Fenugreek (Trigonella foenum-graecum) is an important legume herb in the Fabaceae family. Since ancient times, it has been used for therapeutic purposes due to its significant nutraceutical and pharmacological characteristics. It is seeds and leaves are extremely valuable because they contain medicinally significant phytochemicals such as alkaloids, carbohydrates, steroidal saponins, amino acids, and other vital organic and inorganic substances and minerals. This study aimed to evaluate the ability of biochar and chitosan to enhance fenugreek growth, yield, yield components, and mineral content. Therefore, fenugreek plants were subjected to the different level of biochar and chitosan application under different soil and ecological conditions of diverse localities. The experimental design was factorial with 3 biochar (0, 0.5, and 1% w/w) and chitosan (0, 1 and 5 g/L) application rates. The measured variables were seed yield plant−1, number of pods plant−1, number of seeds pod−1, plant height (g), pod length, number of branches per plant, number of leaves per plant, seed oil percentage, seed oil yield/plant, seed nitrogen, seed total carbohydrates, Potassium (K) %, Phosphorus (P) % and Iron (Fe)%. Results testified that fenugreek responded well in term of yield and related traits along with mineral accumulation in the red Mediterranean silt loam soil than those grown at yellow Mediterranean sandy loam soil. Fenugreek phenology and yield responded positively to the highest rate of chitosan and biochar application in the red Mediterranean silt loam soil. However, seed carbohydrates concentration was analogous at all rates of chitosan and biochar application under both localities. It was concluded that soil diversity and ecological condition of both localities provoked fenugreek phenology, morphology, oil concentration, oil yield, N digestion, Potassium (K)%, Phosphorus (P)% and Iron (Fe)% but did not trigger carbohydrates concentration in the plant. This study provides evidence that will help to develop recommendations for the production of fenugreek as a source of flavonoids and minerals for healthy consumption.
