MACRO AND MICRONUTRIENTS CONTENT OF SORGHUM UNDER WATER STRESS AND PHOSPHATE FERTILIZATION

Abstract

Low phosphorus availability and water stress are among the factors that have limited agricultural yield in soils of tropical regions. Based on that, an experiment was carried out to evaluate the effect of water stress and phosphorus levels on the nutrients accumulation in the shoots of sorghum plants (Sorghum bicolor (L.) Moench.), BR-304 mid-cycle cultivar. The experimental design was randomized blocks arranged in a 2x4 factorial scheme, being two water regimes (with and without water stress) and four phosphorus levels (0 mg dm-³, 50 mg dm-³, 100 mg dm-³, and 150 mg dm-3), with 4 replications. Plants were kept in pots (up to 9 kg of soil) and water stress was imposed 45 days after emergence, and persisted until growth stopped and apical leaves curled. Water stress reduced K accumulation and phosphorus fertilization increased the N, P, Ca, S, Mn, and Fe, and reduced the Zn absorption. The supply of P above 125 mg dm-3 reduced macronutrients accumulation in sorghum plants.

KEY-WORDS: Sorghum bicolor (L.) Moench.; drought tolerance; mineral nutrition; forage plant.