ECONOMICAL ANALYSIS OF THE MACHINE TECHNOLOGY OF THE CULTIVATION OF DROUGHT-TOLERANT PLANTS FOR RENEWABLE ENERGY PRODUCTIONEffects of nitrogen and phosphorus on microbiological soil activity and soybean yield

Abstract

The objective was to analyze the effect of nitrogen and phosphorus (by sowing inoculated and non-inoculated seed) on the microbiological activity of soil (number of physiological and systematic groups of microorganisms in the plant root system, but also the number and weight of the nodes formed) and soybean yield. Trials were conducted on the brown forest soil type in central Šumadija. Sowing inoculated seed tended to raise the average soybean yield by 8.6% as well as number of bacteria in the rhizosphereous soil compared to the non-inoculated variant. Node number and weight were the greatest in the control variant (non-fertilized). Grain yield was higher by applying larger nitrogen rates, both individually and in combination with phosphorus (fertilization variants N100P70 and N100P35 kg/ha) with yields ranging from 2.79 to 3.21 t ha-1. In addition, the greatest number of bacteria in the plant root system was found in these variants. In comparison to the control, a positive effect of fertilization on grain yield amounting to 36% was also registered. In 2002, the number and weight of nodes formed on the plant root were substantially greater than in 2003 as a result of favorable humid weather conditions.

U ovom radu je prikazan uticaj azota i fosfora, setvom inokulisanog i neinokulisanog semena, na mikrobiološku aktivnost zemljišta (brojnost pojedinih fizioloških i sistematskih grupa mikroorganizama u zoni korenovog sistema biljaka, kao i mase i broja obrazovanih kvržica) i prinos soje. Istraživanja su obavljena na zemljištu tipa gajnjača u centralnoj Šumadiji. Dobijeni rezultati pokazuju da je ostvaren viši prosečni prinos soje za 8,6 % setvom inokulisanog semena i veći ukupni broj bakterija u rizosfernom sloju zemljišta u odnosu na neinokulisanu varijantu. Na kontrolnoj varijanti (bez đubrenja) utvrđen je najveći broj i masa kvržica po biljci, što je logično kada se ima u vidu priroda ove biljke. Viši prinosi zrna ostvareni su primenom veće količine azota, kako pojedinačno, tako i u kombinaciji sa fosforom (varijante đubrenja N100P70 i N100P35 kg/ha), kod kojih se prosečni prinos kretao od 2,79 do 3,21 t/ha. Takođe, na ovim varijantama je uglavnom konstatovan i najveći broj bakterija u zoni korenovog sistema. Pozitivan efekat đubrenja na prinos zrna je iznosio i do 36 %, u odnosu na kontrolu. Broj i masa kvržica na korenu biljaka, kao i prinos zrna, bili si značajno veći u 2002. godini, kao posledica znatno povoljnijih uslova vlažnosti u odnosu na 2003. godinu.