Soil fertility index in various community forest in Wonogiri, Indonesia

Abstract The study was carried out to examine the soil fertility index in five land use from July – December 2019 in Batuwarno, Wonogiri, Indonesia. Given the critical state of watersheds in Wonogiri, which are deteriorating because of deforestation, erosion, and unsustainable land use practices, research on soil fertility is crucial. By managing the soil fertility in community forests, improved management techniques can be done to maintain agricultural output and ecosystem health. Soil samples were collected from the study areas with five samples each land use. This study aimed to determine the fertility index of different types of plant stands. This research used a descriptive exploratory method with a survey approach. Statistical analysis was carried out with correlation analysis and PCA to determine indicators that affect the soil fertility index called the Minimum Soil Fertility Index (MSFI) using Minitab 18 software. The results showed that there were positive and negative correlations between parameters. The soil fertility index with teak, mahogany, acacia, and mixed plant was in the medium class with soil fertility index values of 0.60, 0.59, 0.56, and 0.57 respectively, while the land use with sengon has a low soil fertility index which is 0.47. Based on the research it is crucial to use agroforestry methods to enhance soil fertility in community forests and optimize nutrient management in Sengon stands which has the lowest soil fertility index.