Cropping Systems and Farming Types
What the exam asks
Cropping Systems and Farming Types tests whether you can distinguish sole, mixed, inter, sequence, relay, strip and multistorey cropping, and relate them to subsistence, commercial, dryland, irrigated, organic and precision farming. Expect definition matching, advantage-disadvantage items and a land-equivalent calculation.
Core rules
- Sole cropping grows one crop alone; mixed cropping grows two or more crops together without a definite row arrangement; intercropping uses a definite row proportion.
- Sequential cropping follows one crop after another; relay cropping plants the next crop before the previous one is harvested; strip cropping alternates strips, often for erosion control.
- A good rotation alternates deep and shallow roots, legumes and non-legumes, and exhaustive and restorative crops; it reduces pest carry-over and improves soil fertility.
- Cropping intensity rises with irrigation, short-duration varieties and relay or sequential systems, but higher intensity needs more nutrients and water.
- Land equivalent ratio (LER) = sum of intercrop yields divided by sole-crop yields for each component. LER > 1 indicates a land-use advantage.
Worked example
Pigeonpea sole yield is 1.5 t ha−1; in intercrop it yields 1.2 t ha−1. Urd sole yield is 0.6 t ha−1; in intercrop it yields 0.35 t ha−1. LER = 1.2/1.5 + 0.35/0.6 = 0.80 + 0.58 = 1.38. Reasoning: the intercrop needs only 1/1.38 of the sole-crop land to produce the same total, so it has a land-use advantage. Profit still depends on prices and costs.
Traps
Mixed cropping is not the same as intercropping; relay is not sequential; LER above 1 does not guarantee higher profit. Do not call a farming type a cropping system: organic farming is a management approach, while intercropping is a spatial crop arrangement.