Maize crop response to different levels of mineral and or-ganomineral fertilization associated with plant growth promoting bacteria (PGPBs)

Abstract

Corn has a high nutritional requirement, especially with regard to NPK fertilization. However, the low efficiency of conventional fertilizers combined with the high cost of the input has limited the reach of high yields. The use of fertilizers with increased efficiency seeks to mitigate these limitations, reducing potential losses due to the gradual release of nutrients. The objective of this work was to compare the nutrition, growth and production of maize plants subjected to different doses and special NPK fertilizers fully applied at planting, as well as their residual effect on the soil. A randomized block design was used, in a 3 x 4 factorial scheme, with four replications. The first factor consisted of conventional mineral, polymer coated and organomineral fertilizers inoculated with PGPBs. The second factor was doses of 0, 60, 90 and 120 kg ha-¹ of NPK. Vegetative growth, foliar nutrition (N, P and K), yield growth components, productivity, profitability and P and K nutrient content remaining in the soil after cultivation were evaluated. The conventional mineral fertilizer presented higher production of dry biomass of the aerial part and profitability in relation to the special fertilizers. However, the special fertilizers presented better results in the vegetative and productive growth, in general, still showing a potential reduction of the applied doses, without compromising the grain yield, especially in the organomineral fertilization + PGPBs. The same showed greater residual effect of K in the soil, proving to be relevant longterm studies for better elucidation of these effects in the soil and subsequent culture.