Rice is a plant that needs silicon (Si) as a nutrient to grow well. Silicon is an element of silica (SiO2) found commonly in sand. Rice yields decrease when soils are depleted in available silicon. A possible solution is to add silicon-rich manure to soils. Song et al performed a 10-year field experiment and found that adding silicon-rich manure doubled the amount of available silicon in soils. Using manure brings the additional benefit of recycling organic waste and providing other plant nutrients such as nitrogen and phosphorus
