Abstract:

One-year-old seedlings of Taxodium distichum were grown in a pot under greenhouse conditions with varying soil water contents (W₁, flooding; W₂, 75 of field water capacity; W₃, 25 of field water capacity), and there were four salt (NaCl) contents (0, 0.15, 0.3 and 0.45 of dry weight of soil)under every water content to study the effects of soil water and salt contents on growth and uptake of nutrients of T.distichum. The time of treatment was 130 days. The results showed that there were significant effects of soil water and salt contents on growth and uptake of nutrients of T.distichum. The relative height growth, relative ground diameter growth and biomass increment decreased with increase of soil salt content and decrease of soil water content. The total N, P and Na content in root, stem and leaf and the total Ca and Fe content in leaf increased with increase of soil salt content under the soil condition of flooding, while the total Fe, Ca and Mg content in stem and root had little significant difference. The total N, Na, Ca and Fe content in root, stem and leaf and the total P, K and Mg content in stem and leaf increased in a different degree with increase of soil salt content under the soil condition of W₂, while the total P, K and Mg content in stem decreased under higher soil salt content. The total N, P and K content in leaf, the total Ca and Mg content in stem and leaf and the total Na content in root, stem and leaf increased in a different degree with increase of soil salt content under the soil condition of W₃, while the total N, P and K content in stem and root and the total Fe content in root, stem and leaf decreased with increase of soil salt content.

Key words: Soil water content, Salt stress, Taxodium distichum, Growth, Uptake of nutrient