Establishment of Forages

Selecting the proper varieties is critical to the establishment and productiveness of forages. It is important to select well adapted varieties that are insect and disease resistant with good seedling vigor and post-harvest regrowth and yield potential. Establishment is essential to produce a productive stand. Vigorous stands are required for high yields, and the proper plant population is critical during the initial planting for seed propagated forages. A thick stand leaves little of the soil surface visible. Plant density varies with forage species and will tend to be less under dry, less fertile conditions. As crowns develop during tillering, plant numbers will decrease because less productive plants fail to compete for light, water, and nutrients and only vigorous plants produce new shoots following harvests.

The Seedbed
Successful establishment begins with proper seedbed preparation. Soil tests should be conducted to correct pH, phosphorus (P) and potassium (K) prior to planting. Phosphorus and potassium do not move in the soil and should be incorporated prior to planting. Nitrogen (N) should be applied as needed in split applications. Legumes should only receive 1/2 of the nitrogen that is required for grasses since legumes will synthesize their own nitrogen once established.

All forage grasses grow best under neutral (6.0 to 7.0) pH and fertile soils. Some species will persist under less than ideal conditions, but perform best with proper management. Forage grasses differ in their tolerance to drought, water logged soils, and frequency of harvests. The seedbed should be firm, but loose enough to allow root penetration with small soil particles to allow for good seed-to-soil contact. Plowing, disking, and harrowing the seedbed usually accomplishes this.

Methods of Sowing
Drilling is superior to broadcasting when the soil conditions are dry or the soil is light. Drilling in rows however, provides for weed establishment between the rows. Broadcasting gives a better seed distribution and ground cover. With broadcasting, the seed must be covered with soil to ensure good seed-to-soil contact.

% Germination

Seeding depth

 

1 cm

2 cm

4 cm

6 cm

White clover

40

34

8

0

Red clover

42

39

17

0

Lucerne

38

35

11

0

Ital. Ryegrass, 4n

76

73

57

32

Ital. Ryegrass, 2n

75

68

43

13

Perenn. Ryegrass

62

63

45

11

Meadow Fescue

48

40

8

2

Red Fescue

64

53

12

1

Cocksfoot

47

35

11

2

Timothy

34

10

0

0

Poa pratensis

30

12

0

0


The Influence of Seeding Depth on the Germination of Different Species
Danish Field Experiments

 

Spring
March/April

Summer
August 1st

Fall September 1st  - October 1st

Clover
Grass

No
Yes

Yes
Yes

Yes
Yes

Yes
Yes

No
Yes

Cover
Crop

Winter-
cereal

Spring-
cereal, peas

No

Wintercereals


Time of Sowing
Spring or late summer is the best time for seeding. In the spring, the moisture is almost always adequate; in midsummer this is often not the case. Again, in August, the moisture is normally sufficient and at this time soil temperature ensures a good and quick germination.

Seeding Rate
Seeding rate is determined by seed size and adjusted for pure live seed and other conditions that may affect establishment. Seeding rates should be increased when soil or climatic conditions are less than ideal. Enough seed should be planted so the seedling plants occupy the area as they emerge and develop. When seeding a new stand with a companion species such as legume, seeding rate should be decreased to allow establishment of the companion species.

Fertilizer Application
Soil analysis is a good guide to fertilization. Fertilizers applied in early spring and mid-summer should have a high nitrogen content to encourage growth. Fertilizers applied in the fall should have a lower nitrogen content, but higher phosphate and potash content to encourage root growth.

Weeds
Spraying against annual weeds can be necessary in pure stands where there is less competition. Perennial weeds must be treated with a broad-spectrum herbicide before seeding as new weeds will start to develop.

Summary – Sward Establishment

  • Fine and firm seedbed
  • Fertilization with N, P & K depending on soil status
  • Seeding in spring or late summer
  • Seeding rate depending on species
  • Seeding depth maximum 0 to 1/2 inch
  • Weed control as necessary