Salinity and nitrogen source affect productivity and nutritional value of edible halophytes

Area of Science:

• Agricultural Science
• Plant Physiology
• Environmental Science

Background:

• Declining freshwater resources and increasing soil salinization necessitate exploring alternative food production methods.
• Edible halophytes offer potential for saline agriculture, but their biomass and nutrient accumulation under varying salinity and nitrogen conditions require further investigation.

Purpose of the Study:

• To investigate the impact of increasing salinity levels on the biomass and nutrient accumulation of six edible halophyte species.
• To examine the effects of different nitrogen sources combined with salinity on oxalate accumulation in ice plant and ruby saltbush.

Main Methods:

• Two greenhouse experiments were conducted, exposing halophytes to salinity levels from 0 to 800 mM.
• Shoot biomass and nutrient accumulation (Na, K, Cl, N, P) were measured using ICP-MS.
• Oxalate levels were quantified using HPLC, with a focus on nitrogen source effects in specific species.

Main Results:

• Significant species-specific differences in biomass and nutrient accumulation were observed across salinity gradients.
• Increasing ammonium (NH4+) proportion in nitrogen supply reduced oxalate levels in ice plant and ruby saltbush.
• Reduced oxalate concentrations were associated with decreased shoot biomass, particularly at higher ammonium levels.

Conclusions:

• Edible halophytes exhibit diverse responses to salinity and nitrogen, impacting their suitability for commercial cultivation.
• A trade-off exists between minimizing anti-nutrient oxalate content and maximizing biomass in halophyte production.
• Careful management of salinity and nitrogen sources is crucial for optimizing edible halophyte cultivation for food production.