Which of these is a macronutrient required by plants?
Nitrogen
Plants obtain nutrients like carbon and oxygen from the air and hydrogen from water. All the other nutritional requirements of the plant are derived from the soil. Out of these nutrients, nitrogen, phosphorus, potassium, calcium and magnesium are required in fairly large amounts by the plants and are called macronutrients. Other nutrients like zinc, copper, manganese, chlorine, etc., are required in very minute amounts. These are called micronutrients.