No-Till: Making It Work - Crop Rotation

Table of Contents

1. Crop Rotation, Pest Management and Weed Control
2. Planning a Rotation
3. Some Tips When Planning a Crop Rotation
4. Available in Published Version of No-till

Regardless of the tillage system, rotating crops is always a best management practice. In the absence of tillage, it may become even more important in no-till systems - especially to break insect, disease and weed cycles. Crop rotations can also increase yields, build soil organic matter and enhance nitrogen availability if nitrogen fixing legumes are included. However, there are some challenges in no-till rotations.

Figure 1. No-till is an option for some horticultural crops, such as tomatoes.

Crop Rotation, Pest Management and Weed Control

When crops are rotated properly, they can disrupt insect and disease cycles and weed infestations.

Changing crops also means varying the type and timing of management practices. This will further disrupt crop pests, e.g. corn is not a host for the soybean cyst nematode.

Crop rotation allows opportunity for resource building and protection. The inclusion of forage crops in the rotation can improve seedbed structure, add organic matter, and add nitrogen - while their cover protects soil and water resources.

Each crop has particular impacts upon its growth environment, e.g. soybean residue allows seedbed to warm up quickly; legume crops can have dense canopies, yet add nitrogen to soil.

Figure 2. Hay field.

For maximum benefit, rotate grassy crops with broadleaf crops, i.e. corn and soybeans.

Corn following wheat in no-till can be a problem because:

• the cool/wet seedbed reduces corn seedling emergence
• phytotoxins released from wheat residue slow seedling growth
• slugs may be a problem in a cool wet spring.

Figure 3. Grain crop.

Crop rotations allow for more opportunities for chemical family rotation and help prevent weed resistance to herbicide.

Planning a Rotation

Rotations must be planned to suit each farming operation. Factors affecting crop rotation sequence changes are:

• livestock feed needs
• insect pressures
• equipment available
• labour and management time
• cover crops
• weed control program
• previous crop (crop sequence and residue)
• market for crop
• previous herbicide (chemical) family used
• disease pressure
• current seasonal operations
• available seed
• soil type / management limitations
• nutrient management program
• erosion control / soil quality problems.

Some Tips When Planning a Crop Rotation

• Alternating grass crops with broadleaf crops is the best practice.
• Continuous cropping is the worst practice: the more crops, the better.
• Go for added benefits, e.g. red clover grown between cereals and corn can improve the soil.
• A high residue crop followed by a low residue crop helps maintain sufficient residue cover on the field.

Figure 4. Crop rotation.

In no-till, crop rotation is very important for weed control. You can plan for and control weeds this year that will affect next year's crop.

Available in Published Version of No-till

• Best Management Practices
  • Crop Choices, based on Residues and Inputs - chart
• Tips for Making It Work
  • No-till Alfalfa
  • Corn Following Wheat
  • Management of Cereal Residue on Clay Soil