Gorgan University of Agricultural Sciences International Journal of Plant Production 1735-6814 6 4 2012 08 15 Potential N mineralization and availability to irrigated maize in a calcareous soil amended with organic manures and urea under field conditions 493 512 762 10.22069/ijpp.2012.762 EN P. Alizadeh Former M.Sc. student of agroecology, Faculty of Agriculture, Shahrekord University. S. Fallah Assistant professor of agroecology, Faculty of Agriculture, Shahrekord University. F. Raiesi Professor of soil science, Faculty of Agriculture, Shahrekord University. Journal Article 2012 04 08 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 (<em>Zea mays </em>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. https://ijpp.gau.ac.ir/article_762_6472b37f164bf240994f7acc488cde4a.pdf