Continuous cropping obstacles are the result of a combination of many factors within both crop and soil systems. Plants grow in soil and have a close relationship with soil. Continuous cropping obstacles are mainly caused by soil nutrient imbalance caused by continuous planting of the same type of crops, abnormal soil microbial flora, and accumulation of autotoxic substances secreted by plants or microorganisms in the soil, which affect crop growth.
In recent years, due to the increasing demand for potatoes and the economic benefits of growing potatoes, potatoes have become the main cash crops in many regions. However, potatoes are very sensitive to continuous cropping and belong to crops that are not suitable for continuous cropping. Producing areas are very common.
The causes of continuous cropping obstacles are: 1. Imbalance of soil nutrients. Continuous cropping on the one hand will lead to a lack of certain nutrients. If these nutrients are not supplemented in a timely manner, it will affect the healthy growth of the crops, which will cause continuous cropping obstacles; The occurrence of secondary salinization will also cause continuous cropping obstacles. After continuous cropping of potato, the contents of available nitrogen, phosphorus, and potassium all decreased; after 4 years of continuous cropping, the content of total nitrogen, total phosphorus, and total salt in the soil decreased compared with non-continuous cropping soil.
2. Abnormal soil microflora. The microorganisms in the soil can be generally divided into three categories: beneficial bacteria, neutral bacteria and harmful bacteria according to their effects on plant growth. In the case of normal rotation cultivation, the number and proportion of the three types of microorganisms in the soil are in a dynamic equilibrium. Although harmful microorganisms may exist, they will not become the dominant population in the soil, so they will not affect the normal growth of the crops. After continuous cropping, due to the existence of suitable hosts and suitable growth environments, some pathogenic bacteria will rapidly multiply and eventually become dominant groups in the soil, which will affect crop growth, cause soil-borne diseases, and cause continuous cropping obstacles.
As the duration of continuous cropping increased, the number of Fusarium pathogens of dry rot pathogen in potato root soil showed an upward trend. After continuous cropping of potatoes, the number of cellulose-decomposing bacteria and nitrogen-fixing bacteria in the soil that were beneficial to potato growth decreased compared with non-continuous cropping soil. After the potato, the number of soil-borne disease fungi, Fusarium oxysporum and Fusarium solani, increased in soil, while the number of antagonistic anticoccidial fungi decreased.
3. Accumulation of autotoxic substances. Plants mainly rely on the root system to take in nutrients from the soil. Changes in soil chemistry and microecological environment have a great impact on normal plant growth. Among the autotoxic substances secreted by plants, especially root exudates have the greatest effect on plant growth. Root exudates can directly affect the normal growth of crops by changing the chemical environment of the root soil of the crops; on the other hand, they can indirectly affect the healthy growth of plants by affecting the microflora of the root soils.
The control measures are as follows: 1. Change the planting system and make reasonable rotations and intercropping. Through rotation, the number of pathogenic bacteria and the number of pests in the soil can be significantly reduced.
2. Burn down the plant residues remaining in the field, and then return the plant ash to the field. This can effectively kill the eggs and parasites remaining on the straw, and can effectively provide potassium fertilizer.
3. After the emergence of potatoes, 1000 ml of Avermectin was used to irrigate the roots or to mix soil with Avermectin when planting, which can effectively prevent the occurrence of soil-borne diseases and insect pests.
4. Qualitative and quantitative determination of nutrient elements in the soil before sowing, and formulate a reasonable fertilization system, apply organic fertilizers, and improve soil structure.
5. Planting potato varieties resistant to continuous cropping (such as resistance to pests and diseases, autotoxicity, salt damage, etc.).
Disclaimer: Some articles on this website are transferred from the Internet. If you have third party legal rights, please inform this website to deal with them. phone
Zhejiang Industrial Group Co., Ltd. , https://www.xingyeseafood.com