Effects of Alternate Wetting and Drying Irrigation and Different Ratios of Lime on The Arsenic Uptake and Yield of Rice OM18

Abstract

This study’s aim defined effects of lime combined Alternate Wetting and Drying Irrigation (AWDI) on the As uptake and yield of rice. The fied experiment that was designed A randomised complete block design was designed with six treatments of three lime ratios: 0, 4 and 6 tons CaO per ha for the continuously flooded (CF) (R1, R2 and R3 treatment) and 0, 4 and 6 tons CaO per ha for AWDI (R4, R5 and R6) and NPK fertilizer with four replications. The positive relationship between As contents of the deep well waters and agricultural soils (R²=0.8415), rice grains with agricultural soils (R²=0.8842) had high correlation coefficients. Arsenic concentrations of rice stems and grains in AWDI were lower than that of  rice stems (32.7%) and grains (30.4%) in CF. The rice yield of AWDI was higher than 1.29 % compared to CF. Lime addition treatments of both CF and AWDI decreased As contents of stems (55.8%) and grains (65.7%) and increased the rice yield (33.3%) compared to the no lime treatment in CF. The higher ratio of lime amendment had the lower As concentration in rice stems and grains. Therefore, co-application of NPK and 6 tons CaO combined with AWDI should be recommended to farmers.