Soil fertility evaluation and quality of gambier (Uncaria gambir Roxb) in Kundur, Kepulauan Riau

Abstract

Gambier is the main export commodity of Kepulauan Riau and its quality is highly affected by soil and climate characteristics. The research aim was to study potency of gambier crop based on the soil fertility evaluation and the quality of gambier products in Kundur, Kepulauan Riau. Study was conducted in Kundur Island, Kepulauan Riau from June to October 2018. The study method was a survey to characterize the land, identify the performance of gambier crop, and collect secondary data and gambier product samples. Results revealed that low to moderate soil fertility of the study area was indicated by low soil pH, total-N, P2O5, and K2O, low to moderate soil organic C and low to very low Ca2+, Mg2+, K+, and CEC, sandy loam to sand clay loam soil texture. Evapotranspiration of productive gambier crop is moderately high causing water deficit in January, February, and March. Based on SNI, catechin content of gambier product from West and North Kundur (52.98 and 50.14%) meet the Quality Standard 2, while from Kundur (13.19%) does not meet both Quality Standard 1 and 2. The study areas have a potency for developing gambier crop by providing fertilizer and ameliorant, and applying technology of water supplement.