Unraveling the Tolerance of Moringa oleifera to Excess K through Increased N Absorption and Mg Use Efficiency

Abstract

The tolerance of Moringa oleifera plants to excess K may be linked to nutritional mechanisms, but studies are lacking. The present study was conducted to analyze the tolerance of Moringa oleifera to nutritional imbalance and its importance in the growth of plants submitted to high doses of K in the absence and presence of N. The experiment was conducted in pots with 9 dm3 of Oxisol in a 4 × 2 factorial scheme, with potassium doses of 0, 110, 190, and 265 mg dm−3 combined with nitrogen doses of 0 and 100 mg dm−3. The increase in K uptake by moringa is enhanced by N supply but decreases the uptake of Ca and Mg. Notwithstanding, this was of little importance as the soil cultivated had adequate Ca and Mg contents and was sufficient for adequate plant nutrition without impairing plant growth. The moringa plant is tolerant to nutritional imbalances when grown in environments with high K content probably because N favors an increase in Mg use efficiency, avoiding biological disturbances. The results of this study contributed to our understanding of how moringa induces nutritional mechanisms of action to deal with excess K in crops.