The Role of Organic Fertilizer
- Supply crop nutrients and active substances, and increase photosynthesis intensity. In the process of continuous mineralization in the soil, organic fertilizers can supply a variety of nutrients necessary for crops for a long time, and can also supply a variety of active substances, such as amino acids. , ribonucleic acid, humic acid and various enzymes. Especially in livestock and poultry manure, the enzyme activity is particularly high, which is several to several hundred times of soil enzyme activity. It can not only nourish plants, but also stimulate crop growth, and can also enhance soil microbial activities and improve soil nutrient availability. In the process of decomposition of organic fertilizers, a large amount of CO2 is produced for carbon assimilation of crops. The photosynthesis intensity of plants is within a certain range of CO2 concentration, and increases linearly with the increase of CO2. According to tests in Beijing and Fujian, increasing the concentration of CO2 can increase crop yield by more than 10%. Organic fertilizers are rich in carbon sources and are important for promoting crop growth and increasing yield.
- Improving soil fertility Soil organic matter is one of the main indicators for measuring the level of fertility, the material basis of soil fertility, and the source of material for replenishing and renewing soil organic matter. When organic fertilizer is applied, (1) the organic fertilizer consumed is continuously replenished. Chemical fertilizer alone, not a few years, the soil structure is destroyed and squashed. (2) Continuously increase soil organic matter content. The soil organic matter content in most areas of China is relatively low. Except for the high organic matter content in the black soil region of Northeast China, it can reach 2.5%~7.5%. Most of the areas in North China and Northwest China are less than 1%, and the organic matter content in the paddy fields in Central China and South China is slightly higher. , up to 1.5% to 3.5%. In addition, dryland areas rarely reach more than 2%, of which the organic matter content of cultivated land below 0.5% also accounts for 10.6% of the existing cultivated land area in China. (3) Continuously update soil organic matter. The conversion of organic fertilizers into soil organic matter accounts for about two-thirds of the annual formation of soil organic matter. It can be seen that organic fertilizers must be supplemented to continuously update soil organic matter. It is clear that the application of organic fertilizers to increase soil fertility is very important.
- Improve soil physical and chemical properties After the organic fertilizer enters the soil, it is decomposed by microorganisms and condensed into new humus. It can combine with clay and calcium ions in the soil to form an organic-inorganic complex, which promotes the water-stable aggregate structure in the soil. Formed to coordinate the contradiction between water, fertilizer, gas and heat in the soil. Reduce the soil bulk density, improve the soil’s cohesiveness and adhesion, and make the ploughing better. Since the humus is porous and porous, its adhesion and cohesive force are smaller than clay and larger than sand, so that it can improve the looseness and air permeability of the viscous soil, and can change the loose state on the sand. The dark color of humus can increase the heat absorption capacity of the soil and improve the thermal condition of the soil. The humus loose porous water storage capacity is strong, which can improve the water retention capacity of the soil. The hydroxyl group of the humic molecule, the phenolic hydroxyl group or the alcoholic hydroxyl group can dissociate the H+ ion in water. The humus is negatively charged, so it can adsorb a large amount of cations and exchange with the cations in the soil solution, thereby improving the fertilizer retention capacity of the soil. It can be seen from the above that the application of organic fertilizer can effectively fertilize the soil, which is conducive to high yield and stable yield.
- 4.Improve product quality Single application of fertilizer or improper distribution ratio, will reduce product quality. Practice has shown that the combination of organic fertilizer and chemical fertilizer can improve product quality, such as increasing protein content in wheat and corn kernels. The combined application rate was improved compared with the single application of fertilizer. The protein content of wheat increased by 1%, the gluten increased by 2.3%, and the total nitrogen of the grain increased by 0.19%. Studies by the Soil and Fertilizer Institute of the Chinese Academy of Agricultural Sciences have shown that the irrational and excessive application of nitrogen fertilizers has significantly increased the nitrate content of vegetables, especially the edible parts of cabbage, spinach and lettuce, with nitrates as high as 1000 μg/g, the highest. It can reach 1700μg/g, while the manure area is only 200-500μg/g, and the lowest is only tens of μg/g. For tomatoes and cauliflower, the combination of organic and inorganic fertilizers can increase the content of vitamin C by 16.6-20.0 μg/g.
- Reducing environmental pollution Organic waste contains a large number of pathogens. If not treated in time, it will spread germs, increase the concentration of ammonia, nitrate and soluble organic nitrogen in groundwater, and eutrophication of surface and groundwater, resulting in environmental quality. Deteriorating, even endangering the survival of living things. Therefore, the rational use of these organic fertilizers can not only reduce environmental pollution, but also reduce the investment of chemical fertilizers. Organic fertilizers can also adsorb and bind toxic metal cations such as copper and lead, increasing the fixation of arsenic.