It is more important than NPK in the soil!

It is more important than NPK in the soil!

Soils such as red soil and yellow soil in southern China are sometimes higher in nitrogen, phosphorus and potassium than black soil in northeast China, but their fertility level is not as high as that of black soil, and the yield and quality of crops produced are not comparable to black soil.This shows that NPK content is not an indicator to measure the level of soil fertility. In fact, soil science and plant nutrition have confirmed that the index to measure the level of soil fertility is the amount of organic matter in the soil.

Soil organic matter generally refers to the carbon-containing organic compounds in the soil in various forms. It refers to the substances in the soil derived from life. It is the substances in the soil except for minerals, air and water. It is the most active part of the soil and one of the important indicators to measure soil fertility. It can be said that there is no soil fertility without organic matter.


1. Organic matter is the main source of soil nutrients

Organic matter contains various nutrients required for crop growth, which can directly or indirectly provide N, P, K, Ca, Mg, S and other trace elements for crop growth. More than 95% of N is in the soil in an organic state. In addition to the applied N fertilizer, the main source of soil N is provided by the decomposition of organic matter.

2. Organic matter can promote the growth and development of crops

Humic acid in organic matter can enhance plant respiration, improve the permeability of cell membranes, and enhance the absorption of nutrients. At the same time, vitamins and some hormones in organic matter can promote the growth and development of plants.

3. Organic matter can promote the formation of soil structure and improve soil physical properties

The humus in organic matter is the main cementing agent of soil aggregates, and soil organic colloid is an indispensable cementing material to form a water-stable aggregate structure, so it helps cohesive soil to form a good structure, thus changing the soil pore state and water, Air ratio to create suitable soil tightness. On the other hand, it can improve the agglomeration of sand and improve its overly loose state.

4. Organic matter can improve soil fertility and buffering properties

Organic colloids in soil organic matter have a large number of negative charges and have a strong adsorption capacity, which can absorb a large amount of cations and water. Improve the soil's ability to retain fertilizer and water, and also improve the soil's buffering ability to acid and alkali.

5. Organic matter can promote the activities of soil microbes

Soil organic matter supplies the energy and nutrients needed by soil microbes and is beneficial to the activities of microbes.

6. Organic matter can increase soil temperature

The organic matter is darker in color, generally brown to dark brown, and has a strong ability to absorb heat, which can increase ground temperature and improve soil thermal conditions.

7. Organic matter can improve soil nutrients

Humus in organic matter has a complexing effect and helps to eliminate soil pollution. For low-yield fields, the soil can be fertilized by increasing the organic matter content and improve the soil fertility level. For high-yield fields, due to the continuous decomposition of organic matter, it is also necessary to continuously replenish organic matter. Humus can form complexes or chelates with phosphorus, iron and aluminum ions to avoid the precipitation of insoluble phosphates and increase the amount of effective nutrients.


To sum up, it is not difficult to see that the soil with more soil organic matter content has a higher soil fertility level, which can not only provide abundant nutrients for crop growth, but also have a strong ability to retain water and fertilizer, which can reduce the loss of nutrients and save the amount of chemical fertilizers. , improve fertilizer utilization.

It is determined by the organic matter that the fertile fields will not lose weight for three years, and the thin fields will not become fat for three years.

Therefore, we should do everything possible to increase the application of organic fertilizers and increase the content of soil organic matter, so as to give full play to the yield increase benefits of chemical fertilizers and the yield quality of crops.


Post time: Jun-07-2022