Winter Canola Response To Simulated Grazing In The Southern High Plains.

Winter canola (WC) area is increasing in the Southern High Plains. The crop offers many rotational benefits to winter wheat based cropping systems in the region. The region is deficient of forage due to the presence of large dairy and beef industries. Limited research has shown the forage potential of WC. However, information on seasonal patterns of forage production and forage quality of WC in comparison to winter wheat (WW) and the effect of grazing on seed and oil yield of WC are limited. Therefore, a field study was conducted at the Agricultural Science Center, Clovis, NM in 2012-13 to compare three diverse WC cultivars with WW for simulated grazing response. In spite of differences in plant architecture and growth duration, differences in seasonal patterns of forage yield and quality were smaller in WC varieties compared to differences between WC and WW.  At first freeze, mean forage yield of WC cultivars was 59% higher compared to WW on dry weight basis. However, the difference in forage productivity gradually reduced during early spring months and by the mid April all had similar forage yields. Crude protein (CP) content differences between WC and WW were small. Fiber content of forage varied significantly during the growing season. The Acid Detergent Fiber (ADF) content did not show any clear difference between  WW and WC varieties. However, WW had higher Neutral Detergent Fiber (NDF) compared to WC suggesting higher hemicellulose content in WW compared to WC. Mean Relative Feed Value (RFV) of WC was 65 to 96% higher than WW suggesting better intake potential and digestibility of WC forage. However, nitrate content of WC forage was much higher compared to WW, indicating some concern of feeding only WC forage. Simulated grazing improved productivity of WW in the season characterized by many killer freezes, however, seed yield of WC decreased by grazing. More research is needed to make the system more sustainable.