ABSTRACT

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.

摘要

在受非生物胁迫影响的生态系统中，土壤-植物系统中水的高能状态是一个相关主题。因此，本研究旨在研究用增加的电导率和不同离子组成的水灌溉的Fluvisol中生长的土壤和高粱中的水势。用不同的离子组成（NaCl和盐混合物）和六种增加的电导率（0、2.5、5.0、7.5、10和12.5 dS m ^-1）制备溶液），随机区组设计和4个重复。播种60天后测定叶片水势和叶片渗透势。用饱和糊剂测量土壤渗透势，并通过土壤保水曲线估算基质势。不管所用盐溶液的类型如何，电导率的增加都会导致土壤中水的能量状态受到干扰，尤其是在渗透势方面。盐的类型会影响土壤中的水势。相反，盐类型不影响植物中水的潜力。对于夜间在高粱中测定的土壤，不建议采用相同的总水势值。