Microbial inoculation and phosphate fertilization on sugarcane yield and P fractions in multi-sites of south-central Brazil

• Ano de defesa: 2025
• Autor(a) principal: Silva, Gabriel Pinheiro
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: Saccharum spp; Saccharum spp.; Bioinsumos; Bioresources; Fósforo; Phosphorus
• Link de acesso: https://www.teses.usp.br/teses/disponiveis/11/11140/tde-04042025-095019/

The broadcast application of phosphorus (P) over the entire area, in regions with very low soil P levels, is a common practice in Brazil despite the high P fixation capacity of tropical soils. Inoculation with microorganisms has emerged as a strategy to improve the uptake of P fertilizers by plants, although its use is not yet well established. This study aimed to evaluate the response of sugarcane to different phosphorus fertilization strategies (corrective phosphate application, furrow fertilization, and ratoon reapplication) with or without the use of bioinputs. Two types of studies were conducted: the first investigated the interaction between corrective phosphate application and furrow fertilization at four locations over three cycles (plant cane, first, and second ratoons). The second evaluated phosphorus fertilization strategies, with and without bioinputs, across eight locations and two cycles (plant cane and first ratoon). Two types of bioinputs were assessed: a biological conditioner (Microgeo™, BC) and phosphate-solubilizing bacteria (PSB)-based products. In the first study, the combination of corrective phosphate application and furrow fertilization increased productivity in 4 of the 12 site-cycles evaluated. Corrective phosphate application alone increased productivity in 2 of the 12 site-cycles but showed a negative response in one of them. Furrow P application at rates of 100 to 200 kg P2O5 ha-1 resulted in an average yield increase of 6.5 Mg ha-1 in 3 site-cycles. Applying 150 kg P2O5 ha-1, either as corrective phosphate or furrow fertilization, yielded an average of 97 Mg ha-1 (mean of four locations), compared to 92 Mg ha-1 in the control, with no additional gains observed from combining corrective phosphate application with furrow fertilization. In the second study, the BC increased productivity by 5.7 Mg ha-1 in the plant cane cycle, averaged across the eight locations. The effects of PSB were variable depending on the initial soil P content: in high-P soils, productivity decreased, while in soils with low to medium P levels, productivity was maintained or increased. Ratoon P reapplication increased productivity by 4.9 Mg ha-1, averaged across the eight locations. These studies highlighted the potential for reducing P use in plant cane and ratoon reapplication, as well as the association with bioinputs, which proved to be agronomic practices with the potential to enhance P-use efficiency and improve the sustainability of sugarcane production.