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Changing role of cultivated land in the global carbon cycle

Author:
Buyanovsky, G.A., Wagner, G.H.
Source:
Biology and fertility of soils 1998 v.27 no.3 pp. 242-245
ISSN:
0178-2762
Subject:
agricultural land, biogeochemical cycles, crop yield, soil fertility, crop residues, Triticum aestivum, crop rotation, Zea mays, Trifolium, soil organic matter, continuous cropping, biomass production, Missouri
Abstract:
The carbon balance is ill defined for agricultural lands so that their role in global C balance cannot be accurately estimated. Changes in agriculture in the last 50 years have resulted in a general increase in grain yields, total net annual production (TNAP), and C input to the soil. Amounts of C returned annually with crop residues on Sanborn Field, one of the oldest experimental fields in the United States, increased after 1950, and this was accompanied by C accumulation in soils. Under wheat monocrop (with mineral fertilizer), C accumulated at a rate of 50 g m-2 year-1. A 3-year rotation (corn/wheat/clover) with manure and nitrogen applications sequestered 150 g m-2 year-1 of C. Total C balance for the wheat and corn production area in the United States, approximated on the basis of these rates, indicates that at least 32 Tg C was sequestered annually during the last 40-50 years.
Agid:
1417768