Ecosystem Functions and Services of Biodiversity in Grasslands
Multifunctionality with positive effects on nature and society is a central element of organic agriculture, and a high biodiversity is essential for this. Grassland has the greatest potential for providing this service, but the organic fields are large and biodiversity is low.
The purpose of this project is to increase plant biodiversity in grassland and significantly improve ecosystem functions and services in the nature-farmer-consumer chain and for society, and thus also increase the market value of organic products. We will:
1) design and demonstrate productive and biodiverse grassland with squares of flowering plants,
2) improve conditions for bees and other pollinators using flowering grasslands for hay or silage,
3) increase carbon sequestration via increased plant biodiversity, and grasslands of longer duration,
4) produce high quality cheeses based on species-rich hay,
5) examine relationships between biodiversity and cheese quality, and convey the perception and the product history to the gastronomic world and to the consumer,
6) develop marketing concepts for organic products with multifunctionality and
7) describe the economic and environmental perspectives for multifunctionality in grassland at farm and regional level using systems analysis, economic modeling and life cycle assessment.
In relation to Green Growth the project contributes to increased biodiversity, more connected nature and an increased organic farming area.
Summary: 2011 - progress and activities
Of the seven specific objectives, four have been addressed in 2011:
1) design and demonstrate productive and biodiverse grassland with squares of flowering plants
Several experiments have been established in 2011 – at Aarhus University three plot experiments. One with 17 species in pure stand or all species together and grass-clover established in three replicates. In another, the competitive species (chicory, plantain and caraway) were established with grass-clover in nine replicates. This experiment investigates the competitiveness of the species under different cutting regimes. In a third experiment, plots with two species, a herb and a legume in nine replicates are established. Salad burnet, borage and dandelion are mixed with either red clover, lucerne or birds foot trefoil. This experiment investigates species competition in relation to niche conditions. Furthermore, two plots at two Naturmælk farms were established with 23 herbs and mixtures. In Autumn 2011 a public field day was arranged at one of these farms. 240 plots have been established all in all, and the majority is well established.
2) improve conditions for bees and other pollinators using flowering grasslands for hay or silage
Registrations has been carried out in a number of already established grasslands for hay-making. At 6 separate districts 2-3 grasslands have been chosen with variation in age (3- >100 years). Here grass has been cut for hay. In these grasslands, diversity in flowering bee-plants was registered, as well as pollinator visits, flowering and diversity and number of pollinating insects. We are now in the process of determinating the species of the collected insects and computing the vegetation data. It is too early to draw conclusions, but the immidiate impression is, that the floral diversity is of importance for pollinator diversity and that plant diversity was low in the younger grasslands. The importance of grassland age, fertilization and cutting frequency cannot be estimated for the time being. Although it was clear that cutting reduced flowering - and thereby also the diversity of flower-seeking insects significantly.
3) increase carbon sequestration via increased plant biodiversity and grasslands of longer duration
Registrations of biomass above ground and in roots have been made in an experiment with three mixtures. 1) a herb mix with 9 species (salad burnet, fenogreek, chicory, caraway, birdsfoot trefoil, chervil, plantain, lucerne and melilot), 2) a mixture with 50 % of the herb mixture and 50 % white clover/ryegrass and 3) a mixture of 5% herbs and 95 % grass-clover. The aboveground biomass clearly increased with increasing herb content and fertilizer application at a 4-cut strategy. In the herb mixture, the root biomass generally had more large and less small roots than under grass-clover, which may be of importance for the turnover of root biomass following cultivation. Especially caraway and lucerne had many large roots. At present we investigate the turnover after simulated ploughing by determining CO2-evolution in longterm incubation studies from soils with different mixtures.
4) produce high quality cheeses based on species-rich hay
The plan was to establish multispecies mixtures at two organic dairy farms in 2011. Due to huge interest among farmers, the treatments were established at three farms where it is to be used for milk production in the autumn of 2012. One mixture consists of ryegrass, white clover, red clover, chicory and plantain. Another is furthermore added lucerne, melilot, caraway, salad burnet, borage and yarrow. All mixtures are well-established.
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