SUPPLEMENTARY MATERIAL




       Recovered phosphorus for a more resilient urban agriculture:

      assessment of the fertilizer potential of struvite in hydroponics



     Verónica Arcas-Pilza,1, Martí Rufí-Salísa,b,1, Felipe Paradaa, Anna Petit-Boixc, Gara

                                  Villalbaa,b, Xavier Gabarrella,b,*




a
    Sostenipra Research Group (SGR 01412), Institute of Environmental Sciences and Technology

(MDM-2015-0552), Z Building, Universitat Autònoma de Barcelona (UAB), Campus UAB, 08193

Bellaterra, Barcelona, Spain

b
    Department of Chemical, Biological and Environmental Engineering, Universitat Autònoma de

Barcelona (UAB), Campus UAB, 08193 Bellaterra, Barcelona, Spain

c
    Chair of Societal Transition and Circular Economy, University of Freiburg. Tennenbacher Str. 4,

79106 Freiburg i. Br. (Germany)

1
    These authors contributed equally to this research


Corresponding author: xavier.gabarrell@uab.cat
     Figure SM1: Diagram of the perforated bag




Figure SM2: Distribution of growing lines in the validation test
Figure SM3: Production (g/plant) of the struvite treatments in the validation test, with (VCB) and
without (VC0) perforated bags for each harvest. Sample size for harvests 1, 2, 3, 4 and 5 (35- 54
DAT) corresponds to n=28 plants, for harvests 6, 7 and 8 (63-78 DAT) n=24 plants per treatment.
Figure SM4: Production (g/plant) of the struvite treatments in the validation test, with (VCB) and
without (VC0) perforated bags for each harvest. Same letters (a,b, c) indicate no significant difference
(p>0.05) between treatment for each harvest time. Sample size for harvests 1, 2, 3, 4 and 5 (35- 54
DAT) corresponds to n=28 plants, for harvests 6, 7 and 8 (63-78 DAT) n=24 plants per treatment.
Figure SM5: Production (g/plant) of the control treatments in the validation test, with (VCB) and
without (VC0) perforated bags for each harvest. Sample size for harvests 1, 2, 3, 4 and 5 (35- 54
DAP) corresponds to n=28 plants, for harvests 6, 7 and 8 (63-78 DAP) n=24 plants per treatment.
Figure SM6: Same letters (a, b, c, d, e, f) indicate no significant difference (p>0.05) between
treatment for each harvest time. Sample size for harvests 1, 2, 3, 4 and 5 (35- 54 DAT) corresponds
to n=28 plants, for harvests 6, 7 and 8 (63-78 DAT) n=24 plants per treatment.
Figure SM7: Number of leaves per plant per treatment and Days after Transplanting (DAP) in the
validation test (13, 20, 27, 34 DAP). Same letters (a, b, c, d, e, f, g) indicate no significant
difference (p>0.05) between treatment for each counting time. Sample size n=32 for each
treatment.
Figure SM8: Number of side shoots per plant per treatment and Days after Transplanting (DAP) in
the validation test (13 DAP). Same letters (a, b, c, d, e) indicate no significant difference (p>0.05)
between treatment for each counting time. Sample size n=32 for each treatment.




Figure SM9: Number of open flowers per plant per treatment and Days after Transplanting (DAP)
in the validation test (20, 27, 36 DAP). Same letters (a, b, c, d, e, f) indicate no significant
difference (p>0.05) between treatment for each counting time. Sample size n=32 for each
treatment.
Figure SM10: Number of floral buttons per plant per treatment and Days after Transplanting
(DAP) in the validation test (20, 27, 36 DAP). Same letters (a, b, c, d, e, f) indicate no significant
difference (p>0.05) between treatment for each counting time. Sample size n=32 for each
treatment.
Figure SM11: Height (cm) plant per treatment and Days after Transplanting (DAP) in the validation
test (13 DAP). Same letters (a, b, c, d, e) indicate no significant difference (p>0.05) between
treatment for each counting time. Sample size n=32 for each treatment.
          Figure SM12: Water irrigated (L) per plant in the validation test.




Figure SM13: Phosphorus concentrations in the multiple water streams in the validation test
Figure SM14: P content per plant (g) of the struvite treatment in the validation test. Same letters (a,
b, c, d, e) indicate no significant difference (p>0.05) between treatment for each harvest time.
Sample size for all organs n=4. Undissolved P content n=2.
    Figure SM15: Distribution of growing lines in the validation test




Figure SM16: Mean aggregated production per plant per treatment in the determination test
Figure SM17: Water irrigated and drained per plant in the different treatments in the determination
test




  Figure SM18: Phosphorus concentrations in the multiple water streams in the determination
  test
Figure SM19: Phosphorus concentrations in the different treatments, separated by plant organ and
days after planting (DAP). Same letters (a, b, c, d, e, f, g, h) indicate no significant difference (p>0.05)
between treatment for each harvest time. Sample size for all organs n=4. Undissolved P content
n=2.