Land suitability assessment is essential for the efficient use of diminishing fertile agricultural land. Assessment parameters include soil texture, pH, the sum of basic cations, base saturation, cation exchange capacity, organic carbon, soil depth, slope, and mean annual temperature and precipitation data. Results showed that 76.28% and 23.26% of the total area were optimally and moderately suitable for coffee growth, respectively; 9.6% and 90% were optimally and moderately suitable for cocoa growth, respectively; 1.98%, 78.74%, and 19.26% were optimally, moderately, and marginally suitable for clove growth, respectively; and 6.68%, 86.89%, and 6.41% was optimally, moderately, and marginally suitable for pepper growth, respectively. The final land suitability index (LSI) was strongly influenced by the threshold values used by the researcher and the quality of the land indicator itself. Plant threshold values differed due to variations in plant recruitment. The main limiting factors were mean annual temperature <26°C, acidic soil pH, and low CEC. This study showed that the fuzzy method is ideal for converting the numerical data of various magnitudes into membership function values and representing land suitability. The principal component analysis is an effective method to determine the weights of multiple factors in a systematic and objective manner. The linearity test found a correlation between LSI and production with f = 0.00, indicating that the applied model can predict agricultural production and is applicable to other agricultural land management.

The nickel post-mining soil with an open-pit mining system has poor soil chemical and physical properties. Thus, it requires appropriate site-specific management so that it can be optimized as a plant cultivation area. This study aimed to analyze the effectiveness of compost from oil palm empty...

Reclamation of post-nickel mining soil requires a long process and renewable innovations to improve soil properties. One of the alternative technologies for post-mining soil reclamation is utilizing oil palm empty fruit bunches (OEFB) as biochar and applying calcite (CaCO3). The objective of this research was to determine the effect of OEFB and the application of CaCO3 on the properties of post- nickel mining soil and the growth of Mucuna sp. This research was a pot experiment using a factorial randomized block design method. Treatments tested were combinations of three OEFB biochar (B) levels, i.e., B1 = 2.5%, B2 = 5%, and B3 = 7.5% of soil weight, and three calcite (K) dosages, i.e., K1 = 1.5, K2 = 3, K3 = 4.5 t ha-1. The soil parameters measured included soil pH, available P, organic C, cation exchange capacity, and exchangeable Al, Ca, Mg, K, and Na. The parameters of Mucuna sp. measured were plant height and plant dry weight. The results showed that applying biochar and calcite to post nickel mining soil significantly increased soil pH, available P, organic C, cation exchange capacity, growth of Mucuna sp. and decreased exchangeable Al content. Treatment of biochar 7.5% by weight of soil and 4.5 t calcite ha-1 gave the best effect on improving soil fertility and growth of Mucuna sp. compared to other treatments.

The varied topography will influence the soil formation. This study aims to characterize and classify the soil selected on different topography positions of the sugarcane plantation area. The research was conducted in sugarcane plantation area of Camming, District of Bone, South Sulawesi, which was carried out from November 2017 to March 2018. This study used a descriptive method, observation and description of the nine soil profiles at three transects. Each transect consisted of three profiles points located in different positions, consisting of summit, backslope, and valleys. Each horizon soil samples were analyzed for their physical, chemical and micromorphology characteristics in the laboratory. Soil classification system was done by using soil taxonomy to the level of subgroups. The results showed that an average rainfall annual on the research location was 2.200 mm per year. Soil characteristics such as soil solum, cation exchange capacity, and sum of basic cations tended to increase in parts of the valley than in the back and summit. The primary mineral from the sand fraction included quartz, calcite, biotite, opaque, and orthoclase found especially in the position of the back and valley. The pore types consisted of vugh and packing void pores. Pedofeature type of soil was generally in the form of concretions and nodules that showed the process of oxidation and reduction. The soil type in the study area was classified into Typic Haplustepts and Typic Haplustalf.