Grain, milling, and head rice yields as affected by nitrogen rate and bio-fertilizer application | Vpliv gnojenja z različnimi odmerki dušikovih gnojil in bio-gnojil na pridelek zrnja in mlevske lastnost riža

English. To evaluate the effects of nitrogen rate and bio-fertilizer application on grain, milling, and head rice yields, a field experiment was conducted at Rice Research Station of Tonekabon, Iran, in 2013. The experimental design was a factorial treatment arrangement in a randomized complete block with three replicates. Factors were three N rates (0, 75, and 150 kg ha-1) and two bio-fertilizer applications (inoculation and uninoculation with Nitroxin, a liquid bio-fertilizer containing Azospirillum spp. and Azotobacter spp. bacteria). Analysis of variance showed that rice grain yield, panicle number per m2, grain number per panicle, flag leaves area, biological yield, grains N concentration and uptake, grain protein concentration, and head rice yield were significantly affected by N rate, while bio-fertilizer application had significant effect on rice grain yield, grain number per panicle, flag leaves area, biological yield, harvest index, grains N concentration and uptake, and grain protein concentration. Results showed that regardless of bio-fertilizer application, rice grain and biological yields were significantly increased as N application rate increased from 0 to 75 kg ha-1, but did not significantly increase at the higher N rate (150 kg ha-1). Grain yield was significantly increased following bio-fertilizer application when averaged across N rates. Grains N concentration and uptake were significantly increased as N rate increased up to 75 kg ha-1, but further increases in N rate had no significant effect on these traits. Bio-fertilizer application increased significantly grains N concentration and uptake, when averaged across N rates. Regardless of bio-fertilizer application, head rice yield was significantly increased from 56 % to 60 % when N rate increased from 0 to 150 kg ha-1. Therefore, this experiment illustrated that rice grain and head yields increased with increasing N rate, while bio-fertilizer application increased only rice grain yield.

Slovenian. Z namenom vrednotenja učinkov gnojenja z različnimi odmerki dušika in uporabe bio-gnojil na pridelek riža in njegove mlevske lastnosti je bil izveden poljski poskus na Rice Research Station of Tonekabon, Iran, v letu 2013. Načrt poskusa je bil faktorski naključni bločni poskus s tremi ponovitvami. Preučevani dejavniki v poskusih so bili tri gnojenja z različnimi odmerki dušika (0, 75, in 150 kg ha-1) in uporaba dveh bio-gnojil (z ali brez inolukacije z bio-gnojilom Nitroxin, tekoče bio-gnojilo, ki vsebuje bakterije iz rodov Azospirillum spp. in Azotobacter spp.). Analiza variance je pokazala, da je imelo gnojenje z dušikom značilen učinek na pridelek zrnja riža, število latov na m2, število zrn na lat, površino najvišjega lista (zastavarja), biološki pridelek, privzem in vsebnost N v zrnju, vsebnost beljakovin v zrnju in pridelek oluščenega riža, uporaba bio-gnojil pa je imela značilen vpliv le na pridelek zrna riža, število zrn na lat, površino najvišjega lista, biološki pridelek, žetveni indeks, privzem in vsebnost N v zrnju in vsebnost beljakovin v zrnju. Rezultati raziskave so pokazali, da sta se pridelek zrnja riža in njegov biološki pridelek povečala ne glede na uporabo bio-gnojil, ko se je gnojenje z dušikom povečalo z 0 na 75 kg ha-1, vendar gnojenje z večjimi odmerki N (150 kg ha-1) ni imelo značilnega vpliva na povečanje teh dveh parametrov. Pridelek zrnja se je značilno povečal pri uporabi bio-gnojil pri vseh odmerkih dušika. Vsebnost in privzem N v zrnje sta se značilno povečala pri povečanju gnojenja z dušikom iz 0 na75 kg ha-1, vendar nadaljna povečanja gnojenja z N niso imela značilnega vpliva na ta parametra. Uporaba bio-gnojil je značilno povečala vsebnost in privzem N v zrnju pri vseh odmerkih dušika. Ne glede na uporabo bio-gnojil, se je pridelek oluščenega riža značilno povečal iz 56 % na 60 %, ko se je gnojenje z N povečalo z 0 na 150 kg ha-1. Izsledki te raziskave kažejo, da se je pridelek zrnja riža in oluščenega riža povečal z večjim gnojenjem z dušikom, uporaba bio-gnojil pa je povečala le pridelek zrnja.