Abstract:

Bamboo of different ages was used in a split zone test design with three water replenishment gradients (85%±5%, 65%±5%, 50%±5% of field water holding capacity) and three fertilization gradients (12.50, 6.25, 3.13 kg/m²). The changes in chlorophyll and photosynthetic in different growth month under different treatment was determined and analyzed. Principal component analysis was used to comprehensively judge the optimal water-fertilizer coupling mode under different water and fertilizer coupling treatment, and to explore the water and fertilizer supply mechanism of bamboo under different irrigation conditions to achieve water and fertilizer efficient bamboo forest. The results showed that the chlorophyll content was highest under T4 treatment (field water holding capacity 65% ± 5% fertilizer application 100%). The chlorophyll content of the treated bamboo leaves was the highest in August. The net photosynthetic rate, stomata conductance, intercellular carbon dioxide concentration, and transpiration rate of Moso bamboo leaves in each month of T4 treatment were the highest, indicating that high-fertility water-irrigation could achieve the optimal effect of bamboo growth. During the whole growth stage, the maximum difference of chlorophyll content, net photosynthetic rate, intercellular carbon dioxide concentration and transpiration rate between different water and fertilizer coupling treatment occurred in August, meaning that August was the most critical period for bamboo to apply water and fertilizer.

Key words: Phyllostachys edulis, water and fertilizer, couplingphotosynthetic characteristics