Nitrogen release characteristics of polyethylene-coated controlled-release fertilizers and their dependence on membrane pore structure--颗粒学报PARTICUOLOGY

Yang, X., Jiang, R., Lin, Y., Li, Y., Li, J., & Zhao, B. (2018). Nitrogen release characteristics of polyethylene-coated controlled-release fertilizers and their dependence on membrane pore structure. Particuology, 36, 158-164. https://doi.org/10.1016/j.partic.2017.05.002

Nitrogen release characteristics of polyethylene-coated controlled-release fertilizers and their dependence on membrane pore structure

Xiangdong Yang ^{a b *}, Rongfeng Jiang ^b, Yangzheng Lin ^c, Yanting Li ^a, Juan Li ^a, Bingqiang Zhao ^a

a Key Laboratory of Plant Nutrition and Fertilizer, Ministry of Agriculture/Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
b College of Resources and Environmental Sciences, Centre for Resources, Environment and Food Security, China Agricultural University, Beijing 100193, China
c Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, USA

10.1016/j.partic.2017.05.002

Volume 36, February 2018, Pages 158-164

Received 11 October 2016, Revised 8 May 2017, Accepted 18 May 2017, Available online 29 July 2017, Version of Record 22 December 2017.

E-mail: yangxiangdong@caas.cn

Highlights

• Controlled-release fertilizers (CRFs) with different release periods were prepared.

• The fertilizer release period depended on the effective maximum pore size.

• A relationship between CRFs release period and their effective maximum pore sizes was established.

Abstract

In this study, controlled-release fertilizers (CRFs) with five different nitrogen release periods were prepared by coating large urea particles with polyethylene (PE) membranes under various experimental conditions. The preliminary and differential solubility rates, release periods, and membrane pore sizes of the obtained CRFs were measured using water immersion, scanning electron microscopy, and mercury porosimetry. For all CRF samples, the median pore diameters of the membranes were equal to 4.5–5.3 nm and pores with sizes smaller than 10 nm accounted for 86–96% of the total pore surface area. The obtained pore diameter distributions differed for the five studied types of CRF, having release periods of 1, 2, 4, 6, and 8 months. Thus, for the CRFs with a 1-month release period, the maximum pore diameter reached a magnitude of 4000 nm, while this value did not exceed 30 nm for the CRFs with a release period of 8 months. Hence, we have established a relationship between the release period of CRFs and their effective maximum pore sizes.

Graphical abstract

Keywords

Controlled-release fertilizer; Nutrient release period; Membrane pore structure; Mercury porosimetry; Pore size

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