NEW DELHI: Researchers at the Indian Institute of Technology (IIT), Mandi have developed smart biodegradable microgels to make agricultural practices more sustainable and minimise the adverse impact caused by the use of insecticides and agrochemicals.
The research has been published in the "Carbohydrate Polymers" journal.
According to officials, modern agriculture relies heavily on the application of various agrochemicals such as insecticides, herbicides, and fertilizers on crops to meet the demand for food for the growing population.
"These agrochemicals are excessively used in the fields to compensate for their loss via leaching, degradation, rainfall, evaporation, dust drift etc. The frequent use of such agrochemicals results in high cost and causes adverse effects on the environment, including both groundwater and soil and human health," Garima Agrawal, Assistant Professor, School of Chemical Sciences, IIT Mandi.
"The main objective of this research is to develop sustainable farming practices that can minimise the adverse environmental impact of currently prevalent agricultural practices involving excessive use of agrochemicals. These chemicals when frequently applied to the fields, affect the quality of the soil. Additionally, these excessive agrochemicals slowly percolate through the soil and contaminate the groundwater also," she said.
Agrawal explained that these agrochemicals also get washed away in rain and reach the nearby water sources like lake, river or stream and pollute it.
The use of biodegradable microgels as a smart delivery system for fertilizers and insecticides has the potential to provide a solution to this issue. The team has developed natural polymer-based multi-functional smart microgels for both insecticide and nutrient delivery.
"These are environment friendly due to their biodegradable and stimuli-responsive feature allowing the sustained release of loaded agrochemicals for a longer period. These redox-sensitive chitosan-based microgels can release their contents in response to changes in the surrounding environment. These microgels are also biodegradable, ensuring that they would break down over time and not pollute the environment," she said.
"The developed microgels have high loading capacity for insecticide and nutrient which in turn could be released in a time-dependent manner by taking the advantage of a stimuli-responsive feature of microgels. Developed microgels have excellent foliar adhesion and are biocompatible in nature," Agrawal said.
The researchers investigated the developed formulation with pea plants and the results exhibited no adverse effect on seed germination and plant elongation, thus making them an attractive option for agriculture applications.
"To test the efficacy of the microgels, the team loaded them with a model insecticide and investigated its release over time. They found that the microgels were able to release the loaded insecticide over a period of several days, providing a sustained release that could reduce the need for frequent applications of insecticide," she said.
"The microgels are also able to improve the uptake of nutrients by plants, suggesting that the use of redox-sensitive chitosan-based microgels could have significant benefits for sustainable agriculture practices. The microgels formulation is biocompatible, and biodegradable due to the use of natural polymer chitosan in its synthesis," she added.