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ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Research Unit » Research » Publications at this Location » Publication #322485

Title: Ion-specific limitations of sodium chloride and calcium chloride on growth, nutrient uptake, and mycorrhizal colonization in northern and southern highbush blueberry

item Bryla, David
item Scagel, Carolyn
item LUKAS, SCOTT - Oregon State University
item SULLIVAN, DAN - Oregon State University

Submitted to: Journal of the American Society for Horticultural Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/3/2021
Publication Date: 9/17/2021
Citation: Bryla, D.R., Scagel, C.F., Lukas, S.B., Sullivan, D.M. 2021. Ion-specific limitations of sodium chloride and calcium chloride on growth, nutrient uptake, and mycorrhizal colonization in northern and southern highbush blueberry. Journal of the American Society for Horticultural Science. 146(6):399-410.

Interpretive Summary: Salinity is becoming an increasing problem for production of highbush blueberry in arid and semi-arid regions. The salts originate from soil parent material (weathered rocks and minerals), irrigation water, fertilizers, and soil amendments such as manures and composts. Any salt that accumulates in excessive amounts can limit plant growth and become toxic to the plants, but two of the most dominant forms in saline soils are calcium chloride and sodium chloride. The objective of the present study was to determine the effects of low, medium, and high rates of calcium and sodium chloride on plant growth and nutrient uptake in highbush blueberry. Experiments were conducted on both northern and a southern types of highbush blueberry. Sodium chloride reduced plant growth more than calcium chloride in both of the blueberry types, but calcium chloride resulted in more leaf damage over time. Salinity also reduced root colonization by mycorrhizal fungi, which are beneficial to the plants for nutrient uptake. Mycorrhizal colonization was particularly affected when the plants were treated with sodium chloride. Salinity from sodium chloride also reduced plant uptake of essential nutrients such as potassium and calcium more than salinity from calcium chloride, while both of the salts increased the amount of chloride in the plant tissue, which can be toxic to the plants. The information from this work will be used to develop better salt management practices for commercial blueberry production.

Technical Abstract: Two experiments were conducted to determine the level of salinity in which growth and nutrient uptake is limited in highbush blueberry. The first experiment was conducted on a northern highbush cultivar, Bluecrop, and second was conducted on a southern highbush cultivar, Spring High. The plants in both experiments were exposed to different levels of salinity from either sodium chloride (NaCl) or calcium chloride (CaCl2). Total dry weight of the plants was negatively correlated to electrical conductivity (EC) of the pour-through leachate and, depending on the source and duration of the salinity treatment, decreased linearly at a rate of 1.6–7.4 g per dS/m in Expt. 1 and at a rate of 0.4–12.5 g per dS/m in Expt. 2. Initially, the reduction in total dry weight was similar between the two salinity sources, but by the final harvest at 125 d in Expt. 1 and 111 d in Expt. 2, was greater with NaCl than with CaCl2 in the leaves, stems, and roots. The percentage of root length colonized by mycorrhizal fungi also declined with increasing levels of salinity in Expt. 1 and was lower in both experiments when the plants were treated with NaCl than with CaCl2, while leaf damage from salinity was greater with CaCl2 than with NaCl. In general, CaCl2 salinity had no effect on uptake or concentration of Na in the plant tissues, but NaCl salinity reduced Ca uptake in both experiments and reduced the concentration of Ca in the leaves and stems in Expt. 1 and in each plant part in Expt. 2. Salinity from NaCl also resulted in higher concentrations of Cl and in lower concentrations of K in the plant tissues than CaCl2. The concentration of other nutrients in the plants, including N, P, Mg, S, B, Cu, Fe, Mn, and Zn, was also affected by salinity, but in most cases, the response of these nutrients to salinity was similar between the two salts.