Here are the results from the fifth and final year of our Market Garden Polyculture Study. This study looks at the differences between growing annual vegetables and herbs in polycultures vs growing them in traditional blocks. Although this was the final year of this study, we are just getting started and next year we will be continuing our polyculture study focusing on the productivity of perennial forest gardens and biodiversity within the gardens. Registration for next year's study is now open and you can find out more about that here.
The 2019 Polyculture study crew
Garden Overview
Climate: Temperate
Köppen Climate Classification - Dfc borderline Cfb
USDA Hardiness Zone: 5b - 7a
Latitude: 42°
Elevation: 565m
Average Annual Rainfall: 588.5mm
Prevailing Wind: NW & NE
Garden Name: Aponia - Polyculture Market Garden
The six longer beds in the left hand corner of the photo on the right (the Aceaes) are the trial beds, the focus of this study. You can find the location of the Polyculture Market Garden on google maps here (labelled as Aponia on our Project map).
Garden area: 256.8m2
Cultivated beds area: 165.6 m2
Paths: 50cm wide - 91.2m2
Bed Dimensions - 23m x 1.2m Area - 27.6m2 per bed
Number of beds: 6
The beds are named after common vegetable families in order to familiarise participants with the use of Latin and introduce them to some major plants families. The bed names do not correspond to what is planted in the beds.
The Polycultures
We scaled down to one bed of each polyculture and one bed of control for Zeno this year as opposed to two of each as seen above. We have extrapolated from the data we recorded from each bed to keep the results comparable to the previous years where we were growing on four beds.
Polyculture Zeno
We've been growing Zeno in the garden for around 11 years now. It's been very successful in our home gardens and in 2015 we scaled it up for the market garden.
Zeno Plant List - The following plants and cultivars were used in this polyculture;
Tomato - Solanum lycopersicum 'Ukranian purple'
Tomato - Solanum lycopersicum 'Yellow Pear'
Tomato - Solanum lycopersicum 'Chocolate Pear'
Tomato - Solanum lycopersicum 'Alicante'
French Beans - Phaseolus vulgaris - Local
Courgette - Cucurbita pepo 'Black Beauty'
White Bush Scallop - Cucurbita pepo
Squash - Cucurbita pepo 'Waltham Butternut'
Basil - Ocimum basilcium 'Sweet Genovese'
Pot Marigold - Calendula officinalis
Zeno Planting Scheme
Zeno Control
The control includes all of the above plants but planted in blocks along the bed (see below). We want to see how the two planting schemes compare, i.e. whether or not the polyculture will produce more and the difference in the amount of time needed to cultivate the different layouts. The fertility inputs for both beds are the same.
We have not included a list of native wild plants that are encouraged to grow around the perimeter of each bed that we mow and apply as mulch to the beds during the growing season.
What we Record - Inputs
What we Record - Outputs
Crop Yields - All produce is weighed directly after harvest. The produce is recorded into two categories, fit for market and fit for processing.
N.B. We do not sell all of the produce from the garden. Some of the produce is consumed by the team or preserved.
What we record - Surveys
Soil Analysis - Each spring and autumn we obtain a soil sample and send it to NAAS of the Ministry of Agriculture and Food. To take a sample we take approx. a hand trowel full of the top 20cm of soil from eight random areas from the beds, mix it together and send 400g 'bagged and tagged' to the lab the same day.
Physical Analysis - Each spring the team carry out a series of nine tests that are designed to provide an indication of soil health based on observable physical properties of the soil. It's a soil management tool developed by farmers for farmers to track the developing health of soils. We have slightly modified the test for our purposes.
Pest and Disease - Thanks to Victoria Bezhitashvili, who joined us for the study in 2018, we have a general record of some of the common pests and diseases in the garden. You can find Victoria's observations here.
Results
We'll start off by looking at the results from the soil analysis and soil health tests, then look at the results for each polyculture and finally finish up with the overall garden results.
Soil Results - Mineral Analysis
Each spring and autumn we take soil samples and send them to NAAS of the Ministry of Agriculture and Food. The sample is taken before we add any fertility in March at the beginning of the season.
