氮磷钾肥对水曲柳雌雄株叶片光合生理及化学计量特征的影响.

To clarify the preference of female and male plants of Fraxinus mandshurica for nutrient absorption will help to carry out precise fertilization of female and male plants, improve fertilization efficiency, and promote flowering and fruiting. This study took the female and male plants of F. mandshurica mature plantation as the objects, and carried out a complete test of three factors and three levels of nitrogen, phosphorus and potassium. Nitrogen fertilizer was set at three levels (0. 15、0. 30、0. 45 g / L), phosphorus fertilizer was set at three levels (0. 3、0. 6、0. 9 g / L), and potassium fertilizer was set at three levels (0. 2、0. 4、0. 6 g / L), a total of 27 treatments. The net photosynthetic rate, stomatal conductance, intercellular CO2 concentration, transpiration rate, relative chlorophyll content, leaf area and leaf nutrient content of leaves were measured at the second month after fertilization, and the correlation coefficients between various variables were discussed. The results showed that the mixed fertilization of nitrogen, phosphorus and potassium could promote the improvement of leaf functional traits of male and female F. mandshurica in different degrees. Except for intercellular CO2 concentration, leaf area and leaf phosphorus content, the maximum values of other indicators appeared in N3P2K2(female) and N2P3K3 (male) treatments, which were significantly higher than the control (P<0. 05). Under the same fertilization treatment, the male and female plants of F. mandshurica showed significant gender differences in the measured indicators. The N ∶P ranged from 8. 62 to 14. 08 and 7. 91 to 12. 80, the N ∶K ranged from 2. 33 to 4. 32 and 2. 47 to 4. 22, and the K ∶P ranged from 2. 67 to 4. 36 and 2. 75 to 3. 91, respectively. The mass fraction of nitrogen, phosphorus and potassium in leaves was negatively correlated with intercellular CO2 concentration (P<0. 05), and positively correlated with other physiological indexes (P<0. 01). The above results showed that the female plant of F. mandshurica under N3P2K2 and the male plant under N2P3K3 treatment had the best effect on the functional properties of its leaves. The main limiting element affecting the leaf function of F. mandshurica was N, and nitrogen fertilizer can be appropriately increased in forest land management. [ABSTRACT FROM AUTHOR]