Monday, 30 November 2015

How Productive can Polycultures be? - Polyculture Trials 2015 - Home Garden Records

Here are the results from the second year of our home garden polyculture study where we're looking at the inputs and outputs of annual herb and vegetable polycultures and how we can grow nutrient dense food whilst enhancing biodiversity.

See here for all the results of our polyculture studies from 2014 - 2016

Results in Summary 


From a  9.5 m x 7 m piece of land we harvested 218 kg of vegetables including tomatoes, basil, beans, garlic and winter & summer squash, a 57 kg increase on last year.
The time spent in this garden, including propagating all the plants from seed, preparing the beds, tending the plants, irrigating and harvesting amounted to 52 hrs and 51 mins or approx 14.5 minutes a day from April - October. I'm pretty sure it takes me longer than that to write it all up :)

218 kg works out at just over 6 kg of food produced per m² with an estimated local market value of just over 700 BGN, that's 10.63 BGN per m2 with an hourly rate of pay at 13.59 BGN (€6.95).  Not exactly going to pay for lunch at the Restaurant Le Meurice, Paris, but when you consider the food is as good as you would get there, that the soil and general garden ecosystem is in better condition than it was this time last year, and that the garden provides habitat to all of the below organisms (to highlight but a few) it all starts to look pretty encouraging!


Our goal is to create garden ecosystems that are productive for man and for nature.
Photographs taken from the garden.by Paul Alfrey and Peter Alfrey.

You can find the full spreadsheet that includes all of the data entries here

For an overview of the cultivation methods we use see here and for last year's results see here

Here's some details on where and how we do it.


Garden Overview   


Climate: Continental Temperate
Latitude: 42°
Elevation: 580 m
Average Annual Rainfall: 588.5 mm
Co-ordinates:42°42′N 25°23′E

The Polyculture beds on a mid spring morning

Garden Layout 


Garden area: 66.5m2
Cultivated beds area: 36m2
Paths: 30.5m2

 Path and Bed Layout 

Crop and Cultivar List


11 x Tomato - Solanum lycopersicum 'Black Krim'
11 x Tomato - Solanum lycopersicum 'Tigerealla'
11 x Tomato - Solanum lycopersicum 'Mixed Saved Seed'
11 x Tomato - Solanum lycopersicum 'Rozova Magia'
11 x Tomato - Solanum lycopersicum 'Paulina F1'
11 x Tomato - Solanum lycopersicum 'Citrina'
66 x Basil - Ocimum basilcium 'Sweet Genovese'
24 x Runner Beans - Phaseolus coccineus
24 x French Beans - Phaseolus vulgaris 'Cobra'
24 x French Beans - Phaseolus vulgaris 'Blue Bean'
2 x Courgette - Cucurbita pepo 'Black Beauty'
4 x Bush Scallops - Cucurbita pepo
6 x Butternut Squash - Cucurbita pepo 'Waltham Butternut'
12 x African Marigold - Tagetes erecta
12 x French Marigold - Tagetes patula
12 x Pot Marigold - Calendula officinalis 


Our Tomato cultivars 

The table below shows the floral species composition of each bed including the different cultivars and the dates that the plants were sown or planted.  Beans, courgettes and winter squash were sown, tomatoes, basil, marigolds and pot marigolds were planted.

Other crops such as volunteer sunflowers and nasturtiums were also allowed to grow within the beds. The yield of these plants are not considered in these records. Also not included are the native wild plants that are encouraged to grow around the perimeter of each bed. Many of these plants provide a harvest of salad greens and tea ingredients as well as mulch material when chop and dropped on the beds.




Planting Scheme 


Below is a typical representation of the planting scheme within a bed.

Vegetable Guild/Polyculture

Soil Analysis 


Mineral Analysis - Soil samples were taken in early spring before fertility inputs and sent to the NAAS of the Ministry of Agriculture and Food.




Soil Microbiology Analysis

We had a lovely response after publishing last year's results from Vitalia Baranyai and Birgit Albertsmeier who volunteered to study the microbiology of the soil samples from the gardens. Below are Vitalia's results from samples taken in the spring and high summer. We thank them both for their input and support.

