Long-term effects of soil management practices on selected indicators of chemical soil quality

Abstract

The study was conducted in scope of Catch-C project “Compatibility of agricultural management practices and types of farming in the EU to enhance climate change mitigation and soil health” (7FP), realized in 2012–2014 by the consortium of partners from 10 European countries (http://www.catch-c.eu). This work reports the effects of soil management practices – under different soil and climatic conditions – on the selected soil chemical quality indicators, based on the analysis of data extracted from literature on long term experiments (LTEs) in Europe, as well as from LTEs held by the Catch-C consortium partners. The dataset related to soil chemical quality indicators consisted of 1044 records and referred to 59 long-term trials. The following indicators of chemical soil quality were analyzed: pH, N total content, N total stock, C:N ratio, N mineral content, P and K availability. They are the most frequently used indicators in the European literature on long-term experiments collected in the Catch-C project database. Soil organic carbon, however, the most important indicator was not presented here, due to it was covered by a separate study on indicators for climate change mitigation. The indicators were analyzed using their response ratio (RR) to a management practice. For a given treatment (management practice), this ratio was calculated as the quotient between the indicator value obtained in the treatment, and the indicator value in the reference treatment. The examples were: rotation (with cereals, with legume crops, with tuber or root crops, with grassland) vs. adequate monoculture, catch/cover crops vs. no catch/cover crops, no-tillage and no-inversion tillage vs. conventional tillage, mineral fertilization vs. no fertilization, organic fertilization (compost, farmyard manure, slurry) vs. mineral fertilization at the same available nitrogen input, crop residue incorporation vs. removal. All tested practices influenced soil chemical quality indicators. Both positive and negative effects were observed. When the RR values of seven soil chemical quality indicators were considered in an overall evaluation – based on their significance level, the number of indicators positively affected, and the size of the effects – the best practices among those tested were: farmyard manure application, no-inversion tillage, compost application, mineral fertilization, and no-tillage.