Soil quality assessment on coffee (Coffea spp.) farms in Pigtauranan, Bukidnon, Philippines

Abstract

A study was conducted from September to March 2019 with the following objectives: (i) to determine the physical and chemical properties of soil grown with coffee, (ii) to generate a soil nutrient map of the coffee farm; and (iii) to provide fertilizer recommendations based on the result of analysis of chemical properties. The following criteria for the selection of farm sites were: (i) 1-2 hectares of coffee farm area, (ii) 3-5 years of land use for coffee production; and (iii) the variety of the coffee grown is Robusta (Coffea canephora Pierre ex A.Froehner). Twenty-two (22) farms fit the criteria, and a survey questionnaire was disseminated to gather information. Soil samples were collected, and each was replicated and analyzed at the Soil and Plant Analysis Laboratory CMU. The coffee farms were identified as mostly medium acidic in their pH ranging from 5.6 to 6, marginal in organic matter (2.1 to 3.5%), very deficient in their extractable phosphorus (<9.0 mg dm-3), and very high in exchangeable potassium (167.70 to 245.70 mg dm-3). Most coffee farms were clayey soil texture, the water holding capacity was mostly 50-59%, and most bulk densities were categorized as ideal bulk density with values ranging from (1.0 to 1.3 Mg m-3). The recommended rate of fertilizer were (0.030 to 0.115 g/tree) for Nitrogen, (0.165 to 0.500 g/tree) for Phosphorus, and (0 to 0.090 g/tree) for Potassium. The fertilizer rate of 16-20-0 and 18-46-0, and 0-0-60 will be used to satisfy the nutrient deficiency in the soil, and it is highly recommended to follow the correct application of fertilizer and apply an organic fertilizer to obtain good productivity and higher yield for the coffee farms, though this still needs further studies.