Why do crops need to be rotated? The reasons and significance of crop rotation

Reasons for crop rotation

In agricultural planting, crop rotation and fallow are more important, because fallow rotation can increase the total porosity and soil organic matter content, which is beneficial to the protection of the land. Therefore, the same logic applies to crop rotation.

Maintain, restore and improve soil fertility

Cereal crops consume a lot of nitrogen from the soil, while legumes such as green manure can fix free nitrogen in the air, and cruciferous crops can secrete organic acids. If these crops are rotated, soil fertility can be maintained, restored and improved .

Balanced use of soil nutrients and water

Different crops have different abilities to absorb soil nutrients and water. For example, rice, wheat and other cereal crops absorb more nitrogen and phosphorus, but less calcium, while legumes absorb more phosphorus and calcium.

In this way, crop rotation can balance the use of various nutrients and give full play to the soil's potential for increasing production . Deep root rotation and shallow root rotation can utilize nutrients and water in different soil layers .

Can reduce pests and diseases

Crop rotation can change the host of pathogens, inhibit the growth of pathogens, and reduce harm. Crop rotation, especially water-land rotation, can change the ecological environment of weeds and inhibit or eliminate their growth .

Rational use of agricultural resources

According to the physiological and ecological characteristics of crops, the crops before and after crop rotation should be reasonably matched, and the connection between crops should be close.

This is conducive to making full use of natural resources such as land, light, heat, and water. At the same time, it is also conducive to the rational and balanced use of social resources such as agricultural tools, fertilizers, pesticides, water resources, funds, and the staggered farming seasons.

Common vegetables in crop rotation

Vegetables that belong to the same family taxonomically should not be rotated. For example, tomatoes, eggplants, peppers and sweet peppers belong to the Solanaceae family, so they are not suitable for crop rotation.

cucumber

The previous crop of spring cucumbers is mostly autumn vegetables or spring vegetables and winter vegetables. The subsequent crop is suitable for a variety of autumn vegetables. The previous crop of summer and autumn cucumbers is suitable for various spring and summer vegetables, and the subsequent crop is suitable for winter vegetables or spring vegetables. Cucumbers and tomatoes inhibit each other and are not suitable for rotation and interplanting.

tomato

3 to 5 years of crop rotation, no continuous cropping with Solanaceae crops, the previous crop is various leafy vegetables and root vegetables, the second crop can also be leafy vegetables and root vegetables, intercropped with short-stem crops or vegetables, such as edamame, cabbage, bulb fennel, onion, garlic, etc.

For autumn greenhouse tomatoes, interplanting small vegetables can lower the ground temperature. Interplanting sweet corn between tomatoes can induce moths to lay eggs and eliminate them in a concentrated manner.

eggplant

The previous crop is overwintering leafy vegetables, and it can also be intercropped with early-maturing cabbage, early-maturing cabbage, spring radish, water radish, cherry radish and other vegetables with short growing periods. The second crop can be autumn vegetables such as Chinese cabbage.