Serpentine soils also known as ultramafic soils comprise 5 percent of the total land area of the Philippines. Majority of the ultramafic soils occur at the edges of the mainland and small island groups. However, little information had been known regarding inland ultramafic forest ecosystems just like Mt. Kiamo, which form part of the northern Mindanao ultramafic soils. Nine sampling plots with 20x20m dimensions were established within the lower, middle and top elevations at 1,563 to 1,782 masl. All plants having ≥5cm dbh were identified and recorded. Soil characterization was done by digging a 1x1m hole at variable depths within sampling plots. Composite soil samples were collected on every horizon and analyzed. Result showed that Mt. Kiamo is composed of 151 species belonging to 114 families and 129 genera. The dominant species include Symplocos ophirensis, Myristica sp., Polyosma integrifolia Blume, Calophyllum soulattri, Phyllanthus everettii, Madhuca sp., Scaevola micrantha, Ardisia elliptica, Weinmannia urdanetensis, Morella javanica, and Omalanthus fastuosus. Soil analysis revealed an extremely high level of Ni, Cr, Mn and Fe. Canonical Correspondence Analysis showed that species' dominance, frequency, and diversity was influenced by Ni, soil moisture and thickness while plant density was influenced by Cr and bulk density.

Abstract. Labajo JRN, Pabiona MG. 2022. Physical and chemical properties of soil on selected sugarcane farms in Mt. Nebo, Valencia City, Bukidnon, Philippines. Asian J Agric 6: 79-86. The study was conducted to determine soil's physical and chemical properties on selected sugarcane farms in Mt. Nebo, Valencia City, Bukidnon, Philippines. Soil samples were collected from 24 different sugarcane farms planted with sugarcane following Sloven's Formula for farm selection. Soil samples were collected from August 2018 to April 2019, and the physical and chemical properties of the soil were determined at SPAL, CMU, Musuan, Maramag, Bukidnon, Philippines. Soil texture and percent Water Holding Capacity (%WHC) soil of the sugarcane farms were clayey textured, with %WHC ranging from 54.24-76.30% and bulk Density (BD) and Particle Density (PD) values ranging from 1.05-1.31 Mg m-3 (BD) and 2.28-2.41 Mg m-3, which is ideal for growing sugarcane. Soil samples collected were categorized as medium acidic, marginal in soil organic matter content (SOMC), extractable phosphorus (P) was very deficient, and low on exchangeable potassium (K). That implies these sugarcane farms need soil amendments to meet sugarcane's desired nutrient and pH requirements. Therefore, the sugarcane farms in Mt. Nebo, Valencia City, Bukidnon are required to apply 1.64-7.04 Mg ha-1 of lime and a recommendation rate of 80-200 kg ha-1 Nitrogen (N), 200-500 kg ha-1 of Phosphorus (P), and 170-200 kg ha-1 potassium (K). Moreover, a soil fertility map is necessary to classify and group the delineated soils into map units and capture soil property information to interpret and depict soil spatial distribution on a map.