灌溉模式对河西灌区禾-豆间作系统饲草产量、品质和水分利用的影响

Effects of irrigation modes on forage yield,quality and water use of corn-legume intercropping systems in the Hexi irrigation area

2019-2020年,在甘肃河西地区设置玉米单作(C)、玉米-秣食豆间作(CM)和玉米-拉巴豆间作(CL)3个种植方式,每个种植方式设置重度亏水(T_(1))、后期亏水(T_(2))、交替亏水(T_(3))、后期轻度亏水(T_(4))、前期轻度亏水(T_(5))和充分灌溉(T6)6种灌溉模式,研究灌溉模式对禾-豆间作系统饲草产量、品质和水分利用的影响。结果表明,两年CM和CL处理的群体干草产量显著高于C,2019年较C分别增加6.48%和9.47%,2020年分别增加9.09%和13.11%。两年CM和CL处理的群体酸性洗涤纤维(ADF)和中性洗涤纤维(NDF)含量显著低于C,而群体粗蛋白含量、粗灰分含量及相对饲用价值(RFV)显著高于C,2019年CM和CL处理的RFV较C分别增加10.73%和13.06%,2020年分别增加7.39%和10.59%。两年CL处理的水分利用效率(WUE)和灌水相对生产效率(IPE)显著高于C,2019年较C分别增加7.77%和11.41%,2020年分别增加8.76%和15.11%。两年T_(5)、T6的群体干草产量无明显差异,而T_(5)处理的群体粗蛋白和粗脂肪含量较高,ADF和NDF含量较低,且T_(5)处理的WUE和IPE显著高于T6,2019年较T6分别提高22.14%和48.34%,2020年分别提高25.18%和45.51%。因此,玉米-拉巴豆间作(CL)在前期轻度亏水(T_(5))条件下能够提高群体饲草产量、品质和水分利用效率,是一种适宜河西灌区饲草作物高产优质栽培和水分高效利用的管理模式。

In 2019 and 2020 growing seasons a field experiment was set up in the Hexi region of Gansu with three crop planting configurations:Corn(Zea mays)monocropping(C),Corn-forage soybean(Glycine max)intercropping(CM)and Corn-laba bean(Dolichos lablab)intercropping(CL).In addition,to study their effects in combination with corn-legume intercropping on the yield,quality and crop water use,six irrigation regimes were imposed:severe water deficit(T_(1)),late water deficit(T_(2)),alternate water deficit(T_(3)),late mild water deficit(T_(4)),early mild water deficit(T_(5)),and full irrigation(T6).The total hay yields of CM and CL treatments were,respectively,6.48%and 9.47%higher than the yield of C in 2019 and 9.09%and 13.11%higher than C(P<0.05)in 2020,respectively.The acid detergent fiber(ADF)and neutral detergent fiber(NDF)contents of CM and CL treatments were significantly lower than those of the C treatment in both years,while the crude protein content,crude ash content and relative feeding value(RFV)of CM and CL treatments were significantly higher than those of the C treatment in both years.Compared with C,the RFVs of CM and CL treatments were increased,respectively,by 10.73%and 13.06%in 2019,and by 7.39%and 10.59%in 2020(P<0.05).Compared with C,the water use efficiency(WUE)and irrigation production efficiency(IPE)of CL were increased,respectively,by 7.77%and 11.41%in 2019 and by 8.76%and 15.11%in 2020(P<0.05).There was no significant difference in the total hay yield of T_(5)and T6treatments in the two years.Compared with other treatments,the contents of crude protein and ether extract in treatment T_(5)were higher,while the contents of ADF and NDF were lower.In both years,the WUE and IPE of treatment T_(5)were significantly higher than those of T6,with increases of 22.14%and 48.34%,respectively,in 2019 and of 25.18%and 45.51%in 2020,compared with T6.Corn-laba bean intercropping can improve forage yield,quality and water use efficiency under mild water deficit conditions during the early crop growth stages.It can be recommended as a suitable management regime for cultivation of high-yield and high-quality forage crops and to achieve water use efficiency in the Hexi area.