November 2020
Results from first year of trials
The majority of quantitative data from this year has now been collected. This, alongside qualitative information on growers' observations/experiences, suggests:
• There are range of viable alternatives to plastic - both local and commercially sourced, that can reduce the need for weeding
• It is not possible to draw conclusions on individual mulches or compare results between farms as a wide range of crops, soils and mulches were trialed. However, all growers reported difficulty with biodegradable mulches tearing and disintegrating or detaching from the bed, and some reported extra pest and weed growth, as more light was let in through translucent bio-degradable films.
• Unsurprisingly, un-mulched plots performed the worst in terms of yield and weed coverage
The blackcurrant grower hopes to use woodchip as a mulch as they have access to willow and spruce on farm. Considerations when using woodchip as a mulch include possible mineral deficiencies (type of wood is important) and irrigation.
The group are awaiting data from the onion trial at Five Acres Farm. They also hope to continue the trial into anther year to allow growers to run trials who had expressed interest but were not able to take part this year. This includes growers interested in looking at wool as a mulch.
More information on this field lab, including individual grower data and a video of the trial, can be found in the digital field lab journal: https://innovativefarmers.org/case-studies/
Milestone: Data Collection & Analysis
July 2020
Trial details
Trials this year are taking place at 5 sites.
1) Onion trial at a community farm in Warwickshire, recording yields and weed coverage. This site will compare an unweeded plot with no mulch, a weeded plot with no mulch, and plots of either woven polypropylene, polythene, paper or commercial biodegradable films.
2) Kale trial at a market garden in mid-Wales, recording yields, costs, weed & pest damage. This farm will trial compare biodegradable film to grass cuttings, woodchip and an undersown living mulch.
3) Blackcurrant bush trial at a commercial farm in Essex, recording growth of new bushes planted into the mulches, the number of dwarf and dead bushes and weed coverage. This farm will trial out biodegradable film and willow woodchip in two sizes compared to a unmulched bare earth.
4) Organic farm in Leicestershire, comparing cardboard, hay and grass clippings.
5) Organic community farm in Newcastle-upon-Tyne, comparing woodchip, woven polypropylene and biodegradable film.
Unfortunately, several growers had to drop out due to the impacts of Covid-19 on, slowing the delivery of mulches, hindering some people's ability to get out on site or have colleague support to run their on-farm trial. These will have the option to commence their trial in the second year of the field lab.
Milestone: Application of mulches (depending on crop)
May 2020
Protocol pack - how to run your own trial
Instead of physical workshops to help instruct the group on data collection and mulch laying, the researchers and coordinator have created a how-to guide and an instructional videos.
If you are exploring non-plastic mulches and would like to follow the protocols of this trial, login to download the guide in the 'Documents' section of this page. This includes tips for laying biodegradable mulch.
Milestone: Demonstration workshops/ webinars
March 2020
Group and methods confirmed
Ten growers have signed up to trialing alternative mulches on a range of crops including brassicas, onions, lettuce, beetroot, spinach, leeks, onions, blackcurrants and young top fruit trees.
There is also a range of mulches being trialed by the group: Woodchip, grass, cardboard, under-sown mulches, green waste, straw, hay, wood, compost, biodegradable film and paper against the control of black film or woven plastic.
All of the farmers will collect data on the following parameters:
- Weeds
- Yield
- Qualitative observations
- Costs
Many have chosen to also collect data on soil moisture and pest/disease damage, and a few will measure crop development, microbial activity (measured through respiration rate) and soil nutrients.
Milestone: Group and methods confirmed
February 2020
Objectives agreed
Growers, gardeners, mulch suppliers and researchers met at Garden Organic to agree on the objectives and methods for the trial. There was a wide representation of growers, including (soft fruit) crops; field vegetables; small-scale farms and protected cropping.
The group discussed the following:
- The type(s) of mulch to trial - each farm will decide on which mulches they would like to trial, but they include compost, woodchip, starch-based materials, hay and cardboard
- The size of the trial area - ideally 20-30-metres strips, replicated in several growing spots to generate meaningful data (less for small farms)
- When the mulches should go down - this depends on the mulch and crop
- What, data growers can/want to collect - the priorities are weed cover, crop performance and pest damage (measured on a scale of damage), but where possible, the growers would like to also consider soil moisture, and soil health (most likely via a low-cost solution such as a worm count). Cost and time will also be considered in the final results
Milestone: Objectives agreed
