Recently, a research team led by Prof. WANG Guozhong and LI Wenchao from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences, developed a foliar nitrogen fertilizer that helps nanoagrochemicals better stick to rice leaves and resist being washed away by rain.
The related findings have been published in Environmental Science & Technology.
Rice leaves have waxy surfaces and complex micro/nanostructures, making them highly water-repellent. During spraying, fertilizer droplets can easily shrink, bounce off, or be removed by rainfall after deposition, reducing nutrient utilization efficiency.
To solve this problem, the researchers designed a silica nanoparticle-based foliar fertilizer loaded with nitrogen and added sodium dodecylbenzenesulfonate (SDBS). The new formulation, PSN0.2, improves both the initial spreading of fertilizer droplets and their long-term retention on leaf surfaces.
When sprayed onto rice leaves, SDBS helped fertilizer droplets spread more easily, while the micro/nanostructures of rice leaves helped keep them in place and prevent them from bouncing away.
After drying, the rough silica nanoparticles further enhanced adhesion between the fertilizer and leaf surface. After two simulated rainfall events, PSN0.2 retained 71.33% of its nitrogen on rice leaves, showing improved rainfastness compared with conventional foliar nitrogen fertilizer.
Field experiments showed that combining soil fertilization with PSN0.2 increased rice yield by 17.5% while reducing total nitrogen input by 10%.
The study offers insights into improving foliar fertilizer efficiency and reducing nutrient loss in agricultural applications, according to the team.
Schematic illustration of the foliar adhesion mechanism. (Image by LI Long)
