Dry-season irrigation further promotes the growth of Eucalyptus urophylla × E. grandis plantations under the conventional fertilization

The Impact of Long-Term Dry-Season Irrigation on Eucalyptus Tree Height Growth: Insights from Leaf Photosynthesis and Water Conduction

“…First, the external cause for the differential performance of tree height growth rates among different treatments during the wet and dry seasons in this study may be attributed to variations in soil nutrient availability (Table S1). Through five years of water supplementation, the nutrients increased by fertilization in the WF treatment were also utilized more in the previous dry seasons, which was consistent with previous studies where WF's growth was significantly higher than other treatments [4], resulting in no significant difference in tree height growth rates between the WF and W treatments during the dry season in this study. Similarly, in the F treatment, the fertilization nutrients were not fully utilized during the previous five years' dry seasons.…”

“…Moreover, although there were no significant differences in functional traits (K leaf , A n , and H r ) between the WF and W treatments during the dry season, the functional traits of the W treatment were consistently higher than those of the WF treatment. This may be due to the initial rapid growth of the WF treatment, facilitated by sufficient water and nutrient conditions [4]. As tree height increases, the resistance to water transport to the canopy leaves increases [37], and the pathway for downward transport of organic matter becomes longer, requiring more energy consumption [38].…”

“…Specifically, the dry season spans from October to March of the subsequent year, during which the annual precipitation accounts for less than 20% of the total rainfall [2]. Relevant studies have demonstrated that the growth of Eucalyptus is adversely affected during the dry season due to water scarcity [3][4][5]. Hence, delving into the physiological mechanisms by which Eucalyptus plantations adapt to dry-season irrigation becomes essential in driving their growth and productivity to new heights.…”