Evaluation of Lily Response to Different Proportions of Calcium and Ammonium in Nutrient Solutions of Soilless Culture Systems

Lilium is one of the most valuable cut flowers in the world. Today, due to the global water crisis, the agricultural challenge is to modify cultivation patterns to reduce water requirements by plants. This research was conducted to optimize soilless cultivation systems and nutritional demands to improve morpho-physiological parameters of Oriental × Trumpet (Orienpet; OT) hybrid lily. Four soilless cultivation systems (aeroponic, ultrasonic, hydroponic in pots, and hydroponic in containers) were evaluated using three nutrient solutions (NS1, NS2, NS3), considering two variables: the ratio of ammonium to total nitrogen (0.1, 0.15, and 0.2) and the ratio of calcium to total cations (0.3, 0.5, and 0.7). A factorial experiment was used, arranged as a randomized complete block design. Plants grown in the hydroponic (pot) system treated with nutrient solution NS1 showed favorable and consistent results. Additionally, results revealed that the amount of malondialdehyde and, accordingly, the aging process were lower in the bulbs treated by NS3. Therefore, in addition to NS1, NS3 is also recommended for lily cultivation in the hydroponic (pot) system. Considering that photosynthetic performance improved with increasing ammonium in the nutrient solution of the ultrasonic system, it seems that the lily is an ammonium-feeding plant. However, this issue requires further evaluation.