The first sample taken in March 2015 in the table below is the base sample taken before work in the garden began.
| Sample Location - Aceaes | |||||
| 2019 | |||||
| Nitrogen mg/kg | Phosphorous - Potassium mg/100g | ||||
| April (before adding compost) | pH (KCI) | N03N | NH4N | P205 | K20 |
| 6.8 | 29.4 | 20.2 | 59.9 | 26.4 | |
| 2018 | |||||
| Nitrogen mg/kg | Phosphorous - Potassium mg/100g | ||||
| March (before adding compost) | pH (KCI) | N03N | NH4N | P205 | K20 |
| 6.74 | 9.53 | 5.3 | 130 | 22 | |
| 2017 | |||||
| Nitrogen mg/kg | Phosphorous - Potassium mg/100g | ||||
| March (before adding compost) | pH (KCI) | N03N | NH4N | P205 | K20 |
| 6.73 | 25.1 | 4.85 | 147 | 39.6 | |
| 2016 | |||||
| Nitrogen mg/kg | Phosphorous - Potassium mg/100g | ||||
| March (before adding compost) | pH (KCI) | N03N | NH4N | P205 | K20 |
| 6.65 | 4.43 | 5.79 | 88 | 25.2 | |
| November (after final harvest) | pH (KCI) | N03N | NH4N | P205 | K20 |
| 6.61 | 8.17 | 3.83 | 44.1 | 22.1 | |
| 2015 | |||||
| March (before adding compost) | pH (KCI) | N03N | NH4N | P205 | K20 |
| 5.69 | 15.4 | 2.89 | 16.3 | 13 | |
| November (after final harvest) | pH (KCI) | N03N | NH4N | P205 | K20 |
| 6.44 | 16.2 | 4.45 | 43.9 | 14.4 | |
Soil Results - Soil Health Card
This year's soil health card test scored 72.2 - an increase from last year's test of 65.6. The highest score obtainable for this test is 88.
You can find the full results from 2015 - 2018 in the spreadsheet 2019 Annual Polyculture Market Garden Study - Published Records - Sheet 6.Soil Test Cards
Should you wish to use this soil card, you can download the Soil Health Card forms with instructions on how to carry out the tests here.
Inputs and Outputs - Zeno
| Task | Time in mins |
| Set up | 404 |
| Planting /Sowing | 327 |
| Garden Care | 585 |
| Irrigation | 105 |
| Harvesting | 300 |
| Propagation | 151.5 |
| Fertility | 12 |
| Mowing | 270 |
| Market Prep | 600 |
| Analysis | 5 |
| Total hrs | 46 hrs |
| Fertility Inputs Item |
Total Quantity |
| Strawbales | 31 |
| Compost for Tomatoes (L) |
32.6 L |
| Seedling Mix for Squash (L) |
10.4 L |
| Seedling mix for Beans (L) | 13.2 L |
| Wood Ash kg | 6.72 kg |
| Mulch - Lawn Mower Clipping (L) | 540 L |
| Crop | Weight in g |
| Tomatoes | 20640 |
| Tomatoes - (Processing) | 1770 |
| Beans | 33140 |
| Courgette | 42425 |
| Tomato (projected) | |
| Basil | 995 |
| Total | 197.94kg |
Inputs and Outputs - Zeno Control
| Task | Time in mins |
| Set up | 378 |
| Planting /Sowing | 231 |
| Garden Care | 520 |
| Irrigation | 105 |
| Harvesting | 300 |
| Propagation | 151.5 |
| Fertility | 12 |
| Mowing | 270 |
| Market Prep | 600 |
| Analysis | 5 |
| Total hrs | 42 hrs 50 mins |
| Fertility Inputs Item |
Total Quantity |
| Strawbales | 31 |
| Compost s (L) | 32.6 L |
| Seedling Mix for Squash (L) |
10.4 L |
| Seedling mix for Beans (L) | 13.2 L |
| Wood Ash kg | 6.72kg |
| Mulch - Lawn Mower Clipping (L) | 540 L |
The yield outputs for Zeno totalled 168kg of produce - 3.04kg per m2.
| Crop | Weight in g |
| Tomatoes | 11895 |
| Tomatoes - (Processing) | 2450 |
| Beans | 23770 |
| Courgette | 41880 |
| Tomato (projected) | |
| Basil | 3895 |
| Total | 167.78kg |
Zeno Polyculture vs the Control
This year's results show the polyculture outperforming the control in yield by approx 24kg and taking approx. 7 hrs and 30 minutes longer to manage.
