Water Engineering Department, College of Agriculture, Shiraz University, Shiraz, I.R of Iran.
The objective of the present study is to investigate the effects of irrigation water salinity, cow manure levels and different planting methods on ions variation in soil and their uptake by saffron. A split-split plot arrangement was conducted in a randomized complete block design with irrigation water salinity levels (0.45 (fresh water, S1), 1.0 (S2), 2.0 (S3) and 3.0 (S4) dS m-1) as the main plot, cow manure levels (30 (F1) and 60 (F2) Mg ha-1) as the subplot and planting method (basin (P1) and in-furrow (P2)) as the sub-subplot with three replications. Results showed that the concentration of sodium (Na+), calcium (Ca2+), chloride (Cl-), potassium (K+), sulphate (SO42-) ions in soil was increased significantly with increasing water salinity levels. These variations were in accordance with EC e variations that were 2.6 times in S4 compared with S1 treatment. However, the soil nitrate (NO3-N) decreased in the highest irrigation salinity level by about 30% compared with the lowest salinity level in two growing seasons. These element concentrations were significantly higher in F2 treatment in comparison with F1 due to addition of these ions by higher application rate of cow manure to soil. There was no significant difference between element concentrations in soil for two planting methods. Increasing salinity to the highest level significantly increased the saffron leaf concentration of Na+, Ca2+ and Cl- by about 4.0, 1.4 and 1.5 times, respectively. Increasing salinity resulted in decrease in K+, nitrogen (N) and phosphorus (P) concentration in saffron leaf by about 30, 20 and 39% under the highest water salinity level, respectively. The in-furrow planting method significantly led to increase in K+, N and P concentration in plant by about 10, 3 and 8% in comparison with the basin planting, respectively. Also, higher manure application rate as 60 Mg ha-1 significantly increased plant N and P concentration by about 12 and 20% in two growing seasons, respectively.