|Stevens, William - University Of Missouri|
|Rhine, Matthew - University Of Missouri|
|Vories, Earl - Earl|
Submitted to: Crop, Forage & Turfgrass Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/2/2017
Publication Date: 2/16/2017
Citation: Stevens, W.E., Rhine, M.D., Vories, E.D. 2017. Effect of irrigation and silicon fertilizer on total rice grain arsenic content and yield. Trade Journal Publication. 3:1-6. doi: 10.2134/cftm2016.12.0083.
Interpretive Summary: Rice is an important food source throughout the world; however, questions have been raised regarding levels of the naturally occurring chemical arsenic (As) sometimes observed in the grain. Some studies have suggested that As should be systematically evaluated in rice regarding whether the levels raise concerns for infants and pregnant women. Research was conducted by the University of Missouri and ARS scientists at the Fisher Delta Research Center to determine which practices and amendments favored reduced As levels. Field tests were conducted with different irrigation systems, cultivars and hybrids, and rates of calcium silicate fertilizer to determine the effects on As levels and grain yields. The order of total As content in rice grain from plots was continuous flood > intermittent flood > sprinkler irrigated, while silicon fertilizer and cultivar or hybrid selection did not impact rice grain As levels. However, silicon fertilizer increased yields for the sprinkler irrigated rice. This research will benefit producers by identifying practices for reducing As levels in grain and everyone will benefit from the lower levels of As in the food supply.
Technical Abstract: Field tests were conducted for two years with rice grown with different irrigation systems and rates of calcium silicate fertilizer to determine the effects on brown rice arsenic (As) levels and rough rice yields. Irrigation systems were sprinkler irrigation using a center pivot system, intermittent flooding, and continuous flooding beginning at first tiller rice growth stage. Pelletized calcium silicate fertilizer, byproduct from steel mill, was applied in subplots to bare soil and incorporated. After harvest, rough rice was de-hulled to make brown rice grain and tested for total As content. The high to low order of total As content in rice grain from plots was continuous flood > intermittent flood > sprinkler irrigated. Silicon (Si) fertilizer and cultivar/hybrid selection did not impact rice grain As levels in any of the irrigation programs. Rice grown with sprinkler irrigation applied by a center pivot produced significantly lower yields than intermittent or continuously flooded rice. Rough rice yields grown in aerobic soil conditions with sprinkler irrigation were increased significantly with 54 lb Si/acre. Rice with intermittent flood irrigation contained 350 35% less As in grain than continuous flood but yield was not significantly less than continuously flooded rice.