Pasture Improvement: Renovation

Table of Contents

1. Introduction
2. Light
3. Soil Nutrients
4. Moisture
5. Prior to Renovating
6. At Establishment
7. During Establishment Year
8. Other Pasture Improvement Recommendations
   • Choosing the Improvement Technique
   • Rejuvenation
   • Seeding into the Sod
   • Broadcast Seeding
   • Limited Tillage
   • Frost Seeding
   • Using Livestock to Renovate Pastures
   • Fertilizing Pastures
   • Nutrient Cycling
   • Soil Tests
   • Impact of Grazing Animals on Pasture Fertility
   • Weed Control
   • Trampling Effects
9. Related Links

Introduction

Pasture productivity can be greatly enhanced by introducing high-yielding forage species. Renovation techniques make this possible without ploughing. The success of renovating depends on:

• selecting forage species adapted to the growing conditions in the field, the intended method of renovation and future pasture management
• preparation of the field
• seeding at an appropriate time of year
• inoculating the legumes properly
• moisture conditions at, and following, seeding
• soil fertility at, and following, seeding
• control of competition from the existing plants.

Established plants have all the advantages in renovated pastures. New seedlings must be able to survive the competition with the old plants for light, moisture, space and soil nutrients.

Light

Shading seriously affects the growth of legume seedlings. It reduces root growth more than top growth, and inhibits nodulation and nitrogen fixation.

Soil Nutrients

Existing grasses are better competitors for available soil nitrogen, and new seedlings may suffer from nitrogen deficiency. Legume growth and nitrogen fixation are also limited on soils with low levels of phosphorus. Correct nutrient deficiencies with fertilizer.

Moisture

Due to small root systems, new seedlings are vulnerable to water stress. Old plants with larger roots are able to access a larger soil area for available moisture. Renovating in early spring offers a better chance of having good moisture conditions. However, in early spring, soil under a sod stays cooler for a longer period of time than a bare soil. Low soil temperatures during germination and establishment can reduce plant density, nodulation and nitrogen fixation, and seedling growth rates. Early August growth renovations avoid this problem and can be successful if moisture conditions are good and there are no early killing frosts.

Prior to Renovating

• Cut or graze the area heavily, to weaken existing plants.
• Control problem weeds.
  • Spray the area with an appropriate herbicide in fall, prior to a spring seeding.
  • Take soil tests to determine fertilizer requirements.

At Establishment

• Apply a herbicide to kill or suppress the sod when grass growth reaches 5–10 cm – if one was not used the previous fall.
• Inoculate legume seeds just before seeding.
• Seed as early as possible in spring. Make sure the seed is placed at the right depth. If conditions are dry, plant closer to 1.5 cm, than 0.5 cm.
• Avoid seeding when the ground is wet. This causes smearing of the slot sides leading to impeded drainage. The soil at seeding should be moist and friable.
• Fertilize according to need.

During the Establishment Year

• Control competition from the old sod. Keep the old sod grazed down to allow new plants to establish. Graze the old plants when they reach 8–10 cm in height.
• Use controlled grazing management such as rotational grazing to encourage and protect new seeding.
• Fertilize in the fall according to soil test recommendations.

Related Links

... on forages and pastures, visit Forages and Pastures (OMAFRA)
... on weed control, order Publication 75 Guide to Weed Control: Forage Crops
... on agronomy for field crops, order Pub. 811 Agronomy Guide for Field Crops: Chapter 3 Forages
... on field crop protection, order Publication 812, Field Crop Protection Guide
... on livestock, visit Livestock (OMAFRA)