Bio-stimulants as alternatives to mineral fertilizers: influence on chia (Salvia hispanica L.) growth, yield, and fatty acid composition

Abstract

One of the main components of sustainable agricultural strategies in crop production is substitution of chemical fertilizers with alternatives. This study aimed to examine the effects of partial replacement of mineral fertilizers with bio-stimulants (yeast and/or moringa leaves extract). Field experiment was conducted during two successive seasons 2018/2019 and 2019/2020. The fertilization treatments were distributed in a factorial design. Treatments included 75%, 50% or 0% NPK combined with yeast, moringa extract, or their combination in comparison with control treatment (100% NPK). The partial substitution of mineral fertilizers with yeast and/or moringa extract had significant impacts on growth, yield and quality components. Decreasing NPK level significant decreased growth and yield components of chia plants, except for 75% NPK combined with yeast and/or moringa. In contrast, decreasing NPK level significantly increased the chemical and quality components of chia. Treating with 75% NPK combined with yeast and/or moringa gave the highest micronutrients and fatty acid content. GC analysis showed definition of nine main components, and the major components were linolenic and linoleic acids. Linolenic acid increased with decreasing NPK, and the highest values obtained with bio-stimulant treatments with zero % NPK. The results of this study recommended that partial substitution of 25% of mineral fertilizers with bio-stimulants (yeast and/or moringa) is the best alternative not only for maintaining the growth and yield component, but also improving the quality of chia plants.