What is fertilizer for plants

Plant fertilizers that can be used for both green leaves and flowering: for example, daily rotten vegetable leaves, as well as fruit peels, fish and other flesh and blood can be used as both flower fertilizers, which can be placed directly on the roots, or the fermentation method can be fruit peels, rotten vegetables, etc. leaf. Directly mix it into two-thirds of the sandy soil or put it into small buckets, pots and other containers to seal the mouth with mud, and compost it into humus, which can be used for direct planting or top dressing as flower fertilizer.

Conditions and essential elements for plant growth

There are nearly 60 different elements in plants. However, most of these elements are not necessary for plant growth and development. There are only 16 elements necessary for plant growth and development, which are carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur, potassium, calcium, magnesium, iron, manganese, zinc, copper, molybdenum, boron and chlorine. People refer to these 16 elements as essential elements. They are called essential elements because without any of them, the growth and development of plants will not be normal, and each element cannot be substituted for each other or by elements that are very similar in chemical properties.
Among the 16 elements necessary for plants, 9 elements, such as carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur, potassium, calcium, and magnesium, are absorbed by plants and are called macroelements; iron, manganese, zinc, copper, molybdenum , boron and chlorine and other 7 elements, plants absorb less, called trace elements.
Among the 16 essential elements, carbon, hydrogen, and oxygen come from the atmosphere and water, and the rest of the elements are absorbed from the soil by plant roots (meaning that other elements except carbon, hydrogen, and oxygen cannot be obtained from the air by plants themselves, but must be obtained from the roots. external supplement). There are many compound forms of each element, but the root system can only absorb the compound forms that it can use. For example, for nitrogen, most plants can only absorb ammonium nitrogen (NH4—N) and nitrate nitrogen (NO3— N), another example of phosphorus, the main form used by plants is orthophosphate (H3PO4). Therefore, it is very important to understand how plants absorb elements.

Nutrient absorption characteristics of plants:

Minimum Nutrient Law:

German chemist, advocate of modern agricultural chemistry Liebig proposed (J.V.Liebig)
The Law of Least Nutrient – The Barrel Effect
The minimum nutrient varies with time, place and crop growth period. The guiding significance of the minimum nutrient law for scientific and rational fertilization:
The nutrient demand of crops is not uniform, not the highest content of nutrients affects the yield, but the relatively least content of nutrients restricts the crop yield.

Law of diminishing returns:

The remuneration obtained from a certain land increases with the increase of the amount of labor and capital invested in the land, but after the input exceeds the peak value, as the input increases, the remuneration obtained by the unit of labor and capital decreases.
Illustration of the law of diminishing returns
The guiding significance of the law of diminishing returns on scientific and rational fertilization:
The more fertilizers are applied, the better. Too much fertilizer is not only expensive, but also may cause fertilizer damage, affecting yields or failing to harvest.

Nutrient return theory:

As people grow crops on the land and take these products continuously, this will inevitably lead to a gradual decline in soil fertility, and the soil will contain less and less nutrients.
The guiding significance of nutrient return theory to scientific and rational fertilization:
In order to obtain continuous high and stable yields, it is necessary to supplement various nutrients required for crop growth and development in time.

The Law of Equal Importance:

For crops, both macroelements and microelements are equally important and indispensable. Even if a certain microelement is lacking, although its required amount is very small, it will still affect a certain physiological function and lead to a decrease in yield.
The guiding significance of the law of equal importance to scientific and rational fertilization:
Various nutrients are equally important to crops, and trace elements, rare elements and macro elements are equally important.

The law of irreplaceability:

Each nutrient element required by crops has certain functions in the body of the crop and cannot be replaced with each other. If phosphorus deficiency cannot be replaced by nitrogen, potassium deficiency cannot be replaced by nitrogen and phosphorus. If any nutrient element is missing, it must be supplemented by applying fertilizer containing this element.