Organsko gnojilo iz alg, gojenih na prečiščeni odpadni vodi komunalne čistilne naprave

Gomilšek, Nina (avtor), Kacjan Maršić, Nina (mentor), Mihelič, Rok (komentor)

V diplomskem poskusu, ki je potekal v steklenjaku Centra za rast in razvoj kmetijskih rastlin na laboratorijskem polju BF UL, smo proučevali uporabnost mikroalg kot organskega gnojila za gnojenje solate in kolerabice. Postavili smo lončni poskus, ki je trajal od 4.11. do 11.12. 2024. V poskus smo vključili mineralno gnojilo NPK (15:15:15) in algno brozgo AB – mikroalge, ki so bile gojene na prečiščeni odpadni vodi komunalne čistilne naprave Ajdovščina. Lonce smo napolnili z rastnim substratom Humko, v katerega smo vmešali NPK gnojilo ali algno brozgo v količini, ki je ustrezala odmerku dušika 100 kg N/ha, 200 kg N/ha in 400 kg N/ha. Za kontrolo smo imeli negnojene rastline. Zasnovali smo poskus v šestih ponovitvah. Dinamiko rasti in razvoja smo spremljali s tedenskimi meritvami klorofilnega indeksa s SPAD metrom in štetjem listov. Po 5. tednih smo poskus končali in izmerili maso rastlin in vzorce rastlin pripravili za analizo vsebnosti suhe snovi in vsebnosti nitrata. Ugotovili smo, da se je masa rastlin solate in kolerabice pri AB povečala le pri AB400, pri NPK pa je naraščala z odmerkom dodanega dušika. Rastline, ki smo jih gnojili z NPK gnojilom, so imele večje mase od rastlin, gnojenih z AB. Masa rastlin kolerabice pri AB400 je bila podobna masi rastlin kolerabice pri NPK200; pri solati pa masa rastlin pri AB400 ni dosegla mase pri NPK200. Rastline kolerabice in solate so vsebovale največ nitrata pri NPK400 (1097 in 754 mg/kg sveže mase), pri AB pa 142 in 23 mg/kg sveže mase. Agronomska učinkovitost dušika (AE) je bila pri solati največja pri NPK200 (16 g suhe mase/g Ndodan) in v algni bozgi AB400 (4 g suhe mase/g Ndodan), pri kolerabici pa v NPK100 (15 g suhe mase/g Ndodan) in v AB100 (8 g suhe mase(g Ndodan). Navidezni izkoristek dušika (ARE) je bil pri solati največji pri NPK400 (75 %) in pri algni brozgi v AB400 (13 %) ter pri kolerabici v NPK200 (59 %) in AB400 (25 %).

• Jezik: Slovenski jezik
• Ključne besede: kolerabica, solata, algna brozga, gnojilo, vpliv na rast
• Vrsta gradiva: Diplomsko delo/naloga
• Tipologija: 2.11 - Diplomsko delo
• Organizacija: BF - Biotehniška fakulteta
• Leto izida: 2025
• PID: 20.500.12556/RUL-173807
• COBISS.SI-ID: 250406403
• Datum objave v RUL: 24.09.2025

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Organic fertilizer from algae grown on treated municipal wastewater

Izvleček

In this study, the experiment was carried out in a greenhouse at the Centre for Agricultural Plant Growth and Development, in the BF UL laboratory field to evaluate the usefulness of microalgae as an organic fertiliser for lettuce and kohlrabi. A pot trial was set up that lasted from 4 November to 11 December 2024. Two fertilisers were used in the experiment: mineral NPK (15:15:15) and algae sludge– microalgae grown on treated wastewater from the Ajdovščina municipal wastewater treatment plant. The pots were filled with substrate from Humko, into which NPK fertiliser or algae sludge were mixed in quantities corresponding to a nitrogen dose of 100 kg N/ha, 200 kg N/ha and 400 kg N/ha; unfertilised plants were used as a control. Growth and development dynamics were monitored by weekly measurements of the relative chlorophyll content with the SPAD metre and by counting the leaves. After 5 weeks, the experiment was terminated, the mass of the plants was measured, and the samples were prepared for analysing the dry matter and nitrate content. The mass of lettuce and kohlrabi plants fertilised with algae sludge increased only with AB400, while in NPK-fertilised plants the mass increased with the amount of added nitrogen. Plants fertilised with NPK fertiliser had a higher mass than plants fertilised with AB. The mass of kohlrabi plants at AB400 was similar to that of kohlrabi plants at NPK200; however, the mass of lettuce plants at AB400 did not reach that of plants at NPK200. Kohlrabi and lettuce plants contained the highest nitrate levels at NPK400 (1097 mg/kg FW and 754 mg/kg FW, respectively), while at AB they contained 142 mg/kg FW and 23 mg/kg FW, respectively. Agronomic efficiency (AE) was highest for lettuce at NPK 200 (16 g dry weight/g Nadded) and AB400 (4 g dry weight/g Nadded); for kohlrabi at NPK100 (15 g dry weight/g Nadded and AB100 (8 g dry weight/g Nadded). The apparent nitrogen utilisation efficiency (ARE) was highest for lettuce with NPK400 (75 %) and AB400 (13 %) and for kohlrabi with NPK200 (59 %) and AB400 (25 %).

• Ključne besede: kohlrabi, salad, algal sludge, fertilizer, effect on growth