Bio-seed dressing agent promotes wheat growth and improves fertilizer use efficiency

Efficient and safe bio-seed dressing agents are urgently needed to replace traditional chemical ones in wheat production. Here, we evaluated and compared the field performance of a novel bio-seed dressing formulated with five bacterial strains typically used as animal probiotics against a conventional chemical seed dressing (comprising epoxiconazole, imidacloprid, and chlorpyrifos) in wheat plot trials. Compared with both the undressed control and the chemical treatment, the bio-dressing significantly increased wheat biomass as well as N, P and K accumulation, raising the theoretical grain yield by 8.3% and 10.2%, respectively. Further analyses revealed that the bio-dressing increased both the diversity and abundance of rhizosphere soil bacteria. The Chao1 index (5258.27 ± 87.14) was significantly higher than that of the undressed control (5086.20 ± 29.38) and the chemical treatment (4891.56 ± 87.66). The Shannon index (6.87 ± 0.04) was also significantly higher than that of the undressed control (6.80 ± 0.03) and the chemical treatment (6.82 ± 0.03). The bio-dressing enhanced total N and improved the availability of P and K in rhizosphere soil, thereby promoting mineral nutrient uptake by wheat. These results demonstrate that the bio-seed dressing agent can effectively replace its chemical counterpart to promote wheat growth and increase fertilizer use efficiency.