Reference |
Objective |
Conclusion |
Jamnongkan and Kaewpierom (2010Jamnongkan, T., & Kaewpirom, S. (2010). Controlled-release fertilizer based on chitosan hydrogel: Phosphorus release kinetics. Science Journal Ubon Ratchathani University, 1:43-50. ) |
NPK slow-release fertilizers were produced using glutaraldehyde, PVA, glycerin, and a binder solution. |
Kinetics of P release were well represented by the KP Model (n < 0.5 quasi-Fickian release). The value of the K parameter was between 0.6016 and 0.6875. |
Noppakundilograt et al. (2014Noppakundilograt, S. et al. (2014). Multilayer-coated NPK compound fertilizer hydrogel with controlled nutrient release and water absorbency. Journal of Applied Polymer Science, 132(2): 41249. ) |
OMF NPK was produced through chitosan impregnation |
Release rate was lower when chitosan was present. The kinetics were represented by the Korsmeyer-Peppas model and governed by quasi-Fickian diffusion. |
Gwenzi et al. (2017Gwenzi, W. et al. (2017). Synthesis and nutrient release patterns of a biochar-based N-P-K slow-release. International Journal of Environmental Science and Technology, 15:405-414. ) |
Granulated sawdust biochar was pyrolyzed at 500 °C for 1 h, with NPK fertilizer and starch-PVA binder. |
Release patterns were obtained using the sequential leaching method with water. About 50% of the final P concentration was released by the fifth day, whereas 90% of the final P concentration was released by the 25th day. |
Lustosa Filho et al. (2020Lustosa Filho, J. F. et al. (2020). Aging of biochar-based fertilizers in soil: Effects on phosphorus pools and availability to Urochloa brizantha grass. Science of The Total Environment , 709:136028. ) |
Pyrolysis of chicken litter and TSP was catalyzed by H3PO4 and/or MgO, at 500 °C for 2 h at a heating rate of 10 °C.min-1. The mass ratio between the P source and biomass was 0.5:1. |
Results showed that after the first cultivation cycle, the BBF promoted a higher crop yield than TSP fertilization. The BBF also demonstrated the potential for the slow release of P. |
Buss et al. (2020Buss, W. et al. (2020). Unlocking the fertilizer potential of waste-derived biochar. ACS Sustainable Chemistry & Engineering, 8:12295-12303. ) |
Pyrolysis of sewage sludge at 700 °C was performed after doping it with 5% potassium acetate. |
Percentage of water-extractable total P content increased by 237 times compared to undoped biochar. Due to this easy and inexpensive modification, sewage sludge can generate a safe biochar fertilizer with customized P availability that also supplies K, which improves soil properties and C sequestration. |
Luo et al. (2021Luo, W. et al. (2021). A potential Mg-enriched biochar fertilizer: Excellent slow-release performance and release mechanism of nutrients. Science of The Total Environment , 768:144454. ) |
A BBF was developed by the co-pyrolysis of corn straw doped with MgCl2 and biogas effluent. |
Limited solubility of Mg-P precipitates on the surface of biochar influenced the slow-release performance of P. Also, BBF considerably promoted the development of corn crops. |
Carneiro et al. (2021Carneiro, J. S. et al. (2021). Long-term effect of biochar-based fertilizers application in tropical soil: Agronomic efficiency and phosphorus availability. Science of The Total Environment, 760:143955.) |
A BBF was developed by co-pyrolysis of coffee husk (CH) and poultry litter (PL) doped with phosphoric acid and magnesium oxide at 500 °C for 2 h. |
A total P release of 6.47% (CH) and 8.99% (PL) was recorded in 1 h, which characterized the sample as a slow-release fertilizer. Thus, the production of slow-release P fertilizers was possible. Initially, P availability was limited but later increased due to fertilizer dissolution. |
Yan et al. (2021Yan, T. et al. (2021). Biochar-based fertilizer amendments improve the soil microbial community structure in a karst mountainous area. Science of The Total Environment , 794:148757. ) |
Contribution of BBFs to the restoration of karst-degraded soils was evaluated. |
BBFs stimulated an increase in the quantity and variety of soil microbes. Thus, more keystone species in the soil microbial network participated in soil carbon resource management and nutrient cycling. |
Lv et al. (2021Lv, G. et al. (2021). Biochar-based fertilizer enhanced Cd immobilization and soil quality in soil-rice system. Ecological Engineering, 171:106396. ) |
Immobilization of Cd in soil was investigated using a BBF consisting of rice husk biochar, lime, and inorganic fertilizers. |
BBF improved the heavy metal immobilization in soil, which decreased its bioavailability and mobility in the soil. This occurred due to the presence of active functional groups, high pH, and abundance of micro-porous structures in biochar. The application of BBF in crop production helped reduce soil Cd bioavailability, and hence, plant absorption in Cd-contaminated rice fields. |
Teixeira and Santos (2023Teixeira, G. F., Santos, K. G. (2023). Phosphate organomineral fertilizer based on banana peels and coffee ground waste. Revista Brasileira de Ciência, Tecnologia e Inovação, 7(1):1-17.) |
A slow-release BBF was developed by co-pyrolysis of coffee waste, triple superphosphate, banana peel, and starch. |
The best formulation consisted of 9.2% banana peel, 1.6% starch, 57.3% TSP, and 32% coffee waste, treated at 300 °C for 10 min. The slow-release capacity was 24 times greater than powdered fertilizers and three times greater than the sample without heat treatment. |
Wang et al. (2022Wang, C. et al. (2022). Biochar-based slow-release of fertilizers for sustainable agriculture: A mini review. Environmental Science and Ecotechnology, 10:100167. ) |
BBFs were synthesized via co-pyrolysis of biomass and mineral P source |
The method had considerable benefits, such as simplicity of synthesis, high P loading, and excellent slow-release function. Thus, the efficiency of the growing crops to absorb P may increase. |