sustainability Article Stinging Nettle (Urtica dioica L.) as an Aqueous Plant-Based Extract Fertilizer in Green Bean (Phaseolus vulgaris L.) Sustainable Agriculture Branka Mariˇci´c 1,*, Sanja Radman 2, Marija Romi´c 2, Josipa Perkovi´c 3 , Nikola Major 3 , Branimir Urli´c 4, Igor Palˇci´c 3,* , Dean Ban 3, Zoran Zori´c 5 and Smiljana Goreta Ban 3 1 Department of Ecology, Agronomy and Aquaculture, University of Zadar, 23000 Zadar, Croatia 2 Faculty of Agriculture, University of Zagreb, 10000 Zagreb, Croatia;
[email protected] (S.R.);
[email protected] (M.R.) 3 Institute of Agriculture and Tourism, Department of Agriculture and Nutrition, 52440 Poreˇc,Croatia;
[email protected] (J.P.);
[email protected] (N.M.);
[email protected] (D.B.);
[email protected] (S.G.B.) 4 Institute for Adriatic Crops and Karst Reclamation, Department of Plant Sciences, 21000 Split, Croatia;
[email protected] 5 Faculty of Food Technology and Biotechnology, University of Zagreb, 10000 Zagreb, Croatia;
[email protected] * Correspondence:
[email protected] (B.M.);
[email protected] (I.P.); Tel.: +385-98-981-7375 (B.M.); +385-408-312 (I.P.) Abstract: Plant-based fertilizers, such as liquid plant extracts, contribute to the cultivation of veg- etables, particularly in organic production. The objective of this study was to determine if aqueous nettle extract could be successfully used as a fertilizer, applied on the soil and foliarly, in green bean Citation: Mariˇci´c,B.; Radman, S.; production under field conditions. The hypothesis was that it could successfully replace mineral Romi´c,M.; Perkovi´c,J.; Major, N.; fertilizers and be integrated into sustainable and organic agriculture.