LASER LAND LEVELING EFFECT ON WATER MANAGEMENT AND THERMAL REGIME IN RICE (Oryza sativa L.)

Abstract

Laser land leveling is a technique that offers great potential for water savings and higher yields in rice production. The objective of this study was to evaluate the effect of laser land leveling on water management and thermal regime in rice. The experimental design was completely randomized with two treatments: traditional land leveling-sowing by aircraft and laser land leveling- mechanical sowing. Unevenness of the soil surface, water depth, water temperature and canopy temperature were measured. The results showed that laser land leveling with two years management presented unevenness of 20 mm on soil surface and a slope of 0.28%. Water depth was more uniform with land laser leveling during all the growing season of the rice crop. Distribution uniformity (DU) showed significant difference, presenting higher level under laser land leveling. The thermal regime was adequate for plant protection under both technologies; the canopy temperature was higher than the air temperature, especially in the phenological stages of end of tillering and  flowering. These results showed that laser land leveling improves water management and decreases the susceptibility of rice plants to low temperatures.