Phosphorus availability for bean cultivation due to the application of silicon in oxisol

Abstract

The cultivation of beans (Phaseolus vulgaris) is no longer considered subsistence and has become one of the most profitable agricultural crops with the use of technologies. One of the main limitations to the growth and plant development of common beans in acidic and highly weathered Brazilian soils is the low bioavailability of P in the soil solution, due to the fixation of phosphorus (P) to the soil colloids and the formation of insoluble compounds with iron and aluminum. One of the alternatives to increase the efficiency of phosphate fertilizers is the use of competing anions for phosphate adsorption sites, such as silicate. The addition of Si to the soil can occur through the practice of stonemeal, through the application of silicate rock powder considered a by-product of mining. The objective of this work is to evaluate the effect of the application of sources and doses of Si on the availability of P for the bean culture (variety BRS Estilo - Embrapa) in Oxisol. The experiment will be carried out in a greenhouse, in 5 dm-3 pots, with a randomized block design arranged in a factorial scheme 4x2 + 1, with 9 replications. Treatments include 4 doses (0, 200, 400, and 800 kg ha-1) and two sources of Si (conventional - silicic acid; alternative - silicate rock powder). Fertilization with P will be done as recommended for cultivation in the State of São Paulo. The adsorption of P by soil samples with different doses and sources of Si will be evaluated by batch laboratory experiments, using increasing doses of P (0, 40, 80, 120, 160, 200, 240, 280, 320, 400 mg L-1). The results will be adjusted to the Langmuir model, using the Visual MINTEQ software. At 90 days after emergence, the following parameters will be evaluated: plant height, shoot dry weight, number of pods per plant, pod length, number of grains per pod, and weight of one hundred grains. The biometric results of the plants will be submitted to analysis of variance (ANOVA), and, if significant by the F test (p <0.05), the treatment means will be analyzed by the Scott-Knott test (p <0.05).