This experiment was conducted in a greenhouse to study the influence of five irrigation and three soil-oxygen levels on the uptake of 12 nutrients in citrus seedlings. Different irrigation treatments used in this experiment significantly decreased the total amounts of nitrogen, chloride, sodium, zinc, copper, and iron in the whole seedling, while dry weights of seedlings—and the total amounts of phosphorus, potassium, calcium, magnesium, manganese, and boron—were not affected. A decrease of the soil-oxygen supply to seedling roots decreased the amounts of all elements except sodium, which was increased.