Biological Fertility

Since 1975, Woods End has offered soil testing emphasizing soil organic matter and biological functioning as it influences overall sustainable fertility.

In 1988 Woods End launched the “Soil Quality Audit”, combining perhaps for the first time in America, physical, biological and nutrient tests in a single integrated report. This is very likely the first test offering in the USA for what today is called popularly “soil health analysis”.

Soil health is not a fixed, intrinsic soil property. Therefore, laboratory methods must be designed which can represent a range of qualitative and quantitative factors which interactions are expected to result in healthy functioning.  How soils are handled before and during testing also influences the results with the potential for laboratory artifacts.

To get to soil health itself Woods End has designed a process called “Natural Soil Testing” that includes the following:

  • Minimal sample disturbance:  It is common to use powerful grinders to prepare soils before testing, since homogenization is believed to improve soil test reliability. And so it does for nutrient tests. However, this form of handling, which favors chemical analysis, disrupts and de-structures soil traits relevant to soil health. Woods End applies measures such as soil-rolling to avoid this;
  • Measuring organo-physical traits: Water stable aggregates are among the most dynamic and significant features of a health functioning soil. Woods End has developed a special volumetric (“VAST”) method that enables cost-effective designation of erosion-prone vs dispersion-resistant soils;
  • Biological assays:  Modern science-based farming has traditionally paid little attention to soil biology. To overcome this limitation, assays that are not typically quantitative as soil chemistry is, are required. Soil respiration – the release of CO2 by microbes – is used to evaluate biological carbon turnover. This relates to potential N-mineralization. The accumulation of  organic nitrogen as amino-N forms the basis for a special test for labile amino-N;
  • Eco-Physiographic Regions: Given the wide variety of soil types and climatic zones in the world, the use of a single soil health model for any soil  analysis is unrealistic. To overcome this, Woods End reports are matched regionally to climate, rainfall zone and soil order and sub-orders. This is used to aid setting appropriate benchmarks for more accurate interpretations;
  • Keyed Interpretation: Individual soil health indicators are not universally applicable. Wood End’s experimental approach to soil health testing allows up to constantly improve interpretation and to avoid popular generaizations.

The overall approach is represented by the commonly used “triangle” of chemical, physical and biological traits reported as a unified test, the Solvita Soil Health Suite. Woods End is America’s only lab that has consistently since 1988 used this approach. The test compares to other protocols which also emphasize the interaction of these factors.

1- Premium Soil Health Test

  • Evaluates quality and not just quantity of soil organic matter.
  • Accounts for soil microbial biomass via respiration instead of indirect chemical measures;
  • Evaluates nutrient mineralization potential, the core of the nutrient supply mechanism for plants
  • Represents nutrients likely to be “plant relevant” from lighter-weight extractants

2- Basic Soil Health

  • Our basic soil health test is meant to be a companion to common soil nutrient analyses obtained elsewhere or through your favorite soil lab. The basic adds information about biological and bio-physical traits that are not available elsewhere.  Included is Solvita CO2, SLAN, Water Stable Aggregates, Water soluble carbon (WSOC), Soil C:N ratio, and Respiratory Quotient.

Eco-Physiography: reports include matching US soil samples to eco-physiography, climate/rainfall zone as well as to major soil order and sub-orders.  See Sample Info Form for pricing.

What you get:

  • A comprehensive report with a Fertility Score and a Soil Health Score. The standardized Score uses an open source formula with equal weighting of 5 attributes associated with high functioning soils. The fertility score shows the expected nutrient supply (based on expected crops) integrated with the soil health score.
  • Interpretation Guide: Each customer receives a full interpretation guideline with the report.

Please provide the following:

  1. The soil sample: (wet or dry) in a quart sized ziplock bag, with the date of the sample and the intended crops.  If the location is different than the zip code on the order, please provide specific GPS or sample zip code information which we use to map to your climate zone.
  2. Sample Information Form: Please attach the following Sample-information with each order.

**Mail to our PO BOX if sending via USPS, or our street address if sending via UPS or FEDEX**