A Controlled-Release Nanofertilizer Improves Tomato Growth and Minimizes Nitrogen Consumption

Area of Science:

• Agricultural Science
• Materials Science
• Environmental Science

Background:

• Sustainable agriculture aims to reduce agrochemical inputs, particularly nitrogen, for economic and environmental benefits.
• Biopolymers like lignin offer biodegradable alternatives to petroleum-based synthetic polymers in controlled-release fertilizers (CRFs).
• Lignin, an abundant natural biopolymer, can be utilized in developing eco-friendly agricultural materials.

Purpose of the Study:

• To develop controlled-release urea (CRU) using a biobased nanocomposite of lignin and bentonite clay.
• To evaluate the efficiency of these CRU fertilizers in enhancing tomato plant growth and yield under field conditions.
• To assess the impact of CRU on nitrogen use efficiency (NUpE) and fruit quality parameters.

Main Methods:

• Five types of CRU were synthesized using modified bentonite at different ratios and techniques.
• Tomato plants were treated with CRU at 100%, 50%, and 25% of the recommended nitrogen (N) dose.
• Plant growth parameters, yield, fruit characteristics, and NUpE were measured and compared to a control group.

Main Results:

• All CRU treatments significantly enhanced plant growth (height, leaf number, weight) and yield compared to the control.
• CRU application improved fruit characteristics, with higher firmness and acidity observed at 25% and 50% N levels.
• Nitrogen uptake efficiencies (NUpE) for CRU ranged from 47-88%, substantially higher than the control (33%).

Conclusions:

• Lignin-bentonite CRU fertilizers are effective in improving tomato plant growth, yield, and fruit quality.
• CRU treatments, particularly at a 25% N dose, outperformed conventional urea in multiple growth and yield parameters.
• The developed CRU demonstrates significant potential for enhancing nitrogen use efficiency in sustainable agriculture.