Catch crop

A catch crop is a fast-growing crop cultivated between two main crops in a single agricultural year to make efficient use of time, land, and resources. It is typically sown after one main crop has been harvested and before the next is planted. Catch crops help in maintaining soil fertility, preventing erosion, and suppressing weeds, while also providing additional income or fodder to the farmer. The practice is common in intensive and sustainable farming systems, especially where climatic conditions allow multiple cropping within a year.

Definition and Concept

A catch crop is defined as a temporary, short-duration crop grown to “catch” the benefits of available soil moisture and nutrients that might otherwise be lost between two successive main crops. It is not meant to replace the main crop but to utilise fallow periods efficiently.
Catch crops differ from cover crops and intercrops in purpose and timing:

• Cover crops are mainly grown to protect soil from erosion and improve fertility, not necessarily for harvest.
• Intercrops are grown simultaneously with another crop.
• Catch crops, by contrast, are grown between two main crops in a short gap period.

Objectives of Growing Catch Crops

Catch cropping serves multiple agronomic, economic, and environmental objectives, including:

• Efficient land use: Ensures continuous cropping and avoids idle land periods.
• Soil conservation: Reduces erosion and nutrient leaching by maintaining vegetation cover.
• Weed suppression: Rapid growth shades out weeds, reducing their competition.
• Soil fertility improvement: Leguminous catch crops fix atmospheric nitrogen, enriching soil for subsequent crops.
• Additional yield: Provides extra income through marketable produce or fodder.
• Moisture utilisation: Makes use of residual soil moisture after harvest of the previous crop.
• Pest and disease management: Breaks pest and disease cycles by interrupting host continuity.

Thus, catch cropping forms an integral part of sustainable and integrated farming systems.

Characteristics of an Ideal Catch Crop

An effective catch crop should possess the following characteristics:

• Short growing period: Must mature quickly, usually within 30 to 90 days.
• Rapid germination and early vigour: Enables quick ground cover and weed control.
• Adaptability: Should tolerate variable soil and climatic conditions.
• Low input requirement: Should not compete heavily for water, fertiliser, or labour.
• Compatibility with main crops: Must fit between the harvest of one and the sowing of another without disturbing their schedules.
• Economic value: Should provide some return, either as a food, fodder, green manure, or seed crop.

Common Examples of Catch Crops

Several plant species are cultivated as catch crops depending on climate, soil, and farming system. Examples include:

• Leguminous catch crops:
  • Cowpea (Vigna unguiculata)
  • Green gram (Vigna radiata)
  • Black gram (Vigna mungo)
  • Sesbania spp.
  • Crotalaria juncea (sunn hemp)
• Cereal and non-legume catch crops:
  • Oats (Avena sativa)
  • Barley (Hordeum vulgare)
  • Sorghum (Sorghum bicolor)
  • Maize (Zea mays) (in short-duration hybrids)
• Fodder and vegetable catch crops:
  • Mustard (Brassica juncea)
  • Spinach (Spinacia oleracea)
  • Radish (Raphanus sativus)
  • Turnip (Brassica rapa)

Choice of catch crop depends on regional rainfall, temperature, and the cropping calendar of the main crops.

Examples in Cropping Sequences

Common examples of catch cropping in different regions include:

• Rice–Mustard–Rice rotation: Mustard is used as a catch crop between two rice crops.
• Wheat–Cowpea–Maize sequence: Cowpea improves soil nitrogen before maize planting.
• Sugarcane–Sesbania cropping: Sesbania acts as a green-manure catch crop before sugarcane ratooning.
• Potato–Moong–Paddy sequence: Green gram (moong) is grown between potato and paddy in North Indian systems.

These sequences enhance productivity and soil health without extending the total cropping duration significantly.

Agronomic Management

The success of a catch crop depends on proper agronomic planning and management:

• Timing of sowing: Must be done immediately after the harvest of the preceding crop to utilise residual moisture.
• Soil preparation: Minimal tillage is often sufficient since the crop duration is short.
• Seed rate and spacing: Slightly higher seed rates ensure quick canopy closure.
• Fertilisation: Limited fertiliser is applied, especially if the catch crop is not harvested.
• Irrigation: Often unnecessary if sufficient residual moisture exists; otherwise, light irrigation may be applied.
• Harvesting: Should be timed to avoid interference with the next main crop’s sowing schedule.

Benefits of Catch Cropping

Catch crops provide both agronomic and environmental benefits:

1. Soil fertility enhancement:
   • Leguminous catch crops fix nitrogen, improving the nutrient status for subsequent crops.
2. Soil protection:
   • Prevent erosion and surface runoff during rainy or fallow periods.
3. Improved soil structure:
   • Root systems enhance soil aeration and organic matter content.
4. Weed and pest control:
   • Act as natural suppressants of weeds and break pest life cycles.
5. Efficient water and nutrient use:
   • Capture nutrients that might leach out during fallow periods.
6. Additional production:
   • Yield of vegetables, fodder, or green manure adds to farm profitability.

Limitations of Catch Crops

Despite their benefits, certain limitations must be considered:

• Limited time window: Not always feasible between short-duration main crops.
• Moisture stress: In dry regions, catch crops may deplete water needed for subsequent crops.
• Labour and input demand: Requires additional effort for sowing and harvesting.
• Pest carry-over risk: Some species may host pests affecting the next crop.
• Market constraints: Catch crops with limited market value may not always be profitable.

Proper selection and management minimise these drawbacks and optimise benefits.

Environmental and Sustainable Role

Catch cropping contributes significantly to sustainable agriculture by:

• Enhancing soil health and biodiversity.
• Reducing greenhouse gas emissions through continuous vegetation cover.
• Supporting climate resilience by improving water retention and reducing soil degradation.
• Serving as green manure to promote organic farming practices.