Controlled release fertilizer encapsulated by a κ-carrageenan hydrogel

Abstract

The release kinetics of nitrogen and phosphorous of a granulated fertilizer, encapsulated in a κ-carrageenan-based hydrogel (CBH), was evaluated in order to determine its release mechanism given the potential this hydrogel has as coating material for controlled release fertilizers (CFRs). The effect of pH on the release properties was also investigated. The relationship between the NH 4 + , NO 3-, and PO 4 3release of encapsulated fertilizers and time was determined by short-and long-term laboratory incubations. The mechanism of the release of nutrient ions was determined by comparing the release data with the zero-order, first-order, Higuchi, Hixon-Crowell and Korsmeyer-Peppas kinetic models. The findings showed that the Korsmeyer-Peppas model could be used to describe the release characteristics of the nutrients in the encapsulated fertilizers and that non-Fickian diffusion is the main release mechanism. The experimental hydrogel showed a high water retention capacity able to absorb 300 times its weight water.

Copolymerized Natural Fibre from the Mesocarp of Orbignya phalerata (Babassu Fruit) as an Irrigating-Fertilizer for Growing Cactus Pears

“…The irrigation-fertilization hydrogel from copolymerized natural fiber from the mesocarp of Orbignya phalerata (babassu fruit) showed equal or better performance for the main growth characteristics of the evaluated cactus pears. The use of this type of natural fiber for hydrogel production has potential due to its availability [ 45 ] and economic and environmental advantage [ 46 ].…”

Superabsorbent Hydrogels Based to Polyacrylamide/Cashew Tree Gum for the Controlled Release of Water and Plant Nutrients

“…To investigate the kinetics of fertilizer release from the HCGP hydrogel, the following mathematical models were considered: zero-order [ 22 , 92 ], first-order [ 22 ], Higuchi model [ 22 ], and Korsmeyer–Peppas model [ 22 , 93 ], as shown in Equations (4)–(7): where M t /M ∞ corresponds to the fraction of fertilizer released at a certain time ( t ) , n is an indicator of nutrient release mechanism and K represents the release kinetic constant.…”

“…In addition to water reserve systems, SAHs can also be used for the controlled release of fertilizers, which are substances that play an important role in soil fertility [ 21 ]. It is estimated that a significant percentage of fertilizers are not completely absorbed by the soil due to the high solubility of these substances in water [ 22 ]. For example, about 80.0%–90.0% of phosphorus cannot be absorbed by plants [ 23 ], also representing a great waste for agricultural systems.…”

Regenerated Cellulose Products for Agricultural and Their Potential: A Review

“…The complex structure of polysaccharides has turned them into valuable elements on earth because they provide interesting interaction among themselves and other components such as protein [ 8 ]. The excellent characteristics of polysaccharides such as sustainable, cheap, and edible have made them popular biomaterials that are fabricated into coatings [ 9 ], films [ 10 ], hydrogels [ 11 ], and fibers [ 12 ]. Recently, the idea of using polysaccharide-inspired products for agriculture purposes has emerged as a modern way to overcome the issues related to conventional agriculture.…”