Soil-Specific Optimal Sowing Depth for Coriander: Effects on Seed Germination and Early Growth

Coriander (Coriandrum sativum L.) is a commercially and nutritionally important seed spice crop, with India accounting for over 67% of global production and a leading position in export markets. Despite its prominence, suboptimal agronomic practices-particularly inappropriate sowing depth and soil selection-limit successful stand establishment and early seedling vigor. This study investigates the combined effects of sowing depth (0, 1, 2 and 3 cm) and soil type (red, black, sandy, and alluvial) on seed germination and early growth performance of coriander under controlled pot conditions. A total of 160 seeds were tested across 32 treatment units in a completely randomized design. Germination metrics such as germination percentage (GP), mean germination time (MGT), germination index (GI), and coefficient of velocity of germination (CVG), along with seedling height, leaf number, and stem diameter, were recorded over six weeks. The results revealed that a 1 cm sowing depth in black soil yielded the highest germination efficiency (GI = 6.17, CVG = 61.54%, MGT = 1.63 days) and early vigor. Conversely, germination declined markedly at 3 cm depth, especially in sandy and alluvial soils. Although ANOVA results were not statistically significant due to limited replication, logistic modelling and correlation analyses underscored black soil’s superior performance across depths and sandy soil’s support for enhanced vegetative traits at deeper sowing. These findings suggest that a sowing depth of 1-2 cm, particularly in black or well-drained sandy soils, optimizes both germination kinetics and seedling establishment. Such soil-specific recommendations are crucial for improving coriander productivity in diverse agro-climatic zones