| Abstrakt: |
Nitrogen is a key nutrient for soybean cropping and can be fully supplied by the biological nitrogen fixation (BNF) process. Inoculation with elite Bradyrhizobium strains greatly improves the supply of N to soybean; however, inoculation of large areas in short‐sowing windows delays the sowing process, demanding the development of technologies for pre‐inoculation. Here we report the evaluation of a liquid formulation containing cell protectors that proved, in four field experiments located in different edaphoclimatic conditions of Brazil, symbiotic performance comparable to the peat‐based inoculant, traditionally considered as the best carrier. The liquid inoculant was also effective when applied to seeds not treated with pesticides 15 days before sowing, providing efficient BNF and time‐flexibility to the farmers. Benefits of the liquid inoculant in improving grain yield were confirmed in two areas cropped for the first time and devoid of Bradyrhizobium, with an average increase of 89%, and also in two areas traditionally cropped with inoculated soybean, with an average increase of 6.8%, both in comparison to the non‐inoculated control without N‐fertilizers (NI). It is worth mentioning that, also in comparison to the NI control, the addition of 200 kg N ha−1 impacted grain yield in +54% and −1,8%, in new and traditional areas, respectively, indicating that BNF was more effective than the application of N‐fertilizer. Large increases in total N content in grains were observed as well in response to the liquid inoculant, on average 47% and 27%, when compared to the NI and NI + N controls, respectively. [ABSTRACT FROM AUTHOR] |
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