The role of potassium and zinc in reducing salinity and alkalinity stress conditions in two wheat genotypes

Abstract

Soil salinity may reduce potassium (K) uptake due to strong competition with sodium cations at the root surface. In calcareous soils, zinc (Zn) precipitates in forms unavailable to plants. This study evaluated the responses of two wheat genotypes (C), Baccrosroshan and salinity-tolerant Line No. 4, to K and Zn fertilizers in both greenhouse and farm experiments with similar soil and water conditions. A factorial experiment with four K levels (K0 = 0, K1 = 72, K2 = 144 and K3 = 216 kg K2O ha−1) and three Zn levels (Zn0 = 0, Zn1 = 20 and Zn2 = 40 kg ha−1) based on a randomized complete block design was employed. Analysis of variance results showed significant Zn × K × C interactions on all measured traits. Despite sufficient available potassium and illite clay in the root-growing medium, plants responded to K application. Yield components, grain yield and protein content of the two genotypes increased linearly as Zn × K increased. Considering Zn2K2 and Zn2K3, Line No. 4 produced 17% higher 1000-grain weight, 30% higher weight of grains per ear and 23% higher grain yield than Baccrosroshan in the farm experiment, and 10, 50, 16% higher values, respectively, in the greenhouse experiment. Results showed a significant relationship between grain weight per ear and grain yield. The achieved results highlight the importance of K and Zn nutrition under salt-stress conditions.