Zn (2009) 100 ppm Zn ( g * g -1 ) U GM CS HU NPK S SA DL CMA CH CHA

16 454 FLX pyrosequencing 18 soils sampled in spring after before application of new fertiliser (steady state), after 5 consequtive applications ( yr), corresponding to appr. 50 yr in the accelerated treatments App sequences 16S rrna Classified using the RDP web-site Poulsen, P.H.B., et al., Effects of fertilization with urban and agricultural organic wastes in a field trial e Prokaryotic diversity investigated by pyrosequencing, Soil Biology & Biochemistry (2012), doi: /j.soilbio

17 Highly robust microbial community at phylum level Abundance of firmicutes in the compost ammended soil Abundance of cyanobacteria in the unfertilized soil

18 Antibiotic resistance Soil sampled right after fertilizer amendment: Week Isolation of Pseudomonas from soil using selective media (NAA 1:100) - NAA, NAA+Gentamycin, NAA+Tetracycline

19 Antibiotic resistance in Pseudomonas Average CFU g -1 soil (all treatments, all sampling times): NAA 2.5*10 5 Gen 1.9*10 4 Tet 5.3*10 2 Abundance of Gentamicin-resistant Pseudomonas Abundance of Tetracycline-resistant Pseudomonas Sept Oct Nov 1,2 1,0 Sept Oct Nov ,8 % 8 % 0,6 6 0, ,2 0 Unfertilized Sludge Manure Compost 0,0 Unfertilized Sludge Manure Compost

20 Multiresistance in Pseudomonas Multiresistance of Pseudomonas in general Sept Oct Nov 60 % Unfertilized Sludge Compost Manure Resistant towards 3 or more of: gentamicin (10 μg/ml), tetracycline (10 μg/ml), streptomycin (100 μg/ml), kanamycin (50 μg/ml), ciprofloxacin (4 μg/ml) and mercury(10 μg/ml)

21 Discussion Presented results (and data not shown) indicates that this representative soil is highly resilient towards ill effects on waste recycling We see positive effects on soil structure, fertility, carbon storage, and soil microbial biomass So far we find no support for alarmist views

22 Discussion We contend that when assessing risks of recycling urban waste one should also consider the systemic effects of alternatives e.g. net ghg emmisions upon incineration and other cleanup processes use of animal manure mining of P and other nutrients

23 An invitation for further collaboration We need more knowledge on the good and the bad in recycling of organic waste products We invite the international community to utilize the facility To research new issues To assess risks and opportunities in recycling organic waste through the terrestrial production system

24 Thank you