一、作物需要多种营养元素:作物在生长发育过程中,需要吸收许多营养元素,需要量多的如碳、氢、氧、氮、磷、钾、钙、镁、硫、铁等,叫大量元素。需要量少的如硼、锰、锌、铜、钼等,叫做微量元素。大量元素主要与碳水化合物及蛋白质的合成、运转有关;而微量元素在作物中的含量虽少,但不可缺少,它们往往是酶或辅酶的组成成分,参与作物的光合作用及代谢过程。它们有很强的专一性,是植物正常生长必需和不可代替的。当缺乏任何一种微量元素时,作物的生长发育就要受到抑制,品质和产量下降,并出现各种病症。当小麦和油菜缺硼时,就会“花而不实”。棉花缺硼就会“蕾而不 First, the crop needs a variety of nutrients: crops in the process of growth and development, need to absorb many nutrients, the required amount of carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, element. Less need, such as boron, manganese, zinc, copper, molybdenum, called trace elements. A large number of elements are mainly related to the synthesis and operation of carbohydrates and proteins. Trace elements are indispensable in crops, but they are often the components of enzymes or coenzymes involved in the photosynthesis and metabolism of crops. They are highly specific and are necessary and irreplaceable for the normal growth of plants. When the lack of any trace elements, the growth and development of crops will be suppressed, the quality and yield decline, and a variety of disorders. When wheat and rape are boron-deficient, they are “blossoming.” Cotton boron deficiency will "bud instead