Digging Deeper: planting a mixed hedge for tree, crop and biodiversity
This winter, Inagro is planting its own research and demo plot for agroforestry! Through the 'Digging Deeper' series in our newsletter, you receive a monthly update on our plot and are able to follow our journey from the front row. The nut trees still have to wait a few weeks to be planted, but last month we already planted a mixed hedge on the plot. What is the function of this hedge and what does it look like? Read about it in this fourth edition.
Mixed hedge gets a spot on our agroforestry plot
Let's take another look at the planting plan. You can see that not only rows of trees will be planted this winter, but we will also provide the plot with a mixed hedge with a flanking grass strip on one side. Like the trees, this is an important part of our agroforestry plot. The orientation of the hedge was chosen to be perpendicular to the dominant wind direction. The hedge was successfully planted at the end of November. The grass strip will be sown next spring and will be 3 meters wide.
In this edition of Digging Deeper, we elaborate on the benefits of this hedge and provide some more information around the practical planting and its species composition.
Advantages of mixed hedges
A hedge is often seen solely as a loss of cultivation area. Wrongly so! Although strictly speaking you do lose cultivation area, a mixed hedge also offers many advantages. Both for farmer, biodiversity and environment. It offers:
- Windbreak. On more open plots, a hedge provides a more favourable microclimate for crops and trees, but also for beneficial insects.
- Shelter. Useful insects like to hibernate in the organic litter layer or behind loose bark in the hedge. Birds and other fauna also like to linger there.
- Food. Flowering bushes are a source of food for pollinators and natural enemies during the growing season (both through the flowers and alternative prey), but a hedge also provides berries for songbirds and field birds during winter.
- Ecosystem services. Hedges reduce runoff and erosion, sequester carbon, create an attractive agricultural landscape, support pollinators and natural enemies, ...
Berry-bearing bushes for field birds and songbirds
Our mixed hedges consist mainly of native thicket-forming bushes that provide a rich supply of berries in winter for field- and songbirds. These often thorny and impenetrable bushes also offer the birds good protection from predators and a safe place to nest.
Common hawthorn (30%) and privet (20%) are the main building blocks of the hedge. In addition, red dogwood (10%), field maple (10%), wood rose (10%), guelder rose (10%), dog rose (5%) and medlar (5%) are also part of the hedge.
Before proceeding to plant hawthorn, it was verified that our plot is not located within a 1 km perimeter around professional apple or pear fruit orchards. This is to prevent the spread of fireblight.
But also for beneficial insects!
Of course, not only birds, but also useful insects will eventually benefit from this hedge. The combination with a flanking rough grass strip creates a reinforcing effect, making it even more attractive for beneficial insects. Moreover, the eastern side of our plot is already flanked by a recently planted mixed hedge with the attraction of beneficial insects as the starting point for the choice of species. In this way, we are trying to achieve as much diversity as possible.
Are you mainly aiming for windbreak? Then you can choose to work primarily with fast-growing species such as willow, black alder, black poplar, wych elm,...
Getting started!
The hedge on the south-west side of our plot was planted in late November and is about 50 meters long. Bushes were planted bordered in a double row, with a density of 1 plant per meter. The two rows are spaced 1.2 meters apart and bushes were planted in groups of 4-5 of the same species each time.
We bought small bare-root plants: cheaper and more likely to succeed! During transport and planting, you need to make sure that the roots do not dry out. For now, we do not protect the young bushes against herbivory, but if necessary this can be provided for later. The planting itself was half a day's work, with three of our colleagues rolling up their sleeves together. Or was it just 20 seconds, as we see in the video below?
Future management
We plan to manage the hedge in a way that adds value to birds and insects each year. The first few years after planting, the hedge requires little maintenance. An occasional mowing under the hedge may be necessary to avoid smothering the young bushes.
From year 4 onwards, we will prune the hedge cyclically with pruning every two years: year 4 one side pruned back, year 5 no pruning, year 6 other side pruned, ... This ensures there is always one side that provides cover and bears berries.
If the hedge is taller than 2 meters, we will also prune it back to 1.5 meters. This management is a proven concept within the PARTRIDGE project where Inagro is a partner and where hedges for partridge were planted. Photo: Partridge hedge with cyclical management (c) Jochem Sloothaak.
What happened on the plot since the last edition of 'Digging Deeper'
