This work aimed to study the effect of interaction between four N rates (100%, 75%, 50% and 25% of recommended dose) and spraying with three rates of Mg (0, 1%, and 2%) on Jerusalem artichoke plants growth, tuber chemical analysis and tuber yield under sandy soil conditions. The results indicated that application of 100% or 75% of recommended N were the best treatments for increasing plant growth, most of tuber chemical analysis parameters, and tuber yield / plant as well as per feddan. Spraying with Mg increased all studied parameters compared to control treatment. On the other hand, the best interaction treatments for increasing plant growth, tuber chemical analysis and tuber yield were application of 100% N + spraying with  1% or 2% Mg and application of 75% N+ spraying with 1% Mg approximately.