Assessment of Nitrogen, Phosphorus, and Potassium Nutrient Quality of Organic Growing Media Containing Durian Leaves by Using Simple Methods

Abstract

This study aimed to assess the quality of nitrogen, phosphorus, and potassium nutrients in organic growing media containing durian leaves using simple analytical methods applicable at the field level. Nitrogen quality was assessed in the forms of ammonium (NH4+-N) and nitrate (NO3--N), while phosphorus and potassium were assessed as phosphate (PO43-) and potassium ions (K+), respectively. The organic growing media consisted of soil, coconut coir, and chopped coconut husk as base materials, combined with different types of organic amendments, including durian leaves, vermicompost, and chicken manure, resulting in a total of 12 formulations. All formulations were composted for 60 days prior to random sampling for nutrient analysis using the KU soil test kit. The results showed that all organic growing media formulations contained low levels of ammonium, whereas formulations containing chicken manure exhibited moderate nitrate levels. For phosphorus and potassium, formulations incorporating chicken manure and vermicompost showed high nutrient quality across all mixing ratios. In contrast, formulations containing durian leaves as
the sole organic amendment exhibited low nutrient quality. Additionally, the type of organic amendment had a greater impact on nutrient quality than the mixing ratio.