Co-Authors:
Nissenbaum, A., Isotope Department, Weizmann Institute of Science, Rehovot, Israel, Institute for Soils and Water, Agricultural Research Organization, Bet Dagan, Israel
Schallinger, K.M., Isotope Department, Weizmann Institute of Science, Rehovot, Israel, Institute for Soils and Water, Agricultural Research Organization, Bet Dagan, Israel
Abstract:
The carbon-isotopic composition of fulvic and humic acid from the A horizons of eight soil types, developed under a wide variety of climatological conditions, was measured. The fulvic acid is always enriched in 13C as compared with the humic acid from the same soil by a rather constant factor of 0.9א. The fulvic acids are isotopically closer to the plant source of the organic matter and thus represent an intermediate stage in the formation of humic substances. Depth sections of peat soil showed that carbon isotopes can be used to evaluate the dynamic nature of the fulvic-acid fraction. With depth, a transfer of carbon groups from polysaccharides to fulvic acid is seen. Based on isotopic evidence it is shown that in addition to formation of β-humus, part of the fulvic acid is condensed with depth to a stable humic fraction - humin. © 1974.
תפריט נגישות
ניגודיות עדינה
מונוכרום
הדגשת קישורים
חסימת אנימציה
פונט קריא
סגור
איפוס הגדרות נגישות
להורדת מודול נגישות חינם
