Changes in functional diversity of the soil microbial community in a heterogeneous sandy soil after long-term fertilization with cattle manure and mineral fertilizer

The effects of cattle without and with biodynamic preparations on functional diversity of the soil microbial community were investigated in comparison with mineral fertilization (+ straw incorporation) at low and high application rates to a sandy soil of the long-term fertilization trial in Darmstadt, Germany. The multi-SIR method was used for investigating the respiratory response to 17 individual substrates in surface arable soils (0–5 cm). Multivariate analysis made it possible to significantly separate mineral fertilizer and manure treatments, mainly on the basis of carbohydrates and amino acids. Correlation analysis of the extracted discriminant function showed that the changes in the catabolic profiles of soil microorganisms between the mineral fertilizer and manure treatments were partly caused by differences in soil pH and soil organic C content. The functional diversity of soil microorganisms caused by differences in the community level physiological profile decreased as a result of long-term mineral fertilization with straw incorporation in comparison with farmyard manure application.

► Cattle manure (± biodynamic preparations) was compared with mineral fertilization.
► MicroResp™ was used for community level physiological profiling.
► Discrimination of treatments was mainly caused by carbohydrates and amino acids.
► Functional diversity was reduced in the mineral fertilizer treatments.