Why is crop rotation an effective and sustainable way to improve agricultural yields?
If the same crop is grown on a given piece of land, over time, the yield falls. This is mainly due to persistent pest and disease problems (specific to that crop), reduced soil fertility, soil erosion, or depletion in soil nitrogen content. A ready-made solution to some of these problems is the use of chemicals: pesticides for taking care of pests, extensive fertilization to maintain and improve soil fertility, etc. However, chemical addition is not a sustainable solution and can result in environmental issues, among others.
Crop rotation is a natural and sustainable remedy for this situation. When crops are grown in a cyclic fashion in a given field, they complement each other and provide remedies to the problems mentioned above. For example, including a nitrogen-fixing crop in the crop rotation cycle will ensure that there is sufficient nitrogen in the soil. Crop rotation also helps with managing pests and diseases which are particular to a crop. Since crops are being changed, these pests and diseases will not find hosts for continued survival. Deep-rooting and shallow-rooting crops can be cycled to ensure soil fertility and stability. Crop rotation also improves the physical characteristics of the soil including bulk density, water holding capacity, and porosity.
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