Enhancement of Quinoa Grain Yield and Nutritional Quality by Potassium Fertilization Combined with Foliar Spraying of Seaweed Extract

Abstract

It aimed to investigate the effect of applying potassium fertilizer at 90, 140 and 190 kg K 2 O/ha combined with spraying applications of seaweed extract for four times in a 15-day interval starting at 40 days after sowing at rates of 0.0, 1.5 and 3.0 ml/L on the yield, mineral contents and nutritional quality of quinoa grains cv. CICA. A split-plot design was used in three replicates. Results reported that by increasing the application of potassium from 90 to 190 kg K 2 O/ha, gradual increases in all studied parameters of quinoa grains occurred in the seasons of 2016-2017 and 2017-2018, except for class B grain, Mg and fiber contents. Potassium application at 190 kg K 2 O/ha gave the highest significant values of all determined parameters in comparison with treatment of 90 kg K 2 O/ha. In most cases, insignificant differences were detected between potassium fertilizer levels of 140 and 190 kg K 2 O/ha. Spraying seaweed extract at 3.0 ml/L resulted in superiority of all studied characters except class B grain, Mg and fiber contents, followed by 1.5 ml/L treatment with insignificant differences between them in most cases. There were significant differences among spraying seaweed treatments on Ca, Fe, Mn, protein and fiber contents in both seasons, N, P and K during the first season, and grain yield/plant, total grain yield/ha and Zn content during the second season. The interaction between potassium fertilization levels and spraying applications of seaweed extract had significantly different effects on all studied characters during both seasons, except for Mg percentage. It is evident that the application of potassium fertilization at 140 or 190 kg K 2 O/ha combined with the spraying of seaweed extract at 3.0 ml/L caused an apparent enhancement of the yield, mineral contents and nutritional quality of quinoa grains during the two experimental seasons.

Optimization of macronutrients for improved grain yield of quinoa (Chenopodium quinoa Wild.) crop under semi-arid conditions of Morocco

“…Other work reported that quinoa responded to K application up to 120 kg ha −1 ( Salim et al., 2019 ). The increase in the yield and its components recorded with high K rates could be attributed to the role the K plays in improving the weight and size of grain, which are important traits for quinoa quality ( El-Sayed et al., 2023 ). This nutrient has been found to reduce the negative effect of drought by regulating root morphology and exudates and microbial community ( Xu et al., 2021 ).…”

Morpho-physiological mechanisms of two different quinoa ecotypes to resist salt stress

“…Due to the broad diversity of its native habitats, quinoa is characterized by a marked variability of environmental adaptation, specifically to soil salinity [ 15 – 20 ], drought [ 21 – 23 ], frost [ 24 ], high solar radiation [ 25 ] and temperature [ 26 ]. Quinoa grains are rich in a wide range of important minerals (Ca, P, Mg, Fe, and Zn), vitamins (B1, B9, C, and E), oil (containing large amounts of linoleate, linolenate, and natural antioxidants), and protein-containing ample amounts of essential amino acids such as lysine and methionine [ 27 – 31 ]. Its potential as a nutritious and resistant crop was recognized by the Food and Agriculture Organization of the United Nations (FAO), which declared the year 2013 as the International Year of Quinoa [ 32 ].…”