Effect of phosphorus levels on yield, nutrient uptake and phosphorus utilisation efficiency in rice (Oryza sativa L.) using ³²P radiotracer technique under pot culture

Abstract

Phosphorus (P) is a primary limiting macronutrient in tropical and subtropical rice production. While total soil P may be high, over 50 % of global agricultural soils suffer from low bioavailable orthophosphate due to strong chemical fixation with aluminium (Al) and iron (Fe) oxides in acidic soils, or calcium (Ca) in alkaline soils. Developing and deploying P-efficient rice genotypes capable of maintaining growth and yield under low soil P availability is a key priority for sustainable agriculture. A pot culture experiment was carried out at the Radio Isotope Laboratory, Department of Soil Science and Agricultural Chemistry, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu. The treatment comprised factor A: rice genotypes viz.,TNRH-180, CB08504, CB06732 and ADT 47 and factor B: P levels viz., 0, 25 and 50 kg P ha-1.Phosphorus was applied in the form of the radioisotope ³²P, the experiment aimed to evaluate and quantify yield performance, phosphorus use efficiency (PUE) and the native P supplying capacity of low P soils. The findings indicated that the rice genotypes viz.,TNRH-180 recorded higher yield attributes, yield and PUE viz., productive tillers (8.4 nos.), panicle length (24.1 cm), grains per panicle (167.7 nos.), test weight (17.2 g), grain yield (22.3 g/pot) and PUE (23.72 %) and was followed by CB06732 respectively.