Soil NHþ4 eN was considered to be negligible in the test area [31]. The N budget was calculated for each plot in each year of the experiment. Mineralization (Nmin) was estimated for the N0 treatment using the equation Nmin 1⁄4 Nresi þ Nplant Nini [32] assuming zero N losses from unfertilized plots. Nplant was the aboveground plant N uptake at maturity. Nitrogen losses were estimated from the N budget in the fertilized plots [33] using the formula: N loss 1⁄4 Nfinal þ Nplant Nini Nmin Nfert, where Nfert was the N applied as organic (PS) or mineral fertilizers.