The Salinity and Irrigation Methods Affect the Content of Macronutrients in Different Organs of Quinoa (Chenopodium quinoa Willd.)

Salinity causes nutrient imbalances in plants, even in quinoa (Chenopodium quinoa Willd.), a halophyte with high nutritional value. Current investigation is a complementary study, carried out in continuation of the previous research on quinoa which illustrated that the Salinity Threshold Value (STV) of quinoa varies during different stages of its growth; it was performed in three cultivation periods, each period containing two irrigation methods (IM): i) Irrigating by left-to-right markconstant levels of left-to-right markwater salinity (ECi) (i.e. 0.3, 10, 15, 20, 25dSm(-1)) regardless of STV(P); and ii) Considering STV left-to-right markat each left-to-right markgrowth stage(T). Present study investigated the effect of abovementioned IMs (P, T) and EC(i)s (i.e. 0.3, 10, 15, 20, 25dSm(-1)) on accumulation of nitrogen (N), phosphorus (P), and potassium (K) ions in shoots (end of vegetation) and seeds (end of seed-filling) of quinoa. Results indicated that an increase in ECi left-to-right markfrom 0.3 to 25dSm(-1), especially after STV, caused a 56.6% and 12.8% increase of N while a 44.3% and 27.8% decrease of P, respectively in shoot and seed of quinoa. K only showed 30.2% increase in shoot. The change of all three ions was sharper in shoot than seed due to halophytic properties of quinoa which reduces salinity influence on seed embryo. The seed of quinoa is the main source of N and protein while the shoot is rich in P and K. The T left-to-right markmethod of irrigation was preferred for providing the plant chance to survive in more saline condition.