Comparative impacts of nitrogen, sulfur, and zinc fertilization on grain yield, protein content, antioxidant capacity and its loss during polishing process among rice varieties

Abstract

Increasing grain protein in rice through fertilizer management during cultivation is a promising approach to address protein deficiency, particularly in populations where rice is the staple food and access to high-protein foods is limited. This study aimed to compare the impacts of fertilizer management (control, N, S, and Zn) on grain yield, protein content, and antioxidant capacity among four rice varieties (KDML105, PTT1, KDK, and K4) under field condition for four replicates. The rice varieties responded differently to fertilizer management in terms of grain yield, protein content, and antioxidant capacity. Applying all fertilizers increased grain yield in all varieties compared with the control, although the magnitude of increase varied among varieties. The highest grain protein conte