Evaluation of the different soil organic matter (SOM) pools stability in long-term field experiments of germany by physical fractionation

Abstract

Samples of Ap horizons of different soil types with different clay content selected from nil plot and different fertilized plots of the long-term field experiments Thyrow, Groß Kreutz, Seehausen, Methau, Bad Lauchstädt, Straußfurt located in closely related climatic conditions had been analyzed by method of granulo-densimetric fractionation developed in Dokuchaev Soil Science Institute (Moscow). For comparison mountainous soil from long-term experiment Lauterbach located in more moist and cold conditions had been studied. Three groups of functional significant SOM fractions had been isolated: (1) light fraction (d < 2g·cm^-3), clay fraction (< 1 μm) and fraction rest. The partition of C and N accumulated in these fractions related to the level of soil fertilization and clay content had been estimated. Light fraction is the least stable: it is sensitive to the level and forms of fertilizers as well as to the changing ecological conditions. SOM interacting with clay minerals is a main factor of soil carbon level stabilization. Light fraction is responsible for decomposable SOM pool dynamics and may be appropriate criteria of its estimation.

Keywords :

• soil organic matter (SOM) pools
• granulo-densimetric fraction method
• mineral-organic fractions (accumulation)

The material in this article has been reported at the International Symposium, “Nutritional and Environmental Research in the 21st Century — The value of long-term field experiments”, 5–7 June 2002, Bad Lauchstädt and Halle upon Saale.

The material in this article has been reported at the International Symposium, “Nutritional and Environmental Research in the 21st Century — The value of long-term field experiments”, 5–7 June 2002, Bad Lauchstädt and Halle upon Saale.

Notes

The material in this article has been reported at the International Symposium, “Nutritional and Environmental Research in the 21st Century — The value of long-term field experiments”, 5–7 June 2002, Bad Lauchstädt and Halle upon Saale.

The material in this article has been reported at the International Symposium, “Nutritional and Environmental Research in the 21st Century — The value of long-term field experiments”, 5–7 June 2002, Bad Lauchstädt and Halle upon Saale.