油菜━冬小麦轮作系统中冬小麦的粮饲兼用性能

Grain and forage performances of winter wheat in a rape and wheat rotation system

为探究油菜(Brassica campestris)-冬小麦(Triticum aestivum)轮作下冬小麦的粮饲兼用性能,在黄土高原塬区,对油菜后茬冬小麦(BW)和休闲后冬小麦(FW)系统中冬小麦‘陇育216’分别进行冬季刈割(Cut1)、春季刈割(Cut2)和不刈割(Uncut)处理,测定了冬小麦生育期水分状况、刈割所得饲草产量和品质以及收获期籽粒产量等。结果表明,1)BW轮作条件下,两次刈割处理下所得饲草产量均高于FW,但处理间饲草的营养指标均无显著差异(P>0.05);BW轮作条件下,Cut2所得饲草产量极显著高于Cut1(P<0.01),且Cut1和Cut2所得饲草粗蛋白含量均高于20%,相对饲喂价值高于151%,但微量元素含量较低,不能满足家畜的日常需求。2)与FW相比,BW轮作条件下的冬小麦籽粒产量均减少,尤其Cut2导致显著减产20.9%(P<0.05),主要表现为单位面积穗数显著减少;BW系统中,Cut1和Cut2籽粒产量均低于Uncut,但无显著差异,且Cut1减产程度大于Cut2。油菜-冬小麦轮作系统中冬小麦粮饲兼用可提供大量优质饲草,而籽粒减产不显著,增加了系统产出,且冬小麦作为饲草利用最佳时间为春季。

To investigate the potential of winter wheat to provide grain and forage in a rape and winter wheat rotation system,various cutting treatments were conducted on winter wheat(Triticum aestivum)following either Brassica campestris(BW)or fallow(FW)in the rain-fed region of the Loess Plateau.Cutting treatments were winter mowing(Cut1),spring mowing(Cut2)or no mowing(Uncut).We measured water status in the wheat growing period,the yield and quality of mowed forage,and grain yield and its components at harvest time.The forage yields of winter wheat after winter mowing and spring mowing under BW rotation were higher than that under FW rotation,whereas forage nutritive values of winter wheat between these treatments had no significant difference.In the BW rotation,the forage yield after spring mowing was significantly higher than that after winter mowing.The forage after both winter mowing and spring mowing had high nutritional value with more than 20%crude protein content and more than151%relative feed value(RFV),however,micronutrient level was relatively low which cannot meet the daily requirement of livestock.Compared with FW,the grain yield of winter wheat under BW rotation decreased,especially grain yield decreased by 20.9%after spring mowing which most come from that the reduction of the numbers of panicles per unit of area.In the BW rotation system,the grain yields after winter mowing and spring mowing were lower than that without mowing.Dual-purpose usage of winter wheat for grain and forage in a rape and wheat rotation system could provide high-quality forage production without significant reductions to grain yield.Spring is the most appropriate time to harvest winter wheat for forage under this system.