Spring Sample 








Number of Bacteria per mlMicrograms bact./ mlLength in cm of fungal strands / mlMicrograms of fungi per mlF:B Biomass ratio
3573656000.007147.31445.19270.840.04

Summer Sample 







Number of Bacteria per mlMicrograms bact./ mlLength in cm of fungal strands / mlMicrograms of fungi per mlF:B Biomass ratio
467558400093512741770.019


Results: Inputs 


Input:Time Spent in Garden 


Tasks MinutesHours
Set up/Pack up 4707 hrs
50 mins
Propagation 1041 hr
44 mins
Fertility 2353 hrs
55 mins
Planting out 61110 hrs
11 mins
Mowing Paths 60
1 hr
Irrigation 540
9 hrs
Garden Care and Harvesting 109118 hrs
11 mins
Total minutes 3111


Input: Fertility Inputs Over One Season 



Fertility Inputs Fertility Inputs
Fresh Comfrey Material96 kg Wood Ash 20 L - 5.6 kg
Chicken manure 5.76 kgAutumn Compost for Garlic120 L


Spring Compost 480 L
Kitchen scraps 18 kg Compost for planting out toms22 L
Straw bales 9 (standard bales) Seedling Mix for Squash9 L
Lawn Mower Box of Clippings 128 kg Seedling mix for Beans18 L


Results: Outputs

Output: The Harvest 


The total produce from each of the main crops in the polyculture were as follows;

Tomato - Solanum lycopersicum : 89.84 kg
Tomato - Solanum lycopersicum : (Blemished with cracks or blotches but suitable for processing) 40.58 kg
Basil - Ocimum basilcium : 1.62 kg
Fresh Runner Beans - Phaseolus coccineus and French Beans - Phaseolus vulgaris : 24.33 kg
Courgette - Cucurbita pepo : 33.25 kg
Winter Squash - Cucurbita pepo :21.7 kg 
Fresh Garlic - Allium sativum :6.74 kg
Chicken Eggs - 54



Garden Produce



All produce was weighed directly after harvest and unless otherwise stated, all of the produce recorded was in excellent condition and fit for market. Produce not fit for market was composted or fed to our animals and is not included in these records.


  
Table summarising input and outputs from October 31st 2014 - October 31st 2015


You can find the full spreadsheet that includes all of the data entries here

2015 Study Modifications


  • This year our records included the time it took to propagate all the plants from seed, the time spent gathering materials such as compost, tools, plants and the time taken to harvest the produce from the garden.
  • We added garlic as an interval crop that can be grown during the periods the main crops are not present i.e. from November through to March. November sown garlic will normally mature in June, however we use the small bulbs that are not worth planting as main crop garlic and harvest them in March like spring onions. They are delicious.       
Inferior Garlic bulbs planted 10 cm apart for a spring harvest 
  • Having left the chickens out of the garden study last year to simplify the record keeping, there were noticeably more slugs in the beds so this year we included the chicken rotations in the records. The chickens do a great job of removing the slugs and their eggs from within the beds.  After the last harvest the vegetation is chopped and dropped , the stakes are removed and a 3 x 1 m bottomless chicken house is moved onto the beds moving every 2-3 days.  The time taken for each move and daily feeding of the birds are included in the records as are the outputs in terms of Chicken manure and eggs  
The chicken run 1.3 x 3 m light frame bottomless coop 

Considerations


  • This whole record keeping game is totally new to me and I'm still developing the design of this study. I'm close to being satisfied with the method, but believe there is room for improvement and welcome feedback, criticism and suggestions.
  • I made changes to the task categories with "Garden Care" including a range of very different tasks such as weeding, tying tomatoes, pinching out, harvesting and observation. The reason for this is that you end up doing these jobs together in a polyculture.   
  • This year we experienced a more typical summer with a period of 8 weeks without a drop of rain and high temperatures. During this period, irrigation was practiced once per week. Our irrigation system is unique to our garden in that we flood irrigate using a mountain stream, however I estimate the irrigation needs of the polyculture to be 20 L per m² i,e 120 L per bed or 720 L for the entire garden applied once a week in the absence of rain. The time taken to apply 120 L per bed is estimated at 10 mins so that's 60 mins per irrigation session   
  • A word on our low expenses. They are so low due to the fact we grow our own plants from seed, make composts and sowing mediums, grow summer and autumn mulch and save seeds from plants that do not readily crossbreed such as tomatoes, basil, marigolds and beans. We also provide our own support materials (tomato stakes and bean poles). Time taken to make composts and harvest support stakes are not included in the records. 
  • The market value of the produce was estimated based on the prices we were receiving for the same vegetables grown in a different garden from the local buyers and Trustika buyers club in Sofia. It is not what we actually sold the food for as much of the food from this garden was consumed by us or preserved. 
  • The tasks were predominantly carried out by one person, either myself, my partner Sophie or one of our boys Dylan and Archie. On very few occasions two people were working on tasks at the same time. These occasions are recorded in the management sheet of the record keeping spreadsheet (in the "Notes" row ).    

