Piling up woodchip to be spread over the trial fields. Photo credit: BDB
In our third newsletter (September 2018), we introduced the Belgium study site in Flanders, which is running two different SICS trials. We now have some interesting preliminary findings from their first trial which uses ramial woodchip incorporated as a soil amendment to increase organic matter, soil biodiversity and soil quality in general. Initial results of woodchip applications are being compared to others including manure, food waste and bought-in compost.
Promising outlook…
Nitrogen movement through soil: In the autumn following woodchip applications, there has been a significant amount of nitrogen immobilised in the soil – meaning less is being leached away into groundwater as pollution.
Yield: It’s positive that although there has not been a yield increase, there haven’t been any decreases either! The team are looking forward to seeing if this changes over the next years of trialling.
Organic matter (OM) & water infiltration: After one year it is yet too soon to measure changes in OM levels. However, in other trials that the researchers are undertaking which started in 2016, there is a trend towards higher levels of organic matter in the soil after 3 years of incorporation, as well as enhanced infiltration compared to chemical inputs.
Challenges ahead…
Labour: There are also challenges still to be met – the time and cost of labour involved in making woodchip can be a barrier for farmers; it can take up to 40 hours per hectare to make enough woodchips! The incorporation itself requires twice as much labour as the incorporation of other amendments, such as solid manure.
Farmer views - availability of ramial wood chips
The research team have been working with farmers in the field and asking them about their practices. Farmers of different generations seem to be convinced of woodchip as a key resource for improving their soil quality and resilience, as well as making residual waste more valuable. Farmers are trying to find different sources of woodchips if they don’t have access to their own on-farm – this poses a potential risk around bringing in weeds, diseases and pests. Could this be an incentive for more holistic farm-landscape management, e.g. the re-introduction of small landscape elements such as trees and hedgerows, similar to an agroforestry system, with policy to back it?
Policy views - working together
One of the main questions that arises when farmers want to use ramial woodchip from the maintenance of small landscape elements (e.g. hedgerows), is whether it is considered to be an organic amendment or waste, and can it be applied to agricultural soil?
Current policy in Belgium means that farmers cannot easily use woodchip from sources other than their own farm due to the risk of contamination by pests and disease.
According to the Flemish Public Waste authority, farmers can apply woodchips from the maintenance of small landscape elements, provided that these are "managed in a sustainable way". This means that there should be an approved management plan as well as a so-called "commodity statement" for each application of woodchip. These rules make it very complicated and cumbersome for farmers to apply woodchip on their fields.
Despite this, after a positive consultation with the authorities, the research team are preparing a scientific report on the use of ramial woodchips, specifically based on the results of the SoilCare trial. This report will then be used by the authorities to make a "generic commodity statement". This will allow farmers to use ramial woodchips from sustainable small landscape elements.
A great step towards more holistic farm and landscape management! We look forward to updating you with the progress of this positive collaboration.