What are the criteria for determining essential nutrients for plants?

In order to determine whether an element is necessary for plant growth and development, scientists have proposed the following three criteria for essential elements for plants:

1. Without it, plants cannot complete the vegetative growth and reproductive growth stages in the life cycle;

2. For a certain element, this lack is specific, and only by supplying the element can the deficiency be improved;

3. Elements must be directly involved in the nutrition of plants, which is different from improving some unsuitable microbial or chemical conditions in the outside world.

According to the International Society of Plant Nutrition, how to determine the essential elements?

There are three criteria for determining the essential nutrients of plants: (1) This element is indispensable for the growth and development of all plants, and plants cannot complete their life history without this element. (2) After the deficiency of this element, the plant shows characteristic symptoms, which can only disappear after supplementing with this element.

3) The element must be directly involved in the metabolism or material composition of the plant, and play a direct role in the Zhichang or Zhengwu, rather than an indirect effect on improving the growth environment of the bulky plant.

According to the International Society of Plant Nutrition, how to determine the essential elements?

Hello dear, according to the Although the vast majority of the elements that make up the earth's crust can be found in different plant bodies, not every element is necessary for plants. Some elements are not very needed in plant growth, but accumulate in large quantities in the body; There are some elements that are less abundant in plants but are necessary for plants. The so-called essential nutrients of plants refer to the elements that must not be trusted for plant growth and development.

According to the International Society for Plant Nutrition, the essential elements of a plant must meet three criteria: first, if it is deficient, the growth and development of the plant is stunted and its normal life history cannot be completed; secondly, in addition to the element, the plant exhibits a specific deficiency disease, which can be prevented or restored to normal by adding the element; Thirdly, the sliding element can show a direct effect on plant nutrition and physiology, rather than an indirect effect due to the improvement of the physical, chemical and microbial conditions of the soil. According to the above criteria, 16 essential mineral elements have been identified, which are carbon (c), hydrogen (h), oxygen (0), nitrogen (n), phosphorus (p), potassium (k), calcium (ca), magnesium (mg), sulfur (s), iron (fe), copper (cu), boron (b), zinc (zn), manganese (mn), molybdenum (mo), chlorine (c1).

Essential elements for plants: carbon, hydrogen, nutrients, nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, manganese, boron, zinc, copper, molybdenum, chlorine, nickel, sodium, silicon. A large number of nutrients, they are abundant in the plant body in the amount of a few thousandths to a few percent of the dry weight of the plant.

There are carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium. Moderate nutrients include calcium, magnesium and sulfur. Micronutrients, they are very small in the body of plants, generally only a few hundredths to a few thousandths of dry weight.

It should be 16 kinds.

The nutrients contained in the crop body are not all necessary for the growth and development of crops, and there are generally the following criteria for judging whether an element is necessary for crops:

1) This element is essential for the growth and development of all crops, and when it is lacking, crops cannot complete the whole life process from seed germination to flowering and fruiting;

2) When this element is deficient, the crop shows unique symptoms, and only by supplementing this element can the symptoms be reduced or disappeared, and no other element can play this role;

3) This element plays a direct role in the nutritional function of the car, rather than an indirect effect by improving the environment.

At present, the nutrients that meet these three conditions are found as follows: carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, zinc, copper, manganese, molybdenum, boron, and chlorine. According to the amount in the crop, the 16 essential nutrients of crops are divided into 3 groups:

1) Macronutrients: including carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, the content in the crop body is generally a few percent. Among them, nitrogen, phosphorus, potassium crops need a large amount, but the amount of soil is not enough, often imitate the leakage needs to meet the requirements of crop growth through fertilization, so nitrogen, phosphorus and potassium are called the three elements of crop nutrition or fertilizer three elements;

2) Medium nutrients: calcium, magnesium and sulfur, the content of crops is a few parts per thousand;

3) Micronutrients: including iron, zinc, copper, manganese, molybdenum, boron and chlorine, only a few ten-thousandths in crops.