Soil Water Potentials and Sweet Sorghum under Salinity.

The energetic state of water in the soil-plant system is a relevant theme in ecosystems affected by abiotic stress. Thus, the present study aimed to investigate the water potential in soil and in sorghum grown in Fluvisol irrigated with water of increasing electrical conductivity and different ionic compositions. Solutions were prepared with different ionic compositions (NaCl and a salt mix) and with six increasing levels of electrical conductivity (0, 2.5, 5.0, 7.5, 10, and 12.5 dS m−1), with a randomized block design and 4 repetitions. The leaf water potential and leaf osmotic potential were determined 60 days after sowing. The soil osmotic potential was measured by saturation paste and the matric potential was estimated by the soil water retention curve. The increase in electrical conductivity, regardless of the type of saline solution applied, causes interference in the energy status of the water in the soil, especially concerning the osmotic potential. The type of salt exerts an influence on the water potential in the soil. In contrast, the salt type does not influence the potentials of water in the plant. It is not recommended adopting the same values of water total potential for the soil determined in sorghum at night. [ABSTRACT FROM AUTHOR]