3.3 Herb-rich Grasslands for Cows and Pollinators

Regine Albers (Carl von Ossietzky University Oldenburg)

Historically, grasslands that were shaped by agricultural practice have been some of the most important habitats for pollinators in Central Europe. A great number of plants flowered in them and there were plenty of nesting opportunities. This changed with the intensification of grasslands. Grasses were bred for more biomass, meadows became larger in size, soil were , and fertilizers increased the amount of fodder produced. The productivity increased food production greatly but changed the landscape to a grass-dominated environment with harsh conditions that only few plant species can withstand. Flower strips are not an option in grasslands, but bringing back some of the plant species to the meadows can be of great value for the farmer as well as the insects.

Biodiversity effects can assist in getting the most value out of a meadow. These consist of two mechanisms: the selection effect, meaning that in a mix of species there is always one that can be the most productive under the current conditions, and the complementarity effect. This describes the ability of species to harvest different resources, for example, by having different rooting depths. Both effects lead to the coexistence of species over time.

In the Northwest of Germany, dairy production is of major importance. This is where the University Oldenburg and the Grassland Center started a study on seed mixtures for intensively used grasslands with four to five cuts per year. Five mixtures of increasing diversity were created to and tested on three different soil types. They were surveyed for vegetation development, floral resources, pollinators, and fodder quality. We found that a mix of grasses, legumes, and herbs produced great fodder quality and quantity, frequently provided many flowers, and was popular with insect pollinators.

Grassland seed mix composition

1. Grasses

Grasses are of course the most important part of a grassland seed mix. A highly productive species like perennial ryegrass (Lolium perenne) is a great base. Grasses are most productive in spring when great amounts of fresh roughage are needed for the cattle. Depending on the local conditions and the soil, it can be valuable to include more grass species. Further, mixing several species decreases the spread of plant diseases. Climate change increases the probability of droughts, so including a drought resilient species like cocksfoot (Dactylis glomerata) can reduce the risk of losses that are likely to happen with just L. perenne

2. Legumes

The second component to a good grassland mix are legumes. The most commonly used species are white and red clover (Trifolium repens and T. pratense). Both have a strong summer growth that complements the spring growth of the grasses.

The greatest value of legumes is through, the symbiosis with nitrogen fixing bacteria meaning that they produce their own N fertilizer that they also share with surrounding plants. In our study, the farmers could reduce the use of inorganic fertilizers, lowering production costs.

The high N availability is mirrored in the high protein content of legume fodder. Cows like the taste and even increase their fodder intake when fed legumes. Clovers also have deeper roots that reduce vulnerability to droughts. There are more legumes that can be used, for example birdsfoot trefoil (Lotus corniculatus) which is very popular with bumblebees and thrives on slightly alkaline soils.

3. Herbs

The last part of the mix is herbs which is the most challenging one as most herbs cannot withstand the frequent cutting of an intensive management. We used ribwort plantain (Plantago lanceolata), a deeprooting species that is resilient to drought, produces a lot of biomass in summer and adds easily accessible flowers that attracted many hoverflies in our study. It further adds healthy plant metabolites to the cow’s diet. Another herb with similar properties that is increasingly being used is chicory (Cichorium intybus). This species is of high nutritional value and adds another kind of flowers for pollinators.

Management recommendations

Our five project farmers who managed the 25 ha of BEESPOKE grassland are all convinced that clover is part of the solution and established it on more fields. Some even worked with clovers for many years. They are very engaged in exploring new farming methods and sharing their experiences with others. The knowledge exchange between farmers and project partners was of great worth for both sides.

The fields do not require special management. The mixture is created for cutting but can be adapted for pastures and for oversowing established meadows. The local soil conditions must be taken into account in the selection of plant species. It is important though to control weeds thoroughly as herbicides are not an option after establishment. Furthermore, insect-friendly mowing techniques like mowing from one side to the other or from the middle to the outsides, increase the potential benefits for pollinators. If possible, mowing should take place after the legumes and herbs bloomed.

A diverse environment is essential for the lifecycle of pollinators. The importance of extensively managed or semi-natural habitats like hedges, buffer strips and ditches cannot be overstated. Diverse grasslands can be a valuable addition the landscape mix.

Do you want to learn more about grasslands?

We recorded our webinar on herb-rich grasslands from June 2023. You can watch it here.

Learn about the value of reestablishing diverse herb-rich grasslands, their benefits for pollinators, biodiversity and farmers as well as and the management of those meadows. Our project partners from Germany and the Netherlands share their expertise and learnings from 4 years of the BEESPOKE project.