Relation between soil organic matter and yield levels of nonlegume crops in organic and conventional farming systems

• Published in: Journal of plant nutrition and soil science Vol. 174; no. 4; pp. 568 - 575
• Main Authors: Brock, Christopher, Fließbach, Andreas, Oberholzer, Hans-Rudolf, Schulz, Franz, Wiesinger, Klaus, Reinicke, Frank, Koch, Wernfried, Pallutt, Bernhard, Dittman, Bärbel, Zimmer, Jörg, Hülsbergen, Kurt-Jürgen, Leithold, Günter
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.08.2011; WILEY‐VCH Verlag; Wiley-VCH
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Chemical, physicochemical, biochemical and biological properties; crop yield; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; management impact; Organic matter; Physics, chemistry, biochemistry and biology of agricultural and forest soils; soil organic matter; Soil science; soil services; Soil-plant relationships. Soil fertility; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Production system; Vegetals; Organic matter; Conventional agriculture; management impact; soil organic matter; Alternative agriculture; crop yield; Soils; soil services; Organic agriculture; Level; Yield; Soil science; Cultivated plant; Soil plant relation
• ISSN: 1436-8730; 1522-2624
• DOI: 10.1002/jpln.201000272

The aim of this study was to evaluate the interaction between yield levels of nonleguminous crops and soil organic matter (SOM) under the specific conditions of organic and conventional farming, respectively, and to identify implications for SOM management in arable farming considering the farming system (organic vs. conventional). For that purpose, correlations between yield levels of nonlegume crops and actual SOM level (Corg, Nt, Chwe, Nhwe) as well as SOM‐level development were examined including primary data from selected treatments of seven long‐term field experiments in Germany and Switzerland. Yield levels of nonlegume crops were positively correlated with SOM levels, but the correlation was significant only under conditions of organic farming, and not with conventional farming treatments. While absolute SOM levels had a positive impact on yield levels of nonlegumes, the yield levels of nonlegumes and SOM‐level development over time correlated negatively. Due to an increased demand of N from SOM mineralization, higher yield levels of nonlegumes obviously indicate an increased demand for OM supply to maintain SOM levels. Since this observation is highly significant for farming without mineral‐N fertilization but not for farming with such fertilization, we conclude that the demand of SOM‐level maintenance or enhancement and thus adequate SOM management is highly relevant for crop production in organic farming both from an agronomical and ecological point of view. Under conventional management, the agronomic relevance of SOM with regard to nutrient supply is much lower than under organic management. However, it has to be considered that we excluded other possible benefits of SOM in our survey that may be highly relevant for conventional farming as well.