Bactérias solubilizadoras de fósforo na cultura do milho (Zea mays) em solos com baixo e alto teor de fósforo

Abstract

Phosphorus is the most limiting nutrient in Brazilian soils given its low efficiency of use and high soil adsorption. Thus, strategies such as the use of growth-promoting and nutrient-solubilizing bacteria capable of increasing soil efficiency of use may be the only viable alternative for maintaining the productive capacity of soils in the long term. In this context, this work aimed to evaluate the effect of bacteria with P solubilizing potential (Azospirillum, Pseudomonas, Bacillus aryabhattai and Pseudomonas + Bacillus aryabhattai) in soils with low (2 mg dm3) and high phosphorus content (32 mg dm3). Dry mass of the aerial part and root system of the corn plants showed superiority in the soil with high phosphorus content in relation to the soil with low phosphorus content. There was no difference for dry mass of the aerial part of the corn plants between the control treatment and the growth-promoting bacteria in the soil with low phosphorus content. However, for root dry mass, azospirillum showed superior values than the control treatment in soil with low phosphorus content. The use of growthpromoting bacteria Azospirillum, Pseudomonas and Bacillus aryabhattai showed a higher dry mass of the aerial part of the corn plants in relation to the treatment with Pseudomonas + Bacillus aryabhattai, which did not differ from the control treatment in the soil with high phosphorus content. In the soil with low phosphorus content, all treatments were similar, however, all showed lower dry mass wheight in relation to treatments with high soil phosphorus content. The combined use of Pseudomonas + Bacillus aryabhattai showed lower root dry mass than the isolated treatment with azzospirillum in soil with low phosphorus content. All treatments in the high phosphorus soil showed greater root mass than the treatments in the low phosphorus soil.