How Does Long-Term Organic Matter Treatment Affect the Biological Activity of a Centre European Forest Soil?

Abstract

A significant portion of the increase in atmospheric CO2 enters the environment through a decrease in the level of organic matter (SOM) in soils. One of the reasons for this is the cutting of forests and the conversion of growing areas into arable land, thus changing land use. As a result, SOM today only has approx. 70–80% of the period before the spread of intensive farming. For the long-term study of the effect of varying amounts of SOM, we set up experimental plots for litter manipulation in 2000. In the course of our investigations, we studied how changing the amount of organic matter input the soil affects the CO2 emissions of the soil and its closely related biological activity after five or ten years, in addition to the continuous maintenance of the treatments. According to our assumption, after 10 years, the biological activity of the soil will decrease as a result of the removal treatment of organic matter, and the biological activity will increase as a result of the doubling. The pH value of the soil shifted in the acidic direction over 10 years as a result of the removal of organic matter, while it did not change as a result of the increase. In the first year, we could not detect any significant differences in the enzyme activity values. From our later results, we found that a drastic reduction in the amount of leaf litter has a greater effect on soil enzyme activity and soil respiration to a greater extent than an increase in litter production above natural levels. The pH of the soil was as expected, with litter withdrawal shifting the pH towards acidic over the years.

Keywords

• soil biology
• organic matter
• DIRT
• luvisol
• ß-glucosidase
• soil respiration