MP Board · Class 9 · Science · Improvement in Food ResourcesAnswer the following comprehensive questions regarding Cropping Patterns used in modern sustainable agriculture: Define and explain the concepts of Mixed Cropping, Inter-cropping, and Crop Rotation. State the key criteria used for selecting crop combinations in Inter-cropping and crop sequences in Crop Rotation. List four distinct advantages of practicing Inter-cropping over traditional Mixed Cropping. Explain how Crop Rotation helps in restoring soil fertility and suppressing agricultural pests and diseases naturally.

1. Definitions of Cropping Patterns

• Mixed Cropping: It is the practice of growing two or more crops simultaneously on the same piece of land without any specific row pattern or spatial arrangement (e.g., Wheat + Gram, Mustard + Wheat). Seeds are mixed before sowing.
• Inter-cropping: It is the practice of growing two or more crops simultaneously on the same field in a definite row pattern (e.g., 1 row of Maize alternating with 2 rows of Soyabean). Crops are not mixed randomly.
• Crop Rotation: It is the practice of growing different crops on the same land piece in a pre-planned, sequential order over successive seasons to maintain soil quality and nutrient status.

2. Criteria for Selection of Crops

• For Inter-cropping:
  • Crops must have different nutrient requirements to minimize inter-specific competition.
  • Crops should have different root depths (e.g., deep-taproot paired with shallow-fibrous roots) to extract nutrients from different soil layers.
  • Crops must have different maturation periods and canopy architectures so that harvesting one does not damage the other.
• For Crop Rotation:
  • Selection depends on moisture availability and irrigation facilities.
  • Alternating leguminous crops (which fix nitrogen) with non-leguminous crops (which consume high nitrogen).
  • Alternating high nutrient-demanding crops with low nutrient-demanding crops.

3. Advantages of Inter-cropping Over Mixed Cropping

• Targeted Application of Inputs: Fertilisers, pesticides, and irrigation can be applied individually to specific rows based on specific crop needs.
• Easier Mechanical Operations: Sowing, weeding, spraying, and harvesting can be performed row-wise mechanically without damaging adjacent crops.
• Better Yield per Unit Area: Prevents inter-crop competition for light and space, resulting in higher overall economic yield.
• Prevention of Disease Spread: Row barriers of non-host crops prevent pests and pathogens from spreading across the entire field.

4. Role of Crop Rotation in Soil Fertility and Pest Control

• Soil Fertility Enhancement: Rotating nitrogen-demanding cereal crops (like Wheat or Rice) with nitrogen-fixing leguminous crops (like Gram or Pulses) naturally replenishes soil Nitrogen through symbiotic Rhizobium bacteria, reducing dependence on chemical fertilisers.
• Pest and Pathogen Suppression: Most agricultural pests and soil-borne pathogens are host-specific. Growing non-host crops in successive seasons starves and breaks the life cycle of pests, weeds, and pathogens naturally without excessive chemical pesticides.