The Effect of Calcium Polysulfide on Soil Nutrients and Some Growth Attributes of Sweet Basil (Genovese cultivar) under Salinity Stress

Soil salinity is one of the most important factors reducing plant yield and affects many physiological and metabolic activities of plants, thereby reducing their growth and yield. Food management plays an important role in reducing salinity stress in various environmental conditions. Calcium and sulfur are important elements to increase plant resistance to salinity.

To investigate the effect of different levels of calcium polysulfide (control (0), 15, 20, 25 and 30 liters per hectare) at different salinity levels (1, 2, 3 and 4 dS/m) on soil nutrients and some growth attributes of Ocimum basilicum (Genovese cultivar), an experiment was conducted based on factorial in a completely randomized design with three replications in greenhouse at Qaemshahr in 2018. Measurement traits in this experiment included plant height, lateral branch length, number of lateral branches, number of leaf, leaf area, fresh and dry weight of aerial parts and some soil elements (percentage of organic matter, electrical conductivity of soil, phosphorus, potassium and absorbable sulfur, calcium, Magnesium, sodium and chlorine soluble).

The results showed that the highest shoot dry weight to 27.2 gram per plant was obtained in 1 dS/m salinity with 30 lit/ha calcium polysulfide treatment. Salinity caused a significant decrease in shoot dry weight and other vegetative traits such as number of branches, leaf area and plant height that in these traits, the highest decrease was observed in the absence of calcium polysulfide. However, application of calcium polysulfide at most salinity levels had a positive effect on these traits. Although the maximum effect of calcium polysulfide on leaf area and shoot dry weight was related to 2 dS/m salinity, but the highest effect of calcium polysulfide was observed on plant height, leaf number per plant and stem length at 4 dS/m salinity. With the application of calcium polysulfide, the amount of potassium, zinc, iron and copper in the soil solution decreased, while the amount of calcium, manganese and chlorine in the soil solution increased. Salinity had a negative effect on the amount of phosphorus, zinc and sulphur in the soil, but it did not affect the solubility of other elements.

The results showed that the application of calcium polysulfide can partially reduce the effect of salinity at different salinity levels on the growth attributes of basil.