EFFECTS OF SOIL EXOGENOUS NITROGEN ON BAMBOO (DENDROCALAMUS LATIFLORUS MUNRO) SHOOTS, PHOTOSYNTHETIC CHARACTERISTICS, AND NITROGEN METABOLISM

Abstract

Nitrogen (N) is an essential nutrient element that is involved in almost every aspect of a plant's physiological mechanism. Therefore, the current research aims to determine the optimal amount of N fertilizer for bamboo seedlings for better nutrient management practices to minimize N pollution in bamboo forests. We evaluated the physiological response of Dendrocalamus latiflorus Munro grown under five varying levels of N fertilizer; such as N0, N1, N2, N3, N4, and N5 (0, 1.50, 3.00, 4.50, 6.00, and 7.50 g·pot-1, respectively). N4 treatment had a significant effect on the number of shoots, which was greatly correlated with net photosynthetic rate (Pn) and photosynthetic pigment including carotenoid (Car), total chlorophyll (Chls), and Chl a per b ratio (Chl a/b) as well as N-related indices [leaf N, leaf ammonium N (NH4+-N), and nitrate reductase (NR)]. N supply significantly increased soil carbon and N contents, which could be conducive to the accumulation of leaf chlorophyll content, improving leaf photosynthesis mechanism, and accelerating N metabolism and conversion through an enzymatic reaction. Overall, the N application of 6.00 g·pot-1 was advantageous to improving physiological characteristics and shoot production of seedlings, which provided a theoretical basis for improving bamboo nitrogen use efficiency and high-yield cultivation.