桑树生长发育必要的元素,已知道的有碳、氢、氮、磷、钾、钙、镁、铁、锰、锌、铜、硼、钼。其中碳、氧、氢通过光合作用由二氧化碳和水供给,其它元素主要通过根从土壤供给。一般把碳、氧、氢、氮、磷、钾、钙、镁称作多量要素。铁、锰、锌、铜、硼、钼称为微量要素。 Mulberry tree growth and development of the necessary elements are known to have carbon, hydrogen, nitrogen, phosphorus, potassium, calcium, magnesium, iron, manganese, zinc, copper, boron, molybdenum. Among them, carbon, oxygen, hydrogen are supplied by carbon dioxide and water through photosynthesis, and other elements are supplied from the soil mainly through roots. Carbon, oxygen, hydrogen, nitrogen, phosphorus, potassium, calcium and magnesium are generally referred to as a large number of elements. Iron, manganese, zinc, copper, boron, molybdenum is called trace elements.