Earthworms affect nitrogen cycling directly through the consumption and assimilation of organic N and the turnover of N through excretion and mortality. Although earthworms can process large quantities of organic matter, organic-matter consumption by earthworms based on their nitrogen requirements has not been quanti®ed. Organic-matter consumption and the ef®ciency of nitrogen assimilation by e...

Installation of subsurface tile lines in poorly drained soils is a beneficial management practice that enhances crop productivity. In some instances, however, they can contribute to offsite losses of agricultural chemicals and sediment in drain flow. Movement of these materials through soil macropores (earthworm burrows and cracks) has been shown to contribute to this phenomenon. In order to de...