All India Coordinated Rice Improvement Project, Rajendra Nagar, Hyderabad, 500030, Andhra Pradesh
*Present address: All India Coordinated Scheme of Micronutrients in Soils and Plants, Punjab Agricultural University, Ludhiana 141004, Punjab, India
Changes in soil solution phosphorus (P) in a P deficient submerged Vertisol were followed during the wet and dry rice seasons. Soil solution P was influenced slightly by submergence and increased due to the addition of fertilizer P. Its concentration was about 2.5 times more in the wet season than in the dry season, regardless of the fertilizer application or time of submergence. This increase in water-soluble P was attributed to the higher temperature (̃10°C) in the first two months of the wet season than in the corresponding period of the dry season. These results confirm that the restricted availability of P in the cooler months of the dry season necessitate treatment with higher P doses.
Soil solution P, submerged Vertisol, seasonal variation, P nutrition of rice