Improvements for Future Studies 


Biodiversity Study 
It's our goal to build productive ecosystems that provide for a large diversity of organisms as well as us. We believe our gardens achieve this but currently have no way of quantifying/qualifying this. I'd like to develop a method of biodiversity measurement that can be used and believe that invertebrate diversity would be a great place to start. I'm thinking something like the Plants for Bugs experiment carried out by a team of entomologists at RHS Wisley would work well. During this study invertebrate samples were taken on five occasions throughout the year and recorded.  The samples are gathered using pitfall and baited refuge traps for ground fauna, and direct observation of flying insect visitors and those settled on the plants.

We are currently seeking collaboration with entomologists that could assist us with this part of the study. If you or someone you know is interested in this please do get in touch.

Control Experiment 
The data we will gather during the study is useful to compare with other practices, however a control garden growing the same crops in monocultures at the same time in the same area will be a great addition to the study and is something we're hoping to start next year in the Polyculture Market Garden Study (results from this coming soon).

Measuring Nutrient Density 
We are looking into using a spectrometer for nutrient density analysis of our produce for the Polyculture study next year.  I was considering using a refractometer to take brix readings of our produce but seeing as brix only reliably measures sugar density I'm not sure it is that relevant. It will be fascinating to see how our biologically grown produce compares to supermarket food, local food, and between our two gardens (the 10 yr old garden and the new market garden site).

Sharing, Feedback and Collaboration 


We have our record keeping spreadsheets on Google Drive. These spreadsheets include all of the data entries and task descriptions. You can find the full spreadsheet here. (note there are multiple sheets that can be accessed from the blue tabs running along the top of the sheet). If you would like to run your own study we'd be happy to give you a copy of the spreadsheet, just drop us an email or leave a comment below with your contact details and we will send it over to you. 

If you have any suggestions and feedback on how you think we could improve the study or you have heard about similar studies from other guild/polycultures we'd love to hear from you.


If you would like to get involved in our Polyculture study registration for 2017 is now open. Click below for more info 


                                                                                  

Permaculture Research 


We offer a range of plants and seeds for permaculture and forest gardens from our plant nursery including a new range of fruit and nut cultivars well suited to natural gardens. Delivery to all over Europe available from Nov - March 






6 comments:

  1. Nice work, this kind of data is valuable. It's quite a bit of work to keep records like this, and error prone if you don't have a good system for recording time.

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    Replies
    1. Hi Tim

      What do you think would be a good system for recording time ?

      Cheers,

      Paul

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    2. It sounds simple until you try it Totalbowls. The difficulty is in keeping the data clean. I often walk though my garden for fun, doing a little work here and there. Stop and take photos of the produce. Sometimes I would forget to clock on or off and have to estimate the duration. Or I would get some help for part of the time but not all of it, or they would work slower, or I'd have to explain the task. You have to make decisions about what to record. Keeping it strictly as an experimental plot where you have constraints on how you spend your time will produce the highest quality data, but does that reflect reality? It's all a bit grey.

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    3. I would imagine having all the record keeping tools and materials ready at a highly visible and accessible location would help you make a ritual of the record keeping.

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    4. Hi Tim,

      Thanks for your feedback. I don't find keeping records for this polyculture a problem. It has become habit now. Tasks that take no more than an hour I will carry out without stopping. Longer tasks I generally record the time it takes to carry out a task on 1 bed and multiply that by 6.

      For the market garden it has been more difficult. A method that we'll be using in the market garden next year is to record the time it takes 4 people to undertake a certain task over say 10 m of a bed. We'll then divide the time by 10 to establish the time it takes to do each task per m2 and take the average between the 4 as our record. We can account for rests, disturbances and slowing down by adding 15% to the record. This way we have a standardized method that can replicated easily.

      Not all tasks can be recorded this way but most of them can.

      I also want to include records from the perennial plants at some point but will probably start this after I have 4 -5 yrs of records from the annuals so that I can still enjoy losing time in the garden rather than recording it :)

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