Efficacy and limitations of Triticale as a nitrogen catch crop in a mediterranean environment

During 3 consecutive years (1996/97-1998/99) the efficacy was studied of Triticale as a nitrogen (N) catch crop sown after the harvest of the potato crop cultivated in the preceding summer season under several N fertilizer treatments. In October, shortly after the harvest of the potatoes, there were registered significative differences in the soil N-NO3- levels among N fertilizer treatments of the potato crop. The higher values were recorded on the plots corresponding to higher N doses. At the end of winter, the N status of plants and at the end of experiments (late in April), the N-NO3- in soil, the biomass yield and the N uptake by the catch crop did not reflect the differences registered before in the soil inorganic N. This comparison may suggest that Triticale is little effective in recovering the residual inorganic N of the preceding crop due either to the rainfall occurring in the autumn or to the poor vegetative development of the catch crop during the autumn/winter period. However, at the date of cut, the catch crop removed up to 80 kg N ha(-1). At this time, the soil N-NO3- levels were significantly higher on the fallowed plots. This result shows that the crop was very effective in uptaking the N that is mineralized after the end of winter. (C) 2002 Elsevier Science B.V. All rights reserved.