Influence of polyhalite on biometric, yield parameters and yield of rice (<i>Oryza sativa</i> var. (ADT43)) grown in alluvial soils of Tamil Nadu

Polyhalite is a mineral fertilizer that provides essential nutrients such as K, S, Ca and Mg, which are required by crops in substantial amounts. However, its use as fertilizer for rice has not been extensively studied. Given the high potassium requirement of rice crops for improved growth, the present study was undertaken to assess the impact of polyhalite and muriate of potash (MOP) on biometrics, yield characters, and yield of rice var. ADT43 in sandy clay loam soil, at Department of Soil Science, Annamalai University, Chidambaram, Tamilnadu during kharif of 2023. The experiment was carried out under CRD which included ten treatments viz., T1- Control, T2-NP + K (0), T3-NP + 50% K as MOP, T4-NP + 50% K as Polyhalite, T5-NP + 100% K as MOP, T6-NP + 100% K as Polyhalite, T7-NP + 150% K as MOP, T8-NP + 150% K as Polyhalite, T9-NP + 200% K as MOP, T10- NP + 200% K as Polyhalite. Application of potassium fertilizers at varying levels had a significant effect on biometric and yield parameters of rice. The experimental findings indicated that, application of 200% K as polyhalite + NP (T10) recorded maximum biometric traits viz., plant height, DMP (87.5 g pot-1), yield characters viz., no. of panicle pot-1, no. of grains panicle-1 (81.23). Further, it showed an increase of 67% and 47.6% in grain and straw yield, respectively, over control. Based on the results, this experiment could assist rice-growing farmers in enhancing crop yield by using polyhalite as a source of potassium fertilizer.