Plant nitrogen sources are a complete strategy

it is well known that plant growth requires sunlight, air, moisture and nutrients, which in turn include a wide variety of nutrients. Nitrogen (N) as one of the three major elements of plant nutrition, is the main component of protein, but also the composition of protein, so the amount of nitrogen will directly affect the life activities of plants. If nitrogen is lacking, the vast majority of plants show that the plants are small and the leaves yellow, eventually causing them to fail to grow properly.
from this point of view, nitrogen plays an important role in plants, so in nature, plants need nitrogen in what way to obtain it? Some friends will think, the air nitrogen (N
) content of up to 78%, plants can directly absorb nitrogen and use it? Indeed, the nitrogen content in the air is very rich, but because the nature of nitrogen molecules is very stable, so it is difficult to be directly absorbed and utilized by plants, which is similar to people sailing at sea, even in the face of the ocean, but can not drink sea water to quench thirst. However, the rich nitrogen elements in the atmosphere can be converted into forms that plants can absorb and utilize in two ways:
The first way is to extract nitrogen from the atmosphere and re-combine it with oxygen to produce nitrogen oxides (e.g. NO, NO
), which are then dissolved in rainwater and seep into the soil, eventually becoming forms that plants can absorb and utilize, such as nitrites (NO
) and nitric acids (NO
).
way to reduce nitrogen in the air by microorganisms in the soil to produce nitrogen fertilizers that plants can use. For example, there is a microorganism called rhinoma bacteria, whose extinct activity is through an enzyme in the cell to reduce free-state nitrogen in the air into NH
-state nitrogen fertilizer for plant use. This genobacteria was first found in legume plants, it first invaded the root of the legume plant, and then stimulate the plant at the root to form a root tumor, the root tumor bacteria are wrapped in it. Soybean plants supply the root tumor with water, nutrients, mineral elements, etc. to ensure the survival of the root tumor bacteria, the root tumor bacteria for the soybean plants to provide nitrogen fertilizer. A mutually beneficial symbic relationship is formed between legume plants and root tumor bacteria.
, although there are two ways to provide nitrogen for plants, most plants in nature are still in a state of nitrogen hunger. This is because plants have a greater demand for nitrogen and the main nitrogen-absorbing forms, ammonium ions (NH
) and nitrate ions (NO
), are easily lost. Nitrate ions are easy to lose from the soil with water, but also easy to change under the action of microorganisms N
O, N
and other gases volatile, ammonium ions are easy to be soil clay minerals and organic matter fixed. In order to increase crop yields, humans began to synthesize nitrogen-based fertilizers in chemical plants, including ammonium bicarbonate, urea, ammonium sulfate, and so on. Through the application of synthetic nitrogen fertilizer, the problem of nitrogen deficiency in plants is solved, which greatly meets the agricultural demand.
the use of nitrogen fertilizer is a double-edged sword, excessive use of plants and the environment have many adverse effects. For example, due to excessive fertilization, a large amount of excess nitrogen in the soil with water gathered in lakes and other bodies of water, resulting in the nutrient-rich water body, the rapid growth of algae plants in the water, consumption of most of the oxygen in the water, aquatic animals due to lack of oxygen can not survive, seriously affecting the water ecosystem. At the same time, the large amount of nitrogen fertilizer used in farmland, so that the number of N
O into the atmosphere is increasing, N
O is a stable gas, it enters the stratosphere, it will consume ozone, thereby increasing the amount of ultraviolet radiation reaching the ground.