| Corn and weeds were pulse labeled with ;Numbers of all groups of microarthropods were higher in NT than in CT. Higher numbers of microarthropods were associated with the weeds than with the crop in both tillage treatments. The microarthropod population in the CT litter plots was dominated by Prostigmata; that in the NT litter plots was dominated by Oribatei.;The specific activity of the microarthropods in the pulsed plots was higher in CT than in NT. The specific activity of the microarthropods associated with the weeds was higher than that of the microarthropods associated with the crop.;The crop accumulated higher concentrations of ;The data indicate that different food chains are active on buried and surface litter. Prostigmata was the most active in the uptake of carbon from the buried litter, while Collembola was the most active in surface litter. These data also indicate that roots and residues support different microarthropod communities that are united at the predator level. Oribatei was the most active group in the rhizosphere, Prostigmata and Collembola were the most active in litter. The Mesostigmata, which are predators, have similar levels of activity in both. Collembola was the generalist group, being an important member in both the rhizosphere and litter food chains. Root inputs were shown to be relatively unimportant as compared to residue inputs in NT, whereas they are important in CT systems, where there are less plant residues available as a food source. |
