Effect of salinity levels on the nutritional water productivity of Cucumis myriocarpus as a leafy vegetable
Soil salinization is a major abiotic stress that limits plant growth and development, posing a serious threat to global food security. It occurs due to the build-up of excess salt in the soil, mainly from improper irrigation, poor land management, and excessive fertilizer use. High levels of Na⁺ and Cl⁻ interfere with normal cellular functions and essential metabolic processes, resulting in poor growth, reduced productivity, and, in severe cases, plant death. Based on this, the study was conducted from 2024-25 to determine the responses of nutritional water productivity of selected nutrient elements in the drought-tolerant wild cucumber (Cucumis myriocarpus Naude) leafy vegetable to chloride salinity. Uniform seedlings at the five-leaf stage were each transplanted into 20-cm-diameter plastic pots containing 2,700 mL of steam-pasteurized river sand and Hygromix at a 3:1 (v/v) ratio. A geometric series of NaCl and CaCl₂ at a 3:1 mM ratio induced chloride salinity. At 56 days after treatment, NWP-Ca, NWP-Mg, NWP-P, NWP-Na, NWP-Fe, and NWP-Zn were significantly affected by salinity, with total treatment variation (TTV) of 79%, 78%, 73%, 79%, 55%, and 36%, respectively. However, the same treatments exhibited no significant effect on NWP-K, contributing 6% in TTV. NWP-Ca, NWP-Mg, NWP-P, NWP-Fe, NWP-Na, and NWP-Zn in relation to increasing chloride salinity demonstrated positive quadratic correlations, with models explaining 98%, 96%, 99%, 96%, 89%, and 99% of the variance, respectively. These findings indicate a strong relationship between the NWP of selected nutrient elements' uptake and chloride salinity levels, suggesting that increasing salinity enhances the availability of NWP of selected nutrient elements at lower concentrations while limiting it at high chloride salinity.