Increase in Silicate Fertilization Improves the Biomass of Drought-Tolerant Contrasting Cultivars Without Prejudicial effects in Nutrient Uptake in Sugarcane

Studies are still scarce about silicate fertilization as a silicon (Si) supply to drought-tolerant contrasting sugarcane cultivars. The objective was determined whether the increase of Si rates up to 1000 kg ha(-1)Si improves the Si in soil, Si uptake, and biomass of aerial part and root system of sugarcane without prejudicial effects in chemical attributes of soil and in nutrients absorption and whether Si concentration and biomass of drought-sensitive are increased similar to that of drought-tolerant sugarcane cultivar in the function of Si rates. An experiment was conducted in randomized blocks with cultivars (RB86-7515 = drought-tolerant; RB85-5536 = and drought-sensitive) and Si rates (0, 250, 500, 750, and 1000 kg ha(-1)Si) using silicate in sandy soil. Fertilization increased Si contents in soil, Si contents and biomass of straw and stalks, Si in green leaves, and biomass of roots, independent of cultivars. The Si rates improved also the Ca in green leaves and Mn in straw, but reduced Ca and Mg in the soil and Mg concentration in the straw. Lower biomass and higher Si concentration were found in RB85-5536, and it was also true in RB86-7515 for the roots. Fertilization with Si rates up to 1000 kg ha(-1)Si as silicate in sandy soil was not excessive, increasing Si availability, Si uptake in straw, green leaves, and stalks, and aerial part and root biomass, independently of cultivar without prejudicial effects in chemical attributes of soil and nutrient uptake in sugarcane.