Thesis
Salinity and Nitrogen Nutrition Influence Growth and Quality of Edible Halophytes
Southern Cross University
Masters by Thesis, Southern Cross University
2022
DOI:
https://doi.org/10.25918/thesis.372
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Abstract
Saline agriculture may contribute to food production in the face of the declining availability of fresh water and an expanding area of salinized soils worldwide. We need to identify and characterise alternative crops for farming in salt-affected areas because the majority of modern agricultural crops are salt sensitive. The use of edible halophytic species (salt-loving plants) may be a viable alternative to increase the productive use of land degraded by salinity.
The identification of suitable halophyte species for crop production is in the early stages. This thesis examines the effect of salinity and nitrogen sources on the biomass yield, mineral nutritional quality, and antinutritional compound accumulation of promising edible native and naturalised halophyte species, including Mesembryanthemum crystallinum (Ice Plant), Salsola komarovii (Land seaweed), Enchylaena tomentosa (Ruby Saltbush), Crithmum maritimum (Rock Samphire), Crambe maritima (Sea Kale) and Mertensia maritima (Oyster Plant).
Two glass house experiments were carried out. The first was to study the shoot biomass, and nutrient accumulation response of the selected halophytes under increasing levels of salinity (0 to 800 mM). The second experiment studied the effects of nitrogen source combined with salinity, on levels of oxalate and nitrate in Ice Plant and Ruby Saltbush.
Species differences for biomass and sodium (Na), potassium (K), chloride (Cl), nitrogen (N) and phosphorus (P) accumulation were observed across the range of salt treatments (0 to 800 mM NaCl in the irrigation water). Moderate salinity levels (100 or 200 mM) stimulated the growth of most halophytes (Ice plant, Land seaweed, Ruby saltbush and Rock samphire) without reduction in the concentration of key dietary minerals (Cu, Zn, Fe, Ca and Mg). The survival of all six halophyte species at higher salinity levels (up to 600- 800 mM) indicates that they would all be suitable for cultivation as food crops in saline environments.
Shoot concentrations of the anti-nutrient oxalate decreased significantly in ice plant and ruby saltbush with an increase in the proportion of N provided as NH4+ (up to 100%), while shoot oxalate concentrations in ice plant and ruby saltbush grown in the absence of NaCl were not significantly different to oxalate concentrations in plants treated with 200 mM or 400 mM NaCl. However, the lower shoot oxalate concentrations observed with the increase in NH4+ came with concurrent reductions in shoot biomass. There will need to be a calculated tradeoff between oxalate levels and biomass when growing these plants for commercial purposes.
Details
- Title
- Salinity and Nitrogen Nutrition Influence Growth and Quality of Edible Halophytes
- Creators
- Tania Farzana
- Contributors
- Bronwyn J Barkla (Supervisor) - Southern Cross UniversityTerry J Rose (Supervisor) - Southern Cross University
- Awarding Institution
- Southern Cross University; Masters by Thesis
- Theses
- Masters by Thesis, Southern Cross University
- Publisher
- Southern Cross University
- Number of pages
- xi, 72
- Identifiers
- 991013200113802368
- Copyright
- © T Farzana 2022
- Academic Unit
- Faculty of Science and Engineering
- Resource Type
- Thesis