Manejos nutrifisiológicos e biológicos na cultura da soja em ambiente de elevada altitude

Abstract

The study evaluated the performance of soybean (Glycine max (L.) Merr.) under different nutri-physiological management strategies in high-altitude environments. The experiment was carried out in Mangueirinha-PR, using a randomized block design in a 2 x 3 factorial scheme with five replications. The factors consisted of two environments (with and without biological inoculation) and three managements (two foliar treatments with commercial products and one untreated control). Agronomic variables related to growth and yield were analyzed, including plant height, number of branches, grains per main stem, per branch, per plant, and per square meter, as well as yield and thousand-grain weight. Analysis of variance indicated significant effects of nutri-physiological management on thousand-grain weight, number of grains per branch, per plant, and per square meter, demonstrating that foliar fertilization and biostimulants positively influenced yield components. The interaction between treatment and environment was significant only for plant height, suggesting different growth responses under distinct soil biological conditions. The use of seaweed extracts and micronutrients proved effective in regulating plant structure and enhancing reproductive differentiation, resulting in more productive branches and grains per plant. Positive correlations were found between yield and thousand-grain weight (r = 0.53), and between yield and number of branches (r =0.39), highlighting the structural role of branching in increasing productivity. Conversely, plant height showed a negative correlation with yield (r = -0.29), indicating that taller plants do not necessarily produce more. Overall, the integration of nutri-physiological management with biological products and co-inoculation promoted improvements in soybean agronomic performance under high-altitude conditions, contributing to more efficient and sustainable production systems.