Soil Quality Assessment

Activities focus on the development of a soil condition assessment system for organic farming

Soil health must be in good condition in order to produce high and high quality crops. The aim of the activity is to find out which soil condition assessment methods and analyzes are the most informative and cost-effective in organic crop production. Within the framework of the project, an overview of soil quality assessment scales used in Estonia and elsewhere in the world will be compiled and their suitability for application in organic crop production will be analyzed.

The focus is on:

  • physical properties of the soil
  • chemical properties of the soil
  • general condition of soil biota

Most of the existing soil quality assessment scales (eg fertilizer gradations) have been developed for conventional farming. There is much less scope for improving yield limiting factors in organic production, so there is a need to interpret these assessment scales in the context of the inputs allowed in organic production. There is also scarce systematic information on the biomass of soil microorganisms (incl. pathogens), norms ​​for biodiversity level and regional variability in Estonia. As the use of the potential of soil biota in increasing yield is particularly promising in organic production, the scale for assessing the condition of soil biota is particularly important here.
Assessment system adapted to organic plant production allows producers to assess plant nutrition conditions and make decisions based on precise indications. This is a prerequisite for increasing the yield and quality of organic crops. As a result of the activity, accurate information about the state of soil biota in organic fields will contribute to the selection of suitable crop rotation and agrotechnologies.

These benefits for organic producers are reflected in the increased crop yields, good quality production, which is based on better knowledge of the condition of the soil.

  • Priority and cost-effective soil condition assessment methods  will be identified for organic farming. To this end, organic sample fields are selected, soil samples are collected and a comprehensive soil quality assessment is carried out.
  • The physical and chemical properties of the soil, the general condition of the soil biota and the incidence of soil pathogens such as clubroot disease are analyzed.
  1. In order to evaluate the chemical properties of the soil, primary analyzes of soil samples from 10 fields have been performed in the laboratory of both the University of Life Sciences and the University of Helsinki .
  2. Samples were also collected from the same fields for analysis of the condition of soil biota by the fatty acid analysis (still being performed).
  3. In the laboratory of the University of Life Sciences, general agrochemical parameters and integration fractions of soil were determined from an extended sample of the selected material.
  4. Separate soil samples were collected to assess the occurence of clubroot and to develop its evaluation system. Plasmodiophora brassicae was targeted from soil samples in order to develop accurate evaluation systems (using the qPCR methodology). Additionally, the survey was extended to conventional e.g non-organic production fields. The number of results obtained is very necessary for the establishment of a risk assessment system for nutrients and is applicable to both organic and conventional production companies. 
  5. To date, 360 samples have been studied using the qPCR methodology. The results showed that two of the selected rapeseed fields contained a significant amount of the pathogen P. brassicae (shown in photo below).

This year (2020) additional soil sampling and analysis will be carried out in the test areas. 

In 2021, we will conduct an additional collection of soil samples from potential experimental fields and expand the parameters of the analyzed soil quality indicators.

In 2022, additional tests will be carried out if suitable organic fields are found.

Estonian University of Life Sciences – Kaire Loit, Britt Puidet, Alar Astover, Liina Soonvald, Henn Raave, Merike Kissa, Tõnu Tõnutare
University of Helsinki – Niina Välinen, Topi Kopakkala, Priit Tammeorg, Mina Kiani
University of Tartu – Tanel Vahter, Maarja Öpik, Surya Mudavasseril Sudheer