Enhancing and testing soil quality

Summary

At present, soil fertility testing is based on soil chemical analysis. Organic amendments, either as manure and compost or residue from preceding crops and green manure, are essential for maintaining and enhancing soil quality and nutrient management in organic farming. Thus, organic farming is dependent on biologically mediated processes and functions of the whole soil system. Soil quality can be defined as soil's ability to function, it is dependent on the purpose of soil use, and it is based on chemical, physical, and biological soil properties. In recent years, there has been increasing interest in soil quality estimations. The aim of the study is to develop a soil quality test applicable for both organic and conventional farming. To achieve this, the following goals are set: i) to indicate the most important soil functions and properties, ii) to determine and to test the most promising indicators for soil quality, iii) to identify spatial distribution of soil properties, iv) to introduce methods for analysis of soil organic matter quality, v) to estimate the importance of different soil properties on crop yield, and vi) to test the usefulness of on-farm soil quality assessments. Additionally, the project produces information for education, and helps to find applications for commercial soil quality testing. To achieve the goals, the project is co-operating with several other research projects. Existing data from previous projects will be used for studying the interactions of different soil parameters, and for selection of apparently most relevant soil quality indicators. Spatial sampling and geostatistical approach is used to evaluate the spatial dependence and intercorrelation of measured properties. New methods will be adapted for soil organic matter quality. Existing on-farm soil quality assessments (e.g. USDA Soil Quality Test Kit) are evaluated and further developed. Together with ProAgria Association of Rural Advisory Centres the on-farm soil quality assessments are tested.