13
thInternational IFOAM Scientific Conference, Basel, 28-31 août 2000, VDF Hochschulverlag AG, ETH-Zürich, p. 462
Enhancing species richness with unfertilised sown meadows
Eric Mosimann and Jacques Troxler
Swiss Federal Research Station for Plant Production of Changins (RAC), CH-1260 Nyon e-mail : eric.mosimann@rac.admin.ch
Keywords : extensive meadows, sowing method, management, botanical diversity, nutritive value Introduction
Restoring species richness in lowland regions is a priority in Switzerland. Ecological compensation areas on arable crop land are therefore subsidised. In a first experiment, we tried to optimise the botanical composition by using the generative potential of permanent grassland. In a second trial, we compared the effect of two cutting systems on the forage production of two seeds mixtures.
Material and methods
First experiment. The 0.8 ha field located at an altitude of 500 m a.s.l. has been ploughed after maize in 1995 and is characterised by a slope with superficial soil (xeromorphic) and a depression with deep soil (hydromorphic). In May 1995 a grasses-legumes-flowers mixture has been sown on half of the plot. Main components of these commercial seeds were Arrhenatherum elatius, Dactylis glomerata, Festuca pratensis, Lotus corniculatus and flowers ecotypes. The second part was sown between July and September 1995 using the fresh cut grass from species rich meadows (Mesobromion) of the region spread out on the harrowed soil (meadows seeds).
Second experiment. The experimental field is situated at an altitude of 650 m a.s.l. The trial was carried out in replicated small plots between 1995 and 1997. Main species of the two seeds mixtures were: Arrhenatherum elatius, Dactylis glomerata, Festuca pratensis and Onobrychis viciifolia for mixture 1; Festuca rubra, Lolium perenne, Lotus corniculatus and flowers ecotypes for mixture 2. Treatment 1 was the “ official ” management with a first cut done after the 15th June. Treatment 2 included a first cut before 10th May followed by a long regrowth till end of August, with the goal to favour the reproduction of wild animals.
Results and discussion
First experiment. The meadows seeds were firstly contaminated with annual weeds (fig. 1). In 1999, the main flower in all plots was Rhinantus alectorolophus which caused the decrease of grasses. The plot sown with meadows seeds contained 55 species on superficial soil. The other plots were less diversified with 37 species.
Second experiment. A late first cut influenced favourably legumes when a first cut in May increased the contribution of grasses (tab. 1). In that case the harvested forage can be used for dairy cows. Other cuts have a very low nutritive value, particularly 1st cut in treatment 1 and 2nd cut in treatment 2.
Figure 1. Evolution of the botanical composition (1st experiment, %)
Table 1. Characteristics of two mixtures under two management (2nd experiment)
Conclusions
Enhancing plant species richness of unfertilised sown meadows can be achieved by using the seeds potential of existing meadows. There is no negative effect on the forage production when the management is adapted to the needs of wild animals as lark, hare or deer.
Mixture 1 Mixture 2 Mixture 1 Mixture 2 Botanical composition (%)
grasses 48 46 58 62
legumes 52 36 42 26
flowers - 17 - 12
Yield (t DM ha-1)
1st cut 8.7 5.1 4.1 2.3
2nd cut 3.9 1.7 6.2 4.9
3rd cut 2.7 1.4 3.2 1.7
total 15.3 8.2 13.5 8.9
Energy content (NEL, MJ kg-1 DM)
1st cut 4.6 4.9 6.0 6.3
2nd cut 4.8 5.4 4.6 4.3
3rd cut 5.6 5.3 5.6 5.7
Organic matter digestibility (%)
1st cut 61 64 75 78
2nd cut 62 69 59 61
3rd cut 73 75 73 74
Treatment 1 Treatment 2 (1st cut mid-June) (1st cut beginning of May)
Weeds
Grasses Legumes
Flowers
Meadows seeds Commercial seeds
96 97 98 99
20 40 60 80 100
Weeds
Grasses Legumes
Flowers
96 97 98 99
20 40 60 80 100
Weeds
Grasses Legumes
Flowers
20 40 60 80 100
96 97 98 99
20 40 60 80 100
96 97 98 99
Weeds
Grasses Legumes
Flowers
Xeromorphic soilHydromorphic soil
