根据国内外研究,已知,构成农作物的元素有六十多种。其中,碳、氢、氧、氮、磷、钾、钙、镁、硫、铁、硼、锰、锌、铜、钼等十五种营养元素是农作物生长必不可少的。前九种元素,在作物体内含量高,需要量也大,称为常量元素;后六种元素,在植物体中含量较少,一般只占百万分之几 According to the research at home and abroad, it is known that more than 60 kinds of elements form crops. Among them, fifteen nutrient elements such as carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, boron, manganese, zinc, copper and molybdenum are essential for crop growth. The first nine elements, high content in the crop body, the demand is also large, known as the constant element; the latter six elements in the plant content is less, generally only a few millionths