Plant Responses to Sulfate and Chloride Salinity: Growth and Ionic Relations

Abstract

Growing salt‐tolerant crops is one of the more cost‐effective strategies for coping with soil salinity, which is a significant factor affecting crop production and agricultural sustainability on the Canadian prairies. This study was carried out to determine if salt tolerance data, generated by traditional Cl (NaCl/CaCl2) salinization procedures, are appropriate to the prairies, where SO4 salinity predominates. Barley (Hordeum vulgare L., cv. Bonanza) and kochia [Kochia scoparia (L.) Schrad.] seedlings were grown in sand culture and salinized with either Cl or SO4 salts. The latter system was designed to mimic the natural salinity of prairie soils. The results showed that plant responses to salinity depend on the kind of salts (sulfates or chlorides) contributing to salinity as well as on the total electrolyte concentration. Growth was significantly better (by an average of 17%) on the SO4 system. However, barley salinized with SO4 salts developed severe Ca deficiency at high salt concentrations (electrical conductivity [EC] 17.5–27.5 dS m−1) because of low solubility of Ca. Kochia, which is more efficient than barley in absorbing Ca, was not limited by Ca. Barley and kochia tended to have higher selectivity for nutrient cations (Ca, Mg, and K) over Na when the plants were grown on the Cl salt system. This may be an indication of a beneficial effect of the high Ca supply in the NaCl/CaCl2 salt system on membrane selectivity. Our results show that there are many possible interactions between salt concentration, salt type, and plant nutrition. The significance of these interactions for salt tolerance testing may vary from crop to crop and may depend on factors such as the nutrient concentration in the growing medium. From a practical standpoint, however, response functions generated by NaCl/CaCl2 salinization probably provide an acceptable measure of the tolerance of most crops to SO4 salinity.

Subsoil constraints in Vertosols: crop water use, nutrient concentration, and grain yields of bread wheat, durum wheat, barley, chickpea, and canola

“…Generally, evidence in the literature points to gypsum either having a slight negative or an ameliorative effect on the adverse impact of Cl (e.g. Curtin et al 1993;Marschner 1995). Further, at the high subsoil constraint site, the maximum depth of water extraction was severely restricted, resulting in further reduction in PAWC and grain yield.…”

Effects of Salinity, Imazethapyr, and Chlorimuron Application on Soybean Growth and Yield

“…In prairie soils in the United States, Canada, and the San Joaquin Valley of California, salinity is comprised of both chloride and sulfate salts. Plants may demonstrate different responses to sulfate-dominated salinity than to chloride-based salinity at the same electrical conductivity (Curtin, Steppuhn, and Selles 1993). A larger decrease in soybean biomass production has been observed in soils salinized with chloride salts than with sulfate salts (Gupta and Gupta 1984).…”

Nutrição mineral de mudas de pupunheira sob diferentes níveis de salinidade

“…Com o P ocorreu uma redução do teor nas raízes a partir de 15 mmol L -1 de NaCl, o que está de acordo com os resultados obtidos por Aljuburi (1996), em palmáceas e Saur et al (1995), em Pinus (Tabela 1). Tal fato pode estar relacionado a uma baixa atividade do P 2 O 5 na solução, com o aumento do NaCl (Al-Karaki, 1997), que eleva a força iônica, ou a uma desordem nutricional induzida por elevados teores de Cl nos tecidos da planta, inibindo a absorção de P (Mor & Manchanda, 1992, citados por Curtin et al, 1993).…”

“…Tal comportamento pode ser justificado por uma competição iônica entre o Cl e o S, resultando numa menor absorção e, ou, transporte para a parte aérea (Curtin et al, 1993). O aumento do teor de Na nas folhas foi maior que nos estipes e raízes, indicando a inexistência de mecanismos de exclusão ou de alocação de Na, limitando o transporte para as folhas, características de espécies não tolerantes à salinidade (Yahya, 1998).…”