Growth, grain yield and water use of rice grown under restricted water supply in New South Wales

Abstract

Growth, grain yield and water use by Calrose rice grown under three flood irrigation regimes and four nitrogen fertilizer treatments were examined at Yanco Agricultural Research Centre, New South Wales, to determine the response of rice under a restricted supply of water. Growth under weekly irrigations before panicle initiation severely restricted dry matter production. When nitrogen (90 kg N/ha) was split with 45 kg N/ha at the three-leaf stage and 45 kg N/ha at panicle initiation followed by permanent flood at panicle initiation, yield was 8.67 t/ha. This was equivalent to yields obtained from conventional practice where all fertilizer was applied at the three-leaf stage followed immediately by permanent flood. Delaying permanent flood until panicle initiation resulted in approximately 23% saving in total water use. Weekly irrigation throughout the season produced low vegetative growth and grain yields.