ADUBAÇÃO MINERAL E ORGANOMINERAL, COM E SEM ÁCIDO HÚMICO E FÚLVICO, NA PRODUÇÃO DE MILHO DOCE

Abstract

Organomineral fertilizers and soil conditioners can improve nutrient uptake by plants and, consequently, crop productivity gains. The objective of this study was to evaluate the management of mineral fertilizers (FM) containing potassium chloride (KCL), monoammonium phosphate (MAP) and organomineral fertilizer (FOM) containing potassium sulfate (K2SO4) with and without humic and fulvic acids in the culture of sweet corn. The experimental design was a 3 x 2 factorial, in five replications, with three forms of management: M1- FM formulation of KCL; M2 - FM with MAP and M3 - FOM containing K2SO4, plus three managements M4, M5 and M6 that were the addition of humic and fulvic organic acids. Photosynthetic variables such as photosynthetic rate, respiratory rate, electron transport, stomatal conductance, internal and external carbon ratio were evaluated. Agronomic variables such as stem diameter, ear insertion height, plant height were also evaluated. Also, the foliar contents of potassium, phosphorus, calcium, magnesium, copper, iron, zinc and manganese were evaluated. The variables of the yield components were: ear weight with straw, ear weight without straw, grain weight and grain yield. The use of fertilizers with an adequate supply of potassium chloride promotes improvements in the transport of electrons, increasing the ratio of Internal (Ci) and External Carbon (Ca), as well as greater heights of the plant and the insertion of spikes. Potassium sulfate organomineral fertilizer ensures greater accumulation of copper, iron and zinc in the leaf tissue. Humic and fulvic organic acids ensure greater nutrient accumulation, grain weight and sweet corn yield. The application of humic and fulvic acids and formulation with potassium sulfate promote an increase in the use of soil nutrients and, consequently, an increase in productivity and production quality.