Superabsorbent hydrogels based on polysaccharides for application in agriculture as soil conditioner and nutrient carrier: A review

Slow release coating remedy for nitrogen loss from conventional urea: a review.

Environmentally friendly fertilizers: A review of materials used and their effects on the environment.

Preparation and characterization of slow-release fertilizer encapsulated by starch-based superabsorbent polymer

Agrochemicals are used to improve the production of crops. Conventional formulations of agrochemicals can contaminate the environment, in particular in the case of intensive cropping. Hence, there is a need for controlled-release formulations of agrochemicals such as polysaccharides to reduce pollution and health hazards. Natural polysaccharides are hydrophilic, biodegradable polymers. This article reviews the use of polysaccharides in the form of micro- and nanoparticles, beads and hydrogels. The main points are: (1) slow release formulations minimize environmental impact by reducing agrochemical leaching, volatilization and degradation. For example, 50 % of the encapsulated insecticide chlorpyrifos is released in 5 days, whereas free chlorpyrifos is released in 1 day. (2) Slow release formulations increase the water-holding capacity of soil. (3) Slow release formulations better control weeds in the long run. (4) Polymer-clay formulations store ionic plant nutrients. (5) Polymer hydrogel formulations reduce compaction, erosion, and water run-off. They increase soil permeability and aeration, infiltration rates, and microbial activity, and, in turn, plant performance. In conclusion, polysaccharide formulations can be used for safer use of agrochemicals.

https://link.springer.com/content/pdf/10.1007%2Fs13593-014-0263-0.pdf

Trinh H. Thanh

Papers

Review on materials & methods to produce controlled release coated urea fertilizer.