On-farm response of inbred and hybrid rice cultivars to furrow irrigation

Alternate wetting and drying (AWD) water management reduces irrigation demand compared to a continuous flood in the drill-seeded, delayed-flood rice (Oryza sativa L.) production system, but land preparation is time consuming and labor intensive. This research was conducted to determine whether rice grown in a furrow-irrigated (ROW), raised seedbed system has similar water requirements and profit expectations to AWD. The effects of growing either inbred or hybrid rice under AWD or furrow irrigation management on water applied, grain yield, and net returns were investigated on paired production fields in the Delta region of Mississippi. For both inbred and hybrid rice lines, water applied averaged 587 and 565 mm, respectively, and did not differ between ROW and AWD production (p > 0.05). Compared to AWD, furrow-irrigating inbred rice cultivars either maintained or decreased yield 16% (p = 0.0207). Conversely, seeding hybrid rice in ROW systems reduced yield 7% regardless of year (p = 0.0083). For both inbred and hybrid rice cultivars, transitioning from AWD to furrow irrigation decreased the average net returns $9.80 and $124.02 ha(-1), respectively, and ranged from +$94.48 to -$281.98 ha(-1) over 3 years and three rice prices. Transitioning from AWD to an ROW rice will likely have no effect on freshwater demand but will introduce substantial agronomic and economic risk to the production system.