Affiliation:
1. State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China/Key Laboratory of Plant Nutrition and Fertilizer, Ministry of Agriculture and Rural Affairs/the Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
Abstract
The hydrophobicity and mechanical properties of coating materials and the nitrogen (N) release rates of 11 kinds of controlled-release fertilizers (CRFs) were determined in this study. The results show that the N release periods of the CRFs had negative correlations with the water absorption (WA) of the coating materials (y = 166.06x−1.24, r = 0.986), while they were positively correlated with the water contact angle (WCA) and elongation at break (EB) (y = 37.28x0.18, r = 0.701; y = −19.42 + 2.57x, r = 0.737). According to the fitted functional equation, CRFs that could fulfil the N release period of 30 days had a coating material WA < 2.4%, WCA > 68.8°, and EB > 57.7%. The recommended values for a CRF that can fulfil the N release period of 30 days are WA < 3.0%, WCA > 60.0°, and EB > 30.0% in the coating materials. CRFs with different nutrient release periods can be designed according to the recommended values to meet the needs of different crops. Furthermore, our experiments have illustrated that the N release period target of 30 days can be reached for modified sulfur-coated fertilizers (MSCFs) by improving their mechanical properties.
Funder
National Key R&D Program of China
National Natural Science Foundation of China
Agricultural Science and Technology Innovation Program
Subject
Polymers and Plastics,General Chemistry