Synthesis Optimization and Characterization of Microencapsulated N-P-K Slow-Release Fertilizers

Abstract

Slow-release microencapsulated N, P, and K fertilizer synthesis was optimized and the products exhaustively characterized. Four NPK formulations with nutrient mass ratios of 1:0:0, 1:1:0, 1:1:1, and 2:1:1 were characterized following European Council Regulation 2003/2003 for fertilizers as well as ICP-AES, 1 H-NMR, FT-IR, HPLC, elemental analysis, XPS, SEM, dynamic light scattering, thermogravimetry, differential thermogravimetry, activity index, and leaching rate. These fertilizers have good slow-release properties and decrease waste and crop contaminants, improving environmental protection. Compared to classic granulated fertilizers, plant nutrient availability was improved allowing reduced application. Nutrient leaching parameters describing four different kinetic models were evaluated.

Different Zn loading in Urea–Formaldehyde influences the N controlled release by structure modification

“…Boosts in modern agriculture are crucial to manage the increasing demand for food and other agro-products with the current trend of world population rapid growth. Chemical fertilizers have been essential to increase global agricultural production by approximately 50% over the last decades 1 , 2 . Most technological advances are related to N-based fertilizers, especially urea, the most commonly used N-fertilizer worldwide.…”

“…Due to its high N content and safe handling, it is the least expensive fertilizer in terms of transportation cost per unit of nutrient and affordable to most farmers 3 , 4 . Unfortunately, its high water solubility leads to N losses, especially by volatilization, exceeding 50% of the total N applied and resulting in low fertilizer use efficiency 1 , 2 , 5 , 6 .…”

Different Zn Loading in Urea-Formaldehyde Influences the N Controlled Release by Structure Modification

“…The reaction extension and the effect of Zn sources has been veri ed by NMR techniques. 1 H-and 13 C-NMR and are shown in Fig. 5 and Fig.…”

“…Boosts in modern agriculture are crucial for the increasing demand for food and other agro-products with the current trends of the world population's rapid growth. Chemical fertilizers have been essential to increasing global agricultural production by approximately 50% over the last decades 1,2 . Most technological advances are related to N-based fertilizers, especially urea, the most commonly used Nfertilizer worldwide.…”

“…Due to its high N content and safe handling, it is the least expensive fertilizer in terms of transportation cost per unit of nutrient and affordable to most farmers 3,4 . Unfortunately, its high water solubility leads to N losses, especially by volatilization, exceeding 50% of the total N applied and resulting in low fertilizer use e ciency 1,2,5,6 .…”