Sustained Release of Chemical Fertiliser by Nanochitosan: Insights and Updates

• Published in: BioNanoScience Vol. 14; no. 3; pp. 3679 - 3692
• Main Authors: Thirugnanasambandan, Theivasanthi, Iswarya, S., Ajitha, M., Gopinath, Subash C.B, Selvarani, K.
• Format: Journal Article
• Language: English
• Published: New York Springer US 2024; Springer Nature B.V
• Subjects: Agricultural wastes; Agriculture; Agrochemicals; Antimicrobial activity; Biological and Medical Physics; Biomaterials; Biophysics; Carbon dioxide; Chirality; Chitosan; Circuits and Systems; Commercialization; Controlled release; Delivery contracts; Diffusion rate; Encapsulation; Engineering; Environmental effects; External stimuli; Farmers; Fertilization; Fertilizers; Nanomaterials; Nanoparticles; Nanotechnology; Nutrient release; Nutrients; Plant layout; Plant roots; Polymer coatings; Polymers; Redox reactions; Review; Rhizosphere; Shellfish; Soil properties; Soil swelling; Soil temperature; Stimuli; Sustained release; NPK; Nano-fertiliser; Agriculture; Chitosan; Controlled release
• ISSN: 2191-1630; 2191-1649
• DOI: 10.1007/s12668-024-01533-7

Controlled-release fertilisers are granular particles coated with a polymer that can release nutrients over a long time by preventing moisture contact and allowing the fertiliser to dissolve gradually. Stimuli-responsive controlled-release fertilisers also called smart fertilisers allow for passive nutrient release through response of environmental stimuli. External stimuli may be pH, temperature, redox conditions, enzymes, and light. The respiration from the roots of plants increases the amount of CO 2 in the rhizosphere that decreases the pH in the soil. The properties of polymer-coated fertilisers change because of temperature variation and thereby release the fertiliser. The gel polymers swell as the temperature rises and contract as the temperature decreases. Enzyme-responsive polymers are highly useful in the delivery of insecticides safely exactly to the target. In redox-responsive polymers, the colour, fluorescence ability, and chirality vary according to external redox reactions. Chitosan is made from the outer skeleton of shellfish, crab, lobster, and shrimp. Chitosan possesses antimicrobial activity that finds applications in drug manufacturing. Chitosan can be modified to become chitosan nanoparticles through various synthesis techniques. In addition to its medical applications, chitosan nanoparticles are used in agriculture to encapsulate macronutrients such as nitrogen, phosphorus, and potassium (NPK). NPK fertilisers are essential for the growth of plants. These three essential nutrients are loaded into chitosan nanoparticles. Nanofertilisers are macro- or micronutrients that are encapsulated within nanomaterials so that they can be released slowly or in a controlled manner and allow a slow diffusion into the soil. Commercialisation of nanofertilisers for use in agriculture will support farmers. An increased uptake of nutrients by crops, low fertiliser utilisation, more yield, prevention of over-fertilisation, and reducing the wastage of fertilisers are achieved. Farmers can adopt this new advanced technology in their farming by easily accessing these nano-fertiliser products.