Nitrate Movement Under Corn and Fallow Conditions
1980
Long, F Leslie | Huck, Morris G.
Nitrate movement under corn (Zea mays L.) and fallow conditions was studied in a simulated field soil profile of Dothan loamy sand (Plinthic Paleudults) in the Auburn rhizotron. The rates of N applied were 250 and 500 kg N/ha. The nitrate movement was monitored by analysis of soil solution samples taken at 48- to 72-hour intervals over a 120-day period from the 20-, 40-, 60-, 80-, 100-, and 140-cm depths. Nearly all the nitrate applied to the surface of fallow plots moved with percolating water and was leached below the 100-cm depth within 65 days; this was true for both N rates. Actively-growing corn roots intercepted nitrate from the 250 kg N/ha treatment before it reached the 80-cm depth and from the 500 kg N/ha treatment before it reached the 100-cm depth. At maturity the above-ground portion of the corn contained 20% more N than was applied at the 250 kg N/ha rate and 75% of that applied at 500 kg N/ha. Corn roots effectively prevented leaching of nitrate.
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