Physiological and Biochemical Alterations of Urocholoa brizantha Submitted to Water Deficit and Silicate Fertilization

Abstract

The correction of soil acidity and the evaluation of the effects of correctives used are not frequent practices in pasture areas. The benefits of silicon on the physiology and biochemistry of pastures is a subject that has not been explored in great detail. The objective of this study was to evaluate the performance of Urochloa brizantha plants (cultivar Xaraés) submited to condictions of water deficity and silicate fertilization through physiological and biochemical parameters. The experiment was carried out in pots under greenhouse conditions..The experimental design was randomized blocks, in a 2 × 2 factorial arrangement, with eight replications. The treatments consisted of a combination of the presence and absence of silicon (by means of soil correction using agrosilicon and dolomitic limestone, to raise the base saturation to 50%) with 2 soil water conditions (40 and 80% of field capacity). The analyzes were performed to determine: net CO₂ assimilation rate, stomatal conductance, transpiration rate, water use efficiency, superoxide dismutase and catalase enzyme activities, shoot dry matter ,neutral detergent fiber and acid detergent fiber determinations and leave protein. The application of silicon in Urochloa brizantha cultivar Xaraés has the potential of attenuate the water deficity, increasing the photosynthesis, plant dry matter and antioxidant enzymes activity.