Double-Cropping with Forage Sorghum and Forage Triticale in New York

A rotation trial with forage triticale (x Triticosecale Wittmack) and forage sorghum (Sorghum bicolor [L.] Moench) was conducted in central New York from 2016 to 2018. Treatments included four timings of sorghum harvest followed by next-day triticale planting, five triticale spring N rates (0, 34, 67, 101, 135 kg N ha(-1)), and two N treatments applied at sorghum planting (fertilized, +N, and unfertilized, -N) using a randomized complete block split-split-plot design in four replications. The most economic rate of N (MERN) for triticale in spring 2016 was 86 kg N ha(-1) with a yield at the MERN of 4.0 Mg dry matter (DM) ha(-1). In fall 2016 and spring 2017, total forage yield (triticale plus sorghum) did not increase after the mid-September harvest for the +N and 135 kg spring N ha(-1) plots (23.8 Mg DM ha(-1) average). In fall 2017 and spring 2018, there was no difference in total forage yield across harvest timings (13.4 Mg DM ha(-1) average), likely due to fewer growing degree days (GDD) that year. We recommend harvesting sorghum similar to 1150 GDD after planting or at the soft-dough stage. Earlier harvests resulted in lower yield but greater digestibility and crude protein. Springapplied N did not affect forage sorghum yield or nutritive value. Sorghum fertilized with N resulted in MERNs of 0 kg N ha(-1) for the following triticale crop. Fertilizing sorghum according to N needs and timely harvest can support both sorghum and triticale yields without having to fertilize triticale in the spring.