What are the functions and benefits of organic fertilizer

Supplies crops with nutrients and active substances, and increases the intensity of photosynthesis

In the process of continuous mineralization in the soil, organic fertilizer can supply the various nutrient elements needed by crops continuously over a relatively long period, and at the same time can also supply a variety of active substances, such as amino acids, ribonucleic acid, humic acid and various enzymes. The enzyme activity in livestock and poultry manure in particular is extremely high, tens to hundreds of times that of soil enzyme activity; it can not only nourish plants, but also stimulate crop growth, and can also enhance soil microbial activity and improve the availability of soil nutrients. During the decomposition of organic fertilizer, a large amount of CO2 is produced for crops to carry out carbon assimilation; within a certain CO2 concentration range, the intensity of plant photosynthesis rises linearly with the increase in CO2. According to trials in Beijing, Fujian and other places, increasing the CO2 concentration can raise crop yields by more than 10%. Organic fertilizer is rich in carbon sources, which is of great significance for promoting crop growth and increasing yields.

Improves soil fertility

Soil organic matter is one of the main indicators for measuring the level of fertility; it is the material basis of soil fertility and the material source for replenishing and renewing soil organic matter. When organic fertilizer is applied, (1) the consumed organic fertilizer is continuously replenished. Relying solely on chemical fertilizers, within just a few years the soil structure will be destroyed and become compacted. (2) The soil organic matter content is continuously raised. The soil organic matter content in most regions of our country is relatively low. Apart from the black soil region of the Northeast, where the organic matter content is relatively high and can reach 2.5%-7.5%, most of the North China and Northwest regions are below 1%, while the organic matter content of paddy fields in the Central China and South China areas is somewhat higher, reaching 1.5%-3.5%. In addition, dryland areas rarely reach more than 2%, and among these, cultivated land with an organic matter content below 0.5% still accounts for 10.6% of our country's existing cultivated land area. (3) Soil organic matter is continuously renewed. Organic fertilizer converted into soil organic matter accounts for about two-thirds of the annual formation of soil organic matter, which shows that organic fertilizer must be replenished in order to continuously renew soil organic matter. It is very clear that applying organic fertilizer is extremely important for improving soil fertility.

Improves the physical and chemical properties of soil

After organic fertilizer enters the soil, it is decomposed by microorganisms and condensed into new humus, which can combine with clay and calcium ions in the soil to form organic-inorganic complexes and promote the formation of water-stable aggregate structure in the soil, thereby coordinating the contradictions among water, fertilizer, air and heat in the soil. It lowers soil bulk density, improves the cohesiveness and adhesiveness of the soil, and makes tillage better. Because humus is loose and porous, its adhesiveness and cohesiveness are smaller than those of clay and larger than those of sandy soil, so it can both increase the looseness and aeration of clayey soil and change the loose state of sandy soil. Humus is darker in color, which can increase the soil's heat absorption capacity and improve the soil's thermal conditions. Humus is loose and porous with a strong capacity to absorb and store water, so it can improve the soil's water-holding capacity. The hydroxyl groups of humus molecules, phenolic hydroxyl groups or alcoholic hydroxyl groups, can dissociate H+ ions in water. This makes humus carry a negative charge, so it can adsorb a large number of cations and exchange them with the cations in the soil solution, thereby improving the soil's fertilizer-holding capacity. From the above it can be seen that applying organic fertilizer can effectively build up soil fertility and is conducive to high and stable yields.

Improves product quality

Applying chemical fertilizer alone or with an improper nutrient ratio will lower product quality. Practice has proved that the combined application of organic fertilizer and chemical fertilizer can improve product quality, such as increasing the protein content in wheat and corn kernels. Compared with applying chemical fertilizer alone, the combined application improves quality in every case: wheat protein content increases by 1%, gluten by 2.3%, and total nitrogen in the kernels by 0.19%. Research by the Soil and Fertilizer Institute of the Chinese Academy of Agricultural Sciences shows that unreasonable and excessive topdressing of nitrogen fertilizer significantly increases the nitrate content in vegetables; especially in the edible parts of Chinese cabbage, spinach and lettuce, nitrate reaches as high as 1000μg/g, with the highest reaching 1700μg/g, while in the farmyard manure plots it is only 200-500μg/g, and at the lowest only a few dozen μg/g. For tomatoes and cauliflower types, using a combination of organic and inorganic fertilizers can increase the vitamin C content by 16.6-20.0μg/g.

Reduces environmental pollution

Organic waste contains a large number of pathogenic bacteria and insect eggs. If not treated in time, it will spread pathogens, increase the concentrations of ammoniacal, nitrate and soluble organic nitrogen in groundwater, and cause eutrophication of surface water and groundwater, deteriorating environmental quality and even endangering the survival of organisms. Therefore, rationally using these organic fertilizers can both reduce environmental pollution and cut chemical fertilizer input, achieving two benefits at once. Organic fertilizer can also adsorb and chelate toxic metal cations such as copper and lead, and increase the fixation of arsenic.