Influence of Saline Irrigation Water and Gypsum on Leaf Nutrient Accumulation, Protein, and Oil Seed in Soybean Cultivars

ABSTRACT

Due to the limitation of irrigation water, irrigating with saline water is a common practice used by farmers. Application of saline irrigation water has undesirable effects on growth and yield of plants. Some amendment materials such as gypsum can adjust the undesirable effects. In addition, some plant varieties are tolerant to saline conditions. In this regard, in 2001–2002 growing season three soybean cultivars (‘Sahar’, ‘JK’, and ‘Hill’) were selected, three levels of gypsum (0, 1.5, and 3 g pot^{− 1}), and four levels of electrical conductivity of irrigation water namely 0.7 (well water), 2.5, 4, and 7 dS m^{− 1} (mixture of Caspian seawater and well water) were applied in a completely randomized factorial design with three replications in a greenhouse experiment. The results showed that with increasing saline irrigation water the amounts of potassium (K⁺), sodium (Na⁺), calcium (Ca^{2 +}), and sodium (Na⁺)/Ca^{2 +} ratio increased in leaves. The yield, oil, and protein in seed and the K⁺/Na⁺ ratio amounts accumulated in leaves decreased. Interactive effects of salinity and varieties in K⁺ and Ca^{+ 2}accumulated in leaves and grain protein and oil were significant. Concentrations of K⁺ in leaves of the ‘Hill’ cultivar were more than in the ‘Sahar’ and ‘JK’ varieties. Calcium accumulation in ‘JK’ leaves was more than in the other varieties. The protein content in ‘JK’ was more than other varieties and the amount of oil seed in ‘Hill’ and ‘JK’ varieties was more than in the ‘Sahar’ variety. Application of gypsum increased the yield, Ca^{2 +}, and K⁺ concentrations in leaves and grain protein, but decreased the amount of oil seed (not significant). Meanwhile, interactive effects of salinity, variety, and gypsum in increasing the accumulation of Ca^{2 +}, K⁺, Na⁺, and Na⁺/Ca^{2 +} in leaves were significant.

Keywords:

• gypsum
• potassium
• protein and soybean
• saline irrigation water
• yield

ACKNOWLEDGMENT

The financial support of University of Mazandaran and help of Mr. Bahrololumi, Mr. Aziz zade Firouzi, and Mrs. Quasempour is kindly acknowledged.