Irrigation Water Use On Dry-Seeded Rice Production.

Efficient use of irrigation water in rice production contributes to optimum management of water quality and quantity.  In dry-seeded drilled rice cultivation, permanent flood may occur 4-6 weeks after planting with early flushes for facilitating seed germination.  We quantified irrigation water supply for two large plot studies of dry-seeded drilled-rice cultivation at two locations in 2007; Washington, Louisiana and Proctor, Arkansas, USA.  Water levels in paddies and daily weather data at experimental sites were also monitored.  Total irrigation water supplied was approximately 14 inches at the Louisiana site with a growing season rainfall of 18 inches.  However, irrigation water supplied was four times higher at the Arkansas site where growing season rainfall was about 6 inches.  Soil water balance components during the rice crop for both locations will be presented.