The use of Macroalga Sargassum sp. and Gracilaria verrucosa in improving Sandy and Clay Soil fertility

Abstract

Macroalgae, such as Sargassum and Gracilaria have a great potential to be used as soil conditioner. Addition of macroalgae powder into a certain type of soil could significantly change soil fertility. The presence of gelatinous material in Sargassum and Gracilaria are predicted to be able in changing the chemical characteristic of soil, including organic material content, pH and C/N ratio. This study was focused on the evaluation of soil fertility sandy and clay soil after addition of Sargassum and Gracilaria powder as a soil conditioner. The collected macroalga was dried and soaked in fresh water several time to lower its salinity to reach into a normal level. The dried powder of Sargassum and Gracilaria were added and mixed through into sandy and clay soil (in a composition of 25%:75%). Treated soil was measured for their physical, chemical and physiological properties changes. Each treatment was replicated three times. Data were analyzed using ANOVA single factor and t-test. Results indicated that the addition of soil conditioner from macroalga Sargassum and Gracilaria were significantly increasing organic material content. Addition of Sargassum powder increased organic material more than Gracilaria. C/N ratio in sandy and clay soil was reduced by the presence of this both soil conditioner. Therefore, there was a strong indication in increasing in supporting for more soil fertility. The presence of macroalga was proven also in reducing pH to a normal level. It is recommended to develop this material to improve soil fertility and plant growth.