博文

目前显示的是 十月 8, 2015的博文

Secondary and Micronutrients For VEGETABLES AND FIELD CROPS

Plant nutrients in fertilizers are classified as major nutrients and micronutrients.  The most important. Major  nutrients are nitrogen (N), phosphorus (P) and potassium (K).  Plants require these nutrients in relatively  large amounts,  and these are the nutrients most likely to be deficient for plant growth.  The other major  nutrients, also called secondary nutrients, are calcium (Ca),  magnesium (Mg) and sulfur (S).  They are  also required in relatively large amounts but are less likely to be deficient.  Micronutrients are essential  for plant growth, but plants require relatively small amounts of them.  They include boron (B), copper (Cu),  iron (Fe),manganese (Mn), molybdenum (Mo) and zinc (Zn). These elements may also be referred to as  minor or trace elements, but “micronutrients” is preferred. Calcium Deficiency Symptoms Calcium deficiency is usually observed as a failure of terminal buds and apical root tips to develop. In corn, new leaves fail to emerge from t