Phosphate-solubilizing microorganisms and phosphorus rates affecting yield, nutrient uptake and economic viability of corn and rice in the off-season

Abstract

Increasing crop yield using bio-inputs and optimized fertilizer application is a key strategy for agricultural sustainability. This study aimed to evaluate the effects of inoculation with phosphate-solubilizing microorganisms combined with phosphorus rates on the agronomic performance, production costs and sustainability in off-season corn and upland rice cultivation. The experiment was conducted using a 2 x 4 factorial design for both crops. Treatments consisted of two phosphorus levels [50 % (45 kg ha-1 of P2O5) and 100 % of the recommended rate (90 kg ha-1 of P2O5)], three isolates of multifunctional rhizobacteria [Burkholderia sp. (BRM 32111), Serratia sp. (BRM 63523) and Bacillus sp. (BRM 63524)] and a control treatment (no rhizobacteria). The inoculation with BRM 63524 increased the biomass and nutrient accumulation for both corn and upland rice, highlighting its potential to enhance nutrition and reduce the reliance on synthetic fertilizers, despite the variation in the rice yield response. The reduced phosphorus application (50 % of the recommended dose) generated higher profits, especially for corn, which showed the highest yields and profitability. For rice, the combination of a lower phosphorus rate with rhizobacteria resulted in greater profits than for the full phosphorus application.

KEYWORDS: Zea mays, Oryza sativa, Bacillus, Burkholderia, Serratia.