Interactive Effects of Potassium Fertilization and Rice Residue Management on Soil Potassium Fractions in a Rice-Rice Cropping System
G. Ranjith Kumar *
Department of Soil Science, College of Agriculture, Professor Jayashankar Telangana Agricultural University, Rajendranagar, Hyderabad–500 030, India.
S. Sridevi
College of Agriculture, PJTAU, Rajendranagar, Hyderabad–500 030, India.
Ch. Srinivasa Rao
ICAR–Indian Agricultural Research Institute, New Delhi–110 012, India.
K. Suresh
C-NARE, Professor Jayashankar Telangana Agricultural University, Rajendranagar, Hyderabad–500 030, India.
B. S. Yashavanth
ICAR–National Academy of Agricultural Research Management, Hyderabad–500 030, India.
*Author to whom correspondence should be addressed.
Abstract
Soil potassium (K) dynamics are strongly influenced by fertiliser and crop-residue management in intensive rice systems. A field experiment was conducted at the Agricultural Research Station, Tornala, Telangana, India, during rabi 2024-25 and kharif 2025 to evaluate the effects of potassium fertilisation and rice-residue management on soil K fractions in a rice–rice cropping system. The experiment comprised nine treatment combinations involving three K levels (0, 50 and 100% of the recommended K dose) and three residue-management practices (removal, incorporation and burning), laid out in a randomised block design with three replications. Water-soluble, exchangeable, non-exchangeable and total K were determined at tillering, panicle initiation and harvest. Residue incorporation consistently maintained greater K pools than residue removal, while burning produced intermediate values. Application of 100% recommended potassium fertiliser coupled with residue incorporation maintained the highest K status, whereas residue removal coupled with omission of fertiliser potassium recorded the lowest. At harvest, treatments receiving 100% recommended potassium fertiliser coupled with residue incorporation maintained 70.9, 36.4, 44.5 and 26% greater water-soluble, exchangeable, non-exchangeable and total K, respectively, than residue removal treatments. Residue incorporation also improved K pools without fertiliser K, highlighting the contribution of residue-derived K recycling. Overall, integrating adequate K fertilization with residue incorporation effectively maintained both labile and reserve K pools, thereby strengthening soil K-supplying capacity and environmental sustainability under intensive rice–rice cultivation.
Keywords: Potassium fractions, rice-rice system, residue incorporation, potassium fertilization, K recycling