Growth, development and nitrogen nutrition of colored cotton cv. BRS Topázio under sustainably-constructed soil

Abstract

Agroecological practices such as seed inoculation with diazotrophic bacteria and biofertilizers use have contributed to the development of sustainable agriculture. Therefore, this work aimed to study the effect of biofertilizers and the bacterium Azospirillum brasilense on the growth, development, and mineral nutrition of colored cotton cv. BRS Topázio. Thus, we conducted an experiment with the following treatments: 1) control; 2) inoculation of cotton seeds with nitrogen-fixing bacterium A. brasilense (Nfixed); 3) treatment of seeds with biofertilizer (Bio) + subsequent applications; 4) (Nfixed) + subsequent applications of Bio; and 5) mineral fertilization. The results showed that agroecological practices increase plant growth; the root:aerial ratio increases with conventional agricultural practices such as mineral fertilization, which also provides a lower reproductive mass:vegetative mass ratio of the aerial parts; plants fertilized with mineral sources concentrate more nitrogen (N), crude protein, magnesium (Mg), and sulfur (S) in their tissues; plants from seeds inoculated with A. brasilense accumulated more S when they received anaerobic biofertilizer compared with those that did not receive it; and agroecological practices improve soil fertility.