Optimizing nitrogen management for young rubber trees: gradients effects on nutrient partitioning and root structural...

Area of Science:

• Agricultural Science
• Plant Physiology
• Soil Science

Background:

• Sustainable rubber tree (Hevea brasiliensis) cultivation requires efficient nitrogen (N) management.
• Understanding N application effects on young rubber trees is vital for optimizing growth and resource utilization.

Purpose of the Study:

• To investigate the impact of low, medium, and high nitrogen application rates on rubber tree seedling growth.
• To evaluate the effects on chlorophyll content, nitrogen allocation, and root architecture.

Main Methods:

• Rubber tree seedlings were subjected to three nitrogen (N) levels: low (CK), medium (MN), and high (HN).
• Measurements included plant growth, chlorophyll content, nitrogen derived from fertilizer (Ndff), biomass accumulation, and root architecture traits.
• Correlation analysis was performed to link root N content and Ndff with root traits.

Main Results:

• Medium nitrogen (MN) application optimized plant performance, yielding highest sustained chlorophyll a+b content and lowest chlorophyll a/b ratio.
• MN treatment showed superior nitrogen fertilizer utilization (Ndff) and resulted in the highest whole-plant biomass and total nitrogen accumulation.
• MN promoted a more vigorous fine root system with increased length, diameter, surface area, and volume during dormancy.

Conclusions:

• Medium nitrogen application is the most effective strategy for enhancing growth and nitrogen use efficiency in young rubber tree seedlings.
• High nitrogen application leads to transient chlorophyll increases but results in lower nitrogen uptake efficiency and potential environmental losses.
• Optimized nitrogen management is crucial for sustainable rubber tree cultivation.