Soil fertility assessment in agroforestry farms within community-based forest management areas in Diffun, Quirino, Philippines

<p>Soil fertility assessment is crucial for sustainable land management, especially in agroforestry areas. This study assessed the soil fertility status of agroforestry farms within community-based forest management sites in Diffun, Quirino, using 120 georeferenced soil samples collected at 15 cm depth. From these, 49 composite soil samples were generated by combining samples within each plot with similar soil type, color, and vegetation. Chemical analyses, conducted at the regional soil laboratory, included parameters such as (%OM), available P, K, Mn, Fe, and soil pH. Results showed varying soil acidity across the sites, with Campamento having the most acidic soil (pH 5.79), followed by Rafael Palma (5.97) and Magsaysay (6.20). Campamento also exhibited the most favorable soil fertility, with 3.10% OM, 12.47 mg/kg phosphorus, and 259.07 mg/kg potassium, aligning with the standards set by Evangelista (1992, as cited by Rodriguez, 2009) and the ASEAN Standards for Soil and Nutrient Management. High potassium levels at Campamento, along with elevated manganese and iron, suggest a complex nutrient dynamic likely influenced by intensive crop production and excessive nitrogen fertilizer use. These findings highlight the need for targeted soil management to optimize nutrient availability and improve plant growth.<strong></strong></p>