The Impact of Planting Date on the Establishment and Nitrogen Uptake of Winter Cereals Grown As Double Crops in Corn Silage Rotations in New York.

Winter cereals such as cereal rye (Secale cereal L.) and triticale (x Triticosecale) have shown to be excellent cover and double crops in the northeastern United States due to numerous beneficial environmental and economic qualities. One important role of winter cereals in crop rotations is the potential to scavenge residual N from the previous crop as well as N in fall-applied manure. Here we evaluated the impact of planting date and available N on the biomass accumulation and N uptake of triticale, a winter cereal, in the fall prior to frost. Two planting dates, ranging from late August to early October at four site-years in central and eastern New York were compared. Trials were arranged in a split-plot design, with planting date as the main plot and N application rate (0, 34, 67, 101, 135 kg N ha^-1) as the split plot. All plots were sampled for above ground biomass and N content in November prior to frost. When planted before September 20 more biomass accumulated, the cereals responded in biomass and N uptake when more N was available, and sites had a greater N use efficiency (NUE) and apparent N recovery (ANR). Nitrogen application to late planted winter cereals (after September 20) did not increase biomass or accumulation of N uptake. We conclude winter cereals grown under the conditions in this study can efficiently take up around 70-90 kg N ha^-1 in the fall when planted before September 20, suggesting a promising ability to scavenge nutrients leftover from the previous crop and provide a more environmentally friendly opportunity for spreading manure in the fall. However, N uptake is limited to 15-30 kg N ha^-1 when planting is delayed until after September 20. Additional trials are needed to evaluate this planting date cutoff across a larger number of fields.