Índice de clorofila de espécies arbóreas cultivadas em solo salino-sódico tratado com gesso e casca de ovo

Abstract

The semi-arid region of Brazil presents soils with high salt content that limit their use in agriculture, making it necessary to adopt strategies to reduce the effect of salinity. The general objective of this work was to evaluate the initial growth of aroeira (Myracrodruon urundeuva) and sabiá (Mimosa caesalpiniifolia) in saline-sodic soil treated with gypsum and eggshell, in the city of Teresina, Piauí. The experiment was conducted in a completely randomized design, in a 5 × 2 factorial scheme, with five substrates with different levels of sodicity (saline-sodic soil without corrective; saline-sodic soil + gypsum; saline-sodic soil + eggshell; saline-sodic soil + ½ the amount of gypsum + ½ the amount of eggshell; and a non-saline substrate) and two tree species. Chlorophyll levels were evaluated 165 days after transplanting seedlings into pots with 0.8 dm³ of soil. Saline stress reduced chlorophyll levels in sabiá. Aroeira showed a satisfactory response when the saline-sodic soil received gypsum and eggshell; however, it was more sensitive than sabiá to high percentage of exchangeable sodium (PST) in the treatment without corrective. Correlation analysis indicates that sabiá has greater consistency in morphophysiological relationships than aroeira.