How does rotation of crops work?

Answer 1

Crops are rotated for several reasons. One is that different crops have different nutrient requirements and sometimes when you plant a different crop it allows you to reduce the amount of fertilizer you need to apply. For instance legumes fix their own nitrogen and actually can put some nitrogen back into the soil. Another reason is to manage insect and disease pressures. Disease spores and insects overwinter in soil and crop residue left over. Certain crops are susceptible to certain disease and insect damage so when we change the crop we remove those pests' food source. A third benefit has to do with the crop's root system. Different root systems can reach different levels of the soil profile and therefore they can 'pull up' some nutrients that are deeper in soil profile, maximizing soil nutrients. One final benefit is that crop rotation can often maximize the economic potential of a piece of land while at the same time reducing soil erosion because some crops can be grown at different times of the year, leaving the land fallow for far shorter periods of time.

Answer 2

By growing other crops in between cotton crops. For example, in the southeast US, following cotton with a corn (maize) crop and then a peanut (groundnut) crop before growing cotton again will help reduce the numbers of damaging nematodes and other pests. The other crops also utilize different nutrients than cotton.

Answer 3

Crop rotation works by alternately planting crops which will aid in restoring soil fertility rather than planting only crops which deplete the soil.

Answer 4

Rotating crops has many advantages. One of them is enabling the replenishment of nitrogen in the soil through the use of green manure in sequence with cereals and other crops.