Synthesis of Slow-release Urea Fertilizer Using Starch-based Polymer Nanocomposite Coating and Investigation of Its Effect on Tomato Growth

Document Type : Research Paper


1 Soil Science Department, Faculty of Agricultural Engineering and Technology, University of Tehran, Karaj, Iran

2 Nanotechnology Department, Agriculture Biotechnology Research Institute of Iran, Karaj, Iran


A significant part of the nitrogen fertilizers due to the high solubility in water, penetrates into the lower parts of the soil and become unavailable to the plant. To prevent nitrogen losses, various methods have been used, of which coatings is the most widely used methods to reduce the rate of dissolution in water. The objective of the current study was to produce novel slow release fertilizers (SRFs) using starch-based polymer nanocomposites (in terms of environmental compatibility and degradability) and to investigate the comparative efficiency of these samples on the growth and nutritional responses of tomatoes. Firstly, two formulations of urea fertilizer coated with starch-based polymer nanocomposite reinforced with biochar nanoparticles (A) and pristine polymer without nanoparticles (B) were synthesized. Then, the effects of two levels (180 and 420 kg/ha or 60 and 140 mg/kg) synthesized SRF samples (A and B) and un-coated urea granule fertilizer (as a control) on morphological characteristics of tomatoes were investigated. A factorial design based on the completely randomized blocks with three replications was performed at Agricultural Biotechnology Research Institute, Karaj. The results showed that the presence of nanoparticles increases the release time of urea from the coating layer, and it was prolonged with increasing the amount of NCNPs because of favorable interfacial polymer-filler interactions. So that, the nitrogen release rate from sample A, at pH= 2, 6 and 10, was respectively decreased 49.46, 18.52 and 45.13% as compared to sample B. Moreover, application of SRF samples increased nitrogen use efficiency, nitrogen agronomic efficiency and apparent nitrogen recovery. So that, the nitrogen use efficiency in fertilizer treatments A and B with usage of 420 kg/ha was respectively increased 7/85 and 14/68% compared to urea fertilizer.


