Zuylestein Composting Day: May 10, 2018

On Saturday, May 10th, 2018, I attended a Volunteer Day at Zuylestein. There were 21 volunteers including myself and 2-3 members of the Zuylestein garden crew on hand to work in various activities. I worked with the garden manager, Thea, on creating compost and beginning the garden beds in one of my test plots (7A).

Stage 1:

We layered newspaper until we were 5 layers thick (1cm). The Newspaper was untreated paper directly from the factory. We then soaked the paper and added Stage 2.

Stage 2:

We added 5cm of compost mixed with horse dung.

Stage 3-Layering:

At Stage 3 we added layers of:

1) green compost (grass clippings, rotting vegetable, etc) 5cm deep

2) a layer of brown compost (dried straw, twigs, branches) 5cm deep

3) green compost (grass clippings, rotting vegetable, etc) 5cm deep

4) a layer of horse bedding 5cm deep

5) a thin layer (<1cm) of leaves.

Stage 4:

We covered the last layer with used straw, mulch, and dried nasturtium vines (8cm).

Final Tally:

We only finished 1 full row. We prepped 4 others with the first 2 stages before running out of material and started a smaller lasagna bed in the back next to the shed. 

The final bed was 702cm long, 147cm wide, and 44cm tall.

All in all, it took close to 10 hours with three workers (me included). Moving forward I would complete only one row at a time and not waste time starting the other beds without first knowing if we had enough time and materials. Due to the rain and tarps, I'm not as worried about nutrient loss as I might be somewhere else, but that aspect could have been planned better. I now know for next time.

At the end of the day, we decided to use a mulch from under several fir trees that were removed. I prepped the soil sample and had it tested for OM/C ratios.

The test was performed on 3/12/18

Pre-dried weight: 144.30g

Dried in the small over at 105 degrees for 24 hours.

Post-dried weight: 98.01g

Sieved at 2.01mm

The Organic Matter is the combined biomass plus carbon in the sample after being dried and fired. The Organic Carbon ratio is calculated by dividing the OM by 2 (as per Dirk's request). This gives the percentage of carbon within the OM total number as explained above. SOC is expressed as a % per 100g of soil. 

% OM

Sample 1: 19.04

Sample 2: 21.71

Average: 20.37

% C

Sample 1: 9.52

Sample 2: 10.85

Average: 10.19

These percents are the best we've seen to date and I'm really looking forward to seeing what adding these into the garden will do.