Interação entre bactérias promotoras de crescimento vegetal e fertilização com cama de frango na cultura do milho

Abstract

The effects of applying inoculants with plant growth-promoting bacteria (BPCV) on seeds, associated with the use of poultry litter on corn plants, should be studied to elucidate the agronomic performance of this association and the economic efficiency of corn cultivation. This work aimed to evaluate the association of BPCV with poultry litter in corn. The experiment was carried out in protected cultivation, in a randomized block design and in a 4x5 factorial scheme plus 4 additional treatments and four replications. The first factor was composed of inoculation via seeds with BPCVs: (1) without inoculation; (2) Azospirillum brasilense; (3) Bacillus subtilis + Bacillus megaterium and (4) Pseudomonas fluorescens; and the second factor was the application of 5 doses of chicken litter, as follows: 0; 0.5; 1; 1.5; 2.0 times the recommended dose, which was 3,530 kg ha-1 of chicken litter, while in the additional treatments, commercial management was carried out with chemical fertilizer at a dose of 370 kg ha-1 of the 10-15-15 formula together with 250 kg ha-1 of simple superphosphate (SFS) at the time of sowing and top dressing with 408 kg ha-1 of urea at stage V6, combined with treatments without inoculation and the dose of each inoculant containing the bacteria. The variables evaluated were: Plant height, stem diameter, SPAD index, dry mass of leaves, stem+sheath and root, leaf area, root volume, ear height, ear length, ear diameter, ear weight, number of grains per ear, row per ear, grains per row, total mass of grains and mass of thousand grains, leaf and grain contents of nitrogen, phosphorus, and potassium, net CO2 assimilation rate (A), stomatal conductance (gs), internal CO2 concentration in the substomatal chamber (Ci), leaf transpiration rate (E), in addition to the following relationships: water use efficiency (EUA), intrinsic water use efficiency (EIUA) and instantaneous carboxylation efficiency (EiC). The use of chicken litter in association with BPCV can meet the nutritional needs of corn and can be used to replace mineral fertilizer. The interaction of BPCV and poultry litter influenced the accumulation of biomass and corn production components. There was no interaction between BPCV and chicken litter on indirect chlorophyll content and gas exchange in corn plants.