RICE CULTURE Determining the Potential of Furrow- Irrigated Rice Using a 3- and 5-Day Irrigation Schedule in a Rice-Production System

A field study was initiated to evaluate a 3and 5-day furrow-irrigation schedule in a rice-production system. Averaged across furrow-irrigation schedules, ‘XL723’ height was greater than ‘Cybonnet’ in July and August of the growing season; however, panicle number was greater for Cybonnet than XL723. Yield components (spikelets, total kernels, and total filled kernels/panicle) and rough-rice yields were greater for XL723 than Cybonnet. Percent head and total rice were greater for Cybonnet compared to XL723. Furrow-irrigation schedule did not influence rice heights or panicle number. Yield components, rough-rice yields, and milling percentages were greater following the 3-day schedule than the 5-day schedule. The effect of soil moisture logger location on rice height was minimal; however, yield components observed at the 200-ft location were greater than the 400-ft location. No differences in rough rice yield were observed between the 200and 400-ft locations, but head and total rice percentages were greater at the 200-ft location. Rice location on the raised beds did not influence heights or yield components. Panicle number was greater for rice seeded on top of a raised bed compared to shoulder or furrow rice. Averaged across factors, soil moisture did not reach a detrimentally dry level due to rainfall amounts totalling 18.5 in. during the growing season. INTRODUCTION Rice (Oryza sativa) in the United States is predominately grown with flood-irrigation. In this system, the crop is usually flooded at approximately the V-4 (4-lf) AAES Research Series 550 350 growth stage (Counce et al., 2000) and a continuous flood is typically maintained until physiological maturity. Vories et al. (2002) stated that producers and researchers have investigated the possibility of producing rice in a row-crop culture with other irrigation methods rather than a continuous flood and that potential benefits include water and energy savings, simplified flushing of the soil early in the growing season, savings in levee construction and destruction, and easier harvest due to soil drying. Furrow-irrigated rice-production systems have recently begun to receive increased attention among rice producers and media outlets. Furrow-irrigation can generally saturate the soil and may be similar to flood-irrigation (Vories et al., 2002). Nitrogen fertilizer application timings and rates in furrow-irrigated rice have been investigated (Bollich et al., 1988; Hefner and Tracy, 1991; Wells et al., 1991). Vories et al. (2002) observed a 15.6% yield reduction in furrow-irrigated rice compared to flood-irrigated rice. Unfortunately, little information is available concerning the timing of furrow-irrigation. Therefore, research was initiated to investigate furrow-irrigation schedules on rice yield, yield components, and the effect of soil moisture.