Effects of Nitrogen Applications on Transpiration, Physiological, and Growth Characteristics of Sugarcane (Saccharum spp.)

Improving fertilizer and water use efficiencies is an important strategy in agricultural production. This study aimed to evaluate the effect of nitrogen fertilization on the daily whole-plant transpiration, growth, and physiological activities of sugarcane. The pot experiment was conducted under glass-house conditions. Five treatments of various nitrogen application rates (0, 4, 8, 12, and 16mM) were assigned in a randomized complete block design with three replications. The result showed that higher nitrogen applications led to higher growth, physiological, and biomass parameters. Nevertheless, biomass nitrogen use efficiency and photosynthetic water use efficiency declined because of applying nitrogen at higher rates. During the first weeks of plant growth, no significant differences in plant height, leaf number, SPAD, and whole-plant transpiration among nitrogen treatments indicated that higher nitrogen added was not necessary during this time. Nitrogen and water use efficiencies could be improved if the remaining soil nitrogen and crop growth stage nitrogen requirements are estimated in cultivation practice.