Enhancing Food Crop Sustainability with Nanoparticles

Nanoparticle technology could reduce the need for fertilizer, creating a more sustainable way to grow crops such as mung beans.

The global population is growing, and ensuring that there’s enough food to go around means finding better ways to grow crops.

Phosphorus is a key nutrient for plant growth; it promotes root growth, hastens maturity and is important to the development of new tissues. That’s why it’s commonly used in fertilizers, which are being applied more and more as farmers increase crops for an increasing population.

However, only about 42 percent of this added phosphorus is actually taken up by the plant. The remainder runs off, and when it reaches water it can cause excessive algae growth, poisoning water supplies.

Additionally, phosphorous is a non-renewable resource, making this method of fertilization is not sustainable. Ramesh Raliya, a research scientist at Washington University, estimates that nearly 82 percent of the world’s phosphorus is being used as fertilizer, and if current methods continue, we will run out of phosphorus in as little as 80 years.

Zinc oxide nanoparticles created by a team of chemists and engineers may be the answer. The team synthesized the nanoparticles from a fungus that grows around plant roots and helps them mobilize and take up nutrients from the soil.

Nanoparticles for Better Mung Beans

The nanoparticles are designed to increase the activity of enzymes in the soil, thus facilitating the plants' uptake of phosphorus already present in the soil. This will allow farmers to use less of the phosphorus-based fertilizers.

When the nanoparticles were applied to the leaves of mung beans, their stem height, root volume, leaf protein and chlorophyll contents were all improved. The increased root volume and chlorophyll content also helped soil health by attracting microbial populations.

The microflora in the soil have been affected by changes to temperature and precipitation patterns caused by climate change, resulting in additional difficulties in phosphorous uptake. Raliya hopes that the use of these nanoparticles can compensate for this loss.

(Image courtesy of Washington University.)

These nanoparticles could be highly beneficial to countries like China and India, where mung beans—an affordable plant high in protein—are a staple of agriculture.

This research was lead by Raliya and Pratim Biswas, both professors in the School of Engineering & Applied Science at Washington University. It was based on earlier research by Raliya using similar nanoparticles and clusterbeans.

The results were published in the Journal of Agricultural and Food Chemistry.