Fiuza Denise Almeida Fonseca, Vitorino Luciana Cristina, Souchie Edson Luiz, Neto Moacir Ribeiro, Bessa Layara Alexandre, Silva Cintia Faria da, Trombela Natasha Taline
Laboratory of Agricultural Microbiology, Instituto Federal Goiano, Campus Rio Verde, Highway Sul Goiana, Km 01, Rio Verde 75901-970, GO, Brazil.
Laboratory of Metabolism and Genetics of Biodiversity, Instituto Federal Goiano, Campus Rio Verde, Rio Verde 75901-970, GO, Brazil.
Microorganisms. 2022 Mar 23;10(4):691. doi: 10.3390/microorganisms10040691.
Field experiments testing the effect of phosphate-solubilizing rhizobacteria (PSRB) should consider the cropping history and the method used to inoculate the strains. We evaluated the hypothesis that PSRB previously isolated from soybean seedlings could be effective in promoting growth in this oilseed crop in soils with different cultivation periods. We also evaluated whether this growth promotion could be influenced by cultivation histories or the inoculation method (via seeds or soil). Thus, we conducted an experiment in five fields cultivating during two seasons (2019/2020 and 2020/2021), to test the effectiveness of PSRB (SAF9- sp., SAF11- sp., and SAC36-) compared with results observed for the inoculant BiomaPhos (mix of and ). The present study was based on the evaluation of vegetative growth, nutritional and yield parameters, and microbial biomass carbon (MBC). PSRB were more effective than, or showed similar effectiveness to, BiomaPhos for most of the evaluated vegetative, nutritional, and yield characteristics. In the fields tested in the summer 2019/2020 crop, SAC36 and SAF9 strains stood out as growth promoters, whereas in the 2020/2021 crop, SAF11, SAC36, and BiomaPhos were notable. There did not seem to be a direct relationship between long histories of soybean cultivation as a monoculture and low yield in the field. However, yield seems to be associated with soil nutritional characters such as Ca, Mg, K, P, cation exchange capacity, and organic matter levels. PSRB inoculation positively affected nodulation (NN) and nodule dry mass (NDM) in the evaluated fields in the 2019/2020 crop, and the aerial part dry mass (APDM), NN, NDM, yield, and MBC of the evaluated fields in the 2020/2021 crop. In contrast, the inoculation method was observed to have a strong effect on APDM, NN, root dry mass, and MBC, as the plants inoculated via seed showed higher mean values than those in the plants inoculated via soil. This study demonstrated the growth-promoting potential of new phosphate-solubilizing strains, which may eventually be incorporated by the biostimulants market to freely compete with BiomaPhos.
田间试验若要测试解磷根际细菌（PSRB）的效果，应考虑种植历史以及接种菌株的方法。我们评估了这样一个假设：先前从大豆幼苗中分离出的PSRB在不同种植期的土壤中对这种油料作物的生长促进可能有效。我们还评估了这种生长促进是否会受到种植历史或接种方法（通过种子或土壤）的影响。因此，我们在五个田块进行了一项为期两个季节（2019/2020年和2020/2021年）的试验，以测试PSRB（SAF9菌株、SAF11菌株和SAC36菌株）与接种剂BiomaPhos（[具体成分]的混合物）相比的有效性。本研究基于对营养生长、营养和产量参数以及微生物生物量碳（MBC）的评估。对于大多数评估的营养、营养和产量特征，PSRB比BiomaPhos更有效或显示出相似的有效性。在2019/2020年夏季作物测试的田块中，SAC36菌株和SAF9菌株作为生长促进剂表现突出，而在2020/2021年作物中，SAF11菌株、SAC36菌株和BiomaPhos表现显著。大豆单作的长期种植历史与田间低产之间似乎没有直接关系。然而，产量似乎与土壤营养特性如钙、镁、钾、磷、阳离子交换容量和有机质水平有关。在2019/2020年作物的评估田块中，PSRB接种对结瘤数（NN）和根瘤干重（NDM）有积极影响，在2020/2021年作物的评估田块中，对地上部干重（APDM）、NN数、NDM、产量和MBC有积极影响。相比之下，观察到接种方法对APDM、NN数、根干重和MBC有强烈影响，因为通过种子接种的植株显示出比通过土壤接种的植株更高的平均值。本研究证明了新型解磷菌株的生长促进潜力，这些菌株最终可能被生物刺激剂市场采用，以与BiomaPhos自由竞争。
