Rice (Oryza sativa L.) is an important crop in Iran and other parts of the word and it is also a staple food of nearly one-half of world‘s population contributing high calorie intake. Silicon is considered as a beneficial and nitrogen as an essential element for rice production. In order to study the effects of silicon and nitrogen on some yield components and shoot nutrition ion compositions in rice, a hydroponic culture experiment was conducted under the greenhouse condition. Two factors, including silicon and nitrogen, each one with three levels (0, 50, and 100 ppm) were studied in a completely randomized design in factorial arrangement with 3 replications. The traits including panicle length, unfilled grains, 1000- grain weight and shoot ions including silicon, potassium, and nitrogen were significantly affected by applied silicon levels. All the traits were affected by nitrogen levels except unfilled grains and shoot potassium concentration. The highest grain yield was detected at 100 ppm of silicon application. Shoot silicon ranged from 5.01 to 6.92 ppm in 0 and 100 ppm silicon application. Shoot potassium was increased in high levels of silicon treatment. Significant negative correlation of unfilled grain with shoot silicon and potassium indicated that increasing these shoot ions had reduction effects on unfilled grains. Significant positive correlation was determined between shoot potassium and 1000-grain weight, implied that this trait was affected by indirect effect of silicon via shoot potassium increasing.
