A Comparison of Sprinkler and Flood Irrigation for Rice¹

Abstract

Sprinkler irrigation of rice (Oryza sativa L.) has recently been considered to reduce water use and increase grower flexibility in U.S. production areas where flood irrigation is predominant. Tests were conducted for 2 yr on a Sharkey clay (Vertic Haplaquept) to evaluate selected rice cultivars under sprinkler vs. flood irrigation. Irrigation methods were main plots and three cultivars in 1983 and six cultivars in 1984 were subplots. Sub-subplots in 1984 were single or split application of 101 kg N ha-•. Sprinkler irrigation consisted of three weekly applications of 0.038 m water each in 1983 and a similar scheduling to maintain soil moisture tension above -30 kPa in 1984.In 1983, sprinkler irrigation increased sheath blight (Rhizoctonia solanr") incidence and decreased grain yield (4448 kg ha-• vs. 7139 kg ha-' under flood irrigation), dry matter production, harvest index, and florets per panicle compared to flood irrigation. In 1984, despite chemical control of sheath blight, yields averaged 5901 kg ha -• under sprinkler irrigation vs. 7846 kg ha -• under flood irrigation. Nitrogen timing did not significantly affect yields, but a weak N timing X irrigation method interaction (p=0.061) denoted that split Napplications may benefit yields under sprinkler irrigation. Multiple regression indicated fewer florets per panicle was the primary source of yield loss with sprinkler irrigation. Sprinkler irrigation of rice might decrease water use but it lowers yields and increases need for fungicides compared with flood irrigation.

Effects of Water-Saving Irrigation and Nitrogen Fertilization on Yield and Yield Components of Rice (Oryza sativaL.)

“…This is in contrast to the report by Westcott and Vines (1986) and McCauley (1990). For other yield components, there was no signifi cant difference between continuous fl ooding and sprinkler irrigation.…”

“…The unfi lled grain rate had a negative effect on yield, and other yield components a positive effect. This result is similar to that reported by Westcott and Vines (1986) and McCauley (1990).…”

“…Reduction in grain yield by sprinkler irrigation as compared with continuous fl ooding has been reported previously (Westcott and Vines, 1986;McCauley, 1990;Surek et al, 1996). Also, similar yield reduction has been reported by Tripathi et al (1986), Ibrahim et al (1995), Li and Cui (1996), and Bouman and Tuong (2001) for intermittent fl ooding irrigation.…”

“…But no signifi cant difference was obtained in 2000. Guidice et al (1974) demonstrated that the seed weight was decreased by sprinkler irrigation compared with fl ooding, but according to Westcott and Vines (1986) and McCauley (1990), seed weight was not infl uenced by the irrigation method. Prasertsak and Fukai (1997) also indicated that water stress reduced the spikelet number and HI, but increased the unfi lled grain ratio.…”

Growth of Three Rice (Oryza sativaL.) Cultivars under Upland Conditions with Different Levels of Water Supply

“…Similar results have been reported in other studies conducted in Japan (Hasegawa, 1962;Wada et al, 2002). However, TDM of aerobic rice or under upland conditions was reported to be smaller than in fl ooded lowlands in the Philippines and Louisiana (Westcott and Vines, 1986), despite the supplementary irrigation to keep the soil matric potential above -0.03 MPa at a depth of 15 cm. Temporary drying of the surface soil may occur more frequently in uplands in tropical or arid regions than is the case in temperate regions.…”