Influence of microbiological preparation and phosphorus fertilizer on yield, quality and germination of soybean and maize seed grown on acidic soils

Abstract

Fosfor je drugi najpotrebniji makroelement za rast i razvoj biljaka, odmah poslije dušika. Fiksacija fosfora u tlu ponajviše ovisi o pH reakciji tla, sadržaju vlage u tlu, temperaturi te već prisutnim mineralima u tlu. Fosfor - topive bakterije, tj. phosphor solubilizing bacteria (PSB), posjeduju različite mehanizme pomoću kojih biljkama nepristupačne oblike fosfora mogu prevesti u biljci pristupačne oblike te tako utjecati na nepristupačne zalihe fosfora u tlu. Cilj ovog istraživanja bio je ustanoviti učinak mikrobiološkog pripravka i gnojidbe fosforom na prinos, kvalitetu i klijavost sjemena soje i kukuruza na kiselim tlima. Odabrana su tri tipa tla sličnih pH vrijednosti, različitog sadržaja humusa i koncentracije lakopristupačnog fosfora. U sklopu terenskih istraživanja provedeni su dvogodišnji poljski pokusi te analize biljne tvari i tla. Kao mikrobiološki pripravak korišten je komercijalni pripravak Terra Condi tvrtke EmTehnologija d.o.o. iz Valpova u koji su dodane bakterije Pseudomonas putida (ATCC 12633), Pseudomonas rhizosphaere (DSM 16299) te Pseudomonas fluorescens (ATCC 13525) kao fosfor - topive bakterije. Utvrđeno je da su se bakterije roda Pseudomonas adaptirale u tlu svih lokaliteta. Kontrolna varijanta uz primjenu mikrobiološkog pripravka bilježila je veće prosječne prinose soje i kukuruza na svim lokalitetima u odnosu na kontrolnu varijantu bez primjene mikrobiološkog pripravka. Količine mikrobiološki fiksiranog fosfora kretale su se od 23,34 do 88,88 kg ha-1. Također, utvrđena je vrlo jaka pozitivna korelacija (r = 0,89) između sadržaja fosfora u tlu (AL-metoda) te količine mikrobiološki fiksiranog fosfora na pojedinim varijantama te između sadržaja humusa u tlu i povećanja mikrobiološke fiksacije fosfora (r = 0,81). Prosječne vrijednosti klijavosti soje kretale su se od 91,9 do 93,4 %, a kukuruza od 92,6 do 93,8 %. Potrebna su dodatna i dugotrajnija istraživanja u poljskim uvjetima kako bi što preciznije utvrdili utjecaj mikrobiološkog pripravkaPhosphorus is the second most necessary macro-element for plant growth and development, just after nitrogen. Fixing of phosphorus in soils mostly depends on the pH value of soil, soil moisture, temperature and present soil minerals. Phosphorous solubilizing bacteria (PSB) have different mechanisms by which plant unavailable phosphorous forms can be transformed into available forms to plants, thus affecting phosphorus reserves in the soil. The aim of this study was to determine the effect of microbiological preparation and phosphorus fertilization on the yield, quality and germination of soybean and corn seeds groen on acidic soils. Three locations with soils of similar pH values, different content of humus and concentration of available phosphorus were selected. The researches included a two-year field experiment and analysis of plant material and soil. As a microbiological preparation, a commercial preparation named Terra Condi, producer EmTehnologija d.o.o. from Valpovo, to which bacteria Pseudomonas putida (ATCC 12633), Pseudomonas rhizosphaere (DSM 16299) and Pseudomonas fluorescens (ATCC 13525) were added as phosphorous solubilizing bacteria. It was found that the Pseudomonas strains adapted to the soil of all sites. The control treatment with microbiological preparation recorded higher average yields of soybean and corn at all sites compared to the control treatment without the use of the microbiological preparation. The average amounts of microbially fixed phosphorus ranged from 23.34 to 88.88 kg ha-1. Also, there ware found very significant positive correlation (r = 0.89) between the concentration of available phosphor (AL-method) and the amount of microbially-fixed phosphorus, as well as between the humus content in soil and the increase of microbially-fixed phosphorus (r = 0,81). The average values of soybean germination ranged from 91.9 to 93.4%, and corn from 92.6 to 93.8%. Additional and longer-lasting researches under field conditions are needed to better determine the effects of the microbiological preparation