Earthworm production and role in the nitrogen cycle of a no-tillage agroecosystem on the Georgia Piedmont

Abstract

PARMELEE, R. w& D. A. CROSSLEY, Jr., 1988. Earthworm production and role in the nitrogen cycle of a no-tillage agroecosystem on the Georgia Piedmont. Pedobiologia 32, 355 — 361. Using laboratory growth rates, field soil tamperature and earthworm biomass, earthworm secondary production was calculated for a no-tillage agroecosystem on the Georgia piedmont. Secondary production of earthworms was 47.34g AFDM X m 2a_l, mean annual standing stock biomass was i4.35g AFDM X m—2, and the annual P: B ratio was 3.30. Production was highest in the early spring and fa", and no production occurred in the winter or midsummer because of adverse soil temperatures. Earthworm tissue was 8.4 % nitrogen. Annual nitrogen flux through earthworm tissue was 3.98g N AFDM X m2a1 in the no-tillage system. Literature values were used to determine urine and mucus nitrogen flux. The additional input was 2.26g NXm2a−1. Total nitrogen flux through the earthworm population was estimated to be 6.24 g N x m-a1,5 times the mean annual standing stock of 1.21gx m2a−1.