Application of potassium and magnesium on turmeric (Curcuma longa) to increase productivity in Inceptisols

Abstract

Turmeric (Curcuma longa) is a tropical rhizomatous crop. However, inadequate nutrient management and nutrient mining has led to low productivity of fresh rhizome yield in the major turmeric growing regions in South India. In order to study the effect of potassium and magnesium on turmeric production and on its quality attributes of the crop under conditions of adequate supply of nitrogen and phosphorus, a pot experiment was carried out on the Irugur soil series (Inceptisols) in the western zone of Tamil Nadu. The experimental design was a randomized block design with six treatments: K1 − control (no potash), K2 − (40a + 4b), K3 − (80a + 8b), K4 − (120a + 12b), K5 − (160a + 16b), K6 − (200a + 20b) (akg of K2O ha−1/bkg of MgSO4 ha−1) replicated threefold. The treatment (K6) recorded highest tiller count (14 plant−1), rhizome yield (963 g plant−1), and curcumin content (4.28%), which was statistically significant to all other treatments. These results suggest that the turmeric crop grown under intensive cropping systems requires large amounts of potassium and to certain extent requires magnesium for increasing productivity, enhancing quality, and for maintaining nutrient ratios in turmeric crop.