Slow-released fertilizers optimization and experimental impacts on soil fertility and wheat- maize cropping system

Abstract

ABSTRACT Using of traditional fertilizers to enhance plant productivity extensively causes nutrient loss and environmental hazards. Urea-coated fertilizers are expected to balance the riddle between soil fertility and plant productivity. This study aimed to optimize grain yield prediction based on plant type, soil type, and coated urea levels through the Design Expert Model. Experimental investigations were carried out using sulfur-coated urea (SCU) and urea-formaldehyde (UF) on wheat ( Triticum aestivum L.) and maize ( Zea mays L.) plants across multiple winter/summer seasons (2019/2020-2020/2021) in a split-plot design. The main plots represented sandy, loamy, and clayey soils, and subgroups (T1, T2, T3) denoted urea, SCU, and UF, respectively, at recommended nitrogen doses. The central composite face-centered (CCFC) model explained 89 % of the total variability, highlighting the optimal 100 % coated urea dose for maximum grain yield. The application of sulfur-coated urea (SCU) enhanced soil pH, electrical conductivity (EC), nitrogen (N), phosphorus (P), potassium (K) availability, dehydrogenase (DHA), and urease activities. The N-coated fertilizers positively correlated with soil fertility and soil microbial biomass (SMB), organic matter (OM), grain yield, and microbial population. The highest wheat and maize yields were observed with SCU application in clayey soil. The principal component analysis (PCA) reinforced the positive correlations between SMB, OM, DHA, and urease, emphasizing their significance in grain and straw yield. Consequently, the application of SCU as a slow-release fertilizer for sulfur and nitrogen nutrients proved beneficial in improving soil characteristics and enhancing plant productivity.

Keywords

• coated fertilizers
• optimal approach
• plant productivity
• soil properties