Fertilization and carbon sequestration

Abstract

DOI:10.15414/afz.2015.18.03.56–62

Received 20. February 2015 ǀ Accepted 6. May 2015 ǀ Available online 14. October 2015

The effect of fertilization on the dynamic change of soil organic matter (SOM) in loamy Haplic Luvisol was studied. In 2008-2011, soil samples were taken from following treatments: 1. C– non-fertilized, 2. PR+NPK – plant residues together with NPK fertilizers, and 3. NPK – NPK fertilizers. The results showed that the content of soil organic carbon in water-stable micro-aggregates (SOC in WSA_mi) increased by 11% and by 13% in PR+NPK and NPK treatments, respectively. The ratios of SOC in WSA_mi/SOC in bulk soil in the NPK fertilized treatment and in PR+NPK were 14% and 4% higher than in the non-fertilized treatment, respectively. Overall the ratios of SOM in WSA/SOM in bulk soil were higher in macro-aggregates than micro-aggregates. In fertilized treatments, the statistical significant changes in dynamics of labile carbon in water-stable macro-aggregates (C_L in WSA_ma) and in WSA_ma 0.5-3 mm were observed. In fertilized treatments (PR+NPK and NPK) there were observed significant decrease of the C_L in WSA_ma. The ratios C_L in WSA_mi also WSA_ma/C_L in bulk soil decreased due to ploughed plant residues together with NPK fertilizers, the ratio of C_L in WSA_ma/C_L in soil decreased due to added only NPK fertilizers also.