Soil food webs in agricultural ecosystems - Microbial Ecology in Sustainable Agroecosystems - page 79

Table 4.6 Biomass Estimates (kg C ha −1 ) for the Functional Groups in the Different Food Webs

CPER LH-IF LH-CF HSB-NT HSB-CT KS-B0 KS-B120

Microbes

Bacteria 304 245 228 440 690 740 900

Fungi 63 3.27 2.12 160 150 1,500 2,300

AM fungi 7

Protozoa

Amoebas 3.78 18.9 11.5 40 a 50 a 110 a 34 a

Flagellates 0.16 0.63 0.53

Nematodes

Herbivores 2.90 0.35 0.19 0.40 0.50 0.18 0.29

Bacteriovores 5.80 0.36 0.30 0.46 1.40 0.45 0.50

Fungivores 0.41 0.13 0.08 0.12 0.08 0.20 0.12

Predators b 1.08 0.06 0.06 0.44 0.44

Arthropods

Predatory mites 0.16 0.08 0.06 0.20 c 0.04 c 0.18 d 0.28 d

Nematophagous
mites

0.16 0.006 0.004

Cryptostigmatic mites 1.68 0.003 0.007 0.80 0.22

Noncryptostigmatic
mites

1.36 0.04 0.02 0.90 0.39

Bacteriovorous mites 0.0003 0.001

Fungivorous
Collembola

0.46 0.38 0.47 0.30 0.09 0.17 e 0.17 e

Predatory Collembola 0.008 0.03

Foliar-feeding
arthropods

0.10 0.14

Predatory herbage
arthropods

0.15 0.19

Herbivorous
macroarthropods

0.19 0.19

Microbivorous
macroarthropods

0.25 0.25

Predatory
macroarthropods

0.49 0.49

Annelids

Enchytraeids 0.21 0.43 0.10 0.30 4.20 3.40

Earthworms 63.5 — 100 20 13 13

Note: Values refer to the 0- to 25-cm depth layer, except for the Horseshoe Bend webs (0-15 cm). CPER, Central
Plains Experimental Range (Colorado, United States); LH, Loevinkhoeve (Netherlands); IF, integrated
farming; CF, conventional farming; HSB, Horseshoe Bend (Georgia, United States); CT, conventional till-
age; NT, no tillage; KS, Kjettslinge (Sweden); B0, without fertilizer; B120, with fertilizer.
a Including amoebas and flagellates.
b Including predators and omnivores.
c Including all predatory arthropods.
d Including all predatory microarthropods.
e Including all microbivorous microarthropods.