Abstract
Abstract Exessive use of inorganic fertilizers in rice production systems, causes various negative effects in the environemnt, such as reducing soil fertility and increases pollution, which disturbs agricultural sustainability. Understanding raw materials for developing organic fertilizers which are cheap and adaptive to our environment, is an important study recently. Many researchers reported that brown algae could increase growth and yield of several species of plants. This due to brown algae extract contain plant growth hormone and essential elements to stimulate growth and production of plants. This article report growth and yield of rice plants suplied with mixtured extract of brown algae. Several species of brown algae were collected in coastal beach of Lombok. The seaweeds were cutted into small peaces, extracted with boiled water for 30 minute and filtered using filter whatman no.1 to get solid and liquid extract. Mixtured solid extracts were added in soil media. On the other hand, the mixtured liquid extracts were sprayed to rice plants during vegetative growth. The results shown that mixtured solid extracts increased growth and yield of rice plants. However, mixtured liquid extract did not stimulate growth and yield of rice plants. This suggests that brown algae is a potential raw material for development of organic fertilizers, which are adaptive to environment to support sustainable agriculture.