Vpiv zeolita na učinkovitost gnojenja z dušikom v poljskem poskusu s koruzo (Zea mays)

Vidic, Martina (author), Flajšman, Marko (mentor), Mihelič, Rok (comentor)

V poljskem poskusu s koruzo, izvedenem leta 2023 na laboratorijskem polju Biotehniške fakultete v Ljubljani, smo preučevali vpliv uporabe zeolita iz Zaloške Gorice (Montana d.o.o.) in mineralnega dušika na rast in pridelek koruze ter vsebnost dušika v zrnju in koruznici. Zeolit smo dodajali v odmerkih 0 t/ha, 5 t/ha in 10 t/ha pred setvijo prejšnje glavne kulture, ki je bila pšenica, in strniščnega dosevka Bodenfit (Saatbau d.o.o.). Mineralni dušik smo uporabljali v treh odmerkih: 0 % N (kontrola), 100 % N (polni odmerek 181 kg N/ha) in 70 % N (70 % polnega odmerka, kar znaša 127 kg N/ha). V poskusu smo med rastjo koruze analizirali vpliv gnojenja z dušikom in dodatka zeolita na vsebnost amonijevega (NH₄-N) in nitratnega dušika (NO₃-N) v tleh ter učinkovitost rabe dušika (NUE) in navidezni izkoristek dodanega dušika (ANR) pri pridelavi koruze. Ugotovili smo, da je uporaba zeolita pozitivno vplivala na vsebnost dušika v zrnju in koruznici ter pri zadrževanju dušika v tleh. Mineralni dušik je spodbudil rast rastlin, število listov in prav tako prispeval k povečanju končnega pridelka. Neposredno pred žetvijo koruze je pri gnojenju s 100 odstotnim odmerkom N koncentracija NH₄-N v zgornjih 30 cm tal dosegla 2,03 mg/100 g ter do 0,59 mg/100 g NO₃-N, kar kaže na velik delež neizkoriščenega dušika, dodanega z gnojili. Največjo vsebnost dušika v koruznici (0,62 %) in zrnju (0,96 %) smo izmerili pri dodatku 10 t/ha zeolita pri gnojenju s 100 % N. Analiza rezultatov kaže, da je pri 100 % N izkoristek dušika za pridelek zrnja (NUE) nižji kot pri 70 % N. Brez zeolita je pri 70 % N vrednost NUE 78,3, pri 100 % N pa le 60,9. Uporaba 5 t/ha zeolita je izboljšala NUE na 84,6 pri 70 % N, medtem ko je pri 100 % N znašala 61,5. Pri 10 t/ha zeolita je NUE pri 70 % N 73,0, pri 100 % N pa 67,2. Ti rezultati kažejo, da manjši odmerki dušika v kombinaciji z zeolitom omogočajo boljši izkoristek dušika. Pri izračunu ANR za zrnje so rezultati podobni: brez zeolita je ANR pri 70 % N 46,6 %, pri 100 % N pa 37,2 %. Pri 5 t/ha zeolita je ANR pri 70 % N 47,5 %, pri 100 % N pa 36,6 %. Pri 10 t/ha zeolita je ANR pri 70 % N 46,4 %, pri 100 % N pa 43,7 %. Skupni ANR (zrnje + koruznica) kaže, da se izkoristek dušika pri 70 % N brez zeolita giba okoli 56,8 %, medtem ko pri 100 % N pade na 49,3 %. Uporaba 5 t/ha zeolita dvigne ANR na 60,6 % pri 70 % N, vendar pade na 48,6 % pri 100 % N. Zeolit je izboljšal tako NUE kot ANR, še posebej pri srednjih stopnjah gnojenja (70 % N).

• Language: Slovenian
• Keywords: koruza, Zea mays, zeolit, dušik, morfološke lastnosti
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: BF - Biotechnical Faculty
• Year: 2024
• PID: 20.500.12556/RUL-162389
• COBISS.SI-ID: 208813827
• Publication date in RUL: 22.09.2024

Secondary language

• Language: English
• Title: THE EFFECT OF ZEOLITE ON THE EFFICIENCY OF NITROGEN FERTILIZATION IN A FIELD EXPERIMENT WITH MAIZE (Zea mays)

Abstract

In a field experiment with maize conducted in 2023 at the laboratory field of the Biotechnical Faculty in Ljubljana, we studied the impact of the use of zeolite from Zaloška Gorica (Montana d.o.o.) and mineral nitrogen fertilizer on the growth and yield of maize and on the nitrogen content in grain and stover. Zeolite was applied in doses of 0 t/ha, 5 t/ha and 10 t/ha before sowing the preceding main crop, wheat, and the stubble catch crop Bodenfit (Saatbau d.o.o.). Mineral fertilizer was applied in three doses: 0% N (control), 100% N (full dose of 181 kg N/ha) and 70% N (127 kg N/ha). During the experiment, we analyzed the effects of nitrogen fertilization and zeolite addition on soil ammonium (NH₄-N) and nitrate nitrogen (NO₃-N) content, nitrogen use efficiency (NUE) and apparent nitrogen recovery (ANR) in maize production. We found that the use of zeolite positively influenced the nitrogen content in grain and stover and helped to retain nitrogen in the soil. Mineral nitrogen stimulated plant growth, the number of leaves and also contributed to an increase in final yield. Soil samples (0–30 cm) before the maize harvest showed that with 100% N fertilization, the NH₄-N concentration in the soil reached 2.03 mg/100 g and the NO₃-N concentration up to 0.59 mg/100 g, indicating a large amount of unutilized nitrogen added with fertilizers. The highest nitrogen content in stover (0.62%) and grain (0.96%) was measured with the addition of 10 t/ha zeolite and 100% N fertilization. The results indicate that the NUE value for grain yield is lower at 100% N than at 70% N. Without zeolite, the NUE value at 70% N is 78.3, while at 100% N it is only 60.9. The use of 5 t/ha zeolite improved the NUE value at 70% N to 84.6, while at 100% N it was 61.5. At 10 t/ha of zeolite, the NUE at 70% N was 73.0 and at 100% N 67.2. These results indicate that lower nitrogen doses in combination with zeolite enable better nitrogen utilization. The ANR calculation for maize grain shows similar results: without zeolite, the ANR is 46.6% at 70% N and 37.2% at 100% N. With 5 t/ha of zeolite, the ANR is 47.5% at 70% N and 36.6% at 100% N. With 10 t/ha of zeolite, the ANR is 46.4% at 70% N and 43.7% at 100% N. The total ANR (grain + stover) shows that the nitrogen recovery at 70% N without zeolite is 56.8%, while it drops to 49.3% at 100% N. The use of 5 t/ha zeolite increases the ANR at 70% N to 60.6%, and 48.6% at 100% N. Zeolite improved both NUE and ANR, especially at moderate nitrogen application rates (70% N).

• Keywords: maize, Zea mays, zeolite, nitrogen, morphological properties