This year's results
| Zeno | Control | ||
| Total time | 46 hrs | 42 hrs 50 min | |
| Total Produce | 197.94kg | 167.78kg |
Last year's results
| Zeno | Control | ||
| Total time | 36 hrs 5 min | 35 hrs 20 min | |
| Total Produce | 237.23kg | 191.57kg |
Inputs and Outputs - All Beds
Aponia - The Polyculture Market Garden
The amount of time spent in total was 88 hrs 50 mins:
| Category | Total time |
| Fertility | 24 |
| Analysis | 10 |
| Set up | 782 |
| Market Prep | 1200 |
| Mowing | 540 |
| Planting /Sowing | 558 |
| Garden Care | 1105 |
| Irrigation | 210 |
| Harvesting | 600 |
| Propagation | 303 |
| Total time spent | 5332 min |
Category Description
- Garden Care - includes weeding, tying and pinching out tomatoes, replacing weak plants, inspecting plants
- Propagation - includes sowing seeds, watering seedlings, pricking out seedlings
- Market Prep - includes packing produce for market
- Harvesting - picking produce from garden
- Irrigation - applying water to crops after transplanting and during the high summer
- Mowing - Mowing the pathways and applying the trimmings to the surface of the bed
- Planting - Planting crops into beds and sowing crops directly into the bed
- Fertility - Applying additives (in this case wood ash)to the soil following soil analysis results
- Set up - Preparing beds , forking over , mulching, adding compost, erecting supports and removing supports
The total fertility inputs for all beds:
| Fertility Inputs Item |
Total Quantity |
| Straw Bales | 62 |
| Compost (L) | 65.2 L |
| Seedling Mix for Squash (L) |
20.8 L |
| Seedling mix for Beans (L) | 26.4 L |
| Wood Ash kg | 13.44kg |
| Mulch - Lawn Mower Clipping (L) | 1080 L |
Results in Summary
The time spent on the garden was 88hrs from sowing the first seeds indoors in February to packing up in late October.
The fertility inputs of the garden were 63 straw bales, 1205 L of compost, 20kg of wood ash, 224 L of sowing medium, 1620 L of lawn clippings.
Comments on Results
Time Input
- Not included in the records were other tasks carried out around the site such as making compost, harvesting stakes and support sticks, establishing beneficial habitat such as wildlife ponds, hedgerows/stick piles.
- The time for preparing the produce for market i.e quality control, packaging and delivery, was estimated at two hrs per week.
- Not included here are the set up costs for the garden. These costs were included in the first years results. The costs recorded here are the annual operating costs which is basically the cost of seed, and fuel,oil and maintenance for the lawn mower.
- A polyculture market garden should have a polyculture of revenue. Our study currently focuses on annual vegetable production. We chose to begin our study of annual vegetables as it is the most accessible practice to most people requiring the least amount of investment making it ideal for a novice or curious grower. Next year we begin to look closer at perennial polycultures trails in our new gardens. You can find out more about these trials here.
Considerations
- We aim to grow equal numbers of the same cultivar in the polyculture and the control but this year our courgette and tomato cultivars were not distributed equally.
- Due to the warm autumn and lack of frost Tomato - Solanum lycopersicum 'Currant Sweet Pea' that we planted last year made an appearance in the autumn with a nice crop of fruits from 5-6 plants that had self sown. The yield from these are not included in the records
This is an adapted article from the Balkan Ecology Project blog. For the full article, visit: https://balkanecologyproject.blogspot.com/2019/11/the-polyculture-market-garden-study.html
Useful links
Healthy food production and biodiversity
Video: How to grow an edible, annual polyculture
The polyculture market garden study - year 4 results at Balkan Ecology Project
