Effect of rice hull ash silicon on rice seedling growth

Abstract Silicon (Si) promotes healthy development of rice plants. Research has shown that an adequate supply of Si to rice plants improves the plant resistance to abiotic and biotic stresses such as soil aluminum (Al) and manganese (Mn) toxicities and plant pest and diseases. Rice hull, a major by‐product of rice milling, contains about 8% Si that can be recycled for use in a sustainable rice cultivation system. A greenhouse experiment was conducted to study the effect of Si from rice hull ash (RHA) on the growth of rice (Oryza sativa L.) seedlings. Rice hull ash was applied to two Malawian rice cultivare grown on three soil types at the rate of 0, 0.5, 1, and 2 kg‐m2. The RHA‐treated seedlings produced (average of all treated seedlings) more dry matter (18%) over the untreated seedlings. The treated seedlings also reduced the uptake of N (16.4%), Al (20%), and Mn (34%), but increased uptake of P (7.7%), K (20%), and Si (100%) by shoots than the untreated seedlings. The effects of rice cultivare and soils on the seedling growth were not significant. The RHA application to rice nurseries seems to be an efficient way of recycling plant Si and have agronomic and environmental benefits, especially in developing countries.