Zuylestein Soil Sample Analysis #1 (Internship)

Zuylestein Soil Sample Analysis #1

Logistics:

Location: Landgeod Zuylestein

Address: Rijksstraatweg 7-9, 3956 CH Leersum Netherlands

Date samples taken: November 11, 2017

Date Samples Processed:

• Weighed and Dried: November 15, 2017

• Sifted: November 21-22, 2017

• Chemical Analysis: November 30, 2017

Summary:

Analysis of first soil sample including: Organic Matter, Organic Carbon, Nitrogen, and Phosphorus rates. Proposals to mitigate or enhance above mentioned ratios are given as are proposals for composting methods and notations on compaction issues and mitigation methods.

Scheduled Meetings:

WUR meeting is scheduled for 13:30 on December 14, 2017 (Dirk and Tamisan). 

Zuylestein meeting is scheduled for 13:30 on December 15, 2017 (Thea, Jemima, and Tamisan). 

Plot Map:

Plot Map Legend:

• Plot Number: ex. 1A

• Munsell color chart reference: ex. 4.3

• Specific soil condition

Organic Matter:

The Organic Matter is the combined biomass plus carbon in the sample after being dried and fired. Low OM is typically calculated as below 2%. All 8 Plots showed OM ratios above 3%, which is good. Plots 1A and Plot 5A (taken from the nasturtiums by the cold frame seedling bed) scored the highest at 5.01% and 4.88%. The lowest plots were 2B, 4A, 6A, and 6B. All locations showed various soil mottling and were wetter than the other areas leading to the supposition that mineral and organic leaching was occurring. 

Plots 1-7 all had soils falling between Silt (<1/16 mm) and Fine Sand (1/8-1/4 mm) with compacted soils showing a combination of Silt and Very Fine Sand (1/16-1/8 mm). Plot 7B had a combination of Very Course Sand (1-2mm) and Silt. Primary compaction issues arose in Plots 1A, 4C, 7A & B.  

Proposal: In low areas prone to drainage issues, building up the soil or adding in drainage ditches along the sides of the plots may be helpful. Also, planting deep rooted plants like sunflowers may assist in water infiltration.

Carbon and Organic Matter Rates:

The Organic Carbon ratio is calculated by dividing the OM by 1.724. This gives the percentage of carbon within the OM total number as explained above. SOC is expressed as a % per 100g of soil. SOC is one of the most important constituents of the soil due to its capacity to affect plant growth as both a source of energy and a trigger for nutrient availability through mineralization. 

Soil organic carbon tends to be concentrated in the topsoil. Topsoil ranges from 0.5% to 3.0% organic C for most upland soils. Soils with less than 0.5% organic C are mostly limited to desert areas. Soils containing greater than 12 - 18% organic C are generally classified as organic soils.

The SOC range in the plots is from lowest at 1.822004117 (Plot 2B) to highest at 2.903374785 (Plot 1A). Considering we sampled the first 30cm of topsoil, ranges are as expected for an upland soil.

Goal: to move the SOC levels closer towards ‘organic classification’ with greater than 12% SOC. The scope of this project will be the proposal, that is, composting methods on each of the garden beds with the goal of increasing SOC levels.

Nitrogen and Phosphorus Rates:

Nitrate levels between 25 ppm to 30 ppm are sufficient to grow plants in a vegetable garden. None of the plots had Nitrates of this level. The range for the plots was between 11.86 (Plot 6A) and 18.90 (Plot 1A), with an average of 15.17. This ratio is much lower than we want, hence part of the scope of the project will be to increase Nitrogen fixation within the soil. Note-it rained before and during our sampling, which may account for some N loss.

Phosphorous rates can be measured based upon soil pH. The chart below shows the optimal ratio for a 6-7.5 pH soil as between 10-20 ppm. The range for our plots was 9.60 (Plot 8A) – 14.52 (Plot 5A), with an average of 12.55. Hence we can state that the Phosphorous rates are not something we need to concern ourselves within the scope of this project, though we will monitor them to make sure there is no loss of P.

         optimal     low med         high        excessive

pH          6.0-7.5     <5.0         >7.5

P (ppm) 10-20    <10 10-20 20-40 >40 

Proposal: Add in Nitrogen fixing plants, cover crops, or tillage/composting practices. We should also check the soil pH.

Plot 8A and B:

The area designated as plot 8 was previously a tennis court and a garage. As such we found that the first 1.5cm was construction sand, followed by 1 cm brick, then asphalt for 3 cm. After that we found soil that fell within the mid-range for OM, C, N, & P. An in-depth chemical analysis was not done at this point. 

Proposal: Our recommendations would be to remove the entire top 5cm of soil or place a greenhouse on this plot to mitigate any contamination issues. 

Carbon:Nitrogen Ratios:

The Carbon-to-nitrogen ratios are an indication for nitrogen limitation of plants and fertile, sweet-smelling compost should maintain a C:N ratio somewhere around 25 to 30 parts carbon to 1 part nitrogen, or 25-30:1. If the C:N ratio is too high (excess carbon), decomposition slows down. If the C:N ratio is too low (excess nitrogen) you will end up with a stinky pile. For the location in this report, the soil C:N ratio should be slightly higher than listed above, as areas that are humid and cooler tend to have higher rations then those found in arid, warm environments. The C:N ratio of arable topsoil ranges from 8:1 to 15:1, though it usually falls between 10:1 and 12:1. 

Proposal: When making compost, keep a list of items added and their rough weight. Utilize Appendix 2 for C:N ration guide.  We will do the calculations during the 2nd round of testing to compare our base lines.

**Appendix and plot photos left off of online document.**