Plant-based fertilizers, such as liquid plant extracts, contribute to the cultivation of vegetables, 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 production under field conditions. The hypothesis was that it could successfully replace mineral fertilizers and be integrated into sustainable and organic agriculture. The experiment was conducted at two climatically and pedologically different locations (Zadar and Poreč) throughout two growing seasons (spring and autumn). Two types of aqueous nettle extracts were used: a short-term extract (SE) was prepared by the extraction of wild stinging nettle (183 g 10 L−1 of water) in water for 24 h, while a long-term extract (LE) was prepared at the same ratio with water extraction for 14 days. Both extracts were diluted with water at a ratio of 1:3 (extract:water) before use. The SE was applied foliarly, and LE, by pouring it onto the soil. The abovementioned treatments were compared with mineral fertilization with urea (U) and control (no fertilization (C)). Foliar fertilization with SE proved to be almost as efficient as fertilization with LE, poured onto soil, showing a positive effect on green bean vegetative parameters. Furthermore, aqueous nettle extracts showed a positive effect on the iron accumulation in the leaves.

One of the limiting factors in organic farming is the scarcity of allowed fertilizers and chemicals for plant protection. Plant and compost extracts are a promising solution for fertilization because of their positive effect on plant growth and soil microbial activity. Nettle extract was already successfully applied to some vegetables. Not-aerated nettle extract, obtained from dry nettle leaves, was applied in experiments with green beans in a quantity of 1 L per pot at two-day intervals was studied. A three-factorial experimental design was applied with two soil types (brown—Calcic Gleysol and red—Eutric Cambisol), soil disinfection with dazomet or not, and irrigated with nettle extract or water. Nettle extract application increased all above-ground traits; plant height, leaf area, flower buds, shoot dry weight at flowering, pod length, pod diameter, and shoot dry weight at harvest by 49%, 66%, 43%, 36%, 11%, 9%, and 37%, respectively, the root length at harvest by 59%, total yield by 48%, soil respiration by 91% and 74% in two soil types, and alkaline phosphatase by 30%. Dehydrogenase activity was enhanced by nettle extract application on red soil, while nettle extract application had no effect on root nodulation. The nettle extract application benefits in green bean organic production were attributed to the nutrients and other components present in the extract and not to nitrogen fixation. The optimization of the dose of the extract and experiments in real conditions of green bean production would be the next step toward the implementation of nettle extract as an organic fertilizer.

U radu se prikazuju rezultati analize hortikulturne flore kućnih vrtova Gacke doline koja je s jedne strane omeđena Velebitom, a s druge Kapelom. Istraživanje je provedeno tijekom 2018. i 2019. godine, te revidirano 2021. godine. Nasumično je izabrano 40 vrtova koji se nalaze na različitim lokalitetima Gacke doline. Na istraživanoj površini determinirane su 133 svojte u sklopu 113 rodova i 60 porodica. Brojem svojta dominiraju kritosjemenjače (129 svojta; 96,99 %) i to dvosupnice (114 svojta; 85,71 %). Od prisutnih porodica najzastupljenija je porodica Rosaceae (12,78 %), a od rodova rod Prunus (5,26 %). Prema vrsti habitusa većina svojta su grmovi (30,83 %). Veća je dominantnost vazdazelenih svojti (61 %) u odnosu na listopadne. Prema geografskom podrijetlu su brojnije alohtone vrste (58,65 %) i to podrijetlom iz Amerike (26,92 %). Svojte ukrasnog karaktera (54,14 %) zastupljenije su od utilitarnih.

Na području Nacionalnog parka Paklenica kao i na velikom broju ostalih zaštićenih područja ljudska aktivnost u obliku poljoprivredne proizvodnje je ograničena i mora se odvijati sukladno uvjetima zaštite prirode. Budući da je upravo poljoprivreda jedna od osnovnih djelatnosti vezanih za opstanak stanovništva na takvim je područjima trebalo pronaći model između proizvodnje i očuvanja prirode i okoliša. Tradicionalna, ekološki prihvatljiva poljoprivreda omogućuje proizvodnju namirnica po ekološkim načelima, pridonosi očuvanju biološke raznolikosti, te očuvanju autohtonih kultura i pasmina. U radu su opisane osnovne značajke NP Paklenica (smještaj, geografski položaj, te geološke klimatske i hidrološke značajke). Tijekom ovog istraživanja zabilježen je sveukupno 41 vrt koji se nekada koristio ili se još uvijek koristi za proizvodnju osnovnih poljoprivrednih kultura. Prikazani su najznačajnije biljne i životinjske vrste, te tradicionalan načini proizvodnje. Prikazana je organizacija plodoreda, agrotehnika (obrada, gnojidba i navodnjavanje), te metode njege biljaka. Ovakav način proizvodnje temelji se na ekološki prihvatljivim mjerama čija je svrha smanjiti onečišćenje okoliša i očuvati biološku raznolikost. Premda okarakterizirano kao tradicionalni, neki od navedenih načina proizvodnje predstavljaju okosnicu suvremene ekološke poljoprivrede. Osim toga takva proizvodnja ima izuzetnu vrijednost u etnološkom smislu ali i u obogaćivanju turističke ponude podvelebitskog dijela Zadarske županije.