Phosphorus sources enriched with filter cake and microorganisms in the soil microbiota: Phosphorus absorption and sugar cane dry matter production

Filter cake enriched with biofertilizer (associated with fertilizer phosphate) can increase the available phosphorus, and thus improve the absorption of phosphorus and dry matter accumulation by plants. The objective of this study was to evaluate the effect of phosphorus sources in the absence and presence of filter cake (enriched with biofertilizer or not enriched) on the soil population of microorganisms, soil phosphorus content, phosphorus accumulation in the aerial portion of the plant and production of dry matter in sugar cane plants. The experiment was performed in a greenhouse using sugar cane as the test plant. A completely randomized design was adopted with a 3×3+1 factorial arrangement and three repetitions. The treatments consisted of the application of three phosphorus sources (50 mg dm -3 of P, soluble in citric acid), (i.e., triple superphosphate, reactive phosphate of Bayovar ® and natural phosphate of Araxa), combined with three filter cake treatments (enriched/not enriched with biofertilizer and no filter cake as a control). The experimental unit consisted of a pot (20 dm 3 ) filled with samples of an Oxisol soil containing two plants. Ninety days after the transplantation, samples were evaluated in terms of the soil phosphorus content and the populations of bacteria, fungus and phosphate solubilizer microorganisms. After one hundred and twenty days, the production of dry mass and accumulation of phosphorus were evaluated. The triple superphosphate associated with filter cake enriched with biofertilizer stood out relative to the use of cake only in terms of increasing the phosphorus content in the soil, the phosphorus accumulation in the plant and the dry mass production in sugar cane plants. La cachaza enriquecida con biofertilizante asociado con fertilizantes de fosfato pueden aumentar el fosforo disponible, la absorcion por las plantas y la acumulacion de materia seca. Este trabajo tuvo como objetivo evaluar el efecto de fuentes de fosforo enriquecidas o no con cachaza y microorganismos en la poblacion de microorganismos del suelo, la disponibilidad de fosforo en el suelo, acumulacion de fosforo en la parte aerea de la planta y la produccion de materia seca en las plantas de cana de azucar. El experimento fue desarrollado en invernadero, con la prueba de la planta de cana de azucar. Se adopto un diseno experimental completamente aleatorizado, con tres repeticiones en arreglo factorial 3×3+1. Los tratamientos consistieron en la aplicacion de tres fuentes de fosforo (50 mg dm -3 de P, solubles en acido citrico): superfosfato triple, fosfato reactivo Bayovar ® y fosfato natural de Araxa, combinadas con la cachaza enriquecida con biofertilizante o no enriquecida, sin cachaza y el tratamiento control. La unidad experimental consistio de macetas (20 dm 3 ), llenadas con muestras de un Oxisol, conteniendo dos plantas. A los 90 dias se evaluo el contenido de fosforo en el suelo, las poblaciones de bacterias y de hongos y los microorganismos solubilizadores de fosfato. A los 120 dias se avaluo la produccion de materia seca y acumulacion de fosforo. El superfosfato triple asociado con la torta de filtro enriquecido con biofertilizante se destaco en relacion con el uso de solo la torta, aumentando el contenido de fosforo en el suelo, la acumulacion de fosforo para la planta y la produccion de masa seca en las plantas de cana de azucar.