The Polyculture Market Garden Study - Results from Year 4 - 2018

Location: Bulgaria, Shipka
​Climate: Temperate
Köppen Climate Classification - Dfc borderline Cfb
USDA Hardiness Zone: 5b - 7a
Latitude: 42°
Elevation: 565 m
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.

Garden area: 256.8m2
Cultivated beds area: 165.6m2
Paths: 50cm wide - 91.2m2
Bed Dimensions - 23m x 1.2m  Area - 27.6m2 per bed
Number of beds: 6

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.

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.

A sample of invertebrates from the gardens- Photos by Chris Kirby-Lambert

Pest and Disease - Thanks to Victoria Bezhitashvili, who joined us for the study this year, we also have a general record of some of the pests and diseases in the vegetable garden this year. 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.

Soil Results - Soil Health Card 

This year's soil health card test scored 63.9 - a small decrease 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 2018 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 - Epictetus 

The fertility inputs on Epictetus were as follows:

The yield outputs for Epictetus totalled 68.05kg of produce. This is around 1.23kg of produce per m2.

N.B At the time of publishing this post (03/12/18) there are still parsnips and kale, the yields of which have been estimated for these records.

Inputs and Outputs - Zeno 

The amount of time spent on Zeno was 36 hrs.

Inputs and Outputs - Zeno Control 

The amount of time spent on Zeno Control was 35 hrs and 20 mins.

Task	Time in mins
Set up	318
Planting /Sowing	444
Garden Care	333
Irrigation	180
Harvesting	600
Propagation	245
Total hrs	35 hrs 20 mins

The fertility inputs on Zeno control were as follows:

Fertility Inputs Item	Total Quantity
Strawbales	31
Compost for Tomatoes (L)	17.6 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 191.57kg of produce - 3.47kg per m2.

Crop	Weight in g
Tomatoes	11895
Tomatoes - (Processing)	2450
Beans	23770
Courgette	41880
Tomato (projected)	11895
Basil	3895
Total	191.57kg

Some of the "time" categories were difficult to assign to each polyculture so I clumped them together into a general task category. It's mainly the time preparing the produce for market as well as soil analysis, initial propagation tasks and end of season tidying up and packing away of the garden.

General Tasks
Task	Time in mins
Fertility	24
Analysis	10
Set up	180
Market Prep	2400
Mowing	540
Total hrs	52 hrs 30 mins

Zeno Polyculture vs the Control 

This year's results show the polyculture outperforming the control in yield by approx 46kg and taking approx 45 minutes longer to manage.

This year's results 

		Zeno	Control
Total time		36 hrs 5 min	35 hrs 20 min
Total Produce		237.23kg	191.57kg

Last year's results 

		Zeno	Control
Total time		37 hrs 5 min	37 hrs 30 min
Total Produce		154.429kg	140.670kg

You can find the above results in the spreadsheet 2018 Annual Polyculture Market Garden Study - Published Records - Sheet 9. Inputs and Outputs per Trial. For date stamped harvest records for Zeno see here and for Epictetus see here.

Inputs and Outputs -  All Beds 

 
Aponia - The Polyculture Market Garden

 

The amount of time spent on all beds was 149 hrs.

Time
Tasks	Minutes	Hours
Fertility	96	1.6
Analysis	10	0.16
Set up	720	12
Market Prep	2400	40
Mowing	540	9
Planting /Sowing	1086	18.1
Garden Care	1520	25.3
Irrigation	540	9
Harvesting	1370	22.8
Propagation	660	11
Total time input		149 hrs

The fertility inputs for all beds were as follows:

Fertility Inputs
Total inputs for garden
Strawbales	63 bales
Compost	1205 L
Wood Ash	20kg
Sieved Compost /River Sand 50 /50	224 L
Lawn Clippings	1620 L

The yield outputs for all beds totaled 498.84kg of produce or 4.51kg per m2. 

Produce all beds
Product	Weight in g	Average weight in  g per m 2
Dwarf Beans (Fresh)	8510	154.17
Kale	8770	158.88
Chard	2680	48.55
Beetroot	28760	521.01
Parsnip	17480	316.67
Turnip	1850	16.76
Tomatoes	130140	1178.80
Tomatoes - (Processing)	8440	76.45
Beans	113820	1030.98
Courgette	168610	1527.26
Basil	9780	88.59
Total kg	498.84

Some shots of the market garden

Results in Summary  

The garden produced just under half a ton of produce from a cultivated area of 165.6m2.

The time spent on the garden was 149 hrs 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 2 hrs per week per culture. 

Financial Inputs - Costs 

• 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.

Financial Output - Income 

• 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. This year we have started planting up various perennial polyculture trails in our new garden Ataraxia. You can find out more about these trials here

Other potential revenue from the Polyculture Market Garden includes perennial crops, plant nursery, adding value to produce and courses and training. We plan to add a record of these activities to represent better the financial potential of a Polyculture Market Garden.   

Estimated Harvests

At the time of writing this report there are still crops growing in Epictetus. We estimated the harvest weights of the remaining crops based on what we had already harvested.

Epictetus bed with Parsnips and Kale yet to be harvested. These can remain in the beds until the new year.

Considerations :

• We usually aim to grow at least five different tomato cultivars but this year we only used two cultivars and one of them was cultivar 'Currant Sweet Pea'. This was a mistake and although they performed very well in the gardens and are very tasty they are ridiculously small and for this reason we decided not to include them in the weight records. Instead we used the Tigerella yields to provide an estimated forecast of what we may have harvested.
• We usually aim to grow equal numbers of the same cultivar in the polyculture and the control but this year our courgette cultivars were not distributed equally. 
• The warm and wet summer reduced our irrigation needs significantly this year with only six weeks of the season requiring water (aside from watering of the seedlings in early spring) . We did however need to mow the garden more often due the optimal growing conditions.  

N.B. We took base times for the majority of tasks carried out in the gardens in the first two years of the study. These tasks were carried out by a volunteer team that had little or no prior experience in horticulture. An experienced grower or with repeated experience of these cultivation methods should be able to reduce the task times significantly.

You can access the full spreadsheet here that includes all of the data entries and task descriptions. (Note there are multiple sheets that can be accessed from the blue tabs running along the top of the sheet.) 

Why are we doing this research? 

If you are reading this you're most probably aware of the environmental damage caused by industrial agricultural practices. We believe this damage isunnecessary, and aim to provide healthier models of food production that yield nutritious affordable food while at the same time promoting biodiversity and general ecosystem health.

Polyculture gardens providing food for humans and other organisms

We aim to address the following questions;

• How productive can polycultures be?
• What advantages can polycultures provide ? 
• How much time do polyculture gardens take to establish and manage?
• How economically viable are these gardens?
• How bio-diverse can our food producing systems be?
• Can we provide clean, nutritious, affordable food whilst enhancing biodiversity?

I make no claim that polyculture can feed the world but I do claim with 100% conviction that anyone can grow polycultures and by doing so they are taking a small but significant step in reversing at least a small portion of the damage that industrial agriculture creates.

To read the full and original article, visit: http://balkanecologyproject.blogspot.com/2018/12/the-polyculture-market-garden-study.html

Useful links

More from the Balkan Ecology Project:

5 hectare polyculture design

Nitrogen fixing species for agroforestry systems

Permaculture design: vegetable and herb guilds