Bortolin, A., Aouada, F.A., Mattoso, L.H.C., and  Ribeiro, C. (2013)  Nanocomposite PAAm/Methyl Cellulose/Montmorillonite Hydrogel: Evidence of Synergistic Effects for the Slow Release of Fertilizers Agricultural and Food Chemistry, 61, 7431−7439.
Cataldo, D.A., Haroon, M., Schrader, L.E., & Youngs, V.L. (1975) Rapid, colorimetric determination of nitrate in plant- tissue by nitration of salicylic acid. Communications in Soil Science and Plant Analysis, 6 (1), 71-80.
Chen, J., Fan, X., Zhang, L., Chen, X., Sun, S., and Sun, R. (2020). Research progress in lignin-based slow/controlled release fertilizer. ChemSusChem. doi: 10.1002/cssc.202000455.
Chen, J., & Zhao, Y. (1999). An efficient preparation method for superabsorbent polymers. Applied Polymer Science, 74, 119–124.                     
Dargie, S., Wogi, L., and  Kidanu, S. (2020). Nitrogen use efficiency, yield and yield traits of    wheat response to slow-releasing N fertilizer under balanced fertilization in Vertisols and Cambisols of Tigray, Ethiopia. Environmental Science, 6: 1778996.
Elbarbary, A. M., and Ghobashy, M. M. (2017). Phosphorylation of chitosan/HEMA interpenetrating polymer network prepared by γ-radiation for metal ions removal from aqueous solutions. Carbohydrate Polymers, 162, 16–27.         
Fan, X., Lin, F., & Kumar. D, (2004). Fertilization with a new type of coated urea evaluation for nitrogen efficiency and yield in winter wheat. Journal of Plant Nutrition 25, 853-865.
Fan, X. H., & Li, Y. C. (2009). Effects of Slow-Release Fertilizers on Tomato Growth and Nitrogen Leaching. Communications in Soil Science and Plant Analysis, 40, 3452–3468.
Feng, C., Lu, S., Gao, C., Wang, X., Xu, X., Bai, X., Gao, N., Liu, M., and Wu, L. (2015). “Smart” fertilizer with temperature- and pH-responsive behavior via surface-initiated polymerization for controlled release of nutrients. Sustainable Chemistry Engineering. 5, 3, 3157−3166. doi: 10.1021/acssuschemeng.5b01384.
Geng, B., Wang, Y., Li, B., and Zhong, W. (2014). Segregated polymeric nanocomposites with tunable three-dimensional network of nanoparticles by controlling the dispersion and distribution RSC Advances, 4, 51872–51877.
Golbashy, M., Sabahi, H., Alahdadi, I., Nazokdast, H., and Hosseini, M. (2016). Synthesis of highly intercalated urea-clay nanocomposite via domestic montmorillonite as eco-friendly slow-release. Archives of Agronomy and Soil Science. doi:0.1080/ 03650340.2016.1177175.
Gumelar, M. D., Hamzah, M., Hidayat, A.S., Saputra, D.A., and Idvan. (2020)  Utilization of Chitosan as Coating Material in Making NPK Slow Release Fertilizer. Macromolecular sampoisa. 391 (1) 1900188. doi: 10.1002/masy.201900188.
Haluschak, P., (2006). Laboratory methods of soil analysis. Canada-Manitoba soil survey, 3-133.
Malakouti, M and Baba Akbari,M. (2005). The need to increase the efficiency of nitrogen fertilizers in the country. Technical Journal, No. 425. Soil and Water Research Institute, Sana Publications.(In Farsi).
Motamedi, E., Motesharezedeh, B., Shirinfekr, A., & Samar, S. M. (2020). Synthesis and swelling behavior of environmentally friendly starch-based superabsorbent hydrogels reinforced with natural char nano/ micro particles. Environmental Chemical Engineering, 8, 103583, https:/ / 10.1016/ j.jece.2019.103583.
Nassaj-Bokharaei, S. (2019). The effect of hydrogel-nano biochar composite on the content of soil elements and nutrition response in Tomato plant (Solanum lycopersicum L.). Master dissertation. (In Farsi).
Olad, A. and.Gharakhani, H. (2016). Synthesis, characterizai, The first seminar on applied chemistry in Iran tion and fertilizer release behavior of NaAlg-g-poly (AA-co-co-Aam)/silica silica superabsorbent nanocomposite. The first seminar on applied chemistry in Iran.22-23, August, chemistry college. Tabriz university,Tabriz. (In Farsi).
Pang, W., Hou, D., Wang, H., Sai, S., Wang, B., Ke, J., Wu, G., Li, Q., and Holtzapple, M. (2018). Preparation of microcapsules of slow-release NPK compound fertilizer and the release characteristics. Brazilian Chemical Society. doi: 10.21577/0103-5053.20180117. 
Pour-esmaeil, S., Taheri, N., & Mahdavi, H. (2014). Interpenetrating polymer networks (IPN) based on gelatin / poly (ethylene glycol) dimethacrylate / clay nanocomposites: Structure e properties relationship Materials Chemistry and Physics, 143(3), 1396–1403.
Qiao, D., Liu, H..Yu, L., Bao, X., Simon, P., Petinakis, E. and Chen, L. (2016) Preparation and characterization of slow-release fertilizer encapsulated by starch-based superabsorbent polymer, Carbohydr. Polymers, 147,146–154.
Riyajan, S.,  Sasithornsonti,Y and  Phinyocheep, P. (2012). Green natural rubber-g-modified starch for controlling urea release. Carbohydrate Polymers, 89, 251–258.
Rostamzadeh, A., Golchin, A and Mohammadi, J. (2012). The Effects of Different Sources and Rates of Nitrogen on Nitrogen Use Efficiency and Cucumber Yield. Water and soil Science, 23,15-26. (In Farsi).
Rychter, P., Kot, M., Bajer, B., Rogacz , D., Siskova, A. and Kapusniak, J. (2016).  Utilization of starch films plasticized with urea as fertilizer forimprovement of plant growth. Carbohydrate Polymers, 137, 127–138.
Salimi, M., Motamedi, E., Motesharezedeh, B., Hosseini, H. M., and Alikhani, H. A, (2020).Starch- g-poly (acrylic acid- co-acrylamide) composites reinforced with natural char nanoparticles towad environmentally benign slow release urea fertilizers. Environmental Chemical Engineering 8, 103765. doi:
Saurabh, K. (2016). Nanoclay Polymer Composites (NCPCs) with biodegradable polymers for controlled release of nitrogen in rice and wheat crops. Ph.D dissertation, New Delhi, Indian.
Tian, C., Zhou, X., Liu, Q., Peng, J. W., Wang, W., Zhang, Z., Yangi, T., Song, H., and Ghan, C. (2016). Effects of a controlled-release fertilizer on yield, nutrient uptake, and fertilizer usage efficiency in early ripening rapeseed (Brassica napus L.). Zhejiang University-Science B. 17(10):775-786. doi: 10.1631/jzus.B1500216.
Tisdale, S. and W. Nelson. (1975). Soil fertility and fertilizers. Macmillan, N.Y., P. 202. Usherwood, N.R., 1978. Phosphate fertilization and minor element nutrition, in Phosphorus for Agriculture, Potash/Phosphate Institute, (pp. 113-215), Atlanta, GA
Trenkel, M. E. (2010). "Slow- and Controlled-release and Stabilized Fertilizers: An Option for Enhancing Nutrient Use Efficiency in Agriculture," IFA, International fertilizer industry association. (6th ed.) Paris: France.
Wei, H., Wang, H., Chu, H., and  Li, J. (2019). Preparation and characterization of slow-release and water-retention fertilizer based on starch and halloysite. Biological Macromolecules, 133, 1210-1218.
Wen, P., Wu, Z., He, Y., Han, Y. and Tong, Y.(2016). Characterization of p(AA-co-AM)/ bent / urea and its swelling and slow release behavior in a simulative soil environment, Applied Polymer Science, 133,  1–11.
Xiao, X., Yu, L., Xie, F., Bao, X., Lio, H., Ji, Z., and Chen, L. (2017). One-step method to prepare starch-based superabsorbent polymer for slow release of fertilizer. Chemical Engineering Journal, 309,  607- 616.              
Ye, H. M., Lia, H. F., Wanga, C. S., Yang, J., Guoyong Huang, G., Meng, X.,  and Zhou, Q. (2020). Degradable polyester/urea inclusion complex applied as a facile and environment-friendly strategy for slow-release fertilizer: Performance and mechanism. Chemical Engineering Journal. 381. 12270.
Zareabyaneh, H., and Bayatvarkeshi, M. (2015). Effects of slow-release fertilizers on nitrate leaching, its distribution in soil profile, N-use efficiency, and yield in potato crop. Environmental Earth Sciences, 74,3385–3393.