Hamid Hatami1, Mohammad Reza Tokalloo2, Mojtaba Ghanbarabadi3 and Soghra Kebriaie4
1,2 Faculty member, Bojnourd branch, Islamic Azad University, Bojnourd, Iran, Email: firstname.lastname@example.org
3,4 Graduated Master of Science, Bojnourd branch, Islamic Azad University, Bojnourd, Iran, Email: email@example.com
In order to reduce the use of nitrogen and phosphorus fertilisers in sugar beet cultivation, an experiment was conducted in a completely randomized block design with four replications during 2017 in Iran. Experimental treatments were consisted of: no fertiliser application, 100% of currently recommended rates of N and P fertiliser (110 kg N/ha as urea, 36 kg P/ha as triple superphosphate) and a combination of 75%, 50% and 25% of N and P with two bacterial inoculation products – “Phosphozist”, which contains phosphobacteria that cause soil P to become more readily available to plants, and “Nitrozist” containing free-living N-fixing Azotobacteria. The highest sugar yield of 6.8 t/ha was obtained with 50% of the recommended rate of N and P with both “Phosphozist” and “Nitrozist”. Lower yields were obtained at both 25% and 75% of recommended rates, and the 100% N and P rate without inoculation. The highest concentrations of N and K in the beet (which are contaminants in sugar beet) occurred at the 100% N and P rate without inoculation. The results of the experiment showed that N and P application rates can be halved through inoculation with phosphobacteria and free-living N fixers.