Changes in Soil Nitrogen Availability as Influenced by Direct Seeded Rice and Transplanted Rice Ecosystem, Nutritional Approaches and Slow-release Nitrogen Sources
Ashna Susan Joseph *
Department of Soil Science and Agricultural Chemistry, University of Agricultural Sciences, Raichur, Karnataka, India.
M. V. Ravi
Department of Soil Science and Agricultural Chemistry, University of Agricultural Sciences, Raichur, Karnataka, India.
K. Narayana Rao
Department of Soil Science and Agricultural Chemistry, University of Agricultural Sciences, Raichur, Karnataka, India.
S. N. Bhat
Department of Soil Science and Agricultural Chemistry, University of Agricultural Sciences, Raichur, Karnataka, India.
Y. M. Ramesh
Department of Agronomy, University of Agricultural Sciences, Raichur, Karnataka, India.
H. Sharanagouda
Department of Processing and Food Engineering, University of Agricultural Sciences, Raichur, Karnataka, India.
*Author to whom correspondence should be addressed.
Abstract
An experiment was conducted on nutrient management approaches using RDF, SSNM, STCR and nutrient expert under different rice ecosystem using slow release nitrogen sources viz., neem coated urea and urea supergranules. The initial and final soil N content was analyzed at active tillering, panicle initiation, milking stages and at harvest of direct seeded and transplanted rice. The three-way interaction (M x N x S) proved that a significantly higher value of available N content in soil was noticed in SSNM (6 t ha-1) treated plot with neem coated urea in transplanted rice (M2N3S2) at active tillering stage (245.96 kg ha-1) and at harvest (213.46 kg ha-1), respectively, while application of NCU through SSNM approach (7 t ha-1) in direct seeded rice (M1N4S2) obtained maximum available N content at panicle initiation stage (229.18 kg ha-1) and application of NCU through STCR approach for the yield target of 7 t ha-1 in direct seeded rice (M1N2S2) at milking stage (218.15 kg ha-1).
Keywords: Direct seeded rice, transplanted rice, SSNM, neem coated urea