Novel microencapsulated soil conditioner: improving efficient utilization of core materials and yield of cabbages

ABSTRACT The utilization of microencapsulated soil conditioner (MSC) with a water-soluble core and natural polymer shell offers a potential solution to address the issues of over-fertilization and low efficiency in soil. Fulvic acid (FA), a refined form of humic acid, possesses desirable characteristics such as water solubility, fertilizer retention, and convenient monitoring. Urea, a neutral fertilizer, is beneficial for plant growth, easy to store and apply, and causes minimal harm to the soil. Sodium alginate, as a type of natural polymer, has great potential for use in the agricultural sector due to its biocompatibility, environmental safety, and water-holding abilities. The preparation of MSC incorporating FA and urea involved the employment of double emulsion and ion crosslinking mechanism utilizing the sharp-hole coagulation bath method. Structural analysis confirmed the presence of core materials within the MSC. The analysis of the structure indicated that the MSC possessed a particle size about 200 µm, displaying a uniform spherical shape. Subsequent sustained release and biodegradation tests demonstrated the MSC’s ability to significantly enhance both fertilizer retention and water retention capacities. In addition, a planting experiment involving cabbages was conducted employing these microcapsules. The growth status of the cabbages, their physiological activities, nitrogen balance index value, and photosynthesis rate were thoroughly examined. The statistical analysis findings indicated that the MSC possessed the capability to enhance cabbage yield, rendering it a highly promising sustained-release fertilizer.