The limited knowledge of farmers in cultivating mangosteen causes the quality of the trees to decrease—the decreasing number of production evidence this. So there is a need for efforts to increase mangosteen production with good cultivation or farming techniques. So this service activity is to conduct fertilization training with the bio-pore technique, which can reduce yellow sap contamination and provide calcium according to the tree's needs. This service's stages include counseling and socialization of bio-pore fertilization, land measurements, and satisfaction surveys. In addition, measurements of soil nutrients with acidity levels were carried out to help farmers deal with fruitless trees. As a result of the bio-pore installation activity, 80% of the farmers can understand and will apply the bio-pore technique to the farmers' mangosteen fields.