Corn Root Effects on the Nitrogen-Supplying Capacity of a Conditioned Soil (original) (raw)

that root presence increases decomposition rate of soil organic matter (Billes and Bottner, 1981; Fisher and Gosz, The design of sustainable N management strategies requires a 1986b; Cheng and Coleman, 1990). Others reported no better understanding of the processes influencing the ability of soils to supply N to a growing crop. Although commonly ignored, the change (Cuenca et al., 1983; Harmer and Alexander, release of C by plant roots may have a tremendous impact on soil 1985) or even a reduction in presence of plant roots organic matter turnover under certain soil conditions. The main objec-(Gadgil and Gadgil, 1975; Jenkinson, 1977, Sparling et tive of this study was to determine if living corn (Zea mays L.) roots al., 1982; Fisher and Gosz, 1986a; Staaf, 1988; Faber and would increase the N-supplying capacity of a soil with an enhanced Verhoef, 1991). mineralizable N pool. A rotation of corn-corn-soybean [Glycine max Reports on the influence of roots on N mineralization (L.) Merr.]-wheat (Triticum aestivum L.) in combination with cover have also been contradictory. A stimulatory effect of crops and the application of composted manure were used to increase plant roots on N mineralization has been observed in the mineralizable N pool. The N-supplying capacity of bare soil and some studies (Bartholomew and Clark, 1950; Molina soils planted with corn and wheat was calculated, and changes in N