Although plants have different needs for various nutrients, they have different physiological functions in plant life metabolism, and they are equally important and irreplaceable. Understanding the physiological functions of various elements is of great significance for scientific fertilization and achieving high quality and high yield.
(1) Carbon, hydrogen and oxygen are abundant in plants, accounting for more than 90% of the dry weight of plants. They are the main components of plant organisms. They exist in the form of various carbohydrates, such as cellulose, hemicellulose and pectin, and are components of cell walls. They can also constitute active substances in plants, such as some cellulose and plant hormones. They are also components of sugar, fat and acidic compounds. In addition, hydrogen and oxygen also play a very important role in the biological redox process of plants. Because carbon, hydrogen and oxygen mainly come from carbon dioxide and water in the air, fertilization is generally not considered. However, the application of CO2 fertilizer should be considered in plastic greenhouses and greenhouses, but the concentration of CO2 should be controlled below 0.65438 0%.
(2) Nitrogen is a component of many important organic compounds in plants, which affects the metabolic process and growth and development of plants in many ways. Nitrogen is the main component of protein, the basic substance of plant cell protoplasm and the basis of plant life activities. Without nitrogen, there would be no life phenomenon. Nitrogen is a component of chlorophyll and nucleic acid, and various biological enzymes in plants also contain nitrogen. In addition, nitrogen is also a component of some vitamins (such as vitamin B 1, B2, B6, etc.). ) and alkaloids such as nicotine and theophylline.
(3) Phosphorus is a component of many organic compounds in plants. It participates in various metabolic processes in plants in various ways and plays an important role in plant growth and development. Phosphorus is the main component of nucleic acid, which exists in nucleus and protoplasm. It is extremely important in plant growth, development and metabolism, and is indispensable for cell division and root growth. Phosphorus is a component of phospholipids and an important part of biofilm. Phosphorus is also a component of other important phosphorus compounds, such as adenosine triphosphate (ATP), various dehydrogenases and aminotransferases. Phosphorus can improve the stress resistance and adaptability of plants to external environmental conditions.
(4) Potassium is not a component of organic compounds in plants, but mainly exists in plant cell fluid in ionic state. It is an activator of many enzymes and plays an important role in metabolism. It can not only promote photosynthesis, but also promote nitrogen metabolism and improve the absorption and utilization of nitrogen by plants. Potassium regulates cell osmotic pressure, plant growth and economic water use, and enhances the ability of plants to resist unfavorable factors (drought, cold, disease, salinity and lodging). Potassium can also improve the quality of agricultural products.
(5) Calcium, magnesium and calcium sulfide can stabilize biofilm structure and maintain cell integrity, and play an important role in plant ion selective absorption, growth, senescence, information transmission and plant stress resistance. Magnesium is a component of chlorophyll, and both chlorophyll a and chlorophyll b contain magnesium, which is of great significance to photosynthesis, carbohydrate metabolism and respiration of plants. Sulfur is an indispensable component of protein and enzymes.
(6) Trace element iron is necessary for chlorophyll synthesis and closely related to photosynthesis. Boron can promote the normal operation of carbohydrates, the formation and development of reproductive organs, cell division and cell elongation, and improve the nitrogen fixation ability of leguminous plants. The function of manganese in plants is mainly realized by its influence on enzyme activity, so manganese is also called catalytic element. Copper is a component of many oxidases in plants, or an activator of some enzymes, and participates in many redox reactions. It also participates in photosynthesis, affects nitrogen metabolism and promotes the development of flower organs. Zinc is a component or activator of some enzymes. Through the action of enzymes, zinc widely affects the metabolism of carbon and nitrogen in plants, participates in photosynthesis, participates in the synthesis of auxin, promotes the development of reproductive organs and improves stress resistance. Molybdenum is a component of nitrogenase and nitrate reductase, which is indispensable for nitrogen metabolism and nitrogen fixation of leguminous plants and can also promote photosynthesis. Chlorine participates in plant photosynthesis, regulates the opening and closing of stomata, and enhances the inhibition ability of crops to some diseases.