1Former M.Sc. student of agroecology, Faculty of Agriculture, Shahrekord University.
2Assistant professor of agroecology, Faculty of Agriculture, Shahrekord University.
3Professor of soil science, Faculty of Agriculture, Shahrekord University.
Quantification of the Nitrogen (N)-supplying capacity of organic manures
provides an important insight into more effective N management practices. The aims
of this study were to determine the potential N mineralization of cow manure (CM),
poultry manure (PM), urea fertilizer (UF) and the combined use of cow manure +
urea fertilizer (CM + UF) for silage maize (Zea mays L.) in a calcareous soil under
field conditions. Selected soil samples were collected after different N sources
application, and mineral N (NO3--N and NH4+-N) was determined for a total of 110
days of field incubation, using the buried bag technique. Poultry manure-treated soils
had significantly higher total N mineralization (244 kg ha-1) than CM (109 kg ha-1),
UF (138 kg ha-1) and CM + UF (141 kg ha-1) treated soils. However, N availability
was greater in UF (69%) and PM (61%) treated soils than that of CM + UF (47%)
and CM (28%) fertilized soils. Shoot dry matter of maize and N uptake were
considerably higher in PM treated soil than in UF, CM and CM + UF soils.
Nevertheless, maize N recovery was significantly higher in urea soils (60%) than in
PM (42%) and CM + UF (37%) soils followed by CM soil (15%). In conclusion, our
data indicated that PM and the CM + UF that released N slowly resulted in high
maize silage production, N uptake and N recovery following their application in
these calcareous soils with low SOM content and N availability.