Introduction to major field crops (1+1)

Principles of Crop Rotation

1. The crops with tap roots should be followed by those with fibrous root system. This helps in proper and uniform use of nutrients from the soil.

2. The leguminous crops should be grown after non-leguminous crops. Legumes fix atmosphericnitrogen inthe soil and add moreorganic matter to the soil.
3. More exhaustive crops should be followed by less exhaustive crops.
4. The crop of the same family should not be grown in succession because they act like alternate hosts for pests and diseases.
5. An ideal crop rotation is one whichprovides maximum employment to the familyand farm labour,farm machineriesand equipments are efficiently used.
6. Selection of the crop should be demand based.
7. The selection of crops should be problem based.
8. The selection of crops should suit to the farmer’s financial conditions.
9. The crops selected should also suit to the soil and climate conditions.


Benefits of Crop Rotation

1. Beneficial to succeeding crops.
2. Soil fertility is restored by fixing atmosphericnitrogen.
3. Encourages soil microbial activity.
4. Improves physico-chemical properties of the soil.
5. Avoids accumulation of toxins (HCN etc.).
6. Soil is protected from erosion.
7. Controls pests and diseases.
8. Controls weeds in the fields.
9. The family and farm labour, power, equipment and machineries are well employed.
10. Differential extraction of nutrientsand moisture from different depths.
11. Proper utilization of all the resources and inputs.


Limitations of Crop Rotation

1. Specialization in one crop is not possible.
2. Requirement of equipments and machineries varies from crop to crop.
3. Allopathic effect of preceding crop.
4. Serves as alternate hosts for pests and diseases.