DISTRIBUTION OF NITROGENOUS COMPOUNDS IN A RHODIC PALEUDULT FOLLOWING HEAVY MANURE APPLICATION

The paper reports on a study to determine the effect of high rates of cattle and poultry manure application on the N balance and on the distribution of NH//4** plus , NO//3** minus , NO//2** minus , and total N to a depth of 6 m in a Davidson Clay loam soil (Rhodic Paleudult, clayey, kaolinitic, thermic). A N balance showed that while 36% of the inorganic fertilizer N applied was removed by the crop, with manure application less than 10% of the total was crop recovered. The percentage of the total N in the upper 6 m of the soil profile generally decreased with increased manure N application, although N present increased with increased N applications. The unrecovered N increased with increased N application. The organic N fractions remaining in the soil profile could be adequately estimated using existing decay constants.