Reni Ustiatik

Soil fertility is a determining factor in agricultural productivity and sustainable land management. This study aims to: 1) analyze soil fertility status in various land uses in Dolokgede Village, Bojonegoro Regency; 2) evaluate the effect of land use on soil physical and chemical properties, and; 3) analyze the relationship between soil parameters as indicators of soil fertility. The study was conducted from May to December 2024. Observation points were determined based on Land Mapping Units (LMU) across three land uses (rice fields, drylands, and forests), where a total of 24 composite soil samples were collected at a depth of 0–20 cm. The samples were analyzed for pH, cation exchange capacity (CEC), base saturation (BS), organic C, total N, available P, exchangeable cations (K, Ca, Mg, Na), texture, bulk density, particle density, and porosity. Soil fertility status was classified and mapped using ArcGIS. Data were analyzed using Analysis of Variance (ANOVA) followed by the Least Significant Difference (LSD) test at a 5% significance level, correlation, and regression. The results showed that total N was low (0.11–0.19%) in all land uses. Available P was very high in rice fields (59.31 ppm) due to intensive fertilization, but moderate in drylands and forests. Exchangeable K and organic C were low, while CEC and BS were very high in all land uses. Land use had a significant effect (p < 0.05) on available P and exchangeable Ca, Na, and Mg, but had no effect on other parameters, including all soil physical properties. An increase in organic C was strongly associated with total N (R² = 0.62), whereas high BS was associated with increased available P (R² = 0.99). Soil fertility status at the study site was determined by chemical factors and fertilizer management rather than changes in physical properties due to land use change. The implications of these findings for sustainable land management include organic matter management and balanced fertilizer use as measures to prevent soil degradation.

Nickel (Ni) is the most widely produced mining commodity in Indonesia, but mining activities often leave soils with severe physical and chemical limitations that hinder plant establishment and frequently cause revegetation failure during the early growth phase. Hydroseeding and Plant Growth Promoting Rhizobacteria (PGPR) have been studied as approaches for post-mining land reclamation; however, their combined application across different types of Ni overburden has been rarely evaluated. This study aimed to analyze the interaction between planting methods, bacterial inoculation, and overburden types on the germination index and early leaf formation (3–14 days after sowing). The experiment was conducted through a laboratory-scale early growth test using a completely randomized factorial design, and data were analyzed using Analysis of Variance (ANOVA). The results showed that the interaction between bacterial inoculation and application method consistently influenced the germination rate of Cynodon dactylon. In contrast, the planting method independently played a dominant role in the germination index of Crotalaria juncea and in the number of leaves of both species. The results showed that the interaction between bacterial inoculation and application method consistently affected the germination rate of C. dactylon. Conversely, the planting method independently played a dominant role in the germination index of C. juncea and the number of leaves of both species. Hydroseeding increased the germination by 186.41 – 7062.5% (in C. dactylon) and 15 – 3688% (in C. juncea). Bacterial inoculation was unable to increase the germination of C. dactylon, but it was able to increase the germination of C. juncea by 7.5 – 650% compared to that without inoculation. These findings demonstrate that integrating hydroseeding techniques with microbial inoculation can enhance early plant establishment on Ni mine overburden and support ecological restoration efforts aligned with Sustainable Development Goal 15 (Life on Land). Therefore, it is recommended that revegetation programs in post-Ni mining areas integrate hydroseeding with microbial inoculation and promote community-based restoration initiatives to improve early vegetation establishment and long-term ecosystem recovery.

Open-pit nickel (Ni) mining has expanded rapidly in Indonesia and has become one of the main drivers of land degradation. This review synthesizes scientific evidence on the impacts of open-pit Ni mining on soil properties and evaluates the application of the Soil Quality Index (SQI) as integrative tools for assessing soil degradation and reclamation success. The reviewed studies consistently report severe declines in soil quality following mining, including reductions in soil organic carbon (SOC) from approximately 40.2 g/kg in forest soils to as low as 2.29 g/kg in post-mining soils, increases in bulk density from around 0.88 g/cm to 1.37 g/cm, and substantial decreases in microbial biomass carbon 350 mg C/kg to below 110 mg C/kg in heavily disturbed areas. Sensitive indicators such as soil organic matter, pH, bulk density, microbial biomass carbon, soil respiration, and enzyme activities were identified as key variables responding rapidly to mining disturbance and reclamation measures. Reported SQI values range from very low in active mining areas (0.18–0.30), moderate in reclaimed lands (0.43–0.55), and high in forest ecosystems (0.70–0.81). These findings demonstrate that SQI provides a science-based framework for monitoring post-mining restoration and supports the achievement of SDG 15 (Life on Land), particularly land degradation neutrality targets.

Post-mining land degradation in Indonesia causes severe declines in soil quality and ecosystem functions, potentially affecting environmental sustainability and public health. Therefore, environmentally friendly reclamation technologies are needed to accelerate vegetation establishment and restore ecological stability in degraded mining landscapes. Although hydroseeding has been widely applied for post-mining revegetation, comprehensive reviews evaluating its implications for soil restoration and environmental health in tropical ecosystems remain limited. This review aims to evaluate the effectiveness of hydroseeding for post-mining land reclamation in Indonesia and to identify current challenges and future improvement opportunities. A structured narrative review was conducted using relevant national and international scientific literature published between 2015 and 2025. The reviewed studies indicate that hydroseeding improves soil structure, increases organic carbon content, enhances nutrient availability, stimulates microbial activity, and accelerates vegetation establishment. Increased plant cover also contributes to erosion control and reduces heavy metal mobilization within the soil-plant-water system, thereby supporting environmental recovery. However, hydroseeding effectiveness remains inconsistent due to climatic and topographic variability, poor soil fertility, limited technical expertise, and restricted availability of adapted native plant species. This review highlights the importance of integrating hydroseeding with soil amendments, indigenous vegetation, and biological restoration approaches to support sustainable post-mining land management. These findings contribute to environmentally friendly reclamation strategies that improve soil restoration, ecosystem stability, and environmental health in tropical post-mining areas.

Soil characteristics in the Curahkemadu Micro Watershed are influenced by volcanic parent material and other soil-forming factors, including organisms, topography, climate, and time. This study aims to analyze the spatial distribution of soil up to the subgroup level and identify the dominant factors that shape it using a machine learning approach with the Random Forest (RF) algorithm. Field surveys were conducted at 14 Land Mapping Units (LMU) in the Bocek and Donowarih villages, followed by laboratory analysis of the physical and chemical properties of the soil. Soil classification followed the United States Department of Agriculture (2022) system, utilizing Geographic Information Systems (GIS) and ArcGIS Pro for spatial mapping. The classification results showed the existence of two main subgroups: Andic Humudepts (172.73 ha) and Typic Humudepts (577.73 ha). The spatial distribution of soil was strongly influenced by slope, sub-landform, and elevation, with variable importance values of 40%, 35.7%, and 24.3%, respectively. The RF model showed high performance with good accuracy (overall accuracy = 85.7% and Cohen’s Kappa = 0.69). This research provides an important basis for the optimal and sustainable management of watershed areas.