Microbial biomass, soybean yield and quality under the different levels of mineral nutrients

Abstract

The objective was to analyse the effects of nitrogen and phosphorus (sowing inoculated and non-inoculated seed) on the microbial biomass of soil, soybean yield and quality under the different levels of mineral nutrients. Investigations conducted on the brown forest soil type in central Šumadija. The addition of phosphorus has affected increasing of bacterial biomass in all variants, with and without inoculation in forming pods phase. Inoculation in harvest phase has affected increasing of bacterial and decreasing of fungal biomass. The highest number and mass of nodules was noticed on variants with phosphorus fertilization (P35 i P70 kg/ha) and in control variant (without fertilization). The nitrogen has affected on decreasing of those two parameters. Significant higher average seed yield was noticed on variant of inoculated seed (for 17,0%) concerning variant with non-inoculated seed (3,41 t/ha). All nitrogen and phosphorus fertilization variants have affected significant yield increasing comparing with control variant. However, the highest yield was noticed in combination of those two nutrients (N100P35 and N100P70 kg/ha), up to 4,0 t/ha seed. Seed inoculation has increased protein content for 2,2% comparing on non-inoculated seed. The nitrogen and phosphorus has affected small, but positive effect on protein content just on non-inoculated variant. The highest increasing was on variant with N100P35 and N100P70 kg/ha (4,5 – 5,7%). In general, seed protein content is indeed small because of bigger amount of rainfall in this year.

U ovom radu je prikazan uticaj azota i fosfora, setvom inokulisanog i neinokulisanog semena, na mikrobnu biomasu, prinos i kvalitet soje pri različitim nivoima mineralnih hraniva. Istraživanja su obavljena na zemljištu tipa gajnjača u centralnoj Šumadiji. U fazi obrazovanja mahuna unošenje fosfora je najviše uticalo na povećanje bakterijske biomase u varijantama sa i bez inokulacije. Inokulacija u fazi žetve uticala je na povećanje bakterijske i smanjenje biomase gljiva.Najveći broj i masa kvržica po biljci ostvareni su na varijantama đubrenja fosforom (P35 i P70 kg/ha) i kontrolnoj varijanti (bez đubrenja). Azot je uticao na smanjenje vrednosti ova dva parametra. Ostvaren je značajno veći prosečni prinos semena na varijanti inokulisanog semena (za 17,0%) u odnosu na varijantu bez inokulacije (3,41 t/ha). Sve varijante azota i fosfora dale su značajno povećanje prinosa u odnosu na kontrolu. Ipak, najveći prinos je ostvaren kombinovanom primenom ova dva hraniva (N100P35 i N100P70 kg/ha), preko 4,0 t/ha semena. Inokulacija semena je povećala sadržaj proteina za 2,2% u odnosu na neinokulisano seme. Azot i fosfor su ispoljili mali, ali pozitivan uticaj na sadržaj proteina samo na varijanti bez inokulacije. Najveće povećanje je u varijanti N100P35 i N100P70 (4,5 – 5,7 indeksnih poena). U celini sadržaj proteina u semenu je dosta mali i zbog većih količina padavina u ovoj godini.