Grasses

ILVO recommends using grass mixtures based on varieties whose properties have been tested under Belgian conditions and that are included in the Belgian variety list.

Grasses for green fodder purposes

Only grassland with a good botanical composition can provide high levels of energy and protein. A correct choice of grass types and varieties with future use in mind is crucial, supported by proper planting, a well-maintained cultivation and good exploitation.

In contrast to arable crops and other green fodder crops, mixtures of different species and/or varieties of grasses are often sown. By understanding the properties of grass species and varieties, farmers can choose the most appropriate mixture for their needs.

It is therefore recommended to use grass mixtures based on varieties whose properties have been tested under Belgian conditions and that are included in the Belgian variety list.

View the variety lists

Permanent grassland	Temporary grassland
Perennial ryegrass	Festololium
Timothy	Hybrid ryegrass
Meadow fescue	Italian ryegrass
Cock's foot or Orchard grass	Westerwolds ryegrass
Tall's fescue
Smooth meadow-grass

View the comparative table of characteristics of grasses

Frequently Asked Questions

The choice of the species to be sown is mainly based on the combination of desired agricultural properties: productivity, palatability, flexibility in operation, nutritional value and persistence. Persistence is a very important property for permanent grassland and is mainly dependent on longevity, winter resistance and competitiveness against the co-sown species and the original flora.

The mean heading date corresponds to the date on which 3 heads are visible in 50% of the plants. This is influenced by day length.
Early, late and even intermediate varieties of certain species have been selected based on heading date. Sometimes the early varieties are also called hay types and the late varieties are called pasture types.

What is the impact of heading?

Early varieties have more rapid spring development but the time span between proper shearing and heading is very limited in the first two passes. After heading, palatability decreases and the grass remaining on the pasture increases. Mowing in the spring is practically required for this group for optimal use of the grass. The intermediate and late types offer more options for grazing and can also be mowed, making them far more flexible in use.

The choice of the type(s) to be sown primarily depends on the future duration and method of use. The following table provides an overview of the various options in terms of duration and method of use and which types of grass can be used in each case.

Type selection according to use

Duration of use	Utilization	Species
1 year	mowing	Westerwolds ryegrass Italian ryegrass
1-2 year	mowing	Italian ryegrass Hybrid ryegrass (2 jaar) Festulolium (2 jaar)
more than 2 years	mowing only	Hybrid ryegrass (3 jaar) Festulolium (3 jaar) Perennial ryegrass Meadow fescue Timothy Tall fescue Cocksfoot
more than 2 years	(predominantly) grazing	Perennial ryegrass Timothy Meadow fescue + Smooth meadow grass + White clover

When fertilization standards are imposed, the total N fertilization is limited and exploitation becomes less intensive in certain areas (including water extraction areas). Under these conditions, mixtures with timothy, meadow fescue and white clover come back into the spotlight.

Research of several varieties of perennial ryegrass at two N levels on two locations in Flanders showed that the order of the varieties with regard to the DM yield was not influenced by the fertilization level. This means that the yield data of the descriptive variety list for perennial ryegrass is valid for both intensive and extensive grassland exploitation.

Date of flowering

Only perennial ryegrass has such great differences in date of heading that they are divided into different types (early, intermediate and late). The flowering data stated in the tables comes from observations on experiments set up at 2 locations in Flanders.

Dry matter (DM) yield

In the varieties suitable for permanent grassland, the determination of the DS yield was carried out in at least 2 cycles of 3 years. For Italian ryegrass, the DM yield was determined with a spring sowing (2 years) and an autumn sowing (1 year).

Persistence

With an appropriate mowing regime, without a field period and without preparation, the current varieties of perennial ryegrass retain a well-closed sod for 3 years. Under grazing regime, persistence is significantly lower; this gives a more accurate picture of the varieties for use in practice. The persistence figures shown in this variety list come from grazing trials. These are sown every year at two locations. After three years of practical operation, the varieties are assessed on the percentage of perennial ryegrass that is still present.
For the other grass species, persistence is determined on the basis of assessments of the mowing trial fields and individual plants.

Health

Although diseases reduce yield, the biggest issue is their effect on palatability and absorption during grazing.

The main diseases are:

Ryegrasses: crown rust, leaf spot disease
Meadow fescue: leaf spot disease
Timothy: purple leaf spot disease
Smooth meadow grass: leaf spot disease, yellow rust and brown spot disease

Earliness of spring development

The faster the spring development, the faster the crop can be grazed. Varieties with the same average heading date can differ significantly in growth rate in the spring. The evaluation of the varieties is based on measuring the grass height in the spring.

Nutritional value

Within the grass varieties mentioned here, the differences in digestibility between the current varieties are small. In terms of nutritional value, good exploitation (timely shearing and/or mowing) can achieve much more than with a targeted choice of varieties.

For Italian ryegrass, a score for stem formation (which is detrimental to the nutritional value) in the year of sowing is shown. Different varieties have clearly different scores for this.

Winter hardiness

Too little data is available to make a judgment on this, however we have observed that varieties that are less successful in winter can recover this winter damage to the turf to a greater or lesser extent due to their strong tillering capacity. The decision to re-seed or not must be made on a case-by-